Leeson S, Atteh J O
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Poult Sci. 1995 Dec;74(12):2003-10. doi: 10.3382/ps.0742003.
Two experiments were carried out with young, Large White male turkey poults maintained in either floor pens or metabolism cages. In Experiment 1, poults were fed isoenergetic diets containing either no supplemental fat, or 5% of either tallow, corn oil, soybean oil, animal-vegetable blend fat, or canola oil. Poults generally ate less of the fat-supplemented diets and showed improved feed utilization, although weight gain was little affected. There was improved fat retention when vegetable oils were used (P < .01) and this was reflected in a slight improvement in diet energy level (P > .05). Poults fed tallow or animal-vegetable blend fat also excreted most fat. Diet had no effect (P > .05) on apparent retention of calcium or phosphorus, although retention of magnesium was less with more saturated fats. In Experiment 2, poults were fed diets containing palmitic acid, oleic acid, or a 50:50 (wt/wt) mixture of these fatty acids. There was a reduction (P < .05) in apparent retention of nitrogen, magnesium, calcium, and fat for poults fed palmitic acid, oleic acid, or the mixture. Mixing palmitic acid with oleic acid corrected some of these problems. However, reduced mineral retention was not reflected in any change in levels of bone ash, calcium, or phosphorus. Feeding palmitic acid did result in the most dramatic reduction of bone magnesium content (P < .05). It is concluded that turkey poults, like chicks, are less able to digest saturated fatty acids, and that such undigested fats can lead to reduced retention of some minerals through increased soap formation. However, there is no direct evidence that such soap formation causes a major change in bone calcium or phosphorus content or in gross bone development or poult well-being.
用幼年大白雄性火鸡雏进行了两项实验，这些雏鸡饲养在地面围栏或代谢笼中。在实验1中，给雏鸡饲喂等能量日粮，日粮中要么不添加脂肪，要么添加5%的牛脂、玉米油、大豆油、动植物混合脂肪或菜籽油。雏鸡一般较少采食添加脂肪的日粮，饲料利用率提高，不过体重增加受影响较小。使用植物油时脂肪保留率提高（P < 0.01），这反映在日粮能量水平略有提高（P > 0.05）。饲喂牛脂或动植物混合脂肪的雏鸡也排泄出最多的脂肪。日粮对钙或磷的表观保留率没有影响（P > 0.05），不过饱和脂肪含量越高，镁的保留率越低。在实验2中，给雏鸡饲喂含棕榈酸、油酸或这两种脂肪酸50:50（重量/重量）混合物的日粮。饲喂棕榈酸、油酸或混合物的雏鸡，氮、镁、钙和脂肪的表观保留率降低（P < 0.05）。将棕榈酸与油酸混合可纠正其中一些问题。然而，矿物质保留率降低并未反映在骨灰、钙或磷水平的任何变化上。饲喂棕榈酸确实导致骨镁含量大幅降低（P < 0.05）。得出的结论是，火鸡雏鸡与雏鸡一样，消化饱和脂肪酸的能力较差，这种未消化的脂肪会通过增加皂类形成导致一些矿物质的保留率降低。然而，没有直接证据表明这种皂类形成会导致骨钙或磷含量、骨骼总体发育或雏鸡健康状况发生重大变化。
