Polymorphism in the Beta Casein Gene and analysis of milk characteristicsin Gir and Guzerá dairy cattle

Abstract

ABSTRACT. Several human health problems have been related to the allergenic constitution of bovine milk due to the body's immune reaction to milk proteins. It is necessary find solutions to minimize the occurrence of such reactions, given the importance of milk as a source of animal protein. The aim of this study was to evaluate the allelic frequency of the CSN2 gene and to evaluate differences in the characteristics of Gir and Guzerá bovine milk. One hundred and fifty-six cows were used (68 Gir and 88 Guzerá) from the Felipe Camarão Experimental Station herd of the Agricultural Research Corporation of RN (EMPARN). DNA extractions were carried out from hair follicles of the animals; the gene was then amplified and sequenced in an ABI 3100 automatic sequencer. The obtained sequences were submitted to analysis using the Geneious 5.6.5 ® program. Data were submitted to analysis of variance and to the Tukey- Kramer test at 5% probability and cluster analyses by main components were performed. Allele frequencies were 98 and 97% for the A2 allele and 0.96 and 0.93% for the genotype A2A2 for Gir and Guzerá, respectively. Gir and Guzerá animals showed differences in protein, lactose, and nonfat dry extract levels. Although correlations between milk yield and the production and some milk components are moderate, increases in milk yield are always greater than the increase in constituent yield. In addition, even though Guzerá animals have a higher percentage of protein, lactose, and non-fat dry extract, milk from Zebu breeds is an alternative for individuals sensitive to β-casein protein.

Comparative Genomics, Evolutionary and Gene Regulatory Regions Analysis of Casein Gene Family in Bubalus bubalis

“…Comparative amino acid sequence analysis revealed that CN protein harbor higher amino acid variations in river buffalo (Mediterranean and Murrah) as compared to the swamp buffalo. The results of the present study are in line with previous studies (Masina et al, 2007;Azevedo et al, 2008;Massella et al, 2017;Rangel et al, 2017;Miluchova et al, 2018;Fan et al, 2020;de Oliveira et al, 2021) which reported the potential association of genetic variants in CSN genes with lactation performance, milk composition, and attributes of milk products. Thus, casein gene-based markers are important candidates for the selective breeding of buffalo to improve the quantity and quality of milk (de Oliveira et al, 2021).…”

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

“…The significant association reported for lactose percentages in Egyptian Baladi cows indicates that the ABCG2-HhaI-AA genotype is associated with higher lactose and lower milk yields than the AB genotype. This difference may be due to the negative correlation between milk yield (kg) and lactose (Rangel et al, 2017). Thus, the ABCG2-HhaI-AA genotype could be incorporated into marker-assisted selection for culling of this genotype due to its association with lower milk yields.…”

Leites A1 e A2: revisão sobre seus potenciais efeitos no trato digestório

“…Nos estudos já realizados sobre as variantes A1 e A2 da β-caseína, foram descritas as variações nas frequências gênicas (alélicas) tanto de raçascomumente utilizadas para a produção leiteira, quanto de raças locais.A frequência do alelo A2 é menor nas raças taurinas, à exceção da raça Guernsey (variando de 0,88 a 0,97), provavelmente pelo seu rebanho mais fechado e com menor número de animais. A maior frequência (%) deste alelo é descrita nas raças zebuínas, como segue: Angus (0,05), Ayrshire (0,28-0,52), Brahan (0,01), Gir (0,88-0,98), Guzerá (0,97), Hereford (0,20), Holandesa (0,25-0,55), Jersey (0,49-0,72), Pardo Suíça (0,49-0,72), Shorthorn (0,51), Simental (0,56-0,63) e Vacas Vermelhas Nórdicas (0,23) [12,4,8,13,14,15] .…”