B2: Main reproduction of features of cattle, and most important bovine genetic diseases Flashcards
What are the reproduction traits?
Dairy production,
Beef production,
Maternal effects,
BVE,
Prolificacy genes
Puberty
What are the reproduction traits in dairy production?
Calving is prerequisite.
Major role of bovine placental lactogene (pBL) in
mammogenesis & milk production.
What are the reproduction traits of beef production?
More meat by more calvings.
Increased economy.
the reproduction traits: maternal effects?
Increase number of offspring & genetic pool of dam
the reproduction traits: BVE
Breeding Value Estimation
Progeny testing: Increases effectiveness of selection from maternal lines as well
What are the reproduction traits of prolificacy genes
Great importance (increase granulose cell function, steroid biosynthesis, multiple ovulations, ovulation rate)
What are the reproduction traits in puberty
occurs around ~8 (12-16) months
When does the first breeding usually occur?
around 15 months oe when the animal has reached 75% of adult body mass.
when does first calving occur?
at 2 - 3 years.
depends on breed.
What are the General reproductive features of dam?
- Uniparous (single offspring at brith)
- Low reproductive potential
- Long puberty
- Long gestation
- No seasonality -> Continuous polyoestrus
- Continuous breeding
- Frequent embryonic losses
- Low twinning rate (up to 5%)
- Freemartinism in twins of different sex (>90%)
what is the length of ovarian cycle in a cow
20-21 days
Biphasic – luteal & follicular period
how long is the heat duration of a cow?
24 - 48 hours
what are the signs of oestrus in a cow?
Mucous discharge
Hyperaemic, swollen genitalia
Standing heat by teasing
Bulling – mounting of other females
When does ovulation occur?
number of eggs?
Spontaneous ovulation
10-14 hours after finishing clinical heat
Number of ovulated eggs does note exceed 2
Mature follicles are small but palpable (diameter 2-2.5cm)
When does first heat after calving occur?
occurs 15 days post-partum & is often silent
Mention some ovulatory disorders
- Anovulatory cycles – Only follicular period occurs
- Delayed ovulation
- Persistent atresia of follicles
- Cystic ovaraies
- Longer/shortened cycles
- Corpus luteum persistens (CLP – moderate sign of sterility causing anoestrus): Heat is inducible in cows with CLP by PGF2α.
mention some heat detection methods
Observation of behaviour & clinical signs
Tail chalking
Computer watch system
Foot tags
Rectal palpation
Ultrasound
what is the gestation length of a cow?
(278-287) days
what hormones are important for the maintenance of gestation?
1) bPL hormone (placental lactogenic hormone)
2) Progesterone (in CL graviditatis)
3) Placental oestrogens
where does fertilisation occur?
Occurs in fallopian tube. Migration to uterus @ day 4-5
when does implantation occur?
Innesting of blastocyst @ day 21
what is the length of the lactation period
approx. 300 days
how long is the dry period of a cow?
what is its function?
approx. 2 months,
Needed for udder regeneration & preparation for new lactation.
when is twinning desired?
in beef cattle production
what detects factors responsible for twinning?
o Selective breeding (selection of twinning ability)
o Marker assisted selection (molecular) = Detects factors responsible for twin ovulations.
what are the drawbacks of twinning?
o 1° chimerism (freemartinism)
o Dystocia
o High perinatal calf losses
o Retained placenta
o Subinvolution of uterus
o Prolonged service period
o Delayed rebreeding
What environmental factors can effect reproduction?
- Feed
- Condition
- Climate – Sensitivity to heat stress
- Hormonal factors – Excellent response to hormonal treatment (e.g. induction of ovulation & oestrus cycle)
Parameters used to evaluate reproductive performance:
* Age at 1st calving?
* Insemination index? (avg no. of inseminations).
* Non-return rate (result of 1st insemination)?
* Calving interval?
* 1st fertile heat post-parturition?
* Service period?
* Pregnancy rate (PR %) & calving rate?
* Sterility & selection, culling rate?
* Embryonic & perinatal mortality?
* Lactation period?
* Dry period?
- Age at 1st calving: ~2 yrs
- Insemination index (ave no of inseminations): <1.4 is optimal
- Non-return rate (result of 1st insemination): <60% is excellent.
- Calving interval: 360-380 days, May be up to 400 in high yielding cows.
- 1st fertile heat post-parturition: 12- 15 days.
- Service period (period from 1st service to successful conception): <60 days is desired.
- Pregnancy rate (PR %) & calving rate: >95%
- Sterility & selection, culling rate: <10%
- Embryonic & perinatal mortality: Should remain <5-10%.
- Lactation period; 300 days
- Dry period: 60 days
What are the most important Immunodeficiency-related bovine genetic diseases?
RECESSIVE:
* BLAD (bovine lymphocyte adhesion deficiency)
* Chediak-Higashi syndrome
What are the most important blood circulation / haemostasis-related bovine genetic diseases?
- Hyperbilirubinaemia (dom)
- Protoporphyria (congenital, rare, Auto rec)
- Platelet bleeding disorder
- Haemophilia B (factor IX deficiency) (rec sex-linked on X Chromosome)
What are the most important metabolic-related bovine genetic diseases?
- Lipofuscinosis
- Gangliosidosis
- Mucopolysaccharidosis I
- Pompe disease –> auto rec
- Mannosidosis α & β
- Citrullinaemia –> auto rec
- DUMPS (deficiency of uridine monophosphate synthase) –> auto rec.
- Ahorn-syrup-urine disease
What are the most important muscular-related bovine genetic diseases?
- Muscular hypertrophy (double muscling) ! Breed trait in Belgian blue –> incomp auto dominant.
- Hypo- & dysmyelinisations (lameness of calves)
- Spinal muscular atrophy (SMA) –> auto rec
- Posterior paraplegia
- Lethal spastic paresis
- Weaver syndrome –> autosomal recessive
What are the most important skeletal-related bovine genetic diseases?
- Chondrodysplasia –> bulldog calf syndrome (dom)
- Complex vertebral malformation
- Dwarfism (proportional, STH-receptor mutation) –> auto rec.
- Syndactylia ! Fusion of digits
- Arthrogiposis
- Apodia (lack of homeobox proteins, homeosis)
What are the most important atresia/ agenesia-related bovine genetic diseases?
- Atresia coli –> auto rec
- Kidney dysplasia
- Nephritis
What are the most important intersexes-related bovine genetic diseases?
- XY females
- Tfm (testicular feminisation) syndrome = Lack of androgenic receptors
- Testicular, ovarian & uterine hypoplasia
What are the most important endocrine-related bovine genetic diseases?
Goiter in Afrikaner cattle
What are the most important skin and coat-related bovine genetic diseases?
- Albinism
- Dermatospraxis (cutaneous asthenia)
- Epitheliogenesis imperfecter
- Hypotrichosis
- Oligodontia
- Parakeratosis
What genetic diseases are common in the holstein breed?
DUMPS,
Complex Vertebral Malformation,
Factor IX haemophilia,
hypertrichosis,
oligodontia
What genetic diseases are common in the simmental breed?
platelet bleedng disorder
What genetic diseases are common in the limousine breed?
protoporphyria
What genetic diseases are common in the brown swiss breed?
weaver syndrome,
albinism
What genetic diseases are common in the dexter breed?
dwarfism
What genetic diseases are common in the brahma breed?
pompe disease
