Estimation of breeding values of Rathi sires by different methods for three hundred days milk yield

The least-squares (LS), simplified regressed least-squares (SRLS), Best linear unbiased prediction for estimated breeding values (BLUP-I) and Best linear unbiased prediction for expected breeding values (BLUP-II) methods were used to estimate the breeding values of 27 Rathi sires for milk yield of 300 days (MY300) from performance records of 281 daughters born during 1974 to 1994 at Livestock Research Stations Nohar and Bikaner of Rajasthan Agricultural University, Bikaner, Rajasthan. Model for LS included fixed effect of sire, farm, period and season of birth ignoring the sire group effect. Model for BLUP included fixed effect of farm, period, season of birth and sire group as fixed effects and sires within sire group as a random effect. The lowest range of breeding value (141.73 litres) was estimated by BLUP-II method, while the highest range (654.16 litres) was estimated by LS method. The LS method is not suitable for evaluating the sires with lesser number of progenies per sire. BLUP indicates the real transmitting ability of a bull and is therefore a better estimate of the breeding worth of a bull. The estimates of rank correlation between BLUP-II and BLUP-I was 0.98 indicated that these methods were more or less similar in ranking the sires for their merit. However, better predictability of BLUP-II method could be concluded while appraising the genetic merit of Rathi sires. The sire Nos. 183, 213, 302, 511 and 243 remained common in top five sires with the maximum breeding values both in BLUP-II and BLUP-I methods. These sires were recommended for extensive breeding purposes to effect rapid genetic improvement in Rathi cattle.