干旱区生态环境知识资源中心

Physical morphological measurements and m longissimus lumborum proximate chemical composition of impala (Aepyceros melampus) and the effects of age, sex and region on these parameters were investigated. Impala were randomly sampled from Mara (n = 40, 24 males, 16 females), situated in the Arid Sweet Bushveld region, and Musina (n = 28, 15 males, 13 females), situated in the Mopane Bushveld region in the Limpopo Province of South Africa. The live weights of the Mara (50.23 +/- 9.32 kg) animals were higher (p < 0.05) than those of the Musina animals (44.25 +/- 10.81 kg). The male animals from both regions were significantly heavier than the females (p < 0.05), particularly for the older animals (similar to5 kg for 30-month-old animals and similar to10 kg for 42-month-old animals); however, the dressing percentages between the sexes did not differ. The Mara female group (similar to62%) had significantly (p < 0.05) higher mean dressing percentages than the Musina females (similar to 58%). The mean proportions of external and internal offal were relatively higher in the Musina animals. No significant differences in the dressing percentages between the five age groups were found. Carcass measurements increased linearly with age. Age showed no effect on the m longissimus lumborum chemical carcass composition. Female animals (similar to 19.4 g kg(-1)) had higher (p < 0.05) lipid contents for both regions than the males (similar to14.0 g kg(-1)) but the sex of the animal had no effect on the remaining chemical carcass composition parameters. The crude protein content of the Musina animals (248.8 +/- 10.44 g kg(-1)) was higher (P < 0.05) than for the Mara animals (238.0 +/- 8.404 g kg(-1)). The mean ash content of the impala m longissimus lumborum was similar to 12 g kg(-1). The results indicated that age effects are caused by the increases in size brought about by the growth of the animal and by the development of sexual dimorphism. Age, however, had no effect on the m longissimus lumborum proximate chemical composition. Regional differences were also shown for both the physical parameters as well as for the proximate chemical composition of the muscle. Similarly, females also differed from males for the parameters measured. These factors will have to be taken into consideration by the meat trade when purchasing, processing and marketing impala game meat. (c) 2004 Society of Chemical Industry.