Some Biochemical Aspects Related To Meat Quality

Abstract

Thirty weaned Western Sudan Baggara bull calves ranging in age and weight between 40 to 100 weeks and from 95 to 185 kg, respectively were divided according to age and liveweight into three groups. Each group was assigned either to control or fed ad libitum, or fed 65 % of ad libitum feed. The control groups consisting of six animals were slaughtered at the beginning of the experiment. Animals of the second two groups were assigned to three slaughter points, of various duration in feedlot. At each slaughter point 8 animals were slaughtered, four from each group (fed ad libitum and fed 65 % of ad libitum feed). The slaughtering of the concentrate treated groups was performed at 11, 18 and 32 weeks. These were regarded as slaughtering points No. 2 to 4 whereas the control group was regarded as slaughter point No. 1. Slaughter and dissection data were collected. The difference in concentrate treatment did not affect the developmental patterns of body components except fat and liveweight. From the right side of the carcass; the muscles Posas major, Biceps femoris, Gastronenemius, Supraspinatus and Brachiocephalicus were carefully dissected. Samples from these muscles were used to study the post-mortem changes in glycogen, lactic acid and hydrogen ion concentrations, and the study of percentage of dry matter, intramuscular fat, ash, total proteins water-soluble proteins, water-holding capacity and muscle fibre diameters. In general, Western Baggara cattle responded quite favourably to concentrate feeding. The measurement of the weight of 5 individual muscles revealed that they were more than double compare to their weights in control animals and that the differences in weight between muscles of animals fed ad libitum and those fed 65% of ad libitum feed was negligible. The increase in duration of feeding above 18 weeks hardly increased muscle weights. This was also supported by the fact that fattening increased proportion of fat and inorganic matter at the expense of protein per unit weight of the muscles. A part from lowering protein concentration fattening caused considerable improvement in meat quality as judged by higher initial content of glycogen, lower rate of glycolsis with the resulting gradual change in pH; making way for a possible gradual and delayed ensuing of the rigor mortis. Water-holding capacity was much higher in the muscles from ad libitum fed animals, and fibre diameter thicker compared to muscles from the group fed 65% of ad libitum feed. It can be concluded that meat from animals (Baggara cattle) treated with high plane of nutrition is highly superior to meat of animals from the range.