2. Arunvipas, P., Dohoo, I. R., Vanleeuwen, J. A., Keefe, G. P., 2003: The effect of non-nutritional factors on milk urea nitrogen levels in dairy cows in Prince Edward Island, Canada. Prev. Vet. Med., 59, 1—2, 83—93. DOI: 10.1016/s0167-5877(03)00061-8.
3. Baul, S., Cziszter, L. T., Acatincai, S., Cismas, T., Gavojdian, D., Tripon, I., Erina, S., Buzamat, G., 2013: Effect of parity on dynamics of milk yield and composition during normal lactation in dairy cows. J. Anim. Sci. Biotechnol., 46, 2, 285—289.
4. Bauman, D. E., Griinari, J. M., 2003: Nutritional regulation of milk fat synthesis. Annu. Rev. Nutr., 23, 203—227. DOI: 10.1146/annurev.nutr.23.011702.073408.
6. Bondan, C., Folchini, J. A., Noro, M., Quadros, D. L., Machado, K. M., González, F. H. D., 2018: Milk composition of Holstein cows: A retrospective study. Cienc. Rural, 48, 12, 1—8. DOI: 10.1590/0103-8478cr20180123.
7. Cao, Z., Huang, W., Wang, T., Wang, Y., Wen, W., Ma, M., Li, S., 2010: Effects of parity, days in milk, milk production and milk components on milk urea nitrogen in Chinese Holstein. J. Anim. Vet. Adv., 9, 4, 688—695. DOI: 10.3923/java.2010.688.695.
9. Čobanović, K., Kučević, D., Plavšić, M., Bogdanović, V., 2017: Impact of non-nutritional factors on milk urea concentration and its relationship with production and fertility traits in Vojvodina dairy herds. Mljekarstvo, 67, 4, 267—276. DOI: 10.15567/mljekarstvo.2017.0404.
10. Godden, S. M., Lissemore, K. D., Kelton, D. F., Leslie, K. E., Walton, J. S., Lumsden, J. H., 2001: Factors associated with milk urea concentrations in Ontario dairy cows. J. Dairy Sci., 84, 1, 107—114. DOI: 10.3168/jds.S0022-0302(01)74458-X.
11. Hojman, D., Kroll, O., Adin, G., Gips, M., Hanochi, B., Ezra, E., 2004: Relationship between milk urea and production, nutrition and fertility trails in Israeli dairy herd. J. Dairy Sci., 87, 4, 1001—1011. DOI: 10.3168/jds.S0022-0302(04)73245-2.
13. Idamokoro, E. M., Muchenje, V., Masika, P. J., 2017: Yield and milk composition at different stages of lactation from a small herd of Nguni, Boer, and non-descript goats raised in an extensive production system. Sustainability, 9, 6, 1000. DOI: 10.3390/su9061000.
14. Jílek, F., Řehák, D., Volek, J., Štípková, M., Němcová, E., Fiedlerová, M., Rajmon, R., Švestková, D., 2006: Effect of herd, parity, stage of lactation and milk yield on urea concentration in milk. Czech J. Anim. Sci., 51, 12, 510—517. DOI: 10.17221/3971-CJAS.
15. Johnson, R. G., Young, A. J., 2003: The association between milk urea nitrogen and DHI production variables in western commercial dairy herds. J. Dairy Sci., 86, 9, 3008—3015. DOI: 10.3168/jds.S0022-0302(03)73899-5.
17. Maas, J. A., France, J., McBride, B. W., 1997: Model of milk protein synthesis. A mechanistic model of milk protein synthesis in the lactating bovine mammary gland. J. Theor. Biol., 187, 3, 363—378. DOI: 10.1006/jtbi.1997.0437.
18. Marenjak, T., Poljičak-Milas, N., Stojević, Z., 2004: The aim of urea determination in cows’ milk (In Croatian, English abstract). Praxis Veterinaria, 52, 3, 233—241.
19. Miglior, F., Sewalem, A., Jamrozik, J., Lefebvre, D. M., Moore, R. K., 2006: Analysis of milk urea nitrogen and lactose and their effect on longevity in Canadian dairy cattle. J. Dairy Sci., 89, 12, 4886—4894. DOI: 10.3168/jds.S0022-0302(06)72537-1.
21. Nyamushamba, G. B., Halimani, T. E., Imbayarwo-Chikosi, V. E., Tavirimirwa, B., 2014: Comparative evaluation of non-genetic factors affecting milk yield and composition of Red Dane and Jersey cattle in Zimbabwe. Springer Plus, 3, 88. DOI: 10.1186%2F2193-1801-3-88.
22. Pytlewski, J., A-ntkowiak, I., Skrzypek, R., 2010: Relationships between somatic cells counts and urea level in the milk of polish Holstein-Friesian cows of black-and-white and red-white varieties. Acta Sci. Pol., 9, 2, 39—50.
23. Rajala-Schultz, P. J., Saville, W. J., 2003: Sources of variation in milk urea nitrogen in Ohio dairy herds. J. Dairy Sci., 86, 5, 1653—1661. DOI: 10.3168/jds.S0022-0302(03)73751-5.
24. Stoop, W. M., Bovenhuis, H., Van Arendonk, J. A. M., 2007: Genetic parameters for milk urea nitrogen in relation to milk production traits. J. Dairy Sci., 90, 4, 1981—1986. DOI: 10.3168/jds.2006-434.17369239
25. Tripathi, M. K., 2014: Effect of nutrition on production, composition, fatty acids and nutraceutical properties of milk. J. Adv. Dairy Res., 2, 2, 1—11. DOI: 10.4172/2329-888X.1000115.
26. Vijayakumar, M., Park, J. H., Ki, K. S., Lim, D. H., Kim, S. B., Park, S. M., et al., 2017: The effect of lactation number, stage, length, and milking frequency on milk yield in Korean Holstein dairy cows using automatic milking system. Asian-Australas. J. Anim. Sci., 30, 8, 1093—1098. DOI: 10.5713/ajas.16.0882.549448228423887
27. Yoon, J. T., Lee, J. H., Kim, C. K., Chung, Y. C., Kim, C. H., 2004: Effects of milk production, season, parity and lactation period on variations of milk urea nitrogen concentration and milk components of Holstein dairy cows. Asian-Australas. J. Anim. Sci., 17, 4, 479—484. DOI: 10.5713/ajas.2004.479.