Fatty Acid Profile of Meat from Nellore and Angus Young Bulls Fed a Whole Shelled Corn Diet

Many fatty acids have beneficial and malefic actions to human health; thus, it is extremely important to analyze the effect of nutrition and genetic group on beef fatty acid profile. The objective was to evaluate the fatty acid profile of muscle of Nellore and Angus young bulls fed whole shelled corn (WSC) and a ground corn (GC) diet. Thirty-four bulls with average initial body weight of 381 ± 11.8 kg were used in a completely randomized design and arranged as a 2 × 2 factorial (2 breeds and 2 diets). The GC diet had 30% of corn silage and 70% of a concentrate based on flint corn and soybean meal. The WSC diet had 85% whole shelled flint corn and 15% of a pellet based on soybean meal and minerals. After harvested, samples were taken from the longissimus dorsi (LD) muscle between the 12th and 13th ribs for fatty acid analysis, using gas chromatography. The model included the fixed effects of breed, diet, and their interaction and animals as random effect and was analyzed using PROC MIXED of SAS (SAS Inst. Inc., Cary, NC). A greater (P < 0.01) concentration of palmitic acid (C16:0) was observed in the LD muscle of Angus bulls and a greater (P < 0.01) concentration of linoleic acid (C18:2 n6) was observed in Nellore bulls, regardless of diet. The concentration of myristic (C14:0) (P < 0.01) and stearic acid (C18:0) (P = 0.04) were greater in Angus bulls fed WSC. Nellore bulls fed WSC had a greater (P = 0.02) concentration of α-linolenic (C18:3 n3) and Nellore bulls fed GC had a greater (P = 0.01) concentration of myristoleic (C14:1). Regardless of breed LD muscle of bulls fed WSC had greater (P = 0.01) concentration of CLA C18:2 t10, c12. In addition, feeding WSC tended to increase concentration of trans octadecenoic acid (C18:1) (P = 0.09) and CLA C18:2 c9, t11 (P = 0.10). LD muscle of bulls fed GC had greater (P < 0.01) concentration of palmitic acid (C16:0). In conclusion, WSC diet change FA profiles and may reduce lipogenesis in the LD muscle because it is favorable to increase C18:2 t10, c12 content.