The development of selection index for organic dairy cattle farms in Turkey

The aim of this thesis is to develop a selection index for organic dairy farms in Türkiye by using traits such as milk yield, conformation, longevity, udder health, milking and reproductive efficiency; which can be considered as yield or functional traits. The research was conducted on a private organic dairy cattle farm, that has a capacity of 500 Holstein cows, located in Aydın Province, Southwestern Türkiye. Conformation traits were scored according to the ICAR recommendations, and the udder surface temperatures were determined with an infrared thermometer. The progeny informations of 72 bulls with 3 or more offsprings in the herd, were gathered and included in the pedigree file consisted of 4212 animal. ANOVA was used to determine the factors affecting the traits, Fisher's LSD test was used for multiple comparison tests, REML was used for the estimation of variance components, BLUP AM was used for the EBVs, and Wright's method was used to calculate inbreeding. Minitab, CFC and MTDFREML softwares were used in data analysis. While composing indexes, as the method used in Germany, the estimated breeding value of all animals for each trait was determined and standardized by converting to a normal distribution with a mean of 100 and a standard deviation of 12. Considering the farm management's breeding goals, 5 different composite index scenarios were developed to constitute the Total Performance Index. These are TPI1: Balanced index, TPI2: Yield weighted index, TPI3: Fertility weighted index, TPI4: Conformation weighted index, TPI5: Longevity index. The selection index structures for organic and conventional dairy cattle farms of some leading countries, especially Germany, were examined and adapted for this study in order to create sub and composite indexes. As a result of the research, TPI1 with a balanced structure is recommended for organic dairy cattle breeding.