ASSOCIATIONS OF PIT-1 GENE POLYMORPHISM WITH MILK YIELD AND COMPOSITION TRAITS IN BROWN SWISS CATTLE

İ. Aytekin and S. Boztepe

Faculty of Agriculture, Department of Animal Science, University of Selcuk, Konya, TURKEY
Corresponding Author E-mail: aytekin@selcuk.edu.tr

ABSTRACT

The present study investigated the genetic variability of Pit-1 polymorphisms (HinfI_451 bp) in a total of 301 Brown Swiss cattle, and also evaluated the possible association between the Pit-1 genotypes and dairy traits such as 305 days milk yield (MY305), test day milk yield (TDMY), fat (%),  protein (%), lactose (%), density (kg/m3), solids-non-fat (%),  total solids (%), freezing point (oC), and also pH and conductivity (uS/cm) of milk. Allele frequencies were found as A: 0.374 and B: 0.626 in HinfI (451 bp) polymorphism in Pit–1 gene. No significant difference was detected between the observed and the expected genotype frequencies via Hardy-Weingberg equilibrium (P>0.05). The effect of Pit-1 polymorphisms (HinfI_451 bp) was not observed on milk yield and composition in Brown Swiss populations (P>0.05). The results demostrated that the Pit-1 polymorphisms (HinfI_451 bp) could not be exploited as a candidate gene for selection of dairy traits in Brown Swiss cattle.
Key words: Brown Swiss, Pit-1 (HinfI) polymorphism, RFLP, Milk yield and components.