Effect of morning vs. afternoon grazing on intramuscular fatty acid composition in lamb

Abstract

The aim of this study was to assess whether different grazing management affect animal performance and meat fatty acid composition. Thirty-five lambs were divided into three groups: 12 lambs grazed from 9am to 5pm (8h group); 11 lambs grazed from 9am to 1pm (4hAM group) and 12 lambs grazed from 1pm to 5pm (4hPM group). The trial was conducted over 72days. The 8h lambs had greater DMI (P<0.0005) and final body weight (P<0.05) than the 4hPM and 4hAM lambs while carcass weight was not different between the three groups. The meat of the 4hPM lambs contained greater (P<0.05) percentages of polyunsaturated fatty acids, C18:2 cis-9 trans-11 and lower saturated fatty acids and C18:0 than the meat of the 8h and 4hAM lambs. It is concluded that allowing lambs to graze during the afternoon rather than during 8h does not compromise the carcass yield and results in a healthier meat fatty acid profile.