The aim of this study was to determine the genetic diversity of 4 native Turkish cattle breeds, based on the growth hormone (GH), prolactin (PRL), and diacylglycerol acyltransferase (DGAT1) genes. In order to study the polymorphisms in these genes, the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method was performed. A 329-bp fragment and a 223-bp fragment of GH, a 156-bp fragment of PRL, and a 411-bp fragment of DGAT1, thus 4 loci of 3 genes, were amplified via PCR. These fragments were then restricted with the enzymes MspI, Alu1, RsaI, and CfrI, respectively. In this study, 2 types of alleles, ( + ) and ( - ) for the GH-MspI, L and V for the GH-Alu1, A and B for the PRL, and K and A for the DGAT1 loci, were observed. The results of the present study will contribute to the polymorphism data on the world's cattle breeds. Furthermore, the above-mentioned allele frequencies of Turkish native breeds are evaluated in relation to their genetic relatedness, and to infer their milk production properties on the basis of the available literature. In turn, these results can be utilized for future breeding programs of dairy cattle in Turkey.

The aim of this study was to determine the genetic diversity of 4 native Turkish cattle breeds, based on the growth hormone (GH), prolactin (PRL), and diacylglycerol acyltransferase (DGAT1) genes. In order to study the polymorphisms in these genes, the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method was performed. A 329-bp fragment and a 223-bp fragment of GH, a 156-bp fragment of PRL, and a 411-bp fragment of DGAT1, thus 4 loci of 3 genes, were amplified via PCR. These fragments were then restricted with the enzymes MspI, Alu1, RsaI, and CfrI, respectively. In this study, 2 types of alleles, ( + ) and ( - ) for the GH-MspI, L and V for the GH-Alu1, A and B for the PRL, and K and A for the DGAT1 loci, were observed. The results of the present study will contribute to the polymorphism data on the world's cattle breeds. Furthermore, the above-mentioned allele frequencies of Turkish native breeds are evaluated in relation to their genetic relatedness, and to infer their milk production properties on the basis of the available literature. In turn, these results can be utilized for future breeding programs of dairy cattle in Turkey.