The restriction of grazing duration does not compromise lamb meat colour and oxidative stability

Abstract

Over 72days, 33 lambs were fed: concentrates in stall (S), grass at pasture for 8hours (8h), or grass at pasture for 4hours in the afternoon (4h-PM). The 4h-PM treatment did not affect the carcass yield compared to the 8h treatment. Meat colour development after blooming was unaffected by the treatments. The 4h-PM treatment increased the proportion of polyunsaturated fatty acids (PUFA; P<0.0005) and of the highly peroxidizable fatty acids (HP-PUFA; P<0.001) in meat compared to the 8h treatment. The S treatment increased lipid oxidation (higher TBARS values) and impaired colour stability (higher H* values) of meat over storage compared to the 8h and 4h-PM treatments (P<0.0005 and P=0.003, respectively). No difference in meat oxidative stability was found between the 8h and the 4h-PM treatments. In conclusion, growing lambs can tolerate a restriction of grazing duration without detrimental effects on performances and meat oxidative stability.