Effects of dietary sources and levels of fat on laying hens fed two levels of calcium
1989
Atteh, J.O. | Leeson, S. | Summers, J.D.
The performance, nutrient retention and bone mineralization response of 32 week-old White Leghorn laying hens to dietary animal-vegetable blend fat (AVB), soybean oil (SO), canola oil (CO) or canola soapstock (CS) at 5 or 10% inclusion level, in the presence of 3.6 or 4.2% dietary calcium was investigated over an eight-week period. Birds fed diets with supplemental CS consumed more feed than did those fed diets supplemented with AVB (P less than .05). Weight gain was not affected by any of the sources of fat (P greater than 0.5). Increasing dietary levels of fat and calcium had no effect on weight gain (P greater than .05). Dietary treatments had no effect on egg production, egg weight or egg shell deformation (P greater than .05). While there was no significant effect of increasing dietary levels of SO, CO or CS on fat retention, increasing the level of AVB resulted in increased fat retention (P less than .05). Fat retention was reduced at the high dietary level of calcium in the presence of SO or CS but not in the presence of the other sources of fat. Fecal soap concentration depended on the dietary calcium level and fat sources. There was variation among the different sources of fat in their effect on bone ash content (P less than .01). Increasing the dietary level of fat generally reduced bone ash content (P less than .05). Bone calcium and magnesium contents varied depending on the dietary sources of fat and calcium level (P less than .01).
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