Mossab A, Hallouis J M, Lessire M
Institut National de la Recherche Agronomique, Centre de Tours, Station de Recherches Avicoles 37380, Nouzilly, France.
Poult Sci. 2000 Sep;79(9):1326-31. doi: 10.1093/ps/79.9.1326.
The experiment was conducted to determine the apparent metabolizable energy and apparent fatty acid digestibility of tallow and soybean oil (8% of the basal diet) in young (1 and 3 wk of age) turkeys compared with young chickens. At 1 wk of age, turkeys used fats, particularly saturated fats, more efficiently than young chickens (i.e., total fatty acid digestibility was 96.5 vs. 86.4% for soybean oil and 75.0 vs. 49.1% for tallow). This difference between the two species disappeared at 3 wk of age, when there was an increase (95.7 vs. 99.3% for soybean oil and 64.0 vs. 69.7% for tallow) in fat utilization in young chickens, whereas in turkeys it remained constant (96.5 vs. 99.3% for soybean oil and 75 vs. 69.3% for tallow). This result suggests a greater and earlier maturity of the digestive system for fat utilization in turkeys than in young chickens. This efficient utilization of saturated fatty acids in turkeys seemed to depend more on the fat origin than on bird age, because it remained constant with age (91.4 vs. 96%) when saturated fatty acids were provided by soybean oil, and decreased (particularly for C18:0: 5.08 vs. 35.8%) when saturated fatty acids were provided by tallow. In turkeys, fluctuations in secretion of bile salts or in lipase activity during the trial period may have caused the lower stearic acid digestibility at 3 wk of age. The present study revealed a difference in fat utilization between turkeys and young chickens. For higher validity of the digestibility of fats, it would be preferable to use turkeys to derive metabolizable energy and fatty acid digestibility of fat values in formulating turkey diets.
进行该实验是为了测定与雏鸡相比，幼龄（1周龄和3周龄）火鸡对牛脂和大豆油（占基础日粮的8%）的表观代谢能和表观脂肪酸消化率。在1周龄时，火鸡利用脂肪，尤其是饱和脂肪的效率高于雏鸡（即大豆油的总脂肪酸消化率分别为96.5%和86.4%，牛脂分别为75.0%和49.1%）。当雏鸡脂肪利用率提高（大豆油分别为95.7%和99.3%，牛脂分别为64.0%和69.7%）时，两个物种之间的这种差异在3周龄时消失，而火鸡的脂肪利用率保持不变（大豆油分别为96.5%和99.3%，牛脂分别为75%和69.3%）。这一结果表明，火鸡消化系统对脂肪利用的成熟度比雏鸡更高且更早。火鸡对饱和脂肪酸的这种高效利用似乎更多地取决于脂肪来源而非禽龄，因为当由大豆油提供饱和脂肪酸时，其随年龄保持不变（分别为91.4%和96%），而当由牛脂提供饱和脂肪酸时则下降（特别是对于C18:0：分别为5.08%和35.8%）。在火鸡中，试验期间胆汁盐分泌或脂肪酶活性的波动可能导致了3周龄时硬脂酸消化率较低。本研究揭示了火鸡和雏鸡在脂肪利用方面的差异。为了使脂肪消化率具有更高的有效性，在配制火鸡日粮时，最好用火鸡来确定脂肪的代谢能和脂肪酸消化率。
