C6: Breeding value estimation and selection of sows and boars Flashcards
what Reproduction traits for breeding value estimation are important in swine breeding?
- Number of teats: 5-8 x 2 pairs (12- 14 well spaced).
- Insemination index: <2 (commonly: AI once or twice in a heat).
- Period between two farrowings (births) (farrowing interval): 150-170 days.
- Farrowing number/sow/year: 2,0-2,3.
- Pregnancy and farrowing rate: >95%.
- Average litter size: 6-18 (8-12), highly breed dependent.
- Reared up, weaned number of piglets per year and sow: 20-24 (must account for losses).
- Average birth weight of piglets: 1-(2) kg.
- Sterility and culling rate: <5%.
- Boar: semen quality, fertility, testicle size.
what is performance testing
Performance testing: when an animal is assessed on its own conformation, growth rate, FCR etc
what is progeny testing?
Progeny testing: when an animal’s offspring is assessed for characteristics such as FCR and growth rate etc.
Performance testing & selection: Individual performance of sows.
Individual performance of sows:
* Weight gain up to 85-95kg
* Fleshing (sonography – fat & muscle measurements)
* Conformation traits (muscling, teat number)
* BCS (body condition score): 4-5
Performance testing & selection: Individual performance of boars
Individual performance of boars:
* Weight gain, fleshing (sonography)
* Conformational traits (testicle circumference, fertility, semen quality)
* Health traits
* Hereditary disorder free
* Test matings - Full sib, half sib & progeny testing
* Gain & carcass merits
Performance testing & selection: Breeding value estimate for selection of breeding boars & gilts
- Own performance
- BLUP (Best linear unbiased prediction) using breeding value of parents & full grown sibs & half sibs.
Performance testing & selection: Selection of breeding boars for AI
- Maternal performance, conformation scores, MHS-test
- Fertility tests (min 1500 first AI)
- Test-mating for genetic defective
- e results
- Progeny testing (rate of gain & carcass merit)
- BLUP based on progeny testing
what is the breeding value estimate?
- Involves production traits (recorded average daily gain, feed intake and carcass quality) in central testing stations and traits related to reproduction (number of piglets born alive, farrowing interval and number of piglets weaned).
- Estimated breeding value for fertility traits are combined in the so-called IFI.
what is breeding value and what is it used for?
BVi = GMi - GMpop
- Find the most suitable parents based on their breeding value
- Goal of breeding: select best animal for breeding , genetically superior to others.
- Generic merit: sum of calculated averages according to additive and non-additive allelic effects in each loci;
An individuals generic merit is theoretical and remain constant.
EBV
h^2
Pi
Ppop
EBV = h^2 x (Pi - Ppop)
EBV = breeding value
h^2 = heritability estimate
Pi = individuals phenotypic performance
Ppop = mean of population phenotypic performance
what must a bore undergo before entering AI stations?
what happens here?
All boars are required to undergo a minimum of 40 days in an officially approved quarantine facility prior to their movement to the AI Station.
compulsory blood testing for Classical Swine Fever, Aujeszky’s Disease, Brucellosis, and for PRRSV.
what is the suitable storage for semen?
- Semen should be stored at 17ºC in a thermostatically controlled storage box.
- Semen doses should also be gently agitated at least once per day during storage, and be handled carefully to avoid ‘mechanical shock’ to the sperm cells.
