Economic Weights of the Traits Characterizing Milk Yield and Individual Coagulation Ability of Milk in Cows of the Bulgarian Rhodope Cattle

Ivan Mehadzhiyski, Teodora Angelova, Daniela Yordanova, Zhivko Krastanov

Abstract: The economic weights of the signs of selection in dairy cattle play a key role in modern selection based on economically oriented breeding goals. The aim of the present study is to analyze the economic weights of the characteristics characterizing the milk productivity and coagulation ability of milk in the Bulgarian Rhodope cattle. Data from 136 milk samples of cows of the Bulgarian Rhodope bovine breed, reared on 4 farms, were used. Estimates of economic weights are carried out by a bio-economic model in which the economic weight of an traits is defined as a partial derivative of the overall function of the profit for the given traits and expressed for a cow. The Software for Calculating Economic Weights in Livestock, Version 5.1.1 was used. Part 1: Programs EWBC (Version 2.2.1) and EWDC (Version 2.1.2) for Cattle by Jochen Wolf, Marie Wolfová and Emil Krupa (2011). Highest weights for economic weights were found for the 305 days (49.85) and calving interval (28.37). For the traits characterizing the qualitative composition and coagulation ability of milk, approximate values of economic weights (1.22% for fatty substances, 0.68% for protein, 0.91 for coagulation time and 0.74 for curd firmness) were found.

Keywords: coagulation ability of milk; economic weigths; milk production

Date published: 2019-09-19