Vitamin B requirements and duodenal deliveries in lactating dairy cows: Organization of a limited literature

Use of organic phosphorous butafosfan and vitamin B12 combination in transition dairy cows

Phosphorus is critical for life and an indispensable element for biologically occurring organic molecules such as DNA, ATP, and phosphoproteomes. Butafosfan is a synthetically produced organic phosphorous (phosphonic acid) compound that contains 17.3% phosphorus. It does not belong to the group of biologically occurring organic phosphorous compounds. Butafosfan has been used in many animal species as a metabolic stimulant interfering with energy metabolism. Vitamin B12 (VB12) is a unique cobalt-containing vitamin. It functions as a cofactor for the enzymes methionine synthase and methyl-malonyl-CoA mutase. It is necessary for the conversion of propionate into succinyl-CoA in ruminants. A combination of butafosfan and VB12 (iBC) has been available for veterinary use since 1958 and the first publication appeared in the 1970s in cows. However, the first molecular biological studies about its mode of action appeared in early 2000s. Recent studies revealed that iBC has significant effects on carbohydrate and lipid metabolism. Investigations between 1970 and 1994 focused mainly on cows at risk of metabolic and reproductive disease in the dry period. Studies as of 2000 investigated its efficacy for the prevention and treatment of subclinical and secondary ketosis, adjunctive/supportive therapy for displaced abomasum operation, milk fever, improvement of postoperative rumen activity, uterus involution, and mastitis in transition dairy cows.

The Importance of B Vitamins in Enhanced Precision Nutrition of Dairy Cows: The Case of Folates and Vitamin B12

Dairy cow diets are generally balanced for energy and major nutrients with B vitamins generally assumed not to be limiting, in spite of their role as coenzymes, essential to many metabolic reactions in protein, carbohydrate and lipid metabolism. Assuming adequacy of B-vitamin supply may explain some of the discrepancies between the outcomes of metabolic prediction models and measured cow performance. In lactating dairy cow, the amount of B vitamins from the diet and synthesized by the ruminal microbiota is generally sufficient to prevent deficiency symptoms and, as such, is assumed to fulfill requirements. However, reports of beneficial effects of B-vitamin supplementation on dairy cow performance suggest that B-vitamin supply is sometimes lower than its needs, as an insufficient B-vitamin supply decreases metabolic efficiency by driving a shift towards alternative metabolic pathways with greater energy cost. Using information on folates and vitamin B12 illustrated how meeting dairy cow needs for B vitamins should not be overlooked in formulation of rations for lactating dairy cattle. The present review discusses current knowledge and indicates areas presently impeded by the lack of research results, especially the limitations on the ability to estimate B vitamin need and supply.

Methods and approaches to estimate B vitamin status in dairy cows: Knowledge, gaps and advances

Clinical symptoms of B vitamin deficiency are rarely observed in ruminants because these vitamins are synthesized by the rumen microbiota. However, over the last decades, numerous reports of beneficial effects on production and metabolic efficiency of dairy cows have been published supporting that, under some conditions, B vitamin subclinical deficiency is present in these animals. Due to their roles as coenzymes or cofactors in major metabolic pathways, an adequate supply in B vitamins is critical to optimize metabolic efficiency. Nowadays, taking into account the growing interest for the Smart Farming concept, fulfilling ruminant requirements for B vitamins according to their physiological stage under different feeding management cannot be neglected. In dairy cows, B vitamin supply is greatly dependent of the activity of the ruminal microbiota. Indeed, the amount of vitamins reaching the small intestine is dependent of the utilization of the vitamins provided by the diet and their synthesis by the microorganisms present in the rumen. The two major challenges faced to determine B vitamin status of ruminants are the difficulty to estimate B vitamin supply due to the lack of knowledge on factors driving the fate of B vitamins in the digestive tract, especially in the rumen, and the choice and thresholds of biomarkers reflecting adequately the animal status. The present paper aims to present the actual state of knowledge on the methodological approaches used to estimate B vitamin supply and status of ruminant and to point out future research orientations.