Polymorphism of beta (â) casein gene and their association with milk production traits in Sahiwal and HF crossbred cattle

Abstract

Present research work was carried out on 50 Sahiwal and 50 HF Crossbred cattle in the Department of Animal Genetics and Breeding of College of Veterinary Science and A H Jabalpur. During the research work the PCR amplified products of 121bp was digested by restriction endonuclease enzyme DdeI, which recognizes G^AATTC sites. The patterns evolved in the present study showed that the presence of one restriction site on one alleles and absence of restriction site on other alleles resulted in the appearance of three bands of 121, 86 and 35bp.This genotype was referred to as A1A2. When both strand had no restriction sites for the enzyme, only one band of 121bp was observed on the gel such genotype was designated as A2A2 type. The â- casein gene showed A2A2 and A1A2 genotypes were observed in Sahiwal and HF crossbred cattle. The genotypic frequencies of â-casein (CSN2)/ DdeI gene for A1A1, A1A2 and A2A2 are 0.00, 0.30, and 0.70 in Sahiwal and 0.00, 0.64 and 0.36 in HF crossbred cattle, respectively and the gene frequency A1 and A2 is 0.15 and 0.85 in Sahiwal and 0.32 and 0.68 in HF crossbred cattle. High frequency of A2 allele was observed in both the breeds of cattle under the study.

The potential status of A1 and A2 variants of bovine beta-casein locus of some indigenous genetic resources reared in Turkey

“…Although there are breed differences, considering the domestic breeds in different literatures, A1 and A2 allele frequencies were found as 0.20-0.80 in Vechur breed (Muhammed and Stephen, 2012) and 0.20-0.80 in Malnad Gidda breed (Srinivas et al, 2019). To our knowledge of the recent literature on different indigenous breed, A2 allele frequencies were determined as 0.61 in Kasargode breed (Muhammed and Stephen, 2012), 0.94 in Ongole Indian Zebu (Ganguly et al, 2013), 0.88 in Garhwal Badri cattle and 0.87 in Kumaon Badri cattle (Dar et al, 2018), 0.85 in Sahiwal cattle (Pandey et al, 2018), 0.90 in Ladakhi cattle (Sodhi et al, 2018), 0.71 in Deoni, 0.63 in Sahiwal and 0.80 in Malnad Gidda cattle (Srinivas et al, 2019). As a result, it can be stated that the A2 allele frequency is high in these breeds in general, except for the Sarabi (Firouzamandi et al, 2018) and Polish Red (Cieślińska et al, 2019) breeds, and it is compatible with the current study results.…”

“…When it comes to heterozygosity within breed, this value is appropriate for the selection of the desired A2 allele in these breeds for A2 milk production, as they have values close to the maximum heterozygous level of 0.50. The heterozygosity and PIC values are a useful descriptive measure of the polymorphism of a marker locus, and also considered as a parameter of the variation (Aytekin et al, 2011).When attention is paid to heterozygosity, He values reported as 0.322 in Vechur breed (Muhammed and Stephen, 2012), 0.335 in Holstein Friesian crossbreed (Navyashree, 2014) and 0.269/0.435 in Sahival/Holstein Friesian crossbreed (Pandey et al, 2018). PIC, another measure used to assess the quality of a marker, values were found as 0.364 in overall.…”