Distribution of the Beta-Casein Gene Variants in Three Cattle Breeds Reared in Benin

The beta-casein gene is one of the most functional genetic candidate that affect milk quality and composition traits. Among its variants, the A1/A2 are the most common. Therefore, the aim of this study was to identify the distribution of the Beta-casein gene variants (A1/A2) in three different cattle breeds in order to determine which of the breed produce a better milk for consumers’ health. 152 blood samples which comprises 72 (Muturu), 40 (Azawak) and 40 Girolando were used to carry out this study. Genomic DNA was extracted from the blood samples and each variant was subsequently amplified from the extracted DNA samples using an Allele-Specific PCR technique and then confirmed by running the PCR products on 1% agarose gel. The result showed that there were three genotypes (A1A1, A2A1 and A2A2) in the three breeds. The average percentage genotypic frequencies obtained from this study were 42.76%, 31.58% and 25.66% respectively for A1A1, A1A2 and A2A2 genotypes while the percentage allelic frequencies were 58% and 42% respectively for A1 and A2 allele. The genetic parameters of Azawak breed were higher than that of the other breeds, what implies that there was a higher polymorphism and genetic diversity in the Azawak breed in the beta-casein gene compare to the other breeds. The A2 beta-casein variant in milk has been found to be desirable for milk consumer’s health and nutrition. This study therefore showed that the Azawak breed provides a good potential for increasing this favorable allele through appropriate breeding techniques of cattle.

Kappa casein (CSN3) gene polymorphism and its effect on cumulative milk yields of Holstein Friesian dairy cattle

Kappa casein (CSN3) is a standout amongst the most vital milk proteins in mammals that assumes a crucial part in milk quality and coagulation. This study aimed to determine genetic polymorphism of the Kappa casein gene (CSN3) and associate its genotype variants on various cumulative milk yields in Holstein Friesian (HF) dairy cattle. A number of 61 blood samples were collected from 2 Holstein Friesian populations, respectively, from IRIAP Breeding Station in Ciawi (61) and Lembang Artificial Insemination Center (Lembang AIC) (17). Real Time -Polymerase Chain Reaction (RT-PCR) method was used to identify variant genotypes of the Kappa Casein gene. In population were detected all three genotypes GG, GT, and TT. The most frequent genotype was TT, with a frequency of 0.63. Results from the statistical association analysis between g.13975G>T CSN3 genotype and cumulative milk yield in standard lactation length were not significant.

Capa-casein gene polymorphism in cows of different breeds of dairy productivity

Genetic polymorphism of milk proteins, in particular kappa-casein, is of considerable research interest due to its possible associations with economically important traits of dairy cattle. The aim of the study was to determine the polymorphism of the kappa-casein gene and its association with signs of milk productivity in cows of different breeds. Polymorphism of the kappa-casein gene was studied in cows of Ukrainian red-spotted dairy (UCHERM), Ukrainian black-spotted dairy (UCHRM), Montbeliard (M) breeds and crossbred cows obtained by crossing cows of Ukrainian red-spotted dairy breed with Mongolians. DNA studies were performed in the Department of Animal Genetics and Biotechnology of the Institute of Animal Breeding and Genetics nd. a. M.V.Zubets NAAS using the PCR-RFLP method. As a result of research, three genotypes of the kappa-casein gene were identified: AA, AB, BB. Genotypes AA and AB were found in all studied groups of cows, genotype BB was found only in cows of Montbeliard breed with a frequency of 0.366. The highest hopes for 305 days of the first lactation among all studied cows were in crossbred cows with genotype AB (7029 kg), the lowest - in crossbred animals with genotype AA (6359 kg). According to the distribution of genotypes and alleles of the kappa-casein gene, domestic breeds of UCHRM and UCHERM are similar in genetic structure and have a low concentration of B-allelic variant, apparently due to the fact that these breeds were created by reproductive crossing with Holstein breed, in populations of which this allele quite low. The presence of such genotypes in the studied groups of first-borns is determined by the peculiarities of selection work in the herd of SE "DG" Niva "of the Institute of Animal Breeding and Genetics named after MV Tooth of NAAS ». Research results genotypes and alleles of the kappa-casein gene is an additional genetic characteristic of animals, which makes it possible to create herds with the desired characteristics of milk productivity

Genetic Diversity in Casein Gene Cluster in a Dromedary Camel (C. dromedarius) Population from the United Arab Emirates

Genetic polymorphisms, causing variation in casein genes (CSN1S1, CSN1S2, CSN2, and CSN3), have been extensively studied in goats and cows, but there are only few studies reported in camels. Therefore, we aimed to identify alleles with functional roles in the United Arab Emirates dromedary camel (Camelus dromedarius) population to complement previous studies conducted on the same species. Using targeted next-generation sequencing, we sequenced all genes in the casein gene cluster in 93 female camels to identify and characterize novel gene variants. Most variants were found in noncoding introns and upstream sequences, but a few variants showed the possibility of functional impact. CSN2 was found to be most polymorphic, with total 91 different variants, followed by CSN1S1, CSN3 and CSN1S2. CSN1S1, CSN1S2 and CSN2 each had at least two variants while CSN3 had only one functional allele. In future research, the functional impact of these variants should be investigated further.

Characteristics of kappa-casein gene polymorphism in cows of Swiss breed and their productive qualities at a large dairy

Kappa-casein is a fraction of the main milk protein, which determines the technological properties of milk and the quality of dairy products, especially cheese and fermented milk products. The study tested the distribution of kappa-casein gene genotype polymorphism (CSN3) in mothers and daughters of the Swiss breed cows, taking into account their milk productivity qualities. The study was performed on 111 cows of the Swiss breed on a large dairy. The observation group I included 51 cow-mothers of the Swiss breed; group II – 60 cow-daughters of the Swiss breed. In a study of the polymorphism of the kappa-casein gene in cow-mothers and cow-daughters of the Swiss breed, the dominance of allele B (0.73 and 0.70) was found, which was registered more than two times more often than allele A. The incidence of genotypes AA – AB – BB in cow-mothers of the Swiss breed was as follows: 5.9% – 43.1% – 51.0% with indicators of observed heterozygosity 0.43 and expected heterozygosity 0.40. In cow-daughters of the Swiss breed the frequency of the BB genotype was the same, but, genotype АА was registered almost twice as often, with lower indicators of observed heterozygosity and smaller increases of indicators of expected heterozygosity than in cow-mothers. Cow-mothers of the Swiss breed with the AA genotype, in comparison with the AB genotypes, had higher milk yields during lactation (by 43%), fat production (by 86.9%), ratio of fat to protein (by 40.5%). Also note, the cow-mothers of the Swiss breed with the AA genotype, in comparison with the BB genotypes, had reliably high rates of fat to protein (by 35.8%) and only a trend to higher fat production; fat and protein. The production of fat in dairy cows-daughters with the BB genotype was higher than with the AA genotype, but only at the level of tendency. The correlation analysis showed that the AA genotype of the kappa-casein gene in cow-mothers of the Swiss breed was associated with the duration of lactation, indicators of milk yield during lactation, fat production, fat content and protein in milk with registration of reliable and positive coefficients of correlation. The genotypes in cow-daughters did not have a reliable correlation with the duration of lactation and fat or protein content in milk. The results of the kappa-casein gene polymorphism study indicated that the AA genotype of cow-mothers of the Swiss breed was associated with higher productive milk qualities which should be taken into account when forming a highly productive herd of cattle of the Swiss breed under intensiveoperative technology at a large-scale dairy unit.

Genotyping of “Ukrainian” water buffaloes according β-CN (A2-milk), CSN3 and βLG genes

Buffalo breeding in Ukraine is an ancient traditional branch of animal husbandry of the Crimean Tatars and Rusyns of Transcarpathia. Basically, "Ukrainian" buffaloes belong to the river buffalo (Bubalus bubalis) and are bred for dairy and meat production. Polymorphism of genes associated with dairy productivity will allow breeding buffaloes taking into account the “desired” genotypes in relation to economically useful traits. The paper dwells on studying allelic polymorphisms of beta-casein (β-CN), kappa-casein (CSN3) and beta-lactoglobulin (β-LG) genes in population of water buffaloes bred in Ukraine using PCR followed by restriction hydrolysis of the formed fragments (PCR-RFLP). Results of study of the “Ukrainian” population of water buffaloes are discussed, namely: the frequency of genotypes and alleles at the loci of beta-casein, kappa-casein and beta-lactoglobulin genes. Amplified fragment β-CN with the length of 121 bp was digested with DdeI restriction enzyme. A feature of the allelic spectrum of the beta-casein gene (β-CN) in the studied population was absence of A1 allele. All animals carried the β-CNA2A2 genotype of beta-casein gene, respectively, β-CNA2 allele frequency was 1.0. For the CSN3 gene, an amplified fragment in 273 bp was digested with HinfI restriction enzyme. A 100% predominance of animals with the most preferred homozygous CSN3BB genotype was revealed. During the β-LG gene study process, an amplified fragment with a size of 247 bp was digested with HaeIII. It has been determined that the most frequent was allele βLGA and genotype βLGAA of beta-lactoglobulin gene (0.96 and 0.92, respectively). Heterozygous β-LGAB genotype is present in 8 % of buffaloes. The research results are of interest in the field of molecular genetic analysis of the buffalo genome, which are the source of specific properties. The data obtained can be useful for preserving and increasing the genetic diversity of the “Ukrainian” population of water buffaloes, as well as for obtaining valuable products from buffaloes.