The influence of an increased cobalt supply on ruminal parameters and microbial vitamin B₁₂synthesis in the rumen of dairy cows

Abstract

The aim of the study was to examine the effects of an elevated dietary cobalt supply to dairy cows on rumen fermentation parameters and microbial vitamin B12 synthesis in the rumen. Five lactating dairy cows fitted with a ruminal and a duodenal cannula were subsequently fed either a ration containing only the native cobalt content (0.17 mg Co/ kg DM) or a ration supplemented with cobalt sulphate (0.29 mg Co/kg DM). The pH-value, the ammonia concentration as well as the concentration and the molar proportions of short chain fatty acids in the rumen were not significantly influenced by feeding the ration with the higher cobalt content. While there was no difference in microbial protein flow, the cobalamin flow at the duodenum was significantly elevated in supplemented animals (3.67 +/- 0.69 vs. 8.63 +/- 2.22 mg B12/d). The efficiency of cobalt utilisation for ruminal vitamin B12 synthesis was calculated to be 7.1 +/- 1.3% for the unsupplemented and 9.5 +/- 2.4% for the supplemented ration. Further investigation has to prove if there are any benefits for cows resulting from the elevated cobalamin synthesis measured, caused by feeding higher amounts of dietary cobalt.

Supplementing lactating dairy cows with a vitamin B12 precursor, 5,6-dimethylbenzimidazole, increases the apparent ruminal synthesis of vitamin B12

“…However, the proportion of dietary cobalt used for these synthetic processes is relatively low in sheep and cows, varying from 3% to 15% (Smith and Marston, 1970;Stemme et al, 2008;Girard et al, 2009b). In vitro studies demonstrated that addition of different bases to the culture media enhanced the synthesis of the corresponding cobamides at the expense of the other forms (Ford et al, 1955;Gawthorne, 1970b).…”

“…Indeed, in sheep, efficiency of cobalt utilization decreased as the dietary concentration of cobalt increased (Smith and Marston, 1970). In cows fed different diets, efficiency of cobalt utilization for CBL synthesis in the rumen has been reported to be 7.1%, 9.5% and 4.4% for diets providing 0.17, 0.29 and 2.5 mg of Co/kg of DM, respectively (Stemme et al, 2008;Girard et al, 2009a). Therefore, it is likely that the efficiency of bacterial utilization of cobalt for CBL synthesis is influenced by the ingredients and chemical compositions of diets and their effects on microflora and fermentation in rumen.…”

Scientific Opinion on the use of cobalt compounds as additives in animal nutrition

“…More recently, positive effects of supplementary Co were reported based on finding that minimum dietary Co required to maximise feed intake and growth performance of growing cattle finished on a corn silage-based diet was in a range between 0.16 and 0.18 mg Co/kg DM . Although recent experiment with supplementation of 0.3 mg Co/kg DM to basal diet for lactating cows did not result in any change of ruminal pH, ammonia level, molar proportion of short chain fatty acids or microbial protein flow, the Co content of basal diet used (0.17 mg Co/kg DM) was already well above currently set requirements (Stemme et al, 2008). Although recent experiment with supplementation of 0.3 mg Co/kg DM to basal diet for lactating cows did not result in any change of ruminal pH, ammonia level, molar proportion of short chain fatty acids or microbial protein flow, the Co content of basal diet used (0.17 mg Co/kg DM) was already well above currently set requirements (Stemme et al, 2008).…”

“…(Smith and Marston, 1970;Stemme et al, 2008;). Incorporation rate may be characterized by a range of 3 to 15 % and an average range of 10 to 15 %.…”

Вплив Змішанолігандного Комплексу Кобальту На Його Обмін У Організмі Високопродуктивних Корів

“…Крім того макроелементи підтримують кислотно-лужну рівновагу, оптимальний осмотичний тиск , забезпечують роботу серця, м'язової і нервової систем. Мікроелементи створюють необхідні умови для нормальної функції ферментів, гормонів, вітамінів (Cortinhas et al, 2012), знезаражують шкідливі для організму продукти обміну чи отруйні речовини (Mitchell et al, 2007;Stemme et al, 2008). Раціони годівлі високопродуктивних корів дуже часто дефіцитні по Кобальту,функція якого в тваринному організмі дуже різноманітна.…”