A systematic review of effect of calving season and parity as non-genetic factors on milk production traits of cattle

Abstract

This study was carried out to systematically review the effect of calving season and parity on milk production traits. This systematic review was conducted in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Google Scholar, PubMed, ScienceDirect, and Web of Science databases were searched systematically using ‘non-genetic factors/ season of calving /parity’, ‘milk production traits’, and ‘cattle’ as keywords. The results indicated that fifteen (n = 15) articles were used from the ninety-four (n = 94) articles identified and screened. The results of this systematic review indicated that 8 out of 10 articles found milk yield to be significantly affected by parity, whereas 7 out of 13 articles indicated that calving season did not significantly affect milk yield. Out of 4 articles, 3 of them showed that parity had a significant effect on fat. Parity had a significant effect on lactose and protein, 1 of these articles investigated and found significant effect of parity and calving season on somatic cell score (SCS). Out of 13 articles, 5, 4, and 2 of these articles investigated fat, protein, and lactose respectively. The results showed that 3 articles on fat, 4 on protein and 2 on lactose were significantly affected by calving season. In conclusion, parity and calving season had a great influence on fat, protein, lactose, and SCS. Milk yield was not affected by calving season however, it was affected by parity. Thus, calving season and parity can be used to improve milk production traits.