The influence of different genotypes of kappa-casein and beta-lactoglobulin on the productivity of cows of Ayrshire, Holstein and Yaroslavl breeds

Under the conditions of intensification of dairy cattle breeding, genetic markers of protein-milk content, namely allelic variants of kappa-casein and beta-lactoglobulin, are increasingly used. They are established by the method of DNA testing on blood samples of breeding animals. This method is also being introduced in our country, which is especially important when selecting breeding sires for the artificial insemination network. The purpose of the research was to study the quality indicators of milk of cows bred in the region of breeds (Ayrshire, Holstein, Yaroslavl), and the protein-milk product produced from it as cottage cheese, depending on the influence of the genotype. The research has been carried out in CJSC “Agrofirma “Pakhma” in the Yaroslavl region. The object of research was cows of Ayrshire, Holstein and Yaroslavl breeds. The sample included 99 cows, including 36 animals of Ayrshire breed, 33 Holstein and 30 Yaroslavl breed. A comparative comprehensive evaluation of the dairy productivity of cows of Ayrshire, Holstein and Yaroslavl breeds under the conditions in one herd using DNA testing has been carried out, for the entire productive period of economic use, the realization of the genetic potential has been traced. For the first time in the Yaroslavl region DNA testing of Ayrshire cows was carried out and new data on the polymorphism of the CSN3 and LGB genes in Holstein and Yaroslavl cows were obtained. The association of CSN3, LGB genotypes and complex genotypes with milk productivity and technological properties of milk has been investigated. The yield and quality of cottage cheese from the milk of cows of different breeds in association with CSN3 genotypes have been studied. As a result of studying the quality indicators of milk of cows of different breeds and the protein-milk product produced from it as cottage cheese, depending on the influence of the genotype. It has been found that cows of different breeds and different genotypes had significant differences in the quality of milk and cottage cheese produced from it, which must be taken into account when conducting breeding work with these breeds.

Effects of Beta-lactoglobulin Gene Polymorphism and Some Factors on Milk Quality and Yield in Dairy Cattle of Kashmir, India

Background: Polymorphisms in candidate beta-lactoglobulin genes are associated with traits of economic importance in cows and are related to milk composition, quality, production as well as cheese-production. The objective of the study was to evaluate the effects of breed, season and polymorphism on milk quality and yield in Jersey and Crossbred Holstein Friesian cows. Methods: The quality traits studied were fat %, lactose %, protein %, SNF, density and ash while quantity traits were average monthly milk yield, protein yield and fat yield. The beta-lactoglobulin gene exon IV (262 bp) was screened for polymorphisms by PCR-RFLP using BsuRI (Hae III) enzyme. Result: Our investigation revealed only two patterns AA and AB in both the breeds under study. BB genotype was absent. AA genotype was most abundant in Jersey cows (0.68) and crossbred HF cows (0.56). A allele frequency was highest in Crossbred HF cows (0.72) and Jersey cows (0.66). In Jersey genotype AB was observed to be responsible for high milk yield, protein and fat yield in each season whereas it was genotype AA of crossbred HF cows affecting milk yield, protein and fat yield. In crossbred HF cow, genotype effect was observed to be non-significant (p greater than 0.05) on all quality traits and effect of season was significant on lactose % and fat %. In Jersey cows, genotype and season effects were significant (P less than 0.05) on fat % concluding that the breed, season and genotype affectmilk quality and yield.

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.

Disequilibrium linkage (gametic disequilibrium) of structural genes in the bovine population

In the population of Kholmogor cattle (n=824), gametic disequilibrium was studied for alleles of the polymorphic loci β-Lg (LGB), β-Cn (CSN2) and æ-Cn (CSN3). In purebred Kholmogor cattle, the β-casein polymorphism is determined by three alleles with the frequencies of CSN2А 1 – 0.368±0.0076, CSN2А 2 – 0.497±0.0078, CSN2B – 0.136±0.0056 and the frequencies of acasein of CSN3А – 0.689 ±0.0061, CSN3B – 0.311±0.0061, respectively. The beta-lactoglobulin polymorphism is controlled by two alleles LGBA and LGBB with a frequency of 0.237±0.0048 and 0.763±0.0048, respectively. In the population of breeding plants, the gametic disequilibrium was revealed according to the alleles of loci CSN2 and LGB; CSN2 and CSN3. The factor that caused the gametic disequilibrium was probably the initial difference between native Russian cattle and black-and-white cattle of Western Europe on the basis of which the Kholmogor breed gene pool was developed. The population showed an excess of haplotypes β-CnВæ-CnВ, β-CnВβ-LgВ (the "attraction" phase), apparently inherited mainly from native Russian cattle, and β-CnА 1æ-CnА, β-CnА 2β-LgА characteristic mainly for black-and-white cattle of Western Europe and a lack of β-CnВæ-CnА, β-CnВβ-LgА (the "repulsion" phase), probably due to the low frequency of these haplotypes in both initial breeds. The role of various factors in the occurrence and maintenance of gamete disequilibrium is discussed. It is suggested that for alleles of non-linked loci, longtime retention of gametic disequilibrium in population is most likely supported by selection