A total of 7959 first-lactation records were used in evaluating 69 Fleckvich sires. Only sires with at least 100 daughters were included. Sire transmitting abilities (STA) were estimated using the non-matricized method of contemporary comparison (CC) and the matricized method of best linear unbiased predictor (BLUP). Records of 100-day lactation for yields of milk (MI00), fat (F100). protein (P100), fat-plus-protein (FP100 and carrier (C100) were used. The product-moment correlation (r?m) and Spearman rank correlation (rs) were used as criteria for judging the merits of the two methods of sire evaluation. To assess the accuraq of the methods, standard error (SE) of sire evaluation by each method was calculated along with the percentage of reduction in standard error (RSE) due to replacing CC by BLUR Efficiency of STA estimated by a method at 100-dav lactation relative to 305-day lactation was assessed,
For CC and BLUP methods, there were differences in minimum and maximum estimates of STA of 8.40 and 442 kg for NI100-, 840 and 414 kg for C100; 34 and 16 kg for F100; 24 and 11 kg for P100 and 57 arid 28 kg for FPI 00. For all u-as, the largest differences in STA were obtained when using CC and the lowest by using BLUF'. The top ten sires were not identical (VD of common sires in both methods) in CC when compared with BLUP (70-90%). For all traits, the lowest percentages of sires occupying the same rank were found in the CC method when compared with BLUP (0-50%).
Estimates of rpm between CC and BLUP were relat.ively low (0.763- 0.874). The same observation was noticed when considering rs but with lower estimates (0.434-0.666). |
