Cu, Zn and Se Deficiency of Sucked Veal Calves in the Western Massif Central of France

摘要

Sucked veal calves maintained under intensive conditions of farming, i.e. housed in individual boxes with muzzles produced a pale and tender meat that is greatly appreciated by the consumers. Recently the European regulations have ordered to modify the housing conditions, to introduce fibrous components in the milk based diet of these calves and to prohibit the use of muzzles. Since, the application of these new practices the farmers noticed the appearance of behavioural troubles, which are able to modify the quality of the meat of the calves. In order to investigate the possibility of a nutritional or biochemical origin for these behavioural modifications, we compared the serum levels of Cu, Zn and Se between a group of 30 Limousine sucked veal calves presenting troubles of behaviour and a control group (60 calves) which did not present any alteration of behaviour. The animals have been divided into 2 groups GT1 and GT2 with different techniques of calving and were compared within these 2 groups. They have been tested at 4 sampling dates (D15, D60, D90 and D120) after birth. The determinations of Cu, Zn and Se levels were performed by Electrothermal Atomic Absorption Spectrophotometry EAAS with a Zeeman background correction. The Cu values at D15 and D120 in the experimental group were significantly lower than those of the control group (p<0.05). No significant differences in Cu values were noted between GT1 and GT2 groups throughout the study. It was only at D90 in Zn and Se values that a significant difference (p<0.05) appeared for the group GT1 compared to the group GT2. The Zn and Se values of the experimental group were lower than those of the control group throughout the study with a significant difference (p<0.01) at D60 for Zn and during all the study for Se. A Cu and Se deficiency associated with sub normal levels of Zn especially at D60 may be involved in the behavioural troubles of calves under the new conditions of farming. The different conditions of farming of groups GT1 and GT2 does not involved in these abnormalities of behaviour. The importance of the maternal supplementation with trace elements during the late pregnancy may partially explain this syndrome. The Cu and Zn levels of the experimental group at D120 can explain the Cu-Zn antagonism.