Authors: Ali KAYGISIZ
Abstract: The purpose of this is to determine the trends components of 305 day milk yield and Iactation length of Sarı Alaca cattle raised at Kazova (Tokat) State Farm were studied. The environmental effect of the phenotypic trend was estimated by using corrected milk records of cows for 2 consercutive years. The environmental change for 305 days milk yield and lactation length per year was estimated as 100.91 kg/year and -1.58 days/year. The regressions of the corrected milk yield averages on years for were found to be 115.75 kg/year and -5.88 days/year. Considering this value, the genetic change was calculated to be 14.84 kg/year and -4.30 days/year.
Keywords: Sarı Alaca Cattle, Milk Yield, Genetic Trends