Effect of MTHFR gene polymorphism and rumen-protected choline and methionine supplementation on biochemical profile, milk yield and health status during the transition period in Holstein cows

Abstract

This study tested the effects of the methylenetetrahydrofolate reductase (MTHFR) rs110692574 polymorphism and rumen-protected choline and methionine supplementation on biochemical parameters, milk yield, reproductive performance and health status during the transition period in Holstein cows raised in Türkiye. Genotypes of 356 cows were determined using the tetra-primer amplification refractory mutation system–polymerase chain reaction (ARMS-PCR) method. Following genotyping, 80 cows were selected and assigned to four groups based on nucleotide genotype at two loci (homozygous CC and heterozygous CT) and dietary supplement (choline or choline + methionine). Blood samples were collected on day 21 prepartum, on the day of parturition (day 0), and on day 21 postpartum to measure homocysteine, folic acid, vitamin B12, and non-esterified fatty acid concentrations. beta-hydroxybutyric acid (BHBA) values and production data were obtained from the farms’ routine monitoring records. Statistical analyses were performed using repeated-measures analysis of variance (ANOVA) to assess time-dependent effects, and a general linear model was used for between-group comparisons at the same time points. The frequency of the CT genotype was 12.64%. The polymorphism significantly affected folic acid and vitamin B12 concentrations across different stages of the transition period. Feed supplementation had a significant effect on folic acid concentrations on calving day and on day 21 postpartum, as well as on milk yield on days 100, 200 and 305. Moreover, the polymorphism was significantly associated with folic acid and vitamin B12 concentrations on day 21 prepartum and with BHBA values on day 7 postpartum. This variation was linked to specific health issues that could lead to decreased productivity. In conclusion, genotype-based nutritional strategies were found to play a key role in maintaining metabolic balance and enhancing productivity during the transition period.