Tropicultura (Jan 2006)
Effet de la complémentation azotée sur les performances zootechniques de la chèvre locale
Abstract
Effects of Supplementing Grazing by Different Sources of Protein on Tunisian Goat Performances. The effects of supplementing grazing by one of three sources of protein: barley, barley + soya bean, or barley + soya bean treated with formaldehyd, were studied on body weight evolution, milk production (yield and components), and on N-NH3 concentration in the rumen juice of female goats and on growing kids. Forty-five females of the local tunisian breed were used in the experiment. All females were in the first 15 weeks of lactation. Animals were divided into three groups (1st, 2nd and 3rd) of 15 animals each. Groups were homogeneous with respect to age, lactation rank, milk yield in the first test day, and litter size. Each animal received 500 g of vetch-oat hay and 500 g of barley, barley + soya bean, or barley + treated soya bean in the 1st, 2nd and 3rd group, respectively, in addition to pasture. Protein supplementation affected (P< 0.05) growth of goat kids (116 g/day and 94 g /day for 3rd and 1st group, respectively), milk yield (88.1 l and 67.1 l for the 3rd and 1st group, respectively), and fat percentage of milk (5.2% and 4.2% for the 3rd and 1st group, respectively). The N-NH3 concentration was higher (P< 0.05) in the rumen juice of animals fed untreated soya bean than those fed treated soya bean.
