II. Cattle, sheep and goat breeding Flashcards
(107 cards)
Topic 1 – Domestication of cattle, micro-evolutionary consequences
TAXONOMY
Class: Mammalia Order: Artiodactyla Suborder: Ruminantia Family: Bovidae Subfamily: Bovinae (cattle) Genus: Bos (true cattle)
Species
1• Bos PRIMIGENIUS – AUROCHS (extinct)
o Domesticated species ORIGINATE from AUROCHS
a▪ Bos primigenius TAURUS – Taurine (European) cattle
b▪ Bos primigineius INDICUS – Zebu
• Hump formed by hypertrophy of muscles
c▪ Bali cattle
• Draught animal of Indonesia
d▪ Gayal
• Sacrificial animals in Burma, East India, Bangladesh
etc.
2• Bos POEPHAGUS– YAK
o Native to Tibet & Mongolia
o Pack animals used for milk, meat, wool & skin
3• Bos GAURUS – Bos/bibos/gaur
• Bos JAVANICUS – Banteng
• Bos SAUVELIA – Kouprey.Khainag
Wild species
1• Bison
o Only two existing species, B. bison (American bison) & B. bonasus (European bison)
2• Buffalo (Genus BUBALUS)
o Variable chromosome number
(Asian water bufallo =48; river buffalo = 50)
Interspecies hybrids
• Bison (buffalo) x Yak ! YAKALO
Topic 1 – Domestication of cattle, micro-evolutionary consequences
DOMESTICATION
Domestication of AUROCHS began in southern Caucasus/northern MESOPOTAMIA from
~8th millennium BC
Domestication caused such drastic physiological changes that modern domestic cattle are now considered to be a separate species.
FERAL cattle: Aleutian wild cattle, CHILLINGHAM cattle, Enderby Island cattle,
Ushuaia wild cattle
Topic 1 – Domestication of cattle, micro-evolutionary consequences
TERMINOLOGY
- BULL: Entire, adult male
(proven fertile ! AI, breeding, listed bull) - SIRE: Father of an animal (used in dairy breeding)
- COW: Adult female who has had at least one calf.
▪ In-calf/pregnant cow
▪ Nurse cow
▪ Lactating cow
▪ Dairy cows
▪ Dry cows - DAM: Mother of an animal (used in dairy breeding)
5. CALF: Young cattle ▪ Bull calf ▪ Heifer calf ▪ WEANERS (up to 1 yr) ▪ Yearlings ▪ VEAL calves
- HEIFER: Young female before her 1st calf
▪ IN-CALF heifer – Young female pregnant with her 1st calf - STEER: Castrated male
▪ Draft steer <4yrs = working steer - STAG: Castrated adult bull (occurs rarely)
- OX: Castrated male (or occasionally a cow) used for draft work
- FREEMARTIN: Female animal who is the twin of a bull (infertile partial intersex)
- BEEF: Cattle raised for human consumption
Topic 1 – Domestication of cattle, micro-evolutionary consequences
USE of CATTLE
Uses of cattle 1• Beef & Dairy 2• Draught 3• Leather production (cattle hides) 4• Sports – Rodeo, bullfighting 5• Religion – Sacrificial cows (Hindu)
Topic 2 – Breeding goals and characteristics (traits) of dairy cattle, milk
properties
Most important performance traits used in dairy cattle selection:
1• Milk performance (during first 305 days lactation)
-o Average milk yield (kg)
-o Max daily milk yield (kg)
-o FCM – Fat corrected milk yield (kg)
-o Fat yield (kg)
-o Protein yield (kg)
2• Chemical composition
- o Fat content (%)
- o Protein content (%)
- o PFR – Protein to fat ration
- o FPD – Fat protein difference
- o Lactose content (%)
- o SCC (somatic cell count)
Topic 3 – Breeding goal and characteristics (traits) of beef and dual purpose
cattle
Most important performance traits of beef cattle
- Reproductive performance
- Growth & gain performance
- Carcass Merit
Topic 3 – Breeding goal and characteristics (traits) of beef and dual purpose
cattle
- Reproductive performance
Reproductive performance
1• CONCEPTION RATE
o Calf crop percentage (calves born)
o Calf crop percentage (calves weaned)
2• CALVING INTEREVAL
(time elapsed between each calving)
3• BIRTH WEIGHT related to CALVING difficulty
o Calving difficulty SCORES
a) No difficulty, no assistance required
b) Minor difficulty, some assistance
c) Major difficulty, mechanical assistance
d) C-section or other surgery (prolapse etc.)
e) Abnormal presentation
4• MATERNAL/nursing abilities
5• FERTILLITY testing of bulls
6• BULL PERFORMANCE
o Average daily weight gain
o Scrotal circumference (proportional to fertility)
Topic 3 – Breeding goal and characteristics (traits) of beef and dual purpose
cattle
2. Growth & gain performance
- Birth weight
- Weaning weights (adjusted to 205 days)
- Yearling (365 days) & long yearlings (452/550)
- Post weaning rate of gain (min 140 days on test)
- Average daily weight gain
• Actual weight = Birth weight/age in days x 205 days + birth weight
Topic 3 – Breeding goal and characteristics (traits) of beef and dual purpose
cattle
3. Carcass Merit
1• Dressing percent 2• Carcass weight 3• Carcass quality 4• Fat ratio 5• Ribeye area 6• Marbling & tenderness
Topic 4 – Dairy cattle breeding technologies, milk production and hygiene
- Most DAIRY farms sell MALE CALVES for VEAL production or breeding (depending on quality) &
- Keep heifers to replace old animals/increase herd size.
- Most dairy farms also have some arable land ! Production of silage & other feedstuffs to minimize outgoings & maximize profit
Topic 5 – Elements of beef cattle breeding technologies
- VEAL: Meat of young calves
• BOB veal – Calves culled a few days after birth
• Formula/milk fed veal – WHITE VEAL production. Animals marketed ~18-20weeks
• RED/grain fed VEAL –
Animals marketed around 22-26 weeks @ ~300kg
BEEF: Meat of BOVINES
ORGANIC beef: Produced without HORMONES, pesticides & other chemicals
Topic 6 – Main reproduction features, reproduction traits
REPRODUCTION TRAITS
- Dairy production: Calving is prerequisite
- Major role of bovine placental lactogene (pBL) in
mammogenesis & milk production - Beef production:
- More meat by more calvings
- Increased economy
- Maternal effects: Increase nr of offspring & genetic pool of dam - Breeding value estimation (progeny testing)
• Increases effectiveness of selection from maternal lines as well - Prolificacy genes: Great importance
(increase granulose cell function, steroid
biosynthesis, multiple ovulations, ovulation rate) - Puberty: ~8 (12-16) months
- First breeding usually occurs >15 (13-14 MONTHS) or when animal has reached ¾ adult BODY MASS
- First calving @ 2-3 YEARS. (Great breed variance)
Topic 6 – Main reproduction features, reproduction traits
General reproductive features of dam (cow)
- General reproductive features of dam (cow)
• Uniparous
• Low reproductive potential
• Long puberty
• Long gestation
• No seasonality ! Continuous POLYESTRUS!
• Continuous breeding
• Frequent embryonic losses
• LOW twinning rate (up to 5%)
• Freemartinism in twins of different sex (>90%) - Ovarian cycle: 20-21 days
- Biphasic – luteal & follicular period - Heat duration: 24-48 hours
- Oestrus signs:
- Mucous discharge
- Hyperaemic, swollen genitalia
- Standing heat by teasing
- Bulling – mounting of other females - Ovulation: Spontaneous
- 10-14 hours after finishing clinical heat
- Nr of ovulated eggs does NOT exceed 2
- Mature follicles are SMALL but palpable (dia 2-2.5cm) - First heat after calving occurs 15 days post-partum & is OFFEN SILENT.
Topic 6 – Main reproduction features, reproduction traits
Frequent cycle & ovulatory disorders
1• Anovulatory cycles – Only follicular period
2• Delayed ovulation
3• Persistent ATRESIA of follicles
4• Cystic ovaraies
5• Longer/shortened cycles
6• Corpus luteum persistens
(CLP – moderate sign of sterility causing anoestrus)
o Heat is INDUCIBLE in cows with CLP by PGF2α
7. Heat detection: Observation of behaviour & clinical signs - Tail chalking - Computer watch system - Foot tags - Rectal palpation - Ultrasound
Topic 6 – Main reproduction features, reproduction traits
GESTATION of cow
- Length: 282 (278-287) days
- Maintenance: bPL hormone
(placental lactogenic hormone) - PROGESTERONE (in CL graviditatis)
- Placental oestrogens
- Fertilization: Occurs in FALLOPIAN TUBE.
Migration to UTERUS @ day 4-5 - Implantation:
- Innesting of blastocyst @ day 21 - Long lactation period is desired (~300 days)
- Dry period: ~2 months
- Needed for udder regeneration & preparation for new
lactation
8. Pregnancy detection • Rectal palpation • Ultrasound • Hormonal tests • Pregnancy specific proteins (foetoproteins)
- Twinning
• May be desired in beef cattle production
o Selective breeding (selection of twinning ability)
o Marker assisted selection (molecular) !
Detects factors responsible for twin ovulations
• 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
Topic 6 – Main reproduction features, reproduction traits
Environmental factors influencing reproduction
• Feed
• Condition
• Climate – Sensitivity to heat stress
• Hormonal factors
– Excellent response to hormonal treatment
(e.g. induction of ovulation & oestrus cycle)
Topic 6 – Main reproduction features, reproduction traits
Parameters used to evaluate reproductive performance
1• Age at 1st calving
o ~2 yrs
2• Insemination index (ave no of inseminations
o <1.4 is optimal
3• Non-return rate (result of 1st insemination)
o <60% is excellent
4• Calving interval
o 360-380 days
o May be up to 400 in high yielding cows
5.• 1st fertile heat post-parturition
o 35-40 days
6• Service period (period from 1st service to successful conception)
o <60 days is desired
7• Pregnancy rate (PR %) & calving rate
o >95%
8• STERILLITY & selection, culling rate
o <10%
9 • Embryonic & perinatal MORTALLITY
o Should remain <5-10%
10• LACTATION period
o 300 days
11• DRY period
o 60 days
Topic 7 – Most important bovine genetic diseases
In general and breed specific
Immunodeficiency Blood circulation, haemostasis Metabolic diseases (lysosomal storage diseases) Muscular Skeletal Atresia/agenesia Intersexes Endocrine Skin & coat
- Holstein: DUMPS, Complex Vertebral Malformation, Factor IX haemophilia,
hypertrichosis, oligodontia - Simmental: Platelet bleeding disorder
- Limousine: Protoporphyria
- Brown Swiss:
- Weaver syndrome
- Albinism - Dexter: Dwarfism
- Brahma: Pompe disease
- Shorthorn: Parakeratosis/bovine hereditary zinc deficiency
Topic 7 – Most important bovine genetic diseases
Immunodeficiency
- BLAD (bovine lymphocyte adhesion deficiency)
* Chediak-Higashi syndrome
Topic 7 – Most important bovine genetic diseases
Blood/Circulation diseases
Blood circulation, haemostasis • Hyperbilirubinaemia • Protoporphyria (congenital, rare, AR) • Platelet bleeding disorder • Haemophilia B (factor IX deficiency)
Topic 7 – Most important bovine genetic diseases Metabolic diseases (lysosomal storage diseases)
- Lipofuscinosis
- Gangliosidosis
- Mucopolysaccharidosis I
- Glukogenosis V
- Mannosidosis α & β
- Citrullinaemia
- DUMPS (deficiency of uridine monophosphate synthase)
- Ahorn-syrup-urine disease
Topic 7 – Most important bovine genetic diseases
Muscular
• Muscular hypertrophy (DOUBLE muscling) !
Breed trait in BELGIAM BLUE
- Hypo- & dysmyelinisations (lameness of calves)
- Spinal muscular atrophy (SMA)
- Posterior paraplegia
- Lethal spastic paresis
- Weaver syndrome
Topic 7 – Most important bovine genetic diseases
Skeletal
- Chondrodysplasia & achondroplasia (Dexter cattle, AD)
- Complex vertebral malformation
- Dwarfism (proportional, STH-receptor mutation)
- Syndactylia ! Fusion of digits
- Arthrogiposis
- Apodia (lack of homeobox proteins, homeosis)
Topic 7 – Most important bovine genetic diseases
Atresia/agenesia
- Atresia coli
- Kidney dysplasia
- Nephritis