Average daily gain and kleiber ratio in Bharat merino sheep

To investigate the effect of non-genetic factors on average daily gain (ADG) and Kleiber ratio (KR) and to estimate their genetic parameters in Bharat Merino flock, a study was conducted using records of 6931 animals (from 1986 to 2015) maintained in semi-arid region at ICAR-Central Sheep and Wool Research Institute, Avikanagar (Rajasthan) and in sub-temperate region at Southern Regional Research Centre, Mannavanur (Tamil Nadu). The overall least squares means of ADG from 0–3M (ADG1), 3–6M (ADG2) and 6–12M (ADG3) were 158.19±0.53, 68.91±0.55 and 40.95±0.44 g, respectively. Kleiber ratios from 0–3M (3WTKR) and 3–6 months (6WTKR) were 17.97±0.02 and 6.19±0.04, respectively. Location, year, season and sex of birth had significant effect (P<0.01) on all the traits. The effect of ewe's weight was significant (P<0.01) on ADG1, 3WTKR and 6WTKR. The heritability estimates for ADGs and corresponding KRs ranged from 0.14 to 0.18. The estimates of genetic and phenotypic correlations among the traits ranged between-0.28 (ADG2 and ADG3) to 0.96 (ADG2 and 6WTKR) and-0.31 (ADG1 and 6WTKR) to 0.95 (ADG2 and 6WTKR) respectively. Selection for any of the studied traits of Bharat, Merino sheep would be expected to have a large effect on the other growth traits as a result of their moderately positive genetic correlations.