Serum Vitamin B₁₂ Levels in Dairy Cows before and after Parturition

Abstract

Summary Serum vitamin B12 levels were determined by radioisotope assay in 8 clinically normal Ayrshire cows 1–3 weeks prepartum and again 2–5 weeks postpartum. The mean ± SD prepartum level, 395 ± 129 pg/ml, was significantly higher than the postpartum level, 238 ± 50 pg/ml (P < 0.01). Thus the present finding supports the hypothesis that body stores of vitamin B12 in the dairy cow may be depleted during the heavy lactation period after parturition. Zusammenfassung Vitamin‐B12‐Konzentrationen im Serum von Milchkühen vor und nach dem Abkalben Bei 8 klinisch gesunden Ayrshire Kühen wurden 1 bis 3 Wochen vor und 2 bis 5 Wochen nach dem Abkalben die Vitamin‐B12‐Konzentrationen im Serum mittels RIA bestimmt. Die präpartalen Werte (Durchschnitt ± Standardabweichung), 395 ± 129 pg/ml, waren signifikant höher als die postpartalen, 238 ± 50 pg/ml (p < 0,01). Diese Beobachtungen unterstützen die These, daß die Körperreserven an Vitamin B12 bei Milchkühen durch die hohe Laktation nach dem Abkalben erschöpft werden können. Résumé Concentrations de la vitamine B12 dans sérum de vaches avant et après le vêlage On a determine par RIA les concentrations sériques de la vitamine B12 chez 8 vaches Ayrshire cliniquement saines 1 à 3 semaines avant et 2–5 semaines après le vêlage. Les valeurs ante partum (moyenne ± déviation standard), 395 ± 129 pg/ml furent significativement plus élevées que celles relevées post partum, 238 ± 50 pg/ml (p < 0,01). Ces observations appuient la these disant que les réserves du corps en vitamine B12 chez la vache laitière peuvent être épuisées par une forte lactation après le vêlage. Resumen Concentraciones séricas de vitamina B12 en vacas lecheras antes y después del parto En 8 vacas Ayrshire clínicamente sanas se valoraron 1 hasta 3 semanas antes y 2 hasta 5 semanas después del parto los niveles séricos de vitamina B12 mediante RIA. Los valores preportales (media ± desviación estandar), 395 ± 129 pg./ml., eran significantemente mayores que los postpartales, 238 ± 50 pg./ml. (p < 0,01). Estas observaciones apoyan la tesis, de que las reservas corporales en vitamina B12 pueden ser agotadas en las vacas lecheras por medio de la lactación elevada después del parto.

Effect of Dry-Period Diet on the Performance and Metabolism of Dairy Cows in Early Lactation

“…In the present study, the serum vitamin B 12 decrease observed after parturition is in accordance with the results of Girard and Matte [55], which indicated that the serum vitamin B 12 concentration varied over time. In early lactation, the vitamin B 12 concentration was lower because of a high demand for this vitamin in the production of colostrum and milk [56] and in propionate utilization by the liver using a vitamin B 12 dependent pathway [57]. In early lactation, as observed in our study, the serum vitamin B 12 concentration stayed low and constant [58].…”

Effect of multiple intravenous injections of butaphosphan and cyanocobalamin on the metabolism of periparturient dairy cows

“…Serum cyanocobalamin concentrations are low in early lactation , and cyanocobalamin supply is considered a limiting factor for lactation performance. Methylmalonyl-CoA mutase is a cyanocobalamin-dependent enzyme that transforms methylmalonyl-CoA into succinyl-CoA; cyanocobalamin therefore plays a pivotal role in the entry of propionate into the Krebs cycle and the utilization of propionate for gluconeogenesis (Mykkänen and Korpela, 1981;Girard and Matte, 2005). These observations directly lead to the hypothesis that cyanocobalamin deficiency contributes to fat mobilization syndrome by decreasing the rate of propionate utilization for gluconeogenesis.…”

“…Cyanocobalamin is essential for gluconeogenesis from propionate (Mykkänen and Korpela, 1981;Girard and Matte, 2005), and a relative deficiency of cyanocobalamin would be expected to decrease glucose availability and affect bioenergetics and lactose synthesis because propionate is the major gluconeogenic substrate in highyielding dairy cows (Preynat et al, 2009). The higher serum glucose and insulin concentrations, the lower serum NEFA and BHBA concentrations, and higher milk lactose concentration in group C6 cows after calving in this study are consistent with increased glucose availability or increased DMI, although neither factor was directly measured in the study reported here.…”