Effets de l'incorporation de pulpe de betterave dans les aliments du porcelet et du porc en croissance : performances de croissance, digestibilité et composition corporelle

Summary — Consequences of the inclusion of sugar beet pulp in diets for early weaned and growing pigs. The effect of extrusion of wheat and of the inclusion of 6% of sugar beet pulp in a pelleted starter on the performance of the weaned piglet has been studied in two experiments. In the first experiment, 80 crossbred castrated male and female piglets weaned at 21 days of age raised individually y were used in a 2 x 2 factorial arrangement to compare their performance between weaning and 25 kg g live weight. Average feed intake was similar between treatments, but extrusion of wheat had no significant effect on growth performance and feed conversion ratio. The association of normal wheat with sugar beet pulp improved significantly growth rate (P < 0.02) and feed conversion ratio (P < 0.06), in particular during the period following immediatly weaning, ie, 193 vs 156 g/day and 193 vs 2.32, respectively. In the second experiment, 32 crossbred castrated piglets were used to evaluate faecal, then ileal digestibilities of dietary components. Extrusion did not improve digestibility. Ileal digestibility but not faecal digestibility of dry matter and energy was reduced (P < 0.001 ) by the inclusion of sugar beet pulp in the diet. Post-ileal digestibility of all dietary components was higher in animals fed fibrous diet. During the growing-finishing period between 25 and 100 kg live weight, the inclusion of a similar level of 6% of sugar beet pulp in a normal wheat based diet was tested. Piglets of the first experiment were randomly affected to one of the two diets taking into account their previous diet, sex and weight. The average daily gain for the whole period was slighly but not significantly reduced and feed conversion ratio was unchanged in animals receiving sugar beet pulp. However, feed conversion ratio expressed as digeatible energy per kg of body weight gain was reduced in animals receiving beet pulp in their diet. At slaughter, the percentage of lean meat was improved from 52.8 to 54.0% (P < 0.05) as a consequence of a linear decrease in the backfat thickness (P < 0.05) of carcasses of animals receiving sugar beet pulp. No difference in the weight of lean cuts was observed but the use of sugar beet pulp decreased significantly the weight of fat cuts (P < 0.01 It was suggested that for a similar nitrogen retention a reduction in the digestible energy intake reduces the deposition of fatty tissues but the total amount of lean meat in the carcass was not affected by the inclusion of sugar beet in the diet.