Poultry Fat Addition to Finishing Rations Influences the Fatty Acid Composition of Muscle Tissue and Adipose Tissue1

摘要

Poultry fat may be a more economical energy source than other by-products currently used. In cattle finishing diets; however, little research has quantified the effects of poultry fat on the fatty acid composition of beef. Therefore, a 112-d finishingstudy was initiated to determine the effects of dietary fat source (poultry or tallow) on the fatty acid profiles of the subcutaneous and intramuscular fat depots. Sixty Angus crossbred steers (903.8 Ib initial body weight) were stratified by source, blocked by weight, and assigned to 15 pens (four steers/pen). Then, pens were assigned randomly within blocks to one of three dietary treatments consisting of: 1) a corn-soybean meal control diet devoid of added fat; 2) control diet formulated with 4% tallow; or 3) control diet formulated with 4% poultry fat. In the longissimus dorsi (LM), total saturated fats were similar (P > 0.10) among diets. Furthermore, total monounsatu-rated fatty acids (MUFA) were not (P > 0.10) affected by diet. The LM from the steers fed poultry fat had increased (P < 0.05) 18:2 and total polyunsaturated fatty acids compared to that of the steers consuming the other two diets. Conversely, the LM of the tallow fed steers had lower (P < 0.05) concentrations of 20:3 than steers consuming the other two diets. The only changes noted in subcutaneous fat were that the steers consuming the control diet had greater 17:1 concentrations than the (P < 0.05) steers that consumed the poultry fat diet. Therefore, poultry fat may serve as analternative energy source in finishing cattle diets without compromising fatty acid composition of beef.