Effect of Estrus on Milk Yield and Composition in Jersey Cows

AKDAG, F., O. CADIRCI and B. SIRIKEN, 2010. Effect of estrus on milk yield and composition in Jersey cows. Bulg. J. Agric. Sci., 16: 783-787 This study was performed to demonstrate the effect of estrus on milk yield and composition in Jersey. In this study, 15 jersey cows which were at the same estrus period, in the third lactation period and breeding under uniform housing and feeding conditions were selected. Milk production was calculated by sampling milk at the evening hours in the estrus period and 3 days after the end of estrus period. Acidity, pH, density, dry matter, fat and lactose levels, were determined from the obtained milk samples in evening milking. In this study, milk yield of cows in estrus was determined as 4.8 kg while post estrus production elevated to 5.8 kg (P<0.01). Conversely, it was determined that the estrus does not significantly affect compound of the milk (P>0.05). High positive correlation between dry matter and fat content (r = 0.673) in estrus period was detected. In post estrus correlations between milk composition; negative (r = -0.755) between pH and lactose and positive (r = 0.755) phenotypic correlation between dry matter and density were determined. In conclusion, it was indicated that estrus has been important effect on milk yield while does not have a significant effect on milk composition.