PHENOTYPIC AND GENETIC TRENDS FOR SOME MILK YIELD TRAITS OF EGYPTIAN BUFFALOES | ||
| Journal of Animal and Poultry Production | ||
| Article 2, Volume 3, Issue 7, July 2012, Pages 353-364 PDF (362.52 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jappmu.2012.82938 | ||
| Authors | ||
| M. N. El-Arian1; N. A. Shalaby1; A. S. Khattab2; S. A. Darwish3; R. H. Abou-Gamous1 | ||
| 1Animal Production Dept., Fac. of Agric., Mansoura University | ||
| 2Animal Production Dept., Fac. of Agric., Tanta University. | ||
| 3Animal Production Inst., Agric. Res. Center. | ||
| Abstract | ||
| A total number of 600 female buffaloes, having 3321 lactation records, from first to tenth parity, kept at three experimental farms (Mahalet Mousa, El-Nataf El-Gaded and El-Nataf El-Kadem), belonging to the Animal Production Research Institute, Ministry of Agriculture, Cairo, Egypt, during the period from 2000 to 2007 were used to study genetic and phenotypic progress, achieved by the Mixed Model Equations (MME) for the Best Liner Unbiased Prediction. The number of sires were 66 sires and the average number of daughters per sire were 12.50. Mixed Model Least square analyzed was used to estimate fixed effects of month and year of calving, parity and farm on (total milk yield (TMY), lactation period (LP), fat yield (FY), protein yield (PY), lactose yield (LY) and somatic cell count (SCC). Data were analyzed using Multi Trait Animal Model to estimate genetic parameters and breeding values. Unadjusted means of TMY, LP, FY, PY, LY and SCC were 2070 kg, 223 d, 164.4 kg, 89.5 kg, 128.2 kg and 204.8 x 10-3 cells/ml, respectively. Heritability estimates (± SE) of TMY, LP, FY, PY, LY and SCC were 0.41 ± 0.06, 0.31 ± 0.07, 0.20 ± 0.09, 0.19 ± 0.03, 0.22 ± 0.10 and 0.06 ± 0.03, respectively. Estimates of genetic correlations among milk yield traits were positive and ranged from 0.18 to 0.8, while the genetic correlation between SCC and all milk traits are negative and ranged from -0.18 to -0.66. Phenotypic correlation among all traits studied were the same direction of genetic correlations. The range of expected sire breeding values (SBV's) for milk traits were 1418 kg, 13.27 d, 178 kg, 91 kg, 139 kg for TMY, LP, FY, PY and LY, respectively. Annual phenotypic change for TMY, LP, FY, PY and LY were positive and highly significant, being 74.20 kg, 18.84 d, 7.48 kg, 2.89 kg and 2.10 kg, respectively. The corresponding annual genetic change for the same above traits averaged 3.70 kg, 0.55 d, 0.90 kg, 0.60 kg and 0.54 kg, respectively. Positive genetic and phenotypic trends in the present results indicated that the selection plan of that herds was use the best sires, so that in the next generation will excepect genetic improvement for traits under investigation except the SCC of lactating Egyptian buffaloes at these herds. | ||
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