Abstract

Dairymeade is a newly registered breed of dairy sheep in the emerging New Zealand dairy sheep industry. The objective of this study was to estimate heritabilities and genetic correlations for direct and maternal genetic effects on weaning weight, as this trait reflects the genetic ability of the lamb to grow (direct genetic effect), and the genetic ability of the ewe to feed her lambs (maternal genetic effect) and protect them (maternal permanent environment). Records of weaning weight were used from 717 lambs born between 2013 and 2016, with a pedigree of 5091 animals over 11 generations. Average and standard deviation of weaning weight, age at weaning and litter size were 18.1±4.0 kg, 51.5±13.0 days and 2.16±0.7 lambs, respectively. At weaning, ewe lambs were 1.1 kg (SE=0.2 kg, P<0.05) lighter than ram lambs and singleton lambs were 4.1 kg (SE=2.9 kg, P<0.05) heavier than triplet lambs. Estimates of heritability (±SE) were 0.55 (±0.24), 0.24 (±0.17) and 0.28 (±0.13) for direct, maternal and total genetic effects, respectively. The proportion of total variance explained by maternal permanent environmental influences was 0.14 (±0.07). The estimated genetic correlation between direct and maternal genetic effects was ‒0.72 (±0.20). Maternal breeding values can be used to select ewe lambs specifically for milk production.

N, Lopez-Villalobos, M King, J King, and RS Morris

Proceedings of the New Zealand Society of Animal Production, Volume 77, Rotorua, 129-132, 2017