The influence of an isocaloric substitution of soya bean oil for carbohydrates and of the nutrient density of the feed on growth and efficiency of energy utilization in broiler chickens.

Abstract

From 5 weeks until 7 weeks old, broiler chickens were given 8 diets (crude protein 15.1 g/40 g) with metabolizable energy 1392, 1333, 1274, 1214, 1374, 1315, 1255 and 1196 kJ/40 g; in the last 4 diets (high-fat diets) 6 g of soya bean oil was used to replace an isoenergetic amount of carbohydrates (15.4 g) per 40 g basal diet. A decrease in the dietary energy from carbohydrates resulted in lower energy retention, mainly as a result of lower fat deposition. Isoenergetic replacement of carbohydrate by the soya bean oil had no effect on body composition but increased rate of gain and energy retention, and thus increased the efficiency of utilization of metabolizable energy. In another experiment with 5-week-old broilers, the effect of an isoenergetic replacement of carbohydrate by soya bean oil, using 2 different energy:protein ratios, with or without the addition of sand or cellulose as a diluent in the high-fat diets was studied. The replacement of carbohydrate by fat resulted again in improved efficiency of energy utilization. The diluent had no effect on the efficiency of energy utilization in the high-fat diets. Reducing the energy:protein ratio increased rate of gain, but also led to less efficient energy utilization as a result of a lower deposition of carcass fat. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Effect of Feeding Different Levels of Maize Oil on Performance of Broiler Chicks

“…As the result of this, the birds fed the diet with the highest incorporation level of maize oil had significantly (P<0.01) the lowest total heat production (Kcal/chick), together with the highest level of energy retention and the highest percentage of energy utilization. These results were in line with other finding (Carew and Hill, 1964;Fuller and Rendon, 1979;Grimbergen et al, 1982;El-Tazi, 2001) who indicated that, energy from dietary fat sources would improved energy retention and increased the efficiency of energy utilization by broiler chickens. This effect is attributed to the comparatively low heat increment with the diets containing fat, as a result of the efficient utilization of fatty acids for lipogenesis (Blaxter, 1989).…”

Qualité des viandes de volaille : le rôle des matières grasses alimentaires

“…Une réduction de la synthèse d'acides gras devrait donc conduire à des dépôts réduits. Or, à quantité égale d'aliment ingéré, la croissance du poulet et la rétention d'énergie augmentent avec des aliments dont on a substitué une partie des glucides par des lipides (substitution isoénergétique), mais sa composition corporelle n'est pas modifiée (Grimbergen et al 1982). La diminution de la synthèse hépatique pourrait être compensée par le dépôt direct des acides gras absorbés.…”