Genetic analysis of milk production traits of Jamunapari goats

Abstract

Data on 2175 lactation records of 832 goats born during 1993 to 2007 at the Central Institute for Research on Goats, Makhdoom, Mathura, Uttar Pradesh under the All India Coordinated Research Project on Goat Improvement was analyzed. Non-genetic factors studied were period, year and season of kidding, type of kidding, parity and weight of dam at kidding. Period, season, parity and weight of dam at kidding have significant (P<0.01) effect on all the milk production traits. Goats kidded in winter produced highest 90 d, 140 d and TMY whereas highest lactation length was recorded in autumn kidders. Varied milk yield performance over the seasons was mainly attributed to variation in climatic conditions, feed and fodder availability etc. Highest milk production performance (90 d, 140d and TMY) was observed in second parity, which sustained till fifth parity and thereafter declined substantially, however, kidding interval consistently decreased with the increase in parity number. Goats with higher weight at kidding produced more milk. The heritability for 90 days milk yield was moderate and low for total milk yield. The estimates of genetic correlation amongst milk performance traits (90d, 140d, TMY) and among reproduction traits (LL and KI) were high and significant, however, milk production traits were antagonistically correlated with reproduction traits at genetic scale.Investigation suggests that for consistent improvement in this flock selection intensity of bucks should be increased along with optimum voluntary culling of does.