Loading...
Utilization of Half-Sibs information to increase the accuracy of young bull selection
The present study was conducted to compare the breeding values of bulls in different sire evaluation methods and to explore the possibility of information on dam's yield and half-sibs in sire evaluation methods utilizing the data from Progeny Testing Scheme of KLD Board. Total 25 bulls, whic...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Ph.D Thesis |
| Language: | Undetermined |
| Published: |
Mannuthy
Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences
2003
|
| Summary: | The present study was conducted to compare the breeding values of bulls in
different sire evaluation methods and to explore the possibility of information on
dam's yield and half-sibs in sire evaluation methods utilizing the data from Progeny
Testing Scheme of KLD Board. Total 25 bulls, which had minimum of fifteen
progeny and ten half-sibs were used. Out of 1212 records, progeny and half-sibs had
847 and 365 respectively distributed in 43 centres. The overall mean of first
Lactation milk yield (FLMY) of progenies, half-sibs and both together were 2389.0 ±
23.46, 2131.0 ± 36.34 and 2311.3 ± 20.00, kg, respectively. Different centres and
years of calving exerted significant effect on FLMY but season and age at first
calving did not influence FLMY. Heritability estimate of FLMY was found to be
0.221 ± 0.077.
Estimated sire merit (ESM) of bulls were estimated using ten indices viz. based
on performance of dam (M), based on performance of paternal half-sibs (HS), based
on performance of dam and paternal half-sibs (M+HS), based performance of dam,
paternal half-sibs and progeny (M+HS+P), simple daughter average (SDA),
contemporary comparison (CC), least squares (LS), KLD Board method, BLUP
without considering relationship of sires (BLUP-l) liand BLUP considering
relationship of sires (BLUP-2).
The range ofESM were '+62.8745 to +396.8055, -157.169 to +287.358, -24.591
to +316.516, -193.877 to + 307.601, kg for M, HS, M+HS and M+HS+P
respectively. The SDA and ESM of CC ranges were 2153.8 to 2663.2 and -1628.80 to
1876.58, kg respectively whereas CC index ranged from -258.79 to +406.74, kg. The
ESM of LS, KLD Board, BLUP-I and BLUP-2 ranges were -450.92 to +567.69, _
111.83 to +513.78, -329.8 to +370 and -332.8 to +362.6, kg, respectively.
Rankings of sires by different methods were not the same but ranking by SDA,
LS and KLD Board method was almost similar with rank and product-moment
correlations around one. Ranking by CC, BLUP-l and BLUP-2 were similar with
very high rank and product-moment correlations.
The average standard error (SE) of SDA, LS, KLD Board, BLUP-l and BLUP-
2 were estimated. BLUP-J followed by BLUP-2 had lowest SE and SDA had the
highest. The results are suggestive of opting for BLUP procedures for sire evaluation
in Kerala. Additional information on dam and half-sibs did not have much advantage
if more progeny records are available for sire evaluation.
|
|---|