Genetic analysis of somatic cell count and milk yield traits in Egyptian Buffalo

الملخص EN

The objective of this study was to investigate the association between milk, fat and protein yields with somatic cell count in milk, and to study possibilities for improving the performance of the Egyptian buffalo.

A total of 1408 lactation records for somatic cell count and milk yield traits, representing 702 buffalo cows daughter of 103 sires and 544 dams, were analyzed by fitting a multiple-trait repeatability animal model using the restricted maximum likelihood (REML) procedure.

The model included herd-year-season of calving and age nested within parity for the first five parties as fixed effects while additive genetic and permanent environment were used as random effects.

All fixed effects contributed significantly (P < 0.0001) to variations in all traits.

The average lactation yields (SD) of milk, fat and protein (kg) and lactation measure of somatic cell count were 1402 (645), 94.9 (46.5), 53.6 (24.2), and 4.79 (0.31), respectively.

Heritability estimates for lactation yields of milk, fat and protein and somatic cell count were 0.16, 0.12, 0.15 and 0.27, respectively.

The corresponding repeatability estimates were 0.52, 0.50, 0.51 and 0.38.

Phenotypic and genetic correlations between all yield traits were positive and high (0.95 to 0.99).

Correlations between lactation somatic cell count (LSCC) and milk yield traits were low (-0.29 to 0.01).

Therefore, a selection program to improve milk yield is expected to result in a favourable response in other milk yield traits without a negative effect on udder health for the Egyptian buffalo.