Response of early weaned piglets to graded levels of dietary cobalamin

Abstract

House, J. D. and Fletcher, C. M. T. 2003. Response of early weaned piglets to graded levels of dietary cobalamin. Can. J. Anim. Sci. 83: 247-255. The water-soluble vitamin cobalamin plays a central role as a co-factor in key pathways of energy and protein metabolism. The dietary requirement of this vitamin for the young pig (5-10 kg) has been estimated at 17.5 µg kg -1 , but it is derived from estimates made over 40 yr ago. In light of changes in swine production, including the selection for high lean potential genotypes and the move to earlier weaning times, a reassessment of the adequacy of current cobalamin estimates is warranted. To this end, two trials were conducted to test the following alternate hypothesis: The current National Research Council (NRC 1998) estimated cobalamin requirement for the 5-to 10-kg early-weaned piglet is inadequate to maintain optimal cobalamin status, as reflected by growth, feed conversion efficiency, plasma cobalamin and plasma homocysteine concentrations. In trial 1, 60 Cotswold pigs (17 ± 1 d, equal males and females) were randomly assigned to receive diets, formulated with ingredients essentially devoid of cobalamin, and containing either 0, 35, 70, 105, or 140 g crystalline cobalamin kg -1 . After 15 d, growth, feed intake and feed conversion efficiency were not significantly different (P > 0.05) between the dietary cobalamin levels. However, plasma cobalamin was significantly lower (49.9 vs 186.7, 168.0, 164.7, and 178.7 pg mL -1 ; SEM 17.3; P < 0.05) and homocysteine was significantly higher (34.5 vs. 22.5, 26.0, 24.7, and 23.4 µmol L -1 ; SEM 2.9; P < 0.05) in piglets consuming diets containing 0 vs. 35, 70, 105 and 140 µg crystalline cobalamin kg -1 , respectively. Trial 2 retained the same study design as trial 1, but added dietary cobalamin concentrations were equivalent to 0, 10, 20, 30, and 40 g kg -1 . The observed pattern of responses in plasma cobalamin and homocysteine support a requirement of added cobalamin in excess of 30 µg kg -1 of diet. Taken together, the data support a requirement for the addition of 35 µg crystalline cobalamin kg -1 of a diet formulated with ingredients essentially devoid of natural cobalamin for the early-weaned piglet between 5 and 10 kg, a value that is double the current NRC requirement. In addition, the current study uses changes in the plasma concentration of the metabolite homocysteine as a novel approach for the estimation of the dietary requirement for cobalamin in animals. On estime que le jeune porc (de 5 à 10 kg) a besoin de 17,5 µg de cette vitamine par kilo d'aliment, mais cette estimation remonte à plus de 40 ans. La production porcine ayant évolué, notamment par la sélection d'animaux à viande plus maigre et par un sevrage plus rapide, il conviendrait de la revoir. Les auteurs ont effectué deux essais pour vérifier l'hypothèse suivante : la recommandation actuelle du NRC (1998) sur la quantité de cobalamine dont les porcelets sevrés jeunes ont besoin ne permet pas de maintenir un bilan optimal de cette vitamine, comme en...

Methionine, folic acid and vitamin B12in growing-finishing pigs: Impact on growth performance and meat quality

“…Overall, during the whole experimental period, plasma vitamin B 12 concentrations in V1 (136.8 + 4.7 pM) and V2 (156.8 + 6.6 pM) pigs were approximately 35% and 54% higher, respectively, than for V0 (101.6 + 3.5 pM) (Figure 1). Such response of plasma vitamin B 12 to dietary cyanocobalamin is in line with results reported for post-weaning pigs by House and Fletcher (2003), where effects on plasma vitamin B 12 were observed between 0 and 35 mg/kg with no further significant increase beyond 35 and up to 140 mg/kg of dietary cyanocobalamin. However, the present results differ from recent observations in gilts (Simard et al 2007) showing that the concentration of cyanocobalamin, which maximised plasma vitamin B 12 , was estimated at 164 mg/kg.…”

“…The present increased importance of vitamin B 12 on homocysteine response during the finishing period might be in line with the previously mentioned discrepancy of plasma vitamin B 12 responses to dietary cyanocobalamin between piglets, growing-finishing pigs and gilts. In fact, the marginal plasma homocysteine response in V2 vs. V1 pigs during the growing period is consistent with the optimal dietary cyanocobalamin of 35 mg/kg reported by House and Fletcher (2003) for young piglets using plasma homocysteine as a criterion. In contrast, the homocysteine response of V2 over V1 pigs during the finishing period (i.e.…”

Homocysteine metabolism, growth performance, and immune responses in suckling and weanling piglets1

“…Along with the liver content of this vitamin, pHcy appears therefore as a relevant and reliable indicator of B 12 status. This is in agreement with House and Fletcher (2003) who used pHcy as a criterion to determine B 12 requirement for post-weaned piglets.…”

Enhancing the vitamin content of meat and eggs: Implications for the human diet

“…Research in early-weaned piglets has shown that current estimates of vitamin B 12 requirements are too low for this class of pig (House and Fletcher 2003), as evidenced by their increased plasma homocysteine concentrations and low plasma vitamin B 12 levels. In this previously cited study (Giguère et al 2005), the vitamin B 12 concentrations in meat increased as dietary B 12 increased.…”