Abstract
The data about pedigree, growth and body measurements of 1736 Swamp buffalo calves collected during 1980 to 1991 from Surin Livestock Breeding and Research Station, Thailand were utilized for the computation of heritability estimates for various growth traits and body measurements. Restricted maximum likelihood procedure fitting an individual animal model was followed throughout. Various environmental factors observed to be significant sources of variation for various growth traits and body measurements were fitted as fixed effects in the model of analysis. This included sex, year and season of birth and parity for birth weight; year and season of birth and parity for weaning weight; year and season of birth for 2-year weight; sex, year and season of birth and parity for preweaning average daily gain and year and season of birth and parity for postweaning average daily gain. As regards the fixed effects for the analysis of body measurements sex, year of birth and parity were fitted for all the body measurements. Season of birth was fitted only for heart girth at birth, height at birth and at weaning. The heritability estimates were 0.66 ± 0.07, 0.86 ± 0.08 and 0.34 ± 0.13 for birth weight, weaning weight and 2-year weight respectively. The heritability values were 0.83 ± 0.07 and 0.32 ± 0.12 for preweaning average daily gain andpostweaning average daily gain respectively. The corresponding values for body length, heart girth and height at birth were 0.16 ± 0.06, 0.61 ± 0.07 and 0.61 ± 0.08 respectively. The heritability estimates for height at weaning and height at 2 years were 0.71 ± 0.10 and 0.47 ± 0.14 respectively. The moderate to high estimates of heritability for various growth traits and most of the body measurements of Swamp buffaloes indicated that additive gene action is important for these traits and non-additive genetic effects and environmental effects are of minor importance. It implies that there are good prospects of improvement in these performance traits through selection. Key words: Heritability estimates, growth traits, body measurements, swamp buffaloes
