GENETIC AND PHENOTYPIC CORRELATIONS FOR SOME SEXUAL MATURITY TRAITS IN NILI-RAVI
BUFFALO
HEIFERS
N. A. NAZ AND M. AHMAD
Livestock Production Research Institute, Bahadarnagar,
Okara,
Pakistan
Abstract
Data on 202 records of Nili-Ravi buffalo heifers kept at the Livestock
Experiment Station Bahadarnagar,
Okara,
Pakistan
for the period 1994 to 2003, were analyzed to study the genetic and phenotypic
correlations among four traits including age at maturity, weight at maturity,
age at first conception and weight at first conception. The overall means (± SE)
for ages at maturity and first conception were 1166 ± 15.60 and 1311 ± 18.42
days, respectively. The corresponding values for weights were 403 ± 4.58 and 439
± 4.17 kg. The genetic correlations (multivariate analysis) for age at maturity
with; weight at maturity, age at first conception and weight at first conception
were 0.49, 0.88 and 0.07, respectively. The corresponding values for phenotypic
correlations were 0.48, 0.79 and 0.37. The genetic and phenotypic correlations
among other traits (weight at maturity with; age at first conception, weight at
first conception: age at first conception with weight at first conception) were
also estimated from multivariate (tetravariate) analysis.
Key words:
Buffalo
heifers, sexual maturity, body weight, genetic and phenotypic correlations.