Utilization of fats and fatty acids by turkey poults

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.