Full Length Research Paper

Association of IGF-1 gene polymorphism with milk production traits and paternal genetic trends in Iranian Holstein bulls

Yousef Mehmannavaz¹*, Cyrus Amirinia², Mortaza Bonyadi³ and Rasoul Vaez Torshizi⁴

¹Department of Animal Science, Faculty of Agriculture, Science and Research Branch, Islamic Azad University, Tehran, Iran.

²Department of Animal Biotechnology, Animal Science Research Institute of Iran, Karaj, Iran.

³Center of Excellence for Biodiversity, University of Tabriz, Tabriz, Iran.

⁴Animal Science Department, Faculty of Agricultural, Tarbiat Modares University, Tehran, Iran.

*Corresponding author. E-mail: mehman10@yahoo.com

Accepted 12 November, 2009

   Abstract

The effects of Insulin-Like Growth Factor-1 polymorphism were examined on milk production traits and genetic trends in the Iranian Holstein bulls. A total of 282 bulls were genotyped for SnaBI restriction site in the 5' flanking region of IGF-1 by applying PCR-RFLP method. The allele frequencies for C and T alleles were 0.562 and 0.438, respectively. The results indicated that genetic variants at the 5'-noncoding region of the bovine IGF-1 gene had a marked effect on estimated breeding values of milk (EBVM) and fat yields (EBVF). The heterozygous bulls (CT genotype) had higher EBVM and EBVF than homozygous bulls (P < 0.1). The average substitution effects of alleles were not significant for none of studied traits (P > 0.1). The studied polymorphism of IGF-1 showed no significant association with genetic trends of milk related traits (P > 0.1). These results suggest that allelic interaction in IGF-1 polymorphism as over dominance and might be effectiveness in animal improving by crossbreeding. 

Key words: IGF-1, polymorphism, Holstein, genetic trend.