Environmental and genetic effects on growth traits in Jamunapari kids

Jamunapari kids (2759) born during 1985 to 2007 at the Central Institute for Research on Goats, Makhdoom, Mathura, Uttar Pradesh, India were used to estimate the body weight and average daily weight gain (ADG). The overall least squares means for body weight at birth, 3, 6, 9 and 12 months of age were 3.14±0.02, 10.52±0.07, 14.95±0.10, 20.57±0.13 and 25.68±0.15 kg, respectively. The least square mean for ADG during 0–3, 3–6 and 6–12 growth periods were 82.05±0.74, 49.18±0.76 and 59.59±0.61g/day, respectively. The period and season of birth, type of birth, sex, feeding management system and weight of dam at kidding has significantly affected the growth traits at all the ages. Kids born in autumn were of lowest birth weight (3.03±0.05), however, higher growth rate of autumn born kids during 0–3 and 3– 6 months of age significantly excel their body weight over the kids born in other seasons from the age of 3 month onwards. Males were born with higher body weight and maintained their superiority of weight and weight gain over females. Kids born from prima-parous and aged does has slightly less weight at birth and 3 months of age. Kids reared under intensive feeding showed higher (<0.01) body weight and weight gain at different ages. The heritability estimates were 0.275±0.061, 0.362±0.069, 0.297±0.063, 0.293±0.062 and 0.417±0.073 for body weighs at birth, 3, 6, 9 and 12 months ages, respectively. The genetic and phenotypic correlations amongst 6, 9 and 12 months of age were high indicating that age of selecting males for breeding programme could be lowered to 6 months. Present study suggests for more attention up to 6 months of age for higher growth of kids. Jamunapari goats may be commercially reared under stall-feeding system for commercial meat production.