Preventive Veterinary Medicine Flashcards
Prevalence of shedding and antibody to Coxiella burnetii in post-partum dairy cows and its association with reproductive tract diseases and performance: A pilot study
Turcotte et al., 2021
- Cross sectional study in 202 cows from 9 herds in Quebec, Canada
- All 202 RT-PCR-assayed vaginal samples were C. burnetii-negative.
- A positive result for anti-C. burnetii antibodies detection in composite milk was obtained in 25/202 samples and a doubtful result in 4/202 samples
- The proportion of ELISA-positive cows was lower in first parity (0%) compared to second (17.1 %) or third parity cows (20.0 %). The associations between ELISA positivity and reproductive outcomes were not statistically significant.
Quantitative risk assessment of introduction of BVDV and BoHV-1 through indirect contacts based on implemented biosecurity measures in dairy farms of Spain
Benavides et al., 2021
the annual probability of introducing BVDV or BoHV-1 through indirect contacts was very heterogeneous. overall distribution of median values for each farm ranged 0.5-14.6% for BVDV and 1.0-24.9% for BoHV-1.
highest impact on the probability of infection:
1.providing protective clothing and boots to visits
2.not allowing the animal vehicle driver to come into contact with animals present on the farm
3.ensuring that calf vehicles arrived empty, were the measures with the for most farms.
Unravelling Belgian Blue cattle farmers’ adoption intention towards diagnostic tools: Integrating insights from behavioural economics and socio-cognitive theories
Mingolla et al., 2021
Farmers’ positive attitudes towards acaricides use and risk perception towards acaricide resistance made them rather reluctant to implement diagnostic tools.
Farmers’ susceptibility to acaricide resistance occurring on their farm was weakened by the optimism and availability bias.
Economic reasons, usefulness of the diagnostic tool and contribution to animal wellbeing motivated farmers to adopt such tools (i.e., behavioural beliefs).
However, the loss aversion and time discounting bias weakened farmers’ beliefs related to economic reasons. The veterinarian was seen as the responsible actor for implementing diagnostic tools, while colleague-farmers’ opinion related to the diagnostic tool was also valued (i.e., normative beliefs). The latter belief was strengthened by the bandwagon-effect bias.
Antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis: Systematic review and meta-analysis
Molineri et al., 2021
The highest overall prevalence of resistant S. aureus was against penicillin (pestimate 0.451, CI95 % 0.415−0.487), followed by clindamycin, erythromycin, and gentamycin (p-estimate = 0.149, 0.085, and 0.069, respectively).
Ceftiofur and cephalotin presented the lowest overall prevalence of antimicrobial resistance (AMR, p-estimate = 0.020 and 0.015, respectively).
The AMR to almost all the antimicrobials evaluated presented an increasing pattern over time, more apparent from 2009 onwards.
The antimicrobials with a higher increase in their AMR prevalence over time were clindamycin, gentamycin, and oxacillin. Africa, Asia and Latin America were the continents with higher AMR to most compounds included in this study
No differences in AMR were detected regarding the clinical origin of the isolates (subclinical vs clinical mastitis) for almost all antibiotics evaluated. Differences in the method for testing AMR (disc diffusion method vs minimum inhibitory concentration) and type of study design for monitoring AMR were detected underscoring the importance of these variables as critical factors to enable comparisons for evaluating emergence of AMR.
Using farmer observations for animal health syndromic surveillance: Participation and performance of an online enhanced passive surveillance system
Pfeiffer et al., 2021
Survival analysis and classification and regression tree analysis were used to identify farm level factors associated with ‘reliable’ participation (low non-response rates in longitudinal reporting).
Response rate and timeliness were not associated with whether farmers had disease to report, or with different months of the year.
Farmers keeping only sheep were the most reliable and timely respondents.
-Farmers < 43 years of age had lower response rates than older farmers. Farmers with veterinary qualifications and those working full-time on-farm provided less timely reports than other educational backgrounds and farmers who worked part-time on-farm.
A comparison of the value of two machine learning predictive models to support bovine tuberculosis disease control in England
Romero et al., 2021
Regularized regression and random forest machine learning methodologies were implemented using 2016 herd-level data to generate the best possible predictive models for a bTB incident in England and its three surveillance risk areas (High-risk area [HRA], Edge area [EA] and Low-risk area [LRA]).
Random forest models achieved the highest balanced accuracy (i.e. average of sensitivity and specificity) in England, HRA and LRA
-Regularized regression LASSO model highest accuracy in EA.
13% of herds in the whole of England as well as in its HRA, 14 % in its EA and 31 % in its LRA were classified as high-risk. These could be selected for the deployment of additional disease control measures at national or area level. In this way, low-risk herds within the area considered would not be penalised unnecessarily by blanket control measures and limited resources be used more efficiently. The methodology presented in this paper demonstrates a way to accurately identify high-risk farms to inform a targeted disease control and prevention strategy in England that supplements existing population strategies.
Treatment protocols and management of retained fetal membranes in cattle by rural practitioners in Belgium
Eppe et al., 2021
Diary cows RFM:
Beef cows RFM
1. without fever, 35.6 % no AB, while others intrauterine (47.6 %), systemically (10.7 %) or both (6.1 %).
2. WIth fever: systemic (33.5%), intrauterine (2.7%), combined (61.8%)
Diary cows RFM:
Beef cows RFM
1. without fever: 21.5% no AB treatment, while others intrautering (24.2%), systemic (24.8%), both (29.5%)
2. with fever: systemic (34.9%), combined (56.3%)
In case of a parenteral treatment, benzylpenicillin, amoxicillin and ampicillin are by far the most frequently used molecules; only a minority of vets use cephalosporins.
Manual placental removal is attempted by 93.9 % of the respondents.
These results demonstrate that there is room for improvement when considering the treatment protocols of RFM. Many veterinarians use AB in RFM cows not presenting symptoms of general illness, or administer intrauterine AB in cows with or without clinical signs of illness. Concerning the molecules of choice, practical routines are largely in line with national AB recommendations. Beef cows suffering from RFM are treated more rigorously than dairy cows, regardless of their rectal temperature.
Survey of perceptions and attitudes of an international group of veterinarians regarding antibiotic use and resistance on dairy cattle farms
Llanos-Soto et al., 2021
Participants perceived that nearly half of their clients overuse or inappropriately use antibiotics, and nearly half of their colleagues overprescribe or inappropriately prescribe antibiotics. After controlling for other factors, the odds of veterinarians being concerned about antibiotic resistance on dairy farms they served decreased by a factor of 0.91 for each additional year of participants’ experience working with dairy cattle (OR = 0.91, 95 % CI = 0.84−0.99). Participants concerned about antibiotic resistance on clients’ dairy farms were also more likely to consider better adherence to drug labelling as important for reducing farmers’ antibiotic use (OR = 6.86, 95 % CI = 1.21–38.93).
Dry cow therapy and early lactation udder health problems—Associations and risk factors
Niemi et al., 2021
Blanket DCT was associated with lower SCC after calving.
Cows more likely to have high SCC after calving were older cows, cows with high average SCC during the previous lactation, and cows with high milk yield near dry-off.
A mastitis treatment in the early lactation was more likely if, during the previous lactation, the cow had high average SCC, high peak milk production, or high milk yield near dry-off.
Our findings indicate that DCT is still effective in mastitis control. Cows with high milk yield, especially near dry-off, and cows with persistently high SCC require attention when considering next lactation udder health.
Comparison of tests for failure of passive transfer in neonatal calf serum using total protein refractometry and the biuret method
Denholm et al., 2021
Neither the biuret nor the refractometer method provided a high sensitivity for detection of FPT, as defined by RID.
There was no systematic difference between the methods in their estimation of TP, although the biuret method was more accurate than the refractometer method when tested against the reference RID test (accuracy = 83.1 % v 69.3 %) and the refractometer was more likely to overestimate the number of calves with FPT.
Specificity for the biuret test was 93.9% compared with the refractometer specificity of 74.4%
The biuret method is preferable to the refractometer for detecting FPT in calves, despite the superior convenience of the refractometer.
Evaluation of environmental and comfort improvements on affective welfare in heifer calves on smallholder dairy farms
Kimeli et al., 2021
Provision of rubber nipples for non-nutritive sucking lowered proportions of cross-sucking, self-sucking and object-sucking behaviours slightly but not significantly.
Lying time was lower for calves with leaking versus non-leaking roofs.
Lying time was significantly higher for calves on clean versus dirty floors if the age was <190 days
We conclude that the comfort improvements enhanced the welfare and lying experience of heifer calves on smallholder dairy farms.
Simulation modelling to estimate the herd-sensitivity of various pool sizes to test beef herds for Johne’s disease in Australia
Ly et al., 2021
The herd-sensitivity estimate increased with herd size and infection prevalence levels, regardless of the pool size. Higher herd-sensitivity was also achieved for testing scenarios involving larger sample size
The overall herd-sensitivity of the Check test was very low for all infection prevalence levels and pool sizes, but more than doubled, when sample size increased from 50 to 100 animals (11% vs 26% for a herd of 500 cattle with 2% prevalence)
Systematic review and meta-analysis of refractometry for diagnosis of inadequate transfer of passive immunity in dairy calves: Quantifying how accuracy varies with threshold using a Bayesian approach
Buczinski et al., 2021
Pooled points estimates (95 % Bayesian credible intervals) for sensitivity (Se) and specificity (Sp) of refractometry 5.5 g/L were 86.1 % (68.5−97.9%) and 76.2 % (65.9−88.4%)
BRIX < 8.4 % was associated with Se of 91.6 % (77.2−99.5%) and Sp of 88.2 % (65.4−99.8%).
Interestingly, the accuracy (Se + Sp-1) was generally higher for BRIX than for REF at the reported cut-offs.
Evaluation of the performance of slaughterhouse surveillance for bovine tuberculosis detection in Castilla y Leon, Spain
Pozo et al., 2021
Bovine TB compatible lesions were detected in 4,710 (16%) reactors and 828 (0.03%) non-reactor animals, of which >95% were confirmed as infected through bacteriology.
The probability of disclosure of bTB-like lesions was associated with the animal subpopulation, type of source unit, the herd size, the year of slaughter, the breed and age of the animal, and/or the season of slaughter.
The probabilities of detection of bTB-like lesions varied largely depending on the abattoir.
Estimation of the value of Johne’s disease (paratuberculosis) control to Canadian dairy producers
Rasmussen et al., 2021
Assuming a within-herd prevalence of 12.5% and a 50% reduction of that prevalence over 10 years, it was estimated JD control has an annual value of CA$28 per cow for the average Canadian dairy producer.
With the same assumption of 12.5% within-herd prevalence but with 100% reductions in that prevalence, estimated values ranged from over CA$55 to over CA$90 per cow per year depending on the timeframe of the control program
Rumination time as an early predictor of metritis and subclinical ketosis in dairy cows at the beginning of lactation: Systematic review-meta-analysis
Cocco et al., 2021
Rumination time (RT) is a good predictor for early detection of metritis in pre and post-partum.
The RT is not an adequate predictor for subclinical ketosis in pre and post-partum.
Crude protein, net energy and NDF of pre-partum diets influenced RT.
Milk production and parity affected RT.
Our MA demonstrates that RT is a good predictor for early detection of metritis in pre and post-partum; however, it is not an adequate predictor for SCK.
Rearing system with nurse cows and risk factors for Cryptosporidium infection in organic dairy calves
Constancis et al., 2021
Rearing dairy calves with nurse cows is characterized by a fostering of two to four calves during the first month of life by an unmilked lactating cow.
The identified six risk factors for oocyst shedding were:
o Born in the last two thirds of the birth order
o Born between January and July versus August and September
o Calf with its dam in the barn versus on pasture
o Having an artificial milk feeding phase versus being with the dam only
o Contact between peer calves and notably the presence of an oocyst excretory calf fostered by the same nurse.
These results emphasize the role of the environment for the direct and indirect contamination, particularly that related to the accumulation of oocysts from previous or peer calves facilitating the faecal-oral route of transmission. This highlights the crucial role of the premises used intensively during the winter and spring months with higher densities of calves in the barn compared to outdoor situations promoted by this rearing.
Factors associated with daily weight gain in preweaned calves on dairy farms
Hyde et al., 2021
Increasing the maximum preweaned age within the first housing group (0.001 kg/d per 1d increase, 90 % bootstrap confidence interval (BCI): 0.000−0.002), increased mean environmental temperature within the first month of life (0.012 kg/d per 1 °C increase, 90 % BCI: 0.002−0.037) and increased mean volume of milk feeding (0.012 kg/d per 1 L increase, 90 % BCI: 0.001−0.024) were associated with increased DLWG.
An increase in the number of days between the cleaning out of calving pen (-0.001 kg/d per 1d increase, 90 % BCI: -0.001−0.000) and group housing pens (-0.001 kg/d per 1d increase, 90 % BCI: -0.002−0.000) were both associated with decreased DLWG.
Many of these variables represent practical aspects of management with a focus around stocking demographics, milk/colostrum feeding, environmental hygiene and environmental temperature; these variables should now be tested in a randomised controlled trial to elucidate causality.
Longitudinal health outcomes for enteric pathogens in preweaned calves on Ohio dairy farms
Barkley et al., 2021
Rotavirus was the most frequently identified at 68.1 % (188/276), followed by F5 (K99)+ E. coli at 42.5 % (114/268), C. parvum at 28.4 % (66/232), coronavirus at 5.8 % (16/276), and Salmonella had the lowest prevalence at 3.7 % (10/268).
Risk of mortality tended to be higher for calves infected with Salmonella (RR = 3.83; 95 %CI: 0.93, 16.02, p = 0.062);
With the exception of infections caused by Salmonella spp., pathogen diagnosis on the first day of diarrhea was a poor predictor of the outcome and duration of disease
Influence on the implementation of biosecurity measures in dairy cattle farms: Communication between veterinarians and dairy farmers
Moya et al., 2021
Dairy farmers and veterinarians attributed responsibility to one another for not following biosecurity practices.
Contradictions among veterinarians and certain individual veterinary practices that participated in the study lead to doubt and confusion on the part of dairy farmers.
Distinct perceptions were also identified of the role that government authorities should play in relation both to training and sanctions as a means of improving biosecurity on dairy farms.
Evaluation of the association between the introduction of data-driven tools to support calf rearing and reduced calf mortality in dairy herds in the Netherlands
Santman-Berends et al., 2021
Four different calf mortality indicators were defined:
o Perinatal calf mortality risk (i.e., mortality before, during, or shortly after the moment of birth up to the moment of ear-tagging)
o Postnatal calf mortality risk (ear-tagging till 14 d)
o Preweaned calf mortality rate (15 d-55 d)
o Weaned calf mortality rate (56 d-1 yr.)
When the period before implementation of the tools (2016–2017) was compared to the period thereafter (2018–2019), all four calf mortality indicators decreased.
Herds with a higher level of metabolic problems in transition cows had a higher calf mortality and also extreme outside temperatures were associated with higher calf mortality.
Retrospective study of factors associated with bovine infectious abortion and perinatal mortality
Van Loo et al., 2021
Despite extensive diagnostic testing, the diagnostic rate for foetal and perinatal calf mortality is only 39 %.
Neospora caninum was the most detected pathogen, followed by Trueperella pyogenes, BVDv, Escherichia coli, and Aspergillus fumigatus.
Neospora caninum [odds ratio (OR): 0.4; 95 % confidence interval (CI): 0.3–0.7] and Aspergillus fumigatus (OR: 0.1; 95 % CI: 0.1–0.3) were detected less in late versus early gestation.
Aspergillus fumigatus was less common in dairy in comparison to beef abortion cases (OR: 0.2; 95 % CI: 0.1–0.6).
Winter was associated with a lower positivity for Neospora caninum and BVDv in comparison to warmer seasons.
Despite extensive diagnostic testing, an etiological diagnosis was not reached in 61 % of cases, highlighting the need for even more extensive (non-)infectious disease testing or more accurate tests.
Clinical disease incidence during early lactation, risk factors and association with fertility and culling in grazing dairy cows in Uruguay
Cruz et al., 2021
In Primiparous cows, stillbirth incidence was higher than in multiparous (MP) cows (PP=6.9 ± 3.4, SD vs. MP=4.3 ± 2.6, SD), while in MP cows twin births (MP=2.7 ± 1.7, SD vs. PP=0.7 ± 2.7, SD), RP-metritis (MP=4.6 ± 3.9, SD vs. PP=3.8 ± 3.7, SD) and mastitis incidence (MP=30.9 ± 11.4, SD vs. PP=17.2 ± 13.9, SD) was higher
Diseases had a negative impact on time to first service and pregnancy rate and increased culling hazard rate.
Sensitivity of bovine tuberculosis surveillance through intradermal tests in cattle in France: An evaluation of different scenarios
Henaux et al., 2021
The model predicted that the median detection fraction of infected herds by the current programmed surveillance in high-risk areas, which consists in annual testing of herds with a minimum age of testing of 24 months, was 71.5 % (interquartile interval: 47.4−89.4).
o The results showed a significant gain of the detection fraction with a decrease from 24 to 12 months old (83.5 % [60.6−95.9]) or to six weeks old (91.3 % [71.6−99.0]).
Regarding pre-movement surveillance, tests are currently mandatory for bovines that originate from a previously infected herd or from a herd epidemiologically linked to a bTB-infected herd.
o The median detection fraction predicted by the model for this surveillance scenario was 1.2 % [0.7−1.8]. For the alternative scenario, where surveillance would be extended to all herds in high-risk areas, the model predicted a significant increase of the detection fraction to 26.5 % [18.1−37.9].
The results were sensitive to the following input values: the number of infected bovines within herds and, to a lower extent, the comparative intradermal tuberculin test sensitivity for both models, and surveillance coverage for the model on pre-movement surveillance. Our study underlines several complementary ways to improve the detection of infected herds, which is critical for implementing control measures and epidemiological investigations as early as possible. These necessary changes in surveillance must be accompanied by a global reflexion on surveillance financing.
Associations between different udder health groups defined based on a combination of total and differential somatic cell count and the future udder health status of dairy cows
Schwarz et al., 2021
Four udder health groups based upon SCC and DSCC:
A: healthy/normal, ≤200,000 cells/mL and DSCC ≤65 %;
B: suspicious, ≤200,000 cells/mL and DSCC >65 %;
C: (subclinical) mastitis, >200,000 cells/mL and DSCC >65 %;
D: chronic/persistent mastitis, >200,000 cells/mL and DSCC ≤65 %.
Cows in groups C (OR: 2.13, CI: 1.95–2.34) and, particularly, D (OR: 3.91, 95 % CI: 3.31–4.62) were significantly more likely to leave herds compared to cows in group A.
Late-lactating cows indicated the highest likelihood (OR: 16.03, 95 % CI: 14.44–17.81) to leave herds in our analysis.
Interestingly, we found that cows in UHG B had significantly higher odds (OR: 2.77, 95 % CI: 2.58–2.98) to have >200,000 cells/mL at the next test day compared to cows in group A.
As anticipated, cows in UHG B (OR: 0.40, 95 % CI: 0.38–0.42), C (OR: 0.08, 95 % CI: 0.07–0.09), and D (OR: 0.16, 95 % CI: 0.14–0.19) each were significantly less likely to have ≤200,000 cells/mL at the next 3 test days compared to cows in group A
In conclusion, our findings illustrate that the UHG concept reveals additional valuable information about udder health and culling based a single test day over working with SCC only. Actual decisions in day-to-day farm management that could be taken were not investigated here and need to be further explored.
Transmission dynamics of Staphylococcus aureus and Streptococcus agalactiae in a Dutch dairy herd using an automatic milking system
Deng et al., 2021
Transmission rate:
Staph. aureus: range of 0.002 (95 % CI: 0−0.005) quarter-day−1 to 0.019 (95 % CI: 0.010−0.032) quarter-day−1
Strep. Agalactiae: range of 0.007 (95 % CI: 0.005−0.010) quarter-day−1 to 0.019 (95 % CI: 0.011−0.032) quarter-day−1,
Mean duration of chronic IMI
Staph aureus: 95 (95 % CI: 72−125) days
Strep agalactiae: 86 (95 % CI: 67−111) days
R0
Staph aureus: between 0.16 (95 % CI: 0.05−0.27) and 0.34 (95 % CI: 0.20−0.48)
Strep agalactiae: between 0.64 (95 % CI: 0.41−0.87) and 0.68 (95 % CI: 0.48−0.88)
The estimated transmission rate of Staph. aureus in this AMS herd was found to be comparable to those described for CMS herds, while for Strep. agalactiae, it was slightly higher than in CMS herds.
The duration of Staph. aureus IMI was in line with results from CMS farms, while the duration of Strep. agalactiae was lower than what has been described in CMS herds.
The R0 of these contagious pathogens was found to be lower than the estimates in CMS herds.
Seroprevalence of selected endemic infectious diseases in large-scale Estonian dairy herds and their associations with cow longevity and culling rates
Motus et al., 2021
Herd seropositive status for BRSV was associated with lower mean age of culling
Herds with BSRV-seropositive youngstock had increased culling rate.
There was also a tendency of BVDV-negative herds to have a lower CR than BVDV-positive herds
MAP-positive hers had somewhat lower herd mean age of culled cows
Vaccination against BVDV tended to be protective against high culling rate vs infected herds
This study shows that Estonian large-scale dairy herds are endemically infected with several important cattle pathogens. Most of the studied pathogens influence longevity and culling rates, thus entailing health and economic consequences.
Researching 100 t cows: An innovative approach to identify intrinsic cows factors associated with a high lifetime milk production
Eetvelde et al., 2021
Cows born in September and born out of heifers to have the highest odds to become a HT.
When cows received a score ≥ 83 (population average 80) for udder and feet & legs conformation, they had higher odds of reaching the 100,000 kg threshold.
While a greater body condition and larger rump angle increased the odds of becoming a HT, this was decreased in cows with a large body depth.
Breeding values for milk yield, fertility, udder health and claw health were positively associated with the likelihood of reaching a lifetime milk yield of 100,000 kg.
In conclusion, to increase lifetime milk yield in dairy herds, farmers should select heifers with high scores for conformation traits like udder and feet & legs and high breeding values for milk yield, fertility and udder health.
Exploring the relationship between mastitis risk perceptions and farmers’ readiness to engage in milk recording
Regan et al., 2021
Elevated mastitis risk perceptions were linked to an increased readiness to milk record.
However, this relationship was not universal across all farmers.
One segment of farmers in the current study maintain low mastitis risk perceptions and remain unmotivated to engage in milk recording.
The types of risk communication strategies – message framing and two-way risk communication – should reflect farmers’ types of mastitis risk perceptions to have the most effective impact on milk recording uptake
Effect of farm and animal-level factors on youngstock mortality and growth on calf rearing farms
Sandelin et al., 2021
Average calf mortality on Finnish calf rearing farms was 4.5 %
Application of the all in/all out principle and proper washing and disinfection of compartments for milk feeding calves between arrival batches, were associated with lower mortality and increased daily gain.
Higher arrival age was associated with lower mortality during the rearing period and relatively higher arrival age of the calf, compared to other calf in a same arrival batch, was associated with higher daily gain.
Increased number of individual medications during the rearing period was associated with both increased mortality and decreased daily gain.
There was no significant difference in mortality between farm types
Identification of discriminating behavioural and movement variables in lameness scores of dairy cows at pasture from accelerometer and GPS sensors using a Partial Least Squares Discriminant Analysis
Riaboff et al., 2021
Severely lame cows spent 4.5 times less time grazing and almost twice as much time resting as their sound congeners, especially in the lying position.
Exploratory behaviour was also reduced for both moderately and severely lame cows, resulting in 1.2 and 1.7 times less distance travelled respectively, especially during grazing.
These variables could be used as additional variables to improve the performance of existing lameness detection devices in pasture-based systems.
New York State dairy veterinarians’ perceptions of antibiotic use and resistance: A qualitative interview study
Padda et al., 2021
Participants viewed antibiotic overuse as largely due to farmers’ concern for the welfare of their cattle and desire to treat ailments swiftly.
Interviewees believed that it was possible to reduce antibiotic use through regulation, such as the Veterinary Feed Directive and improved herd management activities, such as better colostrum management.
They did not view the dairy industry as a significant contributor to AMR, particularly when compared to the human medical industry.
Milk losses linked to mastitis treatments at dairy farms with automatic milking systems
Adriaens et al., 2021
In a fixed time window of day -5 to 30 around the first treatment, the absolute median milk losses per case were 101.5 kg, highly dependent on the parity and the lactation stage with absolute milk losses being highest in multiparous cows and at peak lactation.
Relative milk losses expressed in percentage were highest on the first treatment day, and full recovery was often not reached within 30 days from treatment onset.
In 62 % of the cases, we found a perturbation in milk yield at the cow level at the time of treatment.
On average, perturbations started 8.7 days before the first treatment and median absolute milk losses increased to 128 kg of milk per perturbation.
Median absolute losses in a fixed 36-day window around treatment varied between 50.2 kg for front and 59.3 kg for hind inflamed quarters compared to respectively 24.7 and 26.3 kg for the median losses in the non-inflamed quarters.
Expressed proportionally to expected yield, the relative median milk losses in inflamed quarters on the treatment day were 20 % higher in inflamed quarters.
This analysis confirms the high impact of mastitis on milk production, and the large variation between quarter losses illustrates the potential of quarter analysis for on-farm monitoring at farms with an automated milking system.
Systematic review and meta-analysis of probiotic use on inflammatory biomarkers and disease prevention in cattle.
Barreto et al., 2021
The overall quality of evidence at the outcome level was assessed as being very low.
On average, the treatment effect on immunoglobulin G (IgG), serum amyloid A (SAA), haptoglobin (Hp) and β-hydroxybutyrate (BoHB) for cows receiving probiotics did not differ from control cows.
Exposure to probiotics was not associated with reduced risk of reproductive disorders (pooled RR = 1.02 95 % CI = 0.81-1.27, P = 0.88).
There is insufficient evidence to support any significant positive effects of probiotics on cattle immunity and disease prevention.
This lack of consistent evidence could be due to dissimilarities in the design of the included studies such as differences in dosage, dose schedule, diet composition and/or physiological state of the host at the time of treatment.
Risk factors associated with pinkeye in Australian cattle
Kneipp et al., 2021
Farm location, farm grazing area, farmer-reported dust levels, fly levels, rain levels, animal zebu content and cattle age were significantly associated with pinkeye prevalence.
Having a farm located in southern Australia, of smaller grazing area with cattle ≤ 2 years of age, was associated with a higher pinkeye prevalence.
Pinkeye prevalence was also greater if respondents ranked their farms as having high fly levels, on farms ranked low for rainfall and on farms ranked as having high dust levels, but moderate dust levels were protective compared to low dust levels
Predictive models to identify Holstein cows at risk of metritis and clinical cure and reproductive/productive failure following antimicrobial treatment
Merenda et al., 2021
We built models containing: routinely-available data [lactation number (1, 2, ≥3), calf sex, still birth, twining, dystocia, vaginal laceration score, days on the close-up diets], body condition score (BCS) and BCS change from enrollment to calving (ΔBCS), behavior (feeding, rumination, idle, and active time), and their interactions.
The area under the curve (AUC) of the models including the above with behavior data at 2 DIM to predict metritis [AUC = 0.82, 95% confidence interval (CI) = 0.78, 0.85] and acute metritis (AUC = 0.87, 95% CI = 0.83, 0.89) were (P < 0.01) excellent
The models predicting cure (AUC = 0.92, 95% CI = 0.85, 0.95) and failure (AUC = 0.90, 95% CI = 0.84, 0.94) were outstanding.
Behavioral changes peripartum contribute for the identification of cows at risk for metritis, allowing the development of preventive strategies. In addition, predicting whether cows will respond to antimicrobial treatment.
Eimeria spp. in naturally infected beef cattle: Dynamics of oocysts excretion, prevalence, and comparison between parasitological diagnostics
Cruvinel et al., 2021
Mean OPG higher in younger animals: Animals up to 14 months had a mean total OPG counts higher than older animals (after 15–16 months of age).
E. zuernii and E. bovis were more frequently identified,
E. zuernii was more frequent in animals from 1 to 2 months of age
E. bovis prevailed from three months old.
Both Mcmaster and FLOTAC techniques can be used for quantification of the excretion of oocysts of Eimeria spp. in cattle feces showing the same OPG mean count (r = 0.9287; p = 0.0025; R² = 0.8625).
Identification and antimicrobial susceptibility of milk pathogen isolated from dairy production systems
Kuhnen et al., 2021
The main isolated agents were Streptococcus spp. (n = 54, 30.5 %) and coagulase-positive Staphylococcus (CPS) (n = 54; 30.5 %).
High levels of antibiotic resistance were detected to many antimicrobials
Neither production systems (p = 0.26) nor farming systems (p = 0.24) significantly affected the resistance rates of samples.
Therefore, intensive production systems may not be a root cause of increased rates of antimicrobial resistance in the milk production chain, suggesting that other environmental factors should be investigated.
Bayesian estimation of diagnostic accuracy of somatic cell counts history and on-farm milk culture using Petrifilm® to identify quarters or cows that should be treated with antimicrobials in selective treatment protocols at dry off
Kabera et al., 2021
Quarter-milk culture Petrifilm: Se82.2%, Sp 62.0%
Quarter-milk standard bacteriology: Se 67.4%, Sp 79.6%
For first parity cows, using only the last Dairy Herd Improvement (DHI) test SCC with a threshold of 100,000 cells/mL: Se 85.6%, Sp 86.0%, PPV 58.0%, NPV 96.4% and reduction of antimicrobial usage 75.3%.
For cows of ≥ 2nd parity, using only the last DHI test SCC with a threshold of 200,000 cells/mL resulted in Se 75.3%, Sp 84.0%, PPV 47.2%, NPV 94.7% and reduction of antimicrobial usage 77.0%.
Adding quarter-level milk culture using Petrifilm® to cows identified as unhealthy using cow-level SCC data improved the test accuracy (mainly the PPV) and further reduced the use of antimicrobials. (e.g. in ≥ 2nd parity cows increased reduction from 77.0% to 89.5%)
Considering the availability of SCC data, the easiness of using just the last DHI test, and the high NPV that could be achieved, producers may consider using just the last DHI test as a potential tool to identify cows that should be treated with antimicrobials at dry off.
It may be used alone or in combination with quarter-level on-farm Petrifilm® milk culture on high SCC cows to further reduce the use of antimicrobials by identifying quarters that need to be treated.
A modified functional hoof trimming technique reduces the risk of lameness and hoof lesion prevalence in housed dairy cattle
Sadiq et al., 2021
To compare the impact of the functional hoof trimming (HT) method to an adaptation that results in increased modelling of the weight bearing claw on time to lameness and lesion prevalence in housed dairy cows
Three groups
TRIM1: Dutch 5 step method (DFSM)
TRIM2: DFSM but with increased modelling of the weight bearing claw
CON: negative untreated control
The overall incidence rate of lameness was 29.3 cases/100/month
Prevalence of hoof lesions in the study population was 36.3 %, with the highest prevalence in CON (45.6 %), followed by TRIM1 (34.6 %) and TRIM2 (28.1 %).
The risk of new lameness event was higher in cows with low BCS (≤2.5) (Hazard ratio; HR = 1.5; 95 % CI 1.1–2.1), while trimming all feet was a protective factor (HR = 0.58; 95 % CI 0.38–0.90)
Time to first lameness event was higher in TRIM2 (mean ± S.E; 8.26 ± 0.16, P = 0.03) than CON (7.32 ± 0.2) and tended to be higher than TRIM1 (7.83 ± 0.19; P = 0.07).
Our results suggest that the adaptation to the functional method reduced the risk of lameness during lactation, however, proper management of under-conditioned cows is equally important.
Prepartum factors associated with postpartum diseases in pasture-based dairy cows
Caldron-Amor et al., 2021
The odds of postpartum lameness were higher for cows that were lame during the prepartum period, had elevated prepartum NEFA concentrations, had greater parity, and for cows that were kept in paddocks with no grass cover.
The odds of metritis were higher in cows with lower parity, with increased prepartum NEFA, in cows that had dystocia, and farms with predominantly Holstein breed, and that did not have calving records.
The odds of clinical mastitis were higher for cows lame during the prepartum period.
The odds of Ca imbalance were higher in cows with a long dry period, dystocic calving, and in farms without prepartum anionic salts supplementation.
The odds of Mg imbalance were higher in cows with lower prepartum Mg concentrations, higher prepartum Ca concentration, and higher parity.
Our findings indicate that farmers could benefit from refining these areas to improve their cows’ health and welfare.
Decision tree analysis for pathogen identification based on circumstantial factors in outbreaks of bovine respiratory disease in calves
Lowie et al., 2021
The general 3- group classification tree was 52.7 % accurate and had a sensitivity of 81.5 % and a specificity 52.2 % for viruses, respectively 51.7 % and 84.4 % for M. bovis and 28.9 % and 93.6 % for Pasteurellaceae. The single-pathogen trees were more specific than sensitive: Histophilus somni (Se = 25.8 %; Sp = 94.5 %), Mannheimia haemolytica (Se = 69.2 %; Sp = 70.6 %), bovine coronavirus (Se = 42.2 %; Sp = 89.6 %) and bovine respiratory syncytial virus (Se = 34.0 %; Sp = 96.6 %).
For Pasteurella multocida, M. bovis and parainfluenzavirus type 3 no meaningful tree was obtained.
The concept and trees are promising, but currently lack sensitivity and specificity in order to be a reliable tool for practice
Effects of dietary starch content and body condition score at calving on reproductive parameters in Holstein dairy cows
Sirjani et al., 2021
Feeding HS diet significantly affected the proportion of cows cycling by 30 and 40 DIM.
Number of services per conception and calving interval (CI) were significantly improved in cows fed the HS compared to the NS diet (2.08 vs. 2.51 and 427.14 vs. 445.30 days for cows fed HS and NS diets, respectively).
Feeding higher starch diets from 16 till 50 DIM could be an effective strategy to improve the economic variables related to reproduction in dairy cows.
Estimation of the true prevalence of inaccurate artificial inseminations in Irish milk recording dairy cows using a Bayesian latent class analysis
Kelly et al., 2021
Median cow-level true prevalence of IAI was 4.4 % (BPI; 1.7–9.0 %).
Median Se and Sp estimates for milk progesterone, at a threshold concentration of ≥ 5 ng/mL were 83.0 % (BPI; 65.0–96.2 %) and were 97.4 % (BPI; 94.6–99.6 %), respectively.
The present study estimates that the overall cow-level true prevalence of IAI in Irish dairy cows is relatively low. This is the first study to report the cow-level true prevalence of IAI using a Bayesian latent class model.
