Genetic analysis of relative growth rates in sirohi kids under field condition

The growth data of 1361 Sirohi kids reared over a period of 3 years was used in the study. The Least Square means of relative growth rate (RGR) at 0–3 months (RGR1), 3–6 months (RGR2), 6–9 months (RGR3) and 9–12 months (RGR4) were 4.11 ± 0.16, 0.444 ± 0.03, 0.218 ± 0.02 and 0.205 ± 0.01 kg/kg, respectively. Relative growth rate is useful for comparing growth of individual with widely different weight or even different species. The relative growth is also the measure of actual growth of kids for particular kid to be retained in flock. Sire effect was significant on the relative growth rate at all age groups except 6–9 months of age. Location, year, season of birth had significant effect on relative growth rate at all age groups except year at 6–9 months of age. The phenotypic and genetic correlation of relative growth rate at particular period with the subsequent periods were mostly negative. The heritability estimates of RGR1, RGR2, RGR3 and RGR4 were 0.315 ± 0.12, 0.313 ± 0.12, 0.065 ± 0.07 and 0.115 ± 0.08, respectively.