Effets de l'adjonction d'huile de maïs à un régime alimentaire pour veaux de boucherie : I. Conséquences zootechniques

Abstract

Eighty young male calves (French Friesian breed) were used to determine linoleic acid [C18 : 2 (n-6)] requirements and were allocated to one of the four following regimens : Group (1) : milk substitute diet without soya lecithin (diet A) containing 2.6 % of lipids as linoleic acid ; Group (2) : same diet but with soya lecithin (diet B) including 3.5 % of lipids as linoleic acid ; Group (3) : same diet as in group 2 (diet B) but additionally, 5 ml of com oil were given on each morning feeding starting day 63 after the beginning of the experiment ; Group (4) : same diet as in group 3 but 5 ml of com oil were given starting on day 6. Both rate and efficiency of live-weight gain were improved by additionnal com oil. This increase was only significant (p < 0,05) in group 3. There were no significant differences between groups for any of the carcass characteristics studied. Before 55 days of age, polyinsaturated fatty acids requirements were met by both diets (with or without soya lecithin) which delivered approximately 1.2 to 1.6 % of total energy as linoleic acid. For calves older thas 2 months, linoleic acid requirements seemed to be within 1.8-2.1 % of total energy. Addition of 5 ml of com oil to diet B starting on day 6 (group 4) induced an excess of linoleic acid and thus reduced the mean growth rate of the individuals.