Fatty acid profile and qualitative characteristics of meat from Zebu steers fed with different oilseeds

Abstract

The objective of this study was to evaluate the effects of the addition of ground oilseeds sources on meat quality, fatty acid profile and CLA content in Zebu steers. Thirty-one Zebu steers with initial average age of 23 months and initial live weight of 365 kg, were used in this study. The experimental period was 84 d, which was preceded by an adaption period of 28 d. The diet was provided ad libitum with a forage:concentrate ratio of 40:60. Corn silage was used as the forage source. Four different concentrates were formulated to each treatment: without additional lipids (NAL, control), ground soybean (SB), ground cottonseed (CS) and ground linseed (LS). The diets of treatments SB, CS and LS were formulated to have 6.5% of ether extract on total diet dry matter basis. The experiment was setup in completely randomised design. After slaughter, samples were taken from the Longissimus thoracis muscle for measurement of fatty acid concentration and evaluation of meat quality. The luminosity index (L*) was higher in the NL and LS diets (P<0.01). The highest percentage of myristic acid (C14:0), palmitic acid (C16:0), trans octadecenoic acid (C18:1; T10-T11-T12) and SFA in the subcutaneous fat were observed in CS treatment (P<0.01). Moreover, the lowest percentage of oleic acid (C18:1 C9) and total unsaturated fatty acids (UFAs) in the subcutaneous fat were also observed in the CS diet (P<0.01). The meat linoleic acid and α-linolenic acid percentage were highest in SB and LS treatments, respectively (P<0.001). The UFA/SFA ratio was lowest for CS diet (P<0.01). A gradual increase in the oxidation was observed as a function of storage time, however, the diets did not affect rancidity of the meat (P>0.05). The fatty acid profile of subcutaneous fat was impaired by the addition of CS. The supply of ground oilseeds was unable to raise the level of CLA in meat.