Genetic and environmental sources of variation of milk yield of Skopelos dairy goats.

摘要

24thin420 lactation records collected during 1988-97 from 4962 Skopelos does at the Centre of Livestock Genetic Improvement in Karditsa (Greece) were used to assess the importance of various environmental effects and to estimate genetic parameters for 90-day milk yield (90MY) and total milk yield (TMY) on untransformed and on log scale. Average 90MY, TMY and days of milking were 164.7, 239.2 kg and 187 days respectively. Herd, production year, kidding month, birth type, lactation number, the herd Xyear, year X month, and year X lactation number interactions and days of milking were significant for TMY. h2 estimates were 0.15 and 0.14 for 90MY and TMY respectively. Higher h2 of 0.24 and of 0.28 were estimated on the log scale for 90MY and TMY respectively. Genetic and phenotypic correlations between 90MY and total milk yield were 0.95 and 0.80 respectively.