A Comparison Between Sire and Animal Model for Lifetime Production Traits in Egyptian Buffaloes.

Abstract

A total of 1621 normal lactation records of Egyptian buffaloes, kept at Mehalat Mosa farm, belonging to the Animal production Research Center, Ministry of Agriculture, Doki, Cairo, Egypt, during the time from 1990 to 2010 were used. Data were analyzed by using sire model (SM) and animal model (AM). For sire model, includes the fixed influences of year, month of birth, age at first calving as covariate and sire as a random effects. For animal model, it includes the fixed influences for month, year of birth, random effects of animals and errors on total milk yield (TMY), totals lactation period (TLP), age at disposal (AGDS) and the numbers of lactation complete (NLC). Means were 10552 kg, 1173 d, 125 mo., and 5.97 for TMY, TLP, AGDS and NLC, respectively. Estimates of heritability from sire model were 0.45, 0.18, 0.90 and 0.36 for TMY, TLP, AGDS and NLC, respectively and from AM were 0.27, 0.17, 0.12 and 0.06 for above traits studied, respectively. Estimates of phenotypic correlations among traits studied ranged from 0.55 to 0.73 for SM and for AM 0.40 to 0.80 and genetic correlations among traits studied ranged from 0.19 to 0.96 for SM and from AM ranged from 0.10 to 0.98. Rank correlations among lifetime and longevity traits as estimated from SM were highly significant (P<0.01) and positive except rank correlation among NLC, TMY and TLP and ranged from 0.08 to 0.98 as estimated from SM. Rank correlations of sire transmitting ability among lifetime and longevity traits as estimated from AM were highly significant (P<0.01) and positive and ranged between 0.33 and 0.88.