Theriogenology Flashcards

Question 1

Q

Changes in antioxidant enzyme activities and metabolic parameters in dairy cows during different reproductive periods

Sayiner et al., 2021

Answer

A

GPx activities increased in first month of dry period (P < 0.05) and peaked during the PP3d and PP8d periods (P < 0.0001), with values decreasing again at the PP3-4w period.
The most significant change in SOD activities was detected in the PP3-4w with a significant decrease (P < 0.05).
BHBA and NEFA concentrations increased significantly during the PPd3 and PPd8 periods (P < 0.05), with BHBA decreased to low values in the PP3-4w (P < 0.05).
Significant positive correlations were found between BHBA, NEFA, total bilirubin and GPx (0.784, 0.874 and 0.871; P < 0.05, P < 0.01 and P < 0.01 respectively).
A significant negative correlation between calcium and cholesterol and GPx was found (-0.857, P < 0.01; and -0.681, P < 0.05, respectively).
A relationship was determined between blood antioxidant enzymes and metabolic parameters at different periods.
GPx’s significant rise in the early postpartum period may be associated with metabolic diseases
Considering GPx and SOD activity measurements in pre- and postpartum periods contributes to better management of these periods and the prevention of complications

Question 2

Q

Farm and cow factors and their interactions on the incidence of retained placenta in holstein dairy cows

Mahnani et al., 2021

Answer

A

With an interaction analysis, although the potential effect of each factors depends on the effect of other factors, but in general dystocia, stillbirth, an extended age at first calving (>28 months), and calving during the spring increased risk of RP for both groups.
The occurrence of dystocia, stillbirth and twinning increased the odds ratio (OR) of RP.
In primiparous cows, occurrence of dystocia and stillbirth increased OR of RP 4.30 and 3.33 times, respectively. In multiparous cows, dystocia, twinning and stillbirth increased OR of RP 4.36, 3.94 and 1.29 times, respectively.
Cows with an age at first calving of >28 months had the highest rate of RP compared with other cows.
Multiparous and primiparous cows with a short (less than 271 d) and long (more than 281 d) pregnancy, respectively, had the highest risk of RP compared to cows in other groups.
Multiparous cows with an extended dry period length (more than 75 d) and produced milk yield more than 13,000 kg/lactation were at higher risk of RP with an average of 13.5%.

In conclusion, identification of risk factors for RP with an interaction analysis can help farm managers to employ the best strategies to reduce the occurrence of this reproductive disorder.

Question 3

Q

The effect of altering the timing of GnRH administration and artificial insemination in a modified 5-d CO-Synch protocol using sex-sorted semen in dairy heifers

Macmillan et al., 2021

Answer

A

In Experiment 1, estrus rate (P = 0.81) and pregnancy per AI (P/AI; P = 0.34) did not differ among control, GnRH56 and GnRH72 groups, so GnRH56 and GnRH72 groups were combined into one split-TAI (STAI) group.
The P/AI was greater in heifers displaying estrus by 48 h compared to those not displaying estrus and receiving GnRH in both groups (69.5 vs. 31.3%; P < 0.01)
In Experiment 2, the estrus rate was increased in TAI80 compared to TAI72 heifers (81.4 vs. 62.7%, P < 0.01); however, there was no difference in P/AI (P = 0.74).
Across both experiments, P/AI was increased in heifers that displayed estrus before AI compared with heifers that did not and performing a STAI tended to increase P/AI in heifers that displayed estrus before AI. Other attempts made to optimize P/AI in the modified 5-d CO-Synch protocol by altering the timing of GnRH administration and/or AI were unsuccessful.

Question 4

Q

Bovine alphaherpesvirus 1 (BHV1) infection in testes and epididymis from bulls from a slaughterhouse

Queiroz-Castro et al., 2021

Answer

A

The percentage of BHV1 presence obtained by the immunolocalization assay corresponded to 95.9% of the testes, 100% of the epidydimal tissue in the head and tail portions, and 98% of the epididymal body.
The nested PCR assay detected the viral nucleic acid in 59.2% of the testicular tissue and in 65.3, 75.5, and 83.7% of epididymis head, body, and tail samples, respectively.
BHV1 detection in testes and epididymides of naturally infected bulls suggests that these organs may be sources of viral infection for semen

Question 5

Q

Characterization of intrauterine cultivable aerobic microbiota at the time of insemination in dairy cows with and without mild endometritis.

Ballas et al., 2021

Answer

A

Overall, Bacillus most frequently isolated (19.6%), followed by Staphylococcus (14.2%), Corynebacterium (10.1%).
Bacterial load and density similar between VDS1 and 0 groups.
More than half of the VDS 0 cows (51.7%) harbored Bacillus spp. at the day of insemination, while in endometritic cows Bacillus spp. were significantly less frequently found (22.6%; P<0.001).
There was a higher prevalence of Corynebacterium in VDS 0 c.f. VDS 1 cows (=0.03).
At the species level, a significant difference in abundance of Bacillus licheniformis and subtilis were detected between groups – endometritic animals harboured neither of these pathogens.
The insemination success in VDS 0 and 1 was 43.1 and 25.8% for the chance of pregnancy following AI.
Presence of CE at the time of AI reduced the chance of pregnancy (OR=0.39, P=0.03)
“presence of certain bacterial species was not causal for persisting mild CE (VDS 1) at the time of insemination”

In summary, cultivable uterine bacteria at AI presumably represent a part of the physiological microbiota, which is not directly linked to impaired fertility. These findings question intrauterine antimicrobial treatment shortly after AI and could represent the basis for the development of future treatment strategies.

Question 6

Q

Monitoring estrous activity in pasture-based dairy cows

Moore et al., 2021

Answer

A

The duration of Moomonitor activity and FlashMate activity was negatively associated with total milk yield during the first five weeks of lactation.
Pregnancy per AI was positively associated with BCS, days in milk, the duration of FlashMate activity and the interval from the onset of Moomonitor and FlashMate activity to AI.
Inseminating cows <= 2 h after FlashMate activation or <= 4 h after Moomonitor activation was associated with reduced odds of pregnancy compared with later timing of AI.
Overall, 55% of cows received mounts for <= 8 h, highlighting the need for >= 3 periods of estrous observation daily or the use of estrous detection aids that continuously monitor cows.
The study reiterated the importance of maximising body condition score and days in milk at breeding to increase behavioural expression of estrus and pregnancy per AI.

Question 7

Q

Changes in miRNA levels of sperm and small extracellular vesicles of seminal plasma are associated with transient scrotal heat stress in bulls

Alves et al., 2021

Answer

A

three sEVs-miRNAs (miR-23b-5p, -489 and -1248) were down-regulated in heat stressed (SHS) bulls compared to CON on D+7.
Sperm oxidative stress was higher, and the level of 21 sperm miRNAs was altered (18 down-, 3 up-regulated) in SHS bulls compared to CON on D+21.
Functional analysis indicated that target genes involved in transcription activation, as well as cell proliferation and differentiation were related to the 18 down-regulated sperm miRNAs.
Scrotal heat stress probably impacted testicular and epididymis functions by reducing the levels of a substantial proportion of sEVs and sperm miRNAs.
Our findings suggest that miR-126-5p was possibly trafficked between sEVs and sperm.

Question 8

Q

Cow-level prevalence and risk factors for estrus detection inaccuracy in seasonal calving pasture-based dairy cows

Kelly et al., 2021

Answer

A

The overall prevalence of EDI was 4.7% with a prevalence of 3.3% of EDI at first insemination and 14.1% at repeat insemination.
Absence of a mounting abrasion (Adjusted odds ratio (AOR) = 3.0) was a significant risk factor for EDI on first insemination while abnormal preceding repeat interval (AOR = 9.5), the absence of an observed standing estrus (AOR = 12.5) and the absence of a mounting abrasion (AOR = 4.1) were significant risk factors for EDI on repeat insemination.
Cow-level estimated prevalence of EDI in a selection of pasture-based herds was low at first insemination but higher for repeat insemination.

Question 9

Q

Feeding yearling Angus bulls low-level ergot daily for 9 weeks decreased serum prolactin concentrations and had subtle effects on sperm end points

Chohan et al., 2021

Answer

A

A 4-fold decrease in plasma prolactin concentrations was detected in supplemented bulls.
Semen end points were not significantly affected, although there were subtle effects on progressive motility, midpiece defects and mitochondrial membrane potential.
Results supported our hypothesis that prolonged low-level ergot will adversely affect plasma prolactin.
However, semen parameters were partially affected, supporting similar work on fescue toxicosis.

Question 10

Q

Interaction of Mycobacterium avium subsp. paratuberculosis with bovine sperm

Caldeira et al., 2020

Answer

A

Sperm in the presence of MAP shows a decrease in motility and vigor, and that the higher the MAP concentration, the lower the sperm performance.
It was possible to determine the viability of MAP after cryopreservation in samples of higher concentrations, which demonstrates the potential of transmission of this pathogen through artificial insemination.
The interaction of MAP with bovine sperm occurs mainly in the midpiece and may be linked to the proteins 85A and 85B present in the MAP membrane

Question 11

Q

Effect of dose and timing of prostaglandin F-2 alpha treatments during a 7-d Ovsynch protocol on progesterone concentration at the end of the protocol and pregnancy outcomes in lactating Holstein cows

Tippenhauer et al., 2021

Answer

A

P/AI was greater for GPPG (40.3%; P < 0.01) than for control (31.8%) and GDPG cows (33.4%).
Between GDPG and control cows, P/AI did not differ (P = 0.46).
Overall the addition of a second PGF treatment on d 8 during a 7-d Ovsynch protocol increased P/AI compared to the traditional 7-d Ovsynch including a single PGF dose on d 7 and to a double PGF dose on d 7.
Doubling the PGF dose on d 7 in a 7-d Ovsynch protocol did not affect P/AI.
Use of a presynchronization protocol, however, seems to influence the effect of a dose frequency modification of PGF treatment in an Ovsynch protocol. Presynchronized cows receiving first postpartum TAI had similarly increased P/AI treated with a double PGF dose compared with treatment with a second PGF dose.

Question 12

Q

Association between heat stress during intrauterine development and the calving-to-conception and calving-to-first-service intervals in Holstein cows

Recce et al., 2021

Answer

A

The exposure of the animals to environments with a THI >= 72 during the first trimester of gestation had a negative impact on the reproductive efficiency parameters analyzed.
The exposure of pregnant females to high THI values has a long-term impact on their daughters, which may contribute to a decrease in their reproductive performance, possibly through inherited epigenetic characteristics that remain in later generations through fetal programming

Question 13

Q

Effects of feeding 60% dried corn distillers grains plus solubles or the equivalent sulfur as CaSO4 on performance and reproductive traits of yearling Angus bulls

Kassetas et al., 2021

Answer

A

For motile populations of sperm, velocity on an average path (VAP) and curvilinear velocity (VCL) were reduced (P <= 0.02) for SULF compared with CON, with 60DDGS being intermediate.
In progressively motile sperm throughout the study, VAP and VSL were reduced (P <= 0.05) in 60DDGS and SULF compared to CON. For VCL, SULF was reduced (P <= 0.02) compared with CON, with 60DDGS being intermediate.
In serum, concentrations of T3 were reduced (P = 0.009) in 60DDGS compared with CON or SULF.
Plasma GPx activity was greater at d56, 112d for 60DDGS.
Therefore, feeding 60% DDGS to developing bulls altered semen kinematics, T3 concentrations, and GPx activity leading to the conclusion that these differences may not be solely dependent on concentrations of dietary sulfur.

Question 14

Q

First postpartum ovulation, metabolites and hormones in follicular fluid and blood in transition dairy cows supplemented with a Saccharomyces cerevisiae fermentation product

Sauls-Hiesterman et al., 2021

Answer

A

Body weight at calving and Day 42 was less (P <= 0.05), and energy balance through Days 28 and 42 was more positive (P < 0.05) in early than late ovulating cows and in SCFP-supplemented compared with control cows (P < 0.05).
Milk fat percentage was increased (P < 0.01) by SCFP supplementation.
Elevated postpartum BHB and FFA in plasma, greater negative energy balance, and greater milk yield and components were associated with later postpartum ovulation
Metabolites and steroid hormones in blood and follicular fluid were unaffected by SCFP treatment or ovulation status except for androstenedione

Question 15

Q

Observed and expected combined effects of metritis and other postpartum diseases on time to conception and rate of conception failure in first lactation cows in Iran

Ehsanollah et al., 2021

Answer

A

Median number of days to conception was higher in 30 cows affected with metritis and RFM (90 days), compared to 287 healthy cows (57 days), 16 cows affected with RFM alone (60 days) or 44 cows affected with metritis alone (60 days), after controlling for herd and calving month (p < 0.05).
In cows affected with metritis and RFM, the rate of conception failure was 3.8 times greater than that of healthy cows, after controlling for study herd and calving month (hazard ratio = 3.8; 95% CI = 2.3, 6.6; p < 0.01); this observed combined effect on conception failure was two times higher than the expected combined effect based on adding or multiplying absolute independent excesses due to metritis or RFM.
The observed combined effect of metritis and RFM on time to conception and rate of conception failure was far in excess, compared to that in cows exposed to metritis or RFM alone.

Question 16

Q

Heat stress influences the attenuation of prostaglandin synthesis by interferon tau in bovine endometrial cells

Sakai et al., 2021

Answer

A

Stimulation of PGF2 alpha production in endometrial epithelial cells by OT was unaffected by HS
Stimulation of PGF2 alpha production in endometrial stromal cells by TNF alpha was enhanced by HS, and this increased PGF2 alpha production was not significantly suppressed by IFNT.
These results suggest that HS disrupted the regulation of PGF2 alpha production by TNFa and IFNT in bovine endometrial stromal cells and it might be one of causes for low conception rate of cattle in summer

Question 17

Q

Timed artificial insemination strategies with or without short-term natural service and pregnancy success in beef heifers

Kasimanickam et al., 2021

Answer

A

Heifers in COSC (Cosynch with CIDR) + TAI + NS (86.8%), SSC (select synch with CIDR) + STAI (84.9%), and SSC + NS (86.5%) treatments had greater estrous response compared with heifers in COSC + TAI (75.8%) treatment.
Treatment regimens influenced first service pregnancy rate (P < 0.05).
Heifers in COSC + TAI + NS treatment had greater first service pregnancy rate (60.3%) compared with COSC + TAI (54.2%) (P < 0.05).
First service pregnancy rate for heifers in SSC + STAI (59.3%) and SSC + NS (57.3%) treatments did not differ from COSC + TAI + NS and COSC + TAI treatments.
In conclusion, progesterone-based CO-Synch timed artificial insemination with short-term natural service treatment regimen resulted in proportionately more pregnancies than without short-term natural service treatment regimen.
64/84 h split-time AI or natural service following Select-Synch treatment regimen could be implemented as an alternative as these treatment regimens resulted in similar pregnancy rate as progesterone based CO-Synch timed artificial insemination with short-term natural service treatment regimen.

Question 18

Q

The impact of elective caesarean section on colostrum characteristics in double-muscled Belgian Blue cows

Tuska et al., 2021

Answer

A

− Primiparity had a significantly negative impact on colostrum production (Volume).
− Time in C-section had a significantly impact on colostrum production (Volume).
− Summer had a significantly negative impact on colostrum production (Volume).
− No significant effects analysed were associated with colostrum quality

Question 19

Q

Comparison of two intravaginal progesterone-releasing devices in shortened-timed artificial insemination protocols in beef cattle

Zwiefelhofer et al., 2021

Answer

A

In Expt. 1, the proportion of heifers displaying oestrus prior to AI was greater (72.0% vs. 61.0%; P = 0.04) in the PRID compared to the CIDR group.
In Expt. 3, there was no difference in the ovulatory follicle diameter at device removal (P = 0.22) or TAI (P = 0.28) between P4 groups.
Treatment with a PRID tended (P = 0.10) to increase the P/AI in cows compared to a CIDR (73.5% vs. 61.0%).
In all experiments combined, the overall P/AI tended to increase (55.2% vs. 51.0%; P = 0.08) and P/AI in cattle exhibiting estrus increased (64.4% vs. 59.7%; P = 0.02) in cattle given a PRID compared to those given a CIDR, respectively

In summary, the type of intravaginal P4 device affected estrus response and P/AI following TAI in beef cows.

Question 20

Q

Evaluation of alpha 5 beta 1 integrin as a candidate marker for fertility in bull sperm samples

Castellano et al., 2021

Answer

A

When the percentage of cells showing alpha 5 beta 1 integrin was compared to fertilization rate, no correlation was observed.
However, the presence of alpha 5 beta 1 integrin in regions post-acrosomal (P) and acrosomal + post-acrosomal (A + P) regions, positively correlated with IVF rate (p < 0.05). While routine semen analyses failed to predict sperm reproductive competence, integrin localization in postacrosomal region (PA pattern) showed a positive correlation with IVF outcome, thus posing an attractive marker to predict more accurately the reproductive performance of an individual

Question 21

Q

Characterizing Anti-Mullerian Hormone (AMH) concentration and change over time in Holstein dairy cattle

Kayla et al., 2021

Answer

A

Age at first calving and AMH in heifers were highly correlated (0.56, P < 0.001).
AFC for heifers differed by AMH group with the HIGH group having the greatest AFC (8.76), followed by the MID (5.87), then the LOW (3.53) group (P < 0.0001).
A drop in circulating AMH occurred post-calving that remained depressed until pre-breeding (45–60 days in milk).

Circulating AMH concentration as a pre-breeding heifer is highly indicative of circulating AMH concentration as a first lactation animal and may be used to predict an adult animal’s AMH concentration. However, it is necessary to compare AMH concentrations to herdmates as published AMH values vary widely from herd to herd. In addition, sampling time should be considered when determining AMH categorization of animals as circulating AMH concentration immediately post-calving may not be indicative of an animal’s true AMH categorization.

Question 22

Q

A comparison of immunological, chemical and surgical castration of Nelore bulls

Yamada et al., 2021

Answer

A

Three castration methods
▪ Immune: Bopriva injection
▪ Chemical: 40% CaCl2 + 0.5% dimethylsulfoxide
▪ Surgical
Immunological castration was a viable alternative to surgical castration, as it supressed testosterone production and spermatogenesis, with the benefits of being much less invasive, with better animal welfare and less stress.

Question 23

Q

Resynchronizing the first eligible estrus in dairy cattle after a prior insemination and fertility of the prior insemination after gonadotropin-releasing hormone and progesterone treatments

Stevenson et al., 2021

Answer

A

Use of GnRH alone (Day 7), a CIDR insert alone (Days 14 through 21), or in combination, failed to increase the proportion of nonpregnant cows in estrus before pregnancy diagnosis on Day 32 compared with controls.
Cows receiving the CIDR insert had increased (P < 0.01) synchrony of estrus by 24-34% points compared with cows that did not receive a CIDR insert.
In both experiments combined, treatments with GnRH or GnRH + CIDR insert increased (P = 0.015) pretreatment pregnancy per AI by 7.1% points, but did not affect pregnancy loss.
Although administering GnRH with or without a CIDR insert synchronized returns to estrus, treatments failed to increase the proportion of nonpregnant cows reinseminated before pregnancy diagnosis, but increased pretreatment pregnancy risk.

Question 24

Q

Prostaglandin F2 alpha regulation and function during ovulation and luteinization in cows

De Moraes et al., 2021

Answer

A

Flunixin meglumine decreased PGF synthesis within the follicle
PGF treatment decreased follicular vascularization.
The in vivo model of intrafollicular injection evidenced that PGF alone is not able to locally induce ovulation

Question 25

Q

Non-steroidal anti-inflammatory drugs at embryo transfer on pregnancy rates in cows: A meta-analysis

Besbaci et al., 2021

Answer

A

NSAID treatment with was associated on average with a 15% higher P/ET compared to no treatment (RR = 1.15, 95% CI = 1.07 to 1.2).
The use of NSAIDs at the time of ET was particularly effective in cows with difficulty in passing the catheter from the cervix during ET, with 71% more likely P/ET (RR = 1.71, 95% CI = 1.07 to 2.74) with the use of NSAIDs for these cows compared to other cows.

Question 26

Q

Vaginal temperature before calving assessed with wireless vaginal temperature sensor in dairy and beef cattle

Sakatani et al., 2021

Answer

A

The Holstein group’s alert detection rate was significantly lower than the Japanese Black group’s (p < 0.05).
The daily average temperature was higher in the Hol group and the primiparous dams
The daily average temperature increased slightly from Day-7 to-3 (Day 0 = the day of calving) and then dropped dramatically on Days-1 and 0.
The hourly vaginal temperature difference from-48 h of calving showed a typical pattern, i.e., a decrease from-30 h of Alert 1 and an increase at-6 h of Alert 1. The decrease and increase might be the regression of the pregnant corpus luteum and the beginning of the contractions, respectively.
The temperature differences were significantly affected by parity and calving ease (p < 0.01), but no typical temperature difference pattern was observed in assisted calving or dystocia.
Measuring vaginal temperatures proved useful for predicting the calving regardless of the breed and parity.

Question 27

Q

Effect of ovulation synchronization program and season on pregnancy to timed artificial insemination in suckled beef cows

Randi et al., 2021

Answer

A

There was a treatment by season interaction for P/AI (P < 0.001). In spring, overall P/AI was 59.1% (414/701) and was affected by treatment (59.3 v 49.6 v 68.2%, for Treatments 1, 2 and 3, respectively P < 0.05).
In contrast, in autumn, ov erall P/AI (51.5%, 364/707) was unaffected (P > 0.05) by treatment (50.1 v 53.7 v 48.7% for Treatments 1, 2 and 3, respectively).
Overall, eCG had a positive effect on P/AI for cows lacking a CL at treatment initiation (P < 0.05).
In addition, in cows with low BCS (<= 2.25), eCG supplementation tended (P = 0.09) to improve P/AI.
Seasonal differences in response to synchronization treatment may be reflective of different management regimens (grazing v confinement) and breed type and remain to be elucidated.

Question 28

Q

Evaluation of PCR assays for Campylobacter fetus detection and discrimination between C. fetus subspecies in bovine preputial wash samples

Polo et al., 2021

Answer

A

The P12 PCR assay targeting the gyrB gene performed best, detecting the pathogen in 95.1% of positive samples.
For the discrimination of C. fetus subspecies, we were able to identify a proportion (85.4%) of the C. fetus-positive samples correctly as C. fetus venerealis with at least one subspecies-specific PCR, but C. fetus fetus was not detected in any of the samples tested.
C. fetus subspecies amplification was observed following PCR on some samples (33.1%) considered C. fetus -negative, highlighting the need for rigorous criteria for discriminating between C. fetus subspecies

Question 29

Q

Progesterone release profile and follicular development in Holstein cows receiving intravaginal progesterone devices

Silva et al., 2021

Answer

A

By comparing circulating P4 concentrations in non-lactating Holstein cows treated with PRID (1.55 g) vs. CIDR (1.38 g) for 7 d, it was found greater circulating P4 produced by the PRID after device insertion, most likely associated with its greater surface area.
Although the circulating P4 profile and mean circulating P4 over 10 d differed among treatments, no effects were observed on the DF diameter and follicular growth rate from Day 7-10 after P4 device insertion.
Devices that provided higher circulating P4 concentrations were associated to a slower DF growth during the treatment period, “which might be associated with greater fertility in dairy cattle”

Question 30

Q

Sperm phenotypic characteristics and oviduct binding ability are altered in breeding bulls with high sperm DNA fragmentation index

Nag et al., 2021

Answer

A

Spermatozoa from bulls with low DFI% had significantly higher (P < 0.05) membrane integrity, acrosome intactness, and mitochondrial membrane potential.
Binding index (BI) was significantly (P < 0.01) higher (>2 times) in the bulls with low-DFI% as compared to high DFI% bulls.
The correlation between binding index and DFI% was negative and significant (r = similar to 0.528; P < 0.05). Further, the binding index was positively correlated with conception rate (r = 0.703), intact sperm membrane (r = 0.631) and mitochondrial membrane potential (r = 0.609).
Sperm phenotypic characteristics and oviduct binding ability are impaired in breeding bulls with high sperm DFI%, which might be associated with low conception rates in these bulls.

Question 31

Q

Effect of supplemental trace minerals on standard and novel measures of bull fertility

Geary et al., 2021

Answer

A

In mature bulls, final liver Zn concentration was positively correlated (P = 0.02) with sperm concentration (r = 0.31) and tended (P = 0.06) to be negatively correlated with acrosome damage (r = -0.39).
Each BSE and novel fertility component improved from Day 0-84 in peripubertal bulls and were not affected (P > 0.10) by mineral supplementation.
Liver Zn was correlated with acrosome damage (−) and sperm concentration (+) in bulls.*
Zn & Cu fed to peripubertal bulls had only minor effects on fertility measures.
Trace minerals improved ability of sperm to withstand oxidative stress in young bulls.
Trace minerals increased sperm viability at 3 h in peripubertal bulls.

In summary, it appears the homeostasis mechanisms for bull trace mineral maintenance are extremely efficient and mineral supplementation of mature and peripubertal bulls did not have major improvements in any laboratory or chute-side measures of bull fertility, however bulls exposed to breeding or in environments with diet antagonists might respond differently.

Question 32

Q

Genome-wide association and genomic prediction for scrotal circumference in Hereford and Braford bulls

Ferreira et al., 2021

Answer

A

The genomic enhancement methods, especially single step GBLUP, that combined phenotype and pedigree data with direct genomic values generated gains in accuracy in relation to pedigree BLUP, suggesting that genomic predictions should be applied to improve genetic gain and to narrow the generation interval compared to traditional methods.

Question 33

Q

Effect of fasting prior to electroejaculation on behavioral responses and reproductive parameters in young Simmental bulls

Romano et al., 2021

Answer

A

Fasting for 24 h prior to semen collection by electroejaculation reduced the bladder size and increased the proportion of bulls with penis protrusion, erection, and ejaculation without any difference detected in behavioral responses, volume of rectal fecal content, and ejaculate parameters.

Question 34

Q

Effect of PGF(2 alpha) treatments during early corpus luteum development on circulating progesterone concentrations and ovulation in breeding-age Holstein heifers

Martins et al., 2021

Answer

A

PGF(2 alpha) treatments during early CL development reduced circulating P4 concentrations 7 d after G1 but did not effectively control CL and follicle function and was an ineffective model to test high vs. low serum P4 on fertility parameters in Holstein heifers.

Question 35

Q

Methionine supply during the peripartum period and early lactation alter immunometabolic gene expression in cytological smear and endometrial tissue of holstein cows

Guadagnin et al., 2021

Answer

A

Supplementation decreased mRNA expression for glucose transporter 4 (GLUT4), interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), interleukin 8 (IL-8), prostaglandin E synthase 3 (PTGES3), translocator protein 18 kDa (TSPO), mucin 1 (MUC1) and superoxide dismutase (SOD1) in cytological smear samples.
For uterine tissue samples, supplementation increased the mRNA expression of lecithin-cholesterol acyltransferase (LCAT), S-adenosyl-L-homocysteine hydrolase (SAAH), FGF7, GLUT4, and apolipoproteins 3 (APOL3), with an effect of time for APOL3 where its expression increased over time.
Supplementation during transition period and early lactation is beneficial for uterine immune response and metabolism in early lactation as indicated by the favorable expressions of genes affecting the uterine immunometabolism during such a challenging period

Question 36

Q

Relationship of molecular breeding value for beef tenderness with heifer traits through weaning of their first calf
Cushman et al., 2021

Answer

A

Polymorphisms in mu-calpain (CAPN1) that beneficially associate with beef tenderness are reported to antagonistically associate with calving day in beef heifers and post-partum interval to estrus in beef cows.
Selecting for tenderness using genomic predictions had minimal or no antagonistic association with reproductive performance in heifers.

Question 37

Q

Effects of GnRH and hCG administration during early luteal phase on estrous cycle length, expression of estrus and fertility in lactating dairy cows

Cunha et al., 2021

Answer

A

In summary, inducing the formation of an accessory corpus luteum from d 5 to 7 of the estrous cycle with hCG reduced expression of estrus in multiparous Holstein cows. Moreover, hCG increased estrous cycle length in Holstein and Jersey cows, and it did not affect first service P/AI at 37 +/- 3 d post-AI in Holstein and multiparous Jersey lactating cows. However, hCG increased P/AI in primiparous Jersey cows

Question 38

Q

Transition cow metabolites and physical traits influence days to first postpartum ovulation in dairy cows

Banuelos et al., 2021

Answer

A

Cows first ovulating before median Day 33 were classified as early, whereas those first ovulating after Day 33 were classified as late.
Compared with late ovulating cows, early ovulating cows had lesser (P < 0.05) concentrations of FFA, BHB, and haptoglobin on Days 0, 3, 7, and 14 after calving
Compared with late ovulating cows, early ovulating cows had lesser (P < 0.05) rectal temperatures (d0,3,7,14) and ear-surface temperatures.
Ear-surface temperatures began to decrease 4 d before parturition
Early ovulating cows tended (P = 0.07) to spend more time eating, and less (P = 0.02) time resting and being active during the first 3 wk after calving, and lost less (P = 0.03) BW and BCS
Although no differences were detected in yields of milk or energy-corrected milk during the first 9 wk after calving, early compared with late ovulating cows produced more (P < 0.01) milk protein. We concluded that metabolic measures during the first 2 wk after calving, and physical and behavioral traits are associated with the onset of postpartum ovarian activity

Question 39

Q

Factors affecting placental size in beef cattle: Maternal and fetal influences

Redifer et al., 2021

Answer

A

Bovine dam prepartum body weight and calf size at birth were positively correlated with dried placental weights.
Determining placental dry matter weights is necessary to better characterize placental size compared with wet weights.
Primiparous dams and dams with low body condition at calving had reduced placental weights.
Proper nutritional management of pregnant cattle is necessary for optimal placental growth.

Question 40

Q

Leptospirosis by Sejroe strains leads to embryonic death (ED) in herds with reproductive disorders

Oliveira et al., 2021

Answer

A

Herds with high seroreactivity (>20%) had more reproductive problems.
Those with a predominance of Sejroe were associated with ED (P < 0.05), while those with Icterohaemorrhagiae were associated with abortion.

Question 41

Q

Increasing of matrix metalloproteinase 3 in bovine endometritis

Zhang et al., 2021

Answer

A

MMP3 mRNA and protein levels significantly increased and positive correlative with severity of endometritis in vivo.
Likewise, MMP3 expression also positive correlative with intensity of LPS inflammatory response in vitro.
Increasing of MMP3 directly correlates with bovine endometritis and may contribute to progression of bovine endometritis

Question 42

Q

Meloxicam administration in the management of postoperative pain and inflammation associated with caesarean section in beef heifers: Evaluation of reproductive parameters

Mauffre et al., 2021

Answer

A

Meloxicam administration before caesarean section had no effect on the incidence of retained placenta (18.2% of treated vs 25.0% of control cows, p = 0.35).
The pregnancy rate was higher in treated than in control cows (83.1% vs 67.8%, p = 0.04 after multivariate analysis)
Survival analysis showed that the median calving interval was 35 days shorter in the meloxicam (t50% = 417 days) compared to the control group (t50% = 452 days, p = 0.05).
A trend was also observed for culling rate to be lower in treated (4.7%) compared to control cows (13.3%, p = 0.09)

In conclusion, this study suggests that there is a beneficial effect of meloxicam administration before caesarean section on reproductive performance in Charolais heifers.

Question 43

Q

Relationships between milk protein concentrations at different phases of first to fourth lactation and subsequent calving intervals in Holstein cows

Makhtoomi et al., 2021

Answer

A

Lactations were divided into four time periods (<50d, 50 < d < 100,100 < d < 200 and 200 < d < 305).
Protein concentrations were also divided into three classes: 1-3%, 3-5%, 5-7%.
There was a negative relationship between MP% in the first 50 days of first lactation in primiparous and multiparous dairy cows and subsequent calving intervals.
▪ Calving intervals decreased as MP% increased and the shortest calving intervals were observed for the third class of milk protein concentrations.

Question 44

Q

Assessing the consequences and economic impact of retained placenta in Holstein dairy cattle

Makhnani et al., 2021

Answer

A

The average incidence of RP per cow over a year was 12.3% (ranged between 9.0 and 15.4%).
Each incidence of RP significantly reduced milk, fat and protein yields in primiparous and multiparous cows (P < 0.05).
The adverse effect of RP on the milk production was much higher in the cows at the early phase of lactation (i.e. 100-d lactation group) than the cows in mid or late lactation.
▪ The estimated production losses (+/- standard deviation) due to the RP event were 282.1 +/- 43.0 and 295.7 +/- 40.8 kg per cow for a 305-d lactation period in primiparous and multiparous cows, respectively.
The fertility performance was less affected by the RP in primiparous compared to multiparous cows.
▪ The average of days open increased by 8.3 +/- 5.3 and 19.8 +/- 7.1 d in primiparous and multiparous cows, respectively.
The financial losses associated with RP were on average US$ 350.4 and US$ 481.2 per incidence in primiparous and multiparous cows, respectively, ranged from US$ 311.9 to 456.2 depending on the parity number (primi-or multiparous) and herd management.
The highest financial losses due to RP were associated with reduction in milk production (38.5% of total loss) and low fertility (28.5% of total loss) had the highest contribution in in primiparous and multiparous cows, respectively

Question 45

Q

Economic comparison of an ear tag automated activity monitor for estrus detection with timed-AI in Holstein heifers

Macmillan et al., 2021

Answer

A

Automated detection Vs FTAI with a 5d Cosynch 72 + P4
There was no difference in overall P/AI or days to pregnancy between treatments.
However, number of AI was greater in the TAI than the AAM group.
For the first AI, the P/AI was less in the TAI compared to the AAM group; however, the interval to first AI was less in TAI.
There was a net gain of $11.97 per heifer when switching from a TAI to AAM protocol, due to the increased P/AI to the first AI and reduced cost of hormones

Considering only the first AI, switching to an AAM collar and a larger herd size all increased the net gain. Considering a greater P/AI to the first AI in the TAI group, outsourcing AI, using more AAM ear tags, and smaller herd sizes resulted in a net loss when switching from TAI to AAM. The AAM system resulted in exceptional P/AI and may be an economically viable alternative to improve heifer reproductive efficiency in herds with suboptimal P/AI to TAI.

Question 46

Q

Prevention of retained fetal membranes and improvement in subsequent fertility with oxytocin administration in cows with assisted calving

Magata et al., 2021

Answer

A

In cows with assisted birth, oxytocin administration accelerated placental expulsion (P < 0.05) and improved several reproductive parameters, such as the number of services until conception (P < 0.05) and the calving to conception intervals (P < 0.05) compared to the control group.
On the other hand, oxytocin administration slightly accelerated placental expulsion (P < 0.05), but failed to improve fertility in cows with unassisted birth.

Question 47

Q

Age, gestational and heat stress effects on ghrelin secretion in dairy cattle

Ioannis et al., 2021

Answer

A

THI – 58 in winter, 73 in summer. BS collected during each season.
In cows, total ghrelin levels differed between gestation stages in winter and summer (p < 0.04), while acylated ghrelin levels differed by gestation stage in winter (p < 0.001) but not in summer.
Both in cows and heifers, acylated ghrelin levels were lower in summer compared to winter, (p < 0.002).
During the summer months the low ghrelin levels might explain the reduced feed consumption of heat stressed animals.

Question 48

Q

Postpartum cows showed high oocyte triacylglycerols concurrently with high plasma free fatty acids

Furukawa et al., 2021

Answer

A

High postpartum plasma FFA concentrations affect the quantity of oocyte TAG:
Plasma FFA positively correlated with oocyte TAG (P < 0.05)
Oocyte TAG was higher during early lactation stages and in cows Vs heifers.
Oocyte FFA quantity and composition were stable regardless of lactation stage.
oocyte quality in postpartum cows may be impaired due to high circulating FFA concentrations.

Question 49

Q

Pharmacokinetics of tulathromycin on plasma and semen of beef bulls

Romano et al., 2021

Answer

A

The mean level of tulathromycin in plasma was 75.8 +/- 40.2 ng/mL, which was lower than mean seminal plasma levels of 781 +/- 482 ng/mL (P = 0.001).
The plasma peak tulathromycin concentration (C-max) was 160 +/- 27 ng/mL at 21 +/- 6 h (T-max) post-administration.
Tulathromycin is a suitable antibiotic based in its pharmacokinetic properties that could be used for treatment of bull genital infections when its application is indicated.

Question 50

Q

Progesterone release profile and follicular development in Nelore cows receiving intravaginal progesterone devices

Silva et al., 2022

Answer

A

Primer (0.5 g); Prociclar (0.75 g); Sincrogest (1 g); or CIDR (1.9 g)
Overall, the devices resulted in distinct increases in circulating P4 concentrations over 10 d
Primer provided the lowest circulating P4 concentrations over time, whereas, CIDR had the greatest concentration
Greater circulating P4 concentrations, mainly during the first 3 d of device insertion, were associated with smaller DF diameters regardless of the treatment

Question 51

Q

The impact of the cavitary corpus luteum on the blood progesterone concentration and pregnancy rate of embryo recipient heifers

Jaskowski et al., 2022

Answer

A

The mean serum P4 concentration was 8.84 ng/ml, higher (P < 0.0001) for females with the CLcav (11.31 ng/ml) than for those with the CLhom (7.15 ng/ml).
The PR was 36.1%, higher (P < 0.05) for recipients with the CLcav (47.7%) compared to the CLhom (29.9%).
The CLcav may give the embryo better chances of surviving the time of pregnancy recognition and in consequence, may have a positive effect on PR in heifers.

Question 52

Q

Late-gestation ear-surface temperatures and subsequent postpartum health, activity, milk yield, and reproductive performance of dairy cows
J.S. Stevenson, 2022

Answer

A

● On Days 230–239 of gestation during May through September (hotter months) cows with high (H, range of 33.67–38.89 °C, mean ± SEM = 32.9 ± 0.2 °C) or medium high (MH, 25.06–31.66 °C, 29.4 ± 0.2 °C) temperatures were grouped together (n = 209 per group).
● For comparable gestational days during October through April (colder months), cows with medium low (ML, 17.82–25.00 °C, 21.1 ± 0.2 °C) and low (L, −0.70 to 17.80 °C, 13.4 ± 0.2 °C) temperatures were grouped together (n = 216 per group).
● Prepartum traits including mean ear temperature, gestation length, days in milk at dry-off, days in close-up pen, previous 305-d milk yield, proportion of heifer calves born, and cow PTA for milk differed (P < 0.05) between seasons, but not between temperature groups within season, except predicted transmitting ability for milk was greater (P = 0.02) for ML than L cows.
● Postpartum treatment with antimicrobials occurred more (P = 0.02) often in H than MH cows, whereas more (P = 0.04) lameness and greater (P = 0.05) projected 305-d mature equivalent milk yield was observed in ML vs. L cows.
● Less (P = 0.04) prepartum eating time during the last 10 d before calving was detected in L than in ML cows, less (P = 0.06) rumination time in ML than L cows, and more (P = 0.03) activity time was observed in H than MH cows.
● After calving, H cows were more (P = 0.03) active than MH cows and ML cows tended (P = 0.07) to be more active than L cows.

In conclusion, late gestational ear-surface temperatures were associated with some postpartum health disorders and modifications in daily eating, ruminating, and active times during the transition period of gravid heifers and dry cows.

Question 53

Q

Serum sRAGE and sE-selectin levels are useful biomarkers of lung injury and prediction of mortality in calves with perinatal asphyxia

M. Ider et al., 2022

Answer

A

● Venous pH, sO2, HCO3, and BE of calves with perinatal asphyxia were significantly lower than the healthy calves.
● sRAGE, sE-selectin, pCO2, and lactate were significantly high in calves with asphyxia.
● Also, pH, pCO2, lactate, HCO3, BE, and respiratory rate along with serum sRAGE and sE-selectin were useful indicators in the prediction of mortality

Question 54

Q

Association between length of proestrus, follicular size, estrus behavior, and pregnancy rate in beef heifers subjected to fixed–time artificial insemination,
R. Núñez–Olivera et al., 2022

Answer

A

For those heifers bearing a CL, pregnancy rate was greater in heifers with a 72 h proestrus length (77.0%, 134/174) than with 48 or 60 h proestrus length (67.7%, 107/158 and 68.5%, 111/162; respectively; P < 0.05).
In heifers without a CL, proestrus length did not affect pregnancy rate.
In summary, extending proestrus length by delaying the interval from device removal to GnRH/FTAI from 48 to 72 h, was associated with a greater diameter of the preovulatory follicle, greater proportion of heifers expressing estrus at the time of FTAI, and greater pregnancy rate in cycling beef heifers.

Question 55

Q

An ex-vivo assessment of differential sperm transport in the female reproductive tract between high and low fertility bulls

Donnellan et al., 2022

Answer

A

Sperm from high fertility bulls had a higher curvilinear velocity and binding affinity to the oviductal epithelium compared to low fertility bulls.
Straight line velocity explained 18.9% of variation in bull sperm rheotaxis, but there was no significant difference between high and low fertility bulls in most of the sperm motility, kinematic and sperm functional parameters (namely, motility, average path velocity, linearity, straightness, amplitude of lateral head movement)
Differences in the kinematics of sperm motility and ability to bind to oviductal explants between high and low fertility bulls were modest and are unlikely to explain the inherent differences in fertility between these cohorts of bulls.

Question 56

Q

Early pregnancy diagnosis based on luteal morphology and blood flow on Days 17–21 post-artificial insemination in Japanese Black cattle

Kanazawa et al., 2022

Answer

A

In pregnant group CL area and CL tissue area were greater (P < 0.001) than those in non-pregnant group (n = 89) on and after Day 19.
Blood Flow Area (BFA) was greater (P < 0.05) in pregnant group on and after Day 18.
The overall central cavity incidence was lower (P < 0.001) and CCA was smaller (P < 0.001) in pregnant group.
The best single predictor for pregnancy diagnosis was BFA on Days 17–20 (sensitivity = 69%–100% and specificity = 65%–91%).
On Day 21, CL area or CL tissue area was the most accurate predictor (cutoff value = 267.78 mm2, sensitivity = 100%, and specificity = 100%).
The best set of predictors for pregnancy diagnosis was specified as the BFA and [CCA × BFA] pair. Setting BFA cutoff value in the cattle without central cavity at 55.26 mm2 yielded the highest sensitivity (97%) and specificity (88%) on Days 18–20.

Question 57

Q

A comparison of the age at first calving of contract-reared versus home-reared replacement dairy heifers

McCarthy et al., 2022

Answer

A

There was no difference in median AFC between home and contract-reared heifers (24.4 months).
At univariate level, variables significantly associated with AFC were occurrence of pyrexia before MSD, pre-breeding ADG, body weight and BCS.
When the frailty effect of farm was incorporated into the multivariable model, these variables were no longer significant, indicating wide variation in individual farm management practices not measured in this study.
Rearing strategy (home versus contract-rearing) did not significantly affect heifer AFC.

Question 58

Q

Composition and diversity of the seminal microbiota in bulls and its association with semen parameters
Koziol et al., 2022

Answer

A

The most abundant genera in the seminal microbiome include Bacteroides, Corynebacterium 1, Escherichia, Gemella, and S5-A14a (an uncultured bacterium from the Clostridiales order).
Bulls with satisfactory spermiograms had a higher abundance of sequence types belonging to many genera including Bacteroides, S5-A14a, Trueperella, and two methanogenic archaea genera Methanosphaera and Methanobrevibacter.
Comparatively, samples from bulls with unsatisfactory speriograms had greater abundance of sequence types belonging to Veillonellaceae, Campylobacter, and Methanobacterium.
In the satisfactory group, Methanobrevibacter cooccurred with twelve amplicon sequence variants (ASVs), indicating that it may be important for maintenance of the microbiota in satisfactory samples, and members of this genus were enriched in the satisfactory group. Opportunistic pathogens such as Campylobacter, and Fusobacterium co-occurred with four and ten ASVs, respectively, in the unsatisfactory group, potentially indicating they are acting in synergy with other member of the microbial community, but only in the unsatisfactory group.

Question 59

Q

Increasing the frequency of ejaculate collection in young dairy bulls increases semen production and field fertility
Taaffe et al., 2022

Answer

A

Ejaculate volume and sperm concentration were not affected by treatment but the first ejaculate of the day (HF only) had a greater volume (P < 0.001) and sperm concentration (P < 0.05) than the second ejaculate.
HF had higher pre-freeze total (P < 0.01) and gross (P < 0.05) motility than LF.
HF had higher post-thaw (2 h) total and gross motility than LF (P < 0.05).
Ejaculate rejection rates did not differ between treatments.
There was no effect of treatment, week or ejaculate number of the day (HF only) on post-thaw motility and kinematic parameters or sperm viability, membrane fluidity, acrosome integrity and DNA fragmentation.
However, HF had lower superoxide production than LF (P < 0.05).
Pregnancy per artificial insemination was 64.5 ± 1.0% and 59.9 ± 1.1% for the HF and LF bulls, respectively (mean ± SEM; P = 0.05).
In conclusion, collecting ejaculates more frequently from young bulls significantly reduced the number of days required to obtain 1000 straws, increased semen quality in terms of lower superoxide production and increased field fertility.

Question 60

Q

Association of post-partum serum Ca patterns with reproduction in Holstein cows
Tsiamadis et al.,2022

Answer

A

Odds for pregnancy by 120 DIM did not differ among clusters, however, cows in clusters SCH-3 and SCH-5 had lower odds for pregnancy by 200 DIM compared to HIGH (OR = 0.55, P = 0.02, and OR = 0.49, P = 0.004, respectively).
SCH-3 and SCH-5 had the highest (36% and 38%, respectively), while NORM and HIGH the lowest (16% and 17%, respectively) proportion of cows not inseminated for the 1st time by 120 DIM,
compared to HIGH, cows in SCH-5 had a lower hazard of pregnancy by 120 DIM (HR = 0.42, P = 0.005)
the proportion of open cows by 200 DIM for NORM and HIGH were 57% and 47%, respectively, while for SCH-3 and SCH-5 66% and 68%, respectively
compared to HIGH, SCH-3 (HR = 0.54, P = 0.008) and SCH-5 (HR = 0.50, P = 0.001) presented the lowest hazard for pregnancy by 200 DIM.
In conclusion, cows that during the entire first week after calving were continuously normocalcemic had the best reproductive performance, while those of SCH-3 and SCH-5 the worst.

Question 61

Q

Fertility comparison of frozen bull semen stored in cryogenic deep freezer (−152 °C) and LN2 container

Tirpan et al. 2022

Answer

A

cryopreserved bull semen comprises 95% of all kinds of semen that is used for artificial insemination in the dairy industry,
-LN2 has been determined as the most suitable for using. Nevertheless, LN2 has some disadvantages like contaminations, affected by climatic and seasonal temperature changes, costs, labor force and human initiative.
-it can be expected that storing frozen semen at lower temperatures than the freezing range does not harm semen.
outcome:
1)Liquid nitrogen based frozen semen storage has lots of disadvantages.
2)Cryogenic deep freezers could be a feasible alternative with their low temperature.
3)Cryogenic deep freezers have negative effects on PMOT and STR, for 1-week storage.
4)Cryogenic deep freezers have no effect on fertility, for 1-week storage.
5)Cryogenic deep freezers might be a limited alternative to store frozen bull semen.

Question 62

Q

Effect of lameness on breeding soundness examination results of beef bulls
Boakari 2022

Answer

A

Outcome
1) Cortisol and testosterone concentrations were not different between bulls from the unsatisfactory and satisfactory groups.
2) The most common limb/foot lesions found in the unsatisfactory and satisfactory groups were laminitis-related.
3) The odds of a satisfactory BSE result were 4.4 times higher in not-lame bulls when compared with lame bulls.

Question 63

Q

Pharmacokinetics of oxytetracycline long-acting on plasma and semen of beef bulls
Romano et al. 2022

Answer

A

1) Oxytetracycline long-acting presents satisfactory pharmacokinetics properties for the treatment of bull genital infections when its use is indicated.
2) The levels of oytetracycline in seminal plasma were 6 or more times higher than plasma levels.
3) The mean residency time of oxytetracycline in seminal plasma was longer than in plasma

Question 64

Q

Factors affecting reproductive outcomes in lactating dairy cows that undergo presynchronization-Ovsynch and successive resynchronization programs

Ill-Hwa 2022

Answer

A

In conclusion, high BCS has beneficial effects during the entire reproductive period, whereas TAI during heat stress, the presence of a pre- or postpartum disorder, a larger number of days to first TAI following calving, and TAI number (second or ≥ fifth) adversely affects the outcomes associated with pregnancy during the early or later breeding periods in lactating dairy cows undergoing Presynchronization-Ovsynch and successive resynchronization programs.

Answer 65

A

1) Corn or wheat in Jersey cows diet induced minimal change in circulating lipids.
2) Type of grain supplement did not affect embryo morphology or recovery rates.
3) Corn supplementation caused reduction in mitochondrial function in embryonic cells.
4) Lipids known to be associated with lower cryotolerance were affected by the diet.
5) Indirect mechanism of lipid uptake leading to mitochondria dysfunction is suspected.

These treatment effects suggest an indirect mechanism potentially impacting embryo quality through mitochondrial dysfunction rather than direct lipid uptake.

Answer 66

A

Early pregnancy induces changes in plasma ISGs, TLRs, complement components.
C1q can be used as an ideal marker for early pregnancy diagnosis in cows.
Development of an immunochromatographic test strip for early pregnancy diagnosis.
Accuracy of pregnancy diagnosis by this test strip was 91.67% (11/12) for pregnant cows and 80% (8/10) nonpregnant cows at day 18 after insemination.

In conclusion, the changes in plasma ISGs, TLRs, complement components, EPF and PAPPA proteins may be related to the maternal systemic immune modulation during early pregnancy, and a colloidal gold immunochromatographic test strip was developed for early pregnancy diagnosis using C1q as the ideal marker in cows. However, this colloidal gold immunochromatographic test strip needs further studies to improve the accuracy.

Answer 67

A

Efficacy trials demonstrated significantly decreased somatic cell count to safe levels in milk samples of umbilical cord-derived mesenchymal stem cells and UCB-MSC-extracellular vesicles treated groups compared to antibiotic group. The leucocytes expression of anti-inflammatory cytokines, anti-microbial peptides, and angiogenic genes were significantly upregulated in UCB-MSCs and UCB-MSC-EVs treated groups as compared to antibiotic therapy group.

Answer 68

A

No serum components measured were within adult bovine reference intervals for all calves at all sampling times. All serum albumin concentrations were outside of reference intervals, and the majority of serum glucose, calcium, phosphorus, potassium, CK, GGT, and total bilirubin were outside of reference intervals. More serum chemistry measures diverged from reference intervals in the first 24 h of neonatal life. Rectal temperature decreased (P = 0.003) from 0 to 6 h of age, then increased (P ≤ 0.02) from 12 to 48 h.

Answer 69

A

Structures from primiparous cows, from those with greater progesterone concentration at insemination, and from cows with seven or less accessory spermatozoa were less likely to be fertilized or of better quality than structures from multiparous cows, from those with lower progesterone concentration in plasma, and from those with more than seven accessory spermatozoa, respectively.
Embryos with more blastomeres or without nonviable blastomeres were more likely to be of better quality than embryos with fewer blastomeres or with nonviable blastomeres.
The results of this analysis highlight the importance of low circulating concentrations of progesterone near artificial insemination and potential positive association with number of accessory spermatozoa reaching the embryo and improvement of embryo development up to the morula stage.

Answer 70

A

Our model suggests that reproductive strategies that use TAI have a better economic performance than those under NM. However, when performing three TAI with an interval of 40 days, the benefit was lower; in some cases, it was even worse than the ONM. Combining TAI with early pregnancy diagnosis resulted in better economic performance than other TAI programs and NM. The 2TAI/24 + NM scenario outperformed the others due to the contrast between its high income and moderate costs.

Answer 71

A

The results showed that cows with the number of inseminations to conception (INS) of ≥4 at a low parity had a higher probability of being RB again at subsequent parities compared with cattle with INS 1 or 2.
- Additionally, the degree of the negative effect of an INS ≥4 on fertility and survival increased as they became older. On the other hand, cows with an INS of 2 had similar fertility and survival with those with an INS of 1.
- In summary, this study suggests that repeat breeders at a low parity have a higher probability of RB again at subsequent parities compared with cattle with INS 1 or 2, and the negative effect of an INS ≥4 increases as parity increases.

Answer 72

A

Estimated genetic correlations between RP and production traits (milk, fat, and protein yields) at 100, 200, and 305 d in milk ranged from -0.12 to -0.29; the greatest correlation (-0.29) was for the first 100 d in milk.
A moderate positive genetic correlation (0.25) was found for RP and DO, DFS, and NIC, whereas a low negative genetic correlation (-0.09) was found between RP and SFI.
The pedigree-based genetic analysis of RP showed that this trait has a low heritability, is linked to other reproductive disorders, and generally has an unfavorable relationship with production and fertility traits. Selection against RP can reduce the incidence of reproductive disorders and improve fertility and production traits.

Selection against RP can reduce the incidence of reproductive disorders and improve fertility and production traits.

Answer 73

A

The estimated heritabilities and repeatabilities of total number of embryos and oocytes were 0.30 and 0.43 by Poisson regression model (POI), 0.35 and 0.47 by zero-inflated Poisson (ZIP) regression models, 0.27 and 0.36 by Gaussian mixed model (GAU), 0.21 and 0.31 by natural log-transformed records (LOG), and 0.24 and 0.35 by Anscombe’s variance stabilizing transformation (ANS), respectively.
Those of number of good embryos were 0.29 and 0.36 by POI, 0.31 and 0.40 by ZIP, 0.18 and 0.25 by GAU, 0.19 and 0.24 by LOG, and 0.20 and 0.25 by ANS, respectively. Under the ZIP, the estimated heritabilities and repeatabilities of the probability of zero counts were 0.43 and 0.71 for TNE and 0.42 and 0.51 for NGE, respectively, and the rank correlations between estimated breeding values of the 1546 donor cows for superovulation response and those for the probability of zero count were around −0.40 for TNE and −0.50 for NGE.

Answer 74

A

In cows with assisted birth, oxytocin administration accelerated placental expulsion (P < 0.05) and improved several reproductive parameters, such as the number of services until conception (P < 0.05) and the calving to conception intervals (P < 0.05) compared to the control group.
On the other hand, oxytocin administration slightly accelerated placental expulsion (P < 0.05), but failed to improve fertility in cows with unassisted birth.

Answer 75

A

No significant difference was found for length of interovulatory interval, however, zebuine heifers presented a greater number of follicular waves, number of antral follicles on day of ovulation, and higher insulin concentration than the other two breeds.
Taurine heifers had highest maximal diameter of first wave dominant and ovulatory follicles and CL volume.
Bubaline heifers presented overall lowest progesterone concentrations and CL volume, but higher IGF1 levels. No difference was observed between taurine and zebuine heifers regarding IGF1 concentration.
Despite higher CL volume found in taurine heifers, no difference in mean progesterone concentration was observed between them and zebuine heifers. Insulin and IGF1 concentrations were greater in follicular phase than in luteal phase when breed was not evaluated.
After evaluating the three breeds simultaneously, at the same nutritional and management status it is possible to conclude that each genetic group has a specific follicular development and endocrinology of the estrous cycle.

Answer 76

A

● In conclusion, the study showed a high prevalence of SE in cows clinically cured after treatment of clinical endometritis with cephapirin or PGF2a and after self-healing. The prevalence of SE was significantly higher in cows with purulent vaginal discharge than with mucopurulent vaginal discharge.
● Therefore, in cows clinically recovered from clinical endometritis, the prevalence of SE should always be considered a negative consequence, and the resulting management of this uterine disease should be implemented at the herd level

Answer 77

A

● Based on the results of the present study, we conclude that Neospora caninum seropositive bulls do not have lower semen quality parameters compared with seronegative bulls.

Answer 78

A

● Regardless of calving season the total bacterial content in the vagina was greater on d 7 compared to d 21. While metritis incidence was increased in the warm season, the vaginal content of total bacteria, Escherichia coli, Trueperella pyogenes, Fusobacterium necrophorum and Prevotella melaninogenica were similar during the cool season and the warm season.
● Our data suggests that prepartum heat stress related to season of calving increased the incidence of metritis and persistence of uterine disease in the dairy cow independent of vaginal bacteria content.

Answer 79

A

● These data indicate that nutrient restriction did not alter mammary hemodynamics nor endocrine profile throughout gestation.

Answer 80

A

● No statistically significant differences were observed between gestational losses when the treatments or temperaments (excitable or adequate) were compared.
● In conclusion, the use of GnRH or P4LA, 7 days after insemination, improves pregnancy rates in excitable animals and is a viable alternative to minimize the negative impact of stress and improve reproductive efficiency in beef cattle.

Answer 81

A

It can be concluded that the median number of CFU was higher in semen compared with penile mucosa, and flushing the preputial cavity either with 0.05% CHG or 1% POI maintained for 10 min reduced the number of CFUs from penile mucosa and semen.
The level of antiseptic activity was higher for CHG than for POI
1% of povidone-iodine solution (POI; 500 mL) or 0.05% chlorhexidine digluconate (CHG; 500 mL

Answer 82

A

Compared with no presynchronization treatment those that included PGF2α or PGF2α and GnRH increased (P < 0.05) first P/AI.
Presynchronization had no association with P/AI for cows with BCS at calving <3.00 compared with those with BCS ≥3.00.
Daily milk yields at first AI differed among parities.
Daily milk yield at first AI decreased (P < 0.001) linearly as BCS at AI increased, with an exacerbated greater negative effect during summer.
More prebreeding loss in BCS was associated with more (P < 0.05) milk yield in first- and second-parity cows.
Cows having BCS ≥2.75 at AI had greater (P < 0.01) first P/AI than cows with BCS <2.75.
As BCS at first AI increased, P/AI increased in a linear (P = 0.04) fashion.
Increasing BCS at AI was associated with decreased (P = 0.01) pregnancy loss.
Multiparous cows tended (P = 0.06) to have greater P/AI when they calved with BCS ≥3.00 compared with <3.00.
Multiparous cows losing more than 0.5 units of BCS tended to have greater pregnancy losses
▪ second-parity cows (P = 0.09)
▪ third or greater (P < 0.001) parity.
We concluded that greater BCS at first AI was associated with improved P/AI, but magnitude of prebreeding BCS loss was not associated with P/AI. In contrast, more pregnancy loss was associated with more prebreeding BCS loss in multiparous cows. Cow having lesser BCS at AI and greater prebreeding loss in BCS produced more milk.

Answer 83

A

echotextural differences were observed in placentomes in the last stage of pregnancy in cows, and there were significant changes in placental and uterine artery blood flow. These changes may be related to placental maturation, especially on the days close to birth.

Answer 84

A

The risk for LEL was associated with serological titers to BVDV (P = 0.03) and tended to be associated with seroconversion to BVDV, given that 19.6% (9/46) in LEL and 6.5% (3/46) in NLEL cows seroconverted to BVDV (P = 0.09).
In addition, BVDV was detected in conceptuses from LEL cows that seroconverted to BVDV but not in LEL cows that did not seroconvert.
Conversely, the risk for LEL was not associated with the titers or seroconversion to BoHV-1 and N. caninum. BoHV-1 and N. caninum were not identified in any of the conceptuses.
Finally, blood progesterone concentration was similar in LEL and NLEL cows, and it was not associated with the risk for LEL (P = 0.54).

In conclusion, BVDV infection is a risk factor for LEL in dairy cows.

Answer 85

A

⋅ When sperm were incubated in capacitating conditions, a higher percentage of viable sperm from HF bulls exhibited high membrane fluidity when compared to LF bulls (8.8 ± 0.8% and 5.8 ± 1.2%, respectively; mean ± standard error; P < 0.05).
⋅ There was no difference between fertility groups in the percentage of acrosome-reacted sperm following the incubation in in vitro capacitating conditions or following the induction of the acrosome reaction using calcium ionophore.
⋅ However, more sperm from HF bulls became hyperactive in response to caffeine stimulation than sperm from LF bulls (21.6 ± 2.5% versus 14.1 ± 2.4%, respectively; mean ± standard error; P < 0.05).
Taken together, sperm from LF bulls had an impaired ability to undergo membrane remodulation and to hyperactivate when induced in vitro. These are key events in the journey of sperm along the female reproductive tract and in the interaction with the oocyte and thus could explain the lower field fertility exhibited by some bulls.

Answer 86

A

These results suggest that an imbalanced protein expression of IL-1β and IL-1Ra in the endometrium of dairy cows could be part of the maternal immune response mechanism necessary to propitiate early conception and probably to maintain pregnancy

Answer 87

A

Treatment with hCG resulted in a greater intensity of estrus expression and CL with a higher Doppler score, which determined rates of utilization, conception, and pregnancy similar to conventional protocols using eCG. However, nulliparous recipients treated with hCG exhibited a lower overall reproductive rate,

Answer 88

A

Therefore, administration of eCG on Day 5 of the designed protocol hastened ovulation of a greater follicle, which produced a larger CL and greater concentrations of progesterone by Day 9 after ovulation, resulting in 11.2% increase in cows pregnant

Answer 89

A

The study suggests that immune function of peripartal cows is in an active state and that, in addition to other well-known factors driving the changes of parameters herein investigated, cortisol could have a role in the immune-modulatory adjustment during peripartum in cows. Furthermore, it can be hypothesized that cortisol is transferred from the cow to newborn calf through the placenta only and not through colostrum, whereas IL-6 levels in calves during the 24 h after birth seem to be influenced by IL-6 values measured in cows around calving due to its transfer through colostrum.

Answer 90

A

Expectedly, the amount of damaged collagen was increased in the cervices of old cows.
Increased HSP47 amounts were observed in the cervices from the old cows, but damaged collagen and HSP47 were not located in the same areas. The age differences were confirmed by western blotting using the anti-HSP47 antibody. These findings revealed the specific location and amounts of denatured collagen in the uterine cervices of old cows compared with those of heifers.

Answer 91

A

Our experiments reinforce the idea that exogenous DNases present in the semen should be considered as one of the primary contributing causes of sperm DNA fragmentation post ejaculation.
In the case of the bull, post-thaw incubation of commercial straws contaminated with bacteria, resulted in increased levels of sperm DNA fragmentation, most likely associated with DNase activity (potentially restriction endonucleases) derived from the bacteria.
Such adverse changes in sperm DNA fragmentation, as described here in vitro, may be also operative after insemination in the female reproductive tract (in vivo) and highlight the importance of implementing high levels of hygiene practice during semen processing, especially in light of future trends of bacterial resistance to the common antibiotics used in semen diluents

Answer 92

A

In conclusion these findings show, that lipid alteration caused by oxidative stress is one essential reason for highly augmented acrosome reacted spermatozoa in bad freezer bulls. Therefore, increased use of antioxidants in the extender could be a possible starting point for developing individualized extenders for bad freezer bulls of high genetic value, in order to raise sperm quality after cryopreservation even in those bulls

Answer 93

A

⋅ Plasma prolactin decreased markedly during treatment (−52.4%; Experimental period p < 0.01).
⋅ Rectal temperature increased during the treatment and post-treatment periods (EP p < 0.01) but was within the normal physiological range.
⋅ Bull weight increased during the study (EP p < 0.01).
⋅ Scrotal circumference in low ergot group increased during treatment (+0.8 cm; Tx∗EP p = 0.05).
⋅ Progressive motility in high ergot group decreased during treatment (−7%; Tx∗EP p = 0.05), however, semen volume and sperm concentrations were unaffected (p ≥ 0.11).
⋅ Live sperm with high and medium MMP decreased during treatment (−1.4 and −3.7%; EP p < 0.01).
Results suggest that feeding ≤2227 μg ergot alkaloids/kg has only minor effects on adult bull semen quality

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