Relationships between milk protein polymorphisms and production traits in cattle: a systematic review and meta-analysis

Abstract

Abstract. Many researchers who have studied the relationships between milk protein polymorphisms and some yield traits in dairy cattle have reported incompatible results. In this study, in order to examine the overall relationships between milk protein genes known as major genes (CSN1S1, CSN2, CSN3, and BLG) and some yield traits (daily milk yield, lactation milk yield, fat yield, fat content, protein yield, and protein content), a meta-analysis was performed using some genetic models reported in the results of previous studies on cattle. The results suggest that the relationships of major milk protein genes with other factors should be studied using the codominant genetic model in general. Relationships among some CSN3 genotypes and fat yield, fat content, and protein content, and relationships between some BLG genotypes and daily milk yield, fat content, protein yield, and protein content were significant (P<0.05). No significant (P>0.05) relationships were found between these genotypes and other milk production traits. In addition, no significant (P>0.05) relationships between the CSN1S1 and CSN2 genotypes with the milk production traits examined were observed.

Polymorphisms in CSN3, CSN2 and LGB Genes and Their Relation to Milk Production in Dairy Cattle in the Czech Republic

“…Trends in milk production (in kg) were opposite, non-significant, hence the differences in protein production per lactation between the AB and BB genotypes were minimal. Ozdemir et al (2018) did not detect any significant influence of the gene on milk yield indicators in their extensive meta-analysis.…”

“…In the association study of these authors, the BB genotype had a significantly higher percentage of fat in milk than both homozygous genotypes (BB 4.23,AA 4.17,AB 4.20). Ozdemir et al (2018) describe the genotype succession such as AB > BB > AA for daily milk production, however, homozygous genotypes were better in milk yield over the lactation period. The authors also state that the B allele is associated with a higher milk fat content.…”

“…Some authors discovered that higher protein content is associated with the presence of the B allele in the genotype. Ozdemir et al (2018) specify in their comparison of the AA with BB genotypes not only a significant effect on the protein content, but also an effect on the fat content in milk. They also discovered a remarkable difference in protein II: Milk production traits (x̄ ± s x ) of different genotypes of CSN2, CSN3 and LGB in cows of Czech Simmental, Holstein and crosses.…”

“…CSN3, CSN2 a LGB loci have been the most examined in this context. There is a large amount of research demonstrating the influence of the above-mentioned genes on quantitative and qualitative components of milk production and on selected milk quality indicators (Ozdemir et al, 2018;Neamt et al, 2017). On the other hand, however, there are also studies that have not confirmed the aforesaid correlations (Duifhuis-Rivera et al, 2014;Dogru, 2015).…”

Variation in the Genetic Effects of ABCG2, Growth Hormone and Growth Hormone Receptor Gene Polymorphisms on Milk Production Traits in Egyptian Native, Holstein and Hybrid Cattle Populations

“…Different genetic variants are present at bovine milk trait loci, and considerable differences in allele frequencies for these traits were observed among breeds (Cohen-Zinder et al, 2005;Komisarek et al, 2011;Alima et al, 2013;Ibeagha-Awemu et al 2016;Ozdemir et al, 2018). Consequently, marker-assisted selection based on SNPs has been used for the selection of milk production traits (Hayes et al, 2007).…”