Fatty acid profile of beef from crossbred steers supplemented in grazing

Abstract

The aim was to evaluate the fatty acid profile of meat of crossbred cattle grazing under different supplementation strategies. Thirty crossbred steers (1/2 Holstein x 1/2 Zebu) were used in a completely randomized design with three groups of different supplementation strategies (SS) according to the climatic season of the year: SS-1 (mineral salt/mineral salt with urea), SS-2 (mineral salt with urea/protein supplement 0.1% PC), and SS-3 (protein supplement 0.1% BW / 0.2% BW protein supplement). Longissimus dorsi muscle samples were collected, stored, and frozen until analysis of the fatty acid (FA) profile. Data were subjected to analysis of variance (ANOVA), using the Tukey test (P < 0.5) (SAS 2008). Our results exhibited that the oleic acid (C18: 1n9cis) was affected by supplementation strategies, the oleic acid was higher (34.91%) in SS-1. In addition, the content Polyunsaturated fatty acids (PUFA; P <0.05); C18: 3n3 (α – linolenic), C18: 2c9t11 (Rumenic / CLA), C18: 2t10c12 (Trans-10, cis-12-octadecadienic / CLA) and C20: 5n3 (eicosapentaenoic - EPA) also were higher in SS-1. In contrast, in SS-3 the C20: 4n6 (arachidonic) was higher (1.09%). The total PUFA content was influenced (P <0.05), with a higher content in the SS-1 group (3.58%). SS-3 influenced higher levels of AG n-6 (1.86%), and AG n-3 (1.02%) being higher in SS-1, producing a lower n-6: n-3 ratio in SS-1 (P <0.05) of 1.57. Grazing animals with mineral supplementation SS-1 showed meat with a higher composition of polyunsaturated fatty acids, mainly omega-3 and CLA, which provided a reduction in the n-6: n-3 ratio, highly related to human health.