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

Lactation records of the Skopelos dairy goat population were used to assess the importance of various environmental effects and to estimate genetic parameters for 90-day milk yield (9OMY) and total milli yield (TMY) on untransformed and on log scale. Average 9OMY, TMY and days of milling were 164.7, 239.2 kg and 187 days, respectively. Herd, production year, lambing month, birth type, lactation number, the herd by year, year by month, year by lactation number interactions and days of milking were found statistically significant for TMY. Heritability estimates were 0.15 and 0.14 for 9OMY and TMY, respectively. Higher heritabilities of 0.24 and of 0.28 were estimated on the log scale for 9OMY and TMY, respectively. Genetic and phenotypic correlations between 9OMY and total milk yield were found high, of 0.95 and 0.80, respectively. (C) 2000 Published by Elsevier Science B.V. All rights reserved.