Effect of anabolic implants on beef intramuscular lipid content

Sixty ribeye steaks were used to determine the effects of anabolic implants on i.m. lipid composition of beef steers. Steaks were obtained from carcas ses (346 kg) of steers assigned to four treatment groups (C = nonimplanted control; ET = 28 mg of estradiol benzoate plus 200 mg of trenbolone acetate on d 0; ET/ET = ET on d 0 and d 61; and S/ET 20 mg of estradiol benzoate p lus 200 mg of progesterone on d 0 and ET on d 61) and fed a high-concentrat e diet for 127 d. Total fatty acid content of the longissimus was less (P < .05) for implanted steers. Implanting increased (P < .05) stearic and lino lenic acid percentages and reduced (P < .05) oleic acid percentage but did not alter (P > .05) percentages of other fatty acids. These changes transla ted into increased (P < .05) percentages of saturated fatty acids and reduc ed (P < .05) monounsaturated fatty acids in the longissimus of implanted st eers. However, on a per-steak weight basis, implanting did not alter (P >.0 5) the amounts of any of the individual fatty acids, but it increased (P < .05) the total cholesterol amount. Implanting with an estrogenic compound f irst reduced (P < .05) the percentage and total amounts of linoleic and pol yunsaturated fatty acids. On a percentage basis, implanting alters fatty ac id amounts; however, when the increase in ribeye size with implanting is ac counted for and fatty acids are evaluated on a per-steak basis, these diffe rences are not significant.