Variation in the Effects of Fat Supplements on Broiler Pigmentation, Growth and Feed Conversion

THE range in price between prime tallow and lower grades of fat such as yellow grease or No. 2 tallow is normally ¾¢ to 1¢ pound. This difference in price is very important to the feed manufacturer, because it means a substantial savings in ingredient cost can be realized if fats such as yellow grease and No. 2 tallow can be substituted for prime tallow without reducing the feeding value of feeds. Yacowitz (1953) found that soybean oil, cottonseed oil and lard at levels of 2½ percent and 5 percent produced similar responses in growth and feed efficiency. March and Biely (1954) reported the results of feeding 5 percent to 10 percent cottonseed oil, herring oil and tallow. The growth response to the fats varied with the composition of the basal ration. Tallow was the most consistent supplement for improving growth rate. Both herring oil and cottonseed oil depressed growth …