Factors Affecting Milk Yield Estimated with Different Methods in Brown Swiss Cattle

The aim of this study was to determine the effects of some environmental factors on milk yield levels that were estimated with different methods in Brown Swiss cattle raised in Altınova Farm. Study was carried out under similar feeding and management program. The effects of lactation turn, year and season were analysed in terms of measurable environmental factors. The data was statistically analyzed by means of the least-square method for the determination of the effects of environmental factors and by contrast-test (GLM procedure). Lactation milk yield (6294.7 kg, 6320.8 kg, 6313.9 kg) and 305 day milk yield (5927.1 kg, 6016.2 kg and 6047.5 kg) were estimated by Dutch (Holland), Swedish and Trapez methods in Brown Swiss cattle. The effects of lactation turn, year and season on lactation milk yield and 305 day milk yield were found as statistically significant (P 0.001).