ANSC 1011 Lecture : Animal Breeding And Genetics Notes
Document Summary
Animal breeding- selection of breeding stock through selection for the next generation using genetic principles- sets the limits of production. Tools: markers assisted selection (mas) or genomic estimated breeding value (gebv, transgenic animals- gmo"s (plants for examples; tomatoes, quantitative (statistics) widely used today, important concepts, pleitropy- single gene influences multiple traits, epistasis- multiple genes influence single traits. Heritability: a measure of the amount of phenotypic variation that is due to additive gene effects. The proportion of differences between individuals that is genetic. Two factors- genetics and environment: 3 classes of heritability, low (less than . 2)- reproductive traits, moderate (. 2-. 4)- growth traits, high (greater than . 4)- carcass traits. Fertility, litter size, twining, age at puberty: moderate, 20-40%: milk yield, feed efficiency, birth weight, weaning weight, high, 45-60%: muscle mass, fatness, mature size, curability. Selection tools: epd"s- expected progeny difference- used for beef cattle, pigs, and sheep, pta"s- predicted transmitting ability- used got dairy cattle** ansc.
