Influence of complex genotypes of CSN2/CSN3 genes on economically useful traits of holmogor cows

Objective. To reveal the influence of complex genotypes of beta-casein and kappa-casein genes on milk productivity indices of Kholmogorsk cows. Methods. DNA extraction was carried out using the reagent kit “MagnoPrime VET”. Allele-specific PCR (AS-PCR) was used to determine allele polymorphism of CSN2 gene. Determination of DNA restriction fragments by visualizing the results by horizontal electrophoresis with 3% agarose gel. Restriction fragment length polymorphism (PCR-PDRF) was used to determine the A and B alleles of the CSN3 gene. Results. In the course of molecular genetic analysis of Kholmogor breed animals, polymorphism of genetic variants of beta-casein (CSN2) and kappa-casein (CSN3) proteins was detected, and the frequency of occurrence of different complex genotypes was studied. The most common complex genotype was found to be A1A2/AA, occurring in 41.15% of the animals, representing 158 individuals. The least common genotype combinations were A1A1/BB and A1A2/BB with a total number of 8 animals (less than 2.5%). No individuals with A2A2/BB genotypes were found. Animals with a combination of A2A2/AA genotypes had the best milk yield, fat mass fraction, protein mass fraction, milk fat quantity and milk protein quantity among heifer cows. The lowest values for mass fraction of protein, milk fat and milk protein had animals with A1A1/AB genotype combination. Among all the studied herd, cows with complex genotype A2A2/AA had the best result in many indicators of milk productivity. Whereas the lowest signs of milk productivity were shown by animals with a combination of A1A1/ BB genotypes. Scientific novelty consisted in the study of the relationship between the complex genotypes of betacasein, kappa-casein genes and their influence on milk productivity of Kholmogorsk cows. At the moment, there are very few scientific works devoted to the study of complex genotypes of these genes, and there are no studies conducted on the Kholmogorsk breed of cattle.

1. Amalfitano N., Stocco G., Maurmayr A. et al., Quantitative and qualitative detailed milk protein profiles of 6 cattle breeds: Sources of variation and contribution of protein genetic variants, Journal of Dairy Science, 2020, Vol. 103, pp. 11190–11208, DOI: 10.3168/jds.2020-18497.

2. Citek J., Hanusova L., Liskovcova L. et al., Polymorphisms in CSN3, CSN2 and LGB genes and their relation to milk production in dairy cattle in the Czech Republic, Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2019, Vol. 67(1), pp. 19 – 24, DOI: 10.11118/actaun201967010019.

3. Ardicli S., Aldevir O., Aksu E. et al., The variation in the beta-casein genotypes and its effect on milk yield and genomic values in Holstein-Friesian cows, Animal Biotechnology, 2023, Vol. 34, pp. 4116–4125, DOI: 10.1080/10495398.2023.2267614.

4. Fiedorowicz E., Markiewicz L.H., Sidor K. et al., The influence of breast milk and infant formulae hydrolysates on bacterial adhesion and Caco-2 cells functioning, Food Research International, 2016, Vol. 89, pp. 679–688, DOI: 10.1016/j.foodres.2016.09.022.

5. Milan A.M., Shrestha A., Karlstrom H.J. et al., Comparison of the impact of bovine milk β-casein variants on digestive comfort in females self-reporting dairy intolerance: a randomized controlled trial, The American Journal of Clinical Nutrition, 2020, Vol. 111, pp. 149–160, DOI: 10.1093/ajcn/nqz279.

6. Amalfitano N., Mota L.F.M., Rosa G.M. et al., Role of CSN2, CSN3, and BLG genes and the polygenic background in the cattle milk protein profile, Journal of Dairy Science, 2022, Vol. 105, pp. 6001–6020, DOI: 10.3168/jds.2021-21421.

7. Sebastiani C., Arcangeli C., Ciullo M. et al., Frequencies Evaluation of β-Casein Gene Polymorphisms in Dairy Cows Reared in Central Italy, Animals, 2020, Vol. 10(2), pp. 1–7, DOI: 10.3390/ani10020252.

8. Cieslinska A., Fiedorowicz E., Rozmus D. et al., Does a Little Difference Make a Big Difference? Bovine β-Casein A1 and A2 Variants and Human Health-An Update, International Journal of Molecular Sciences, 2022, Vol. 23, pp. 15637, DOI: 10.3390/ijms232415637.

9. Snigirev S.O., Lamonov S.A., Skorkina I.A. et al., Vestnik Michurinskogo gosudarstvennogo agrarnogo universiteta, 2023, No. 1(72), pp. 86–89. (In Russ.)

10. Asledottir T., Le T.T., Poulsen N.A. et al., Release of β-casomorphin-7 from bovine milk of different β-casein variants after ex vivo gastrointestinal digestion, International Dairy Journal, 2018, Vol. 81, pp. 8–11, DOI: 10.1016/j.idairyj.2017.12.014 (In English)

11. Thiruvengadam M., Venkidasamy B., Thirupathi P. et al., β-Casomorphin: A complete health perspective, Food Chemistry, 2021, Vol. 337, pp. 127765, DOI: 10.1016/j.foodchem.2020.127765.

12. Volkandari S.D., Indriawati I., Margawati E.T., Genetic polymorphism of kappa-casein gene in Friesian Holstein: a basic selection of dairy cattle superiority, Journal of the Indonesian Tropical Animal Agriculture, 2017, Vol. 42, pp. 213–219, DOI: 10.14710/jitaa.42.4.213-219.

13. Barbosa S.B.P., Araujo I.I.M., Martins M.F. et al., Genetic association of variations in the kappa-casein and β-lactoglobulin genes with milk traits in girolando cattle, Revista Brasileira de Saúde e Produção Animal, 2019, Vol. 20, pp. 1–12, DOI: 10.1590/S1519-9940200312019.

14. Gatilova E.V., Efimova L.V., Ivanova O.V., Vestnik APK Stavropol’ya, 2020, No. 4(40), pp. 42–47, DOI: 10.31279/2222-9345-2020-9-40-42-47 (In Russ.)

15. Sudarev N.P., Chargeishvili S.V., Marzanov N.S., Agrarnyy Vestnik Verkhnevolzh’ya, 2024, No. 1, pp. 78–83, DOI:10.35523/2307-5872-2024-46-1-78-83 (In Russ.)

16. Bangar Y.C., Magotra A., Chauhan A., Genetic polymorphisms of kappa casein gene and its association with milk and composition traits in cows: An updated meta-analysis, Meta Gene, 2021, Vol. 30, pp. 100948, DOI: 10.1016/j.mgene.2021.100948.