Free Access
Reprod. Nutr. Dev.
Volume 45, Number 4, July-August 2005
Page(s) 453 - 467
Reprod. Nutr. Dev. 45 (2005) 453-467
DOI: 10.1051/rnd:2005038

Nutritional value of meat: the influence of nutrition and physical activity on vitamin B12 concentrations in ruminant tissues

Isabelle Ortigues-Martya, Didier Micola, Sophie Prachea, Dominique Doziasb and Christiane L. Girardc

a  Unité de Recherches sur les Herbivores, INRA, Theix, 63122 Saint-Genès-Champanelle, France
b  Domaine Expérimental INRA du Pin au Haras, 61310 Le Pin-au-Haras, France
c  Centre de Recherche et de Développement sur le Bovin Laitier et le Porc, Agriculture et Agroalimentaire Canada, 2000 route 108 Est, CP 90, Lennoxville, Québec, Canada

(Received 13 January 2005; accepted 23 March 2005)

Abstract - An important nutritional characteristic of ruminant meat is its high content in vitamin B12. The variability of these contents is not known. Three studies were been set up in order to test the influence of the animal species (2 studies on Charolais steers slaughtered at 30-32 months of age, n = 24 and n = 30 and a third one on lambs slaughtered at 4.5 months of age, n = 21), of the nature of the diet (grass vs. maize silage, lucerne or concentrate diets) and of physical activity (without or with walking) on the vitamin B12 contents of different muscle types (rather oxidative (Rectus Abdominis, RA), intermediate (Longissimus Dorsi, LD), or glycolytic (Semi Tendinosus, ST)) and on the liver. The animals were supplemented in macro and trace minerals according to usual feeding practices in France in order to theoretically avoid any risk of deficiency. For this reason, cobalt allowances, which are necessary for the ruminal synthesis of vitamin B12, could differ among treatments. The results indicate the following: (1) cobalt allowances varied widely among treatments, from (sub-)deficient to plethoric allowances, influencing vitamin B12 contents of the liver, and muscles (only in case of deficiency), (2) the effects of dietary treatments or of physical exercise were essentially related to differences in cobalt allowances, (3) the oxidative type muscle (RA) showed contents which were double those in glycolytic type muscle (RA 10.8 vs. ST 5.0 ng·g-1) and (4) vitamin B12 contents of raw muscles were lower than the values indicated in tables of feed composition for humans for cooked meat (0.5 to 1 vs. 2 to 3 $\mu$g·100 g-1).

Key words: meat / ruminant / muscle / liver / vitamin B12 / nutritional value / nutrition

Corresponding author: Isabelle Ortigues-Marty

© INRA, EDP Sciences 2005