An experiment was carried out to investigate the effect of supplementation of spray-dried beef tallow (BT) on fat nutrition , and to discuss the possibility of improving meat quality by stimulation of fat deposition in the muscles of fattening sheep. There were no clear differences in growth rate between the BT-supplemented group and control group, so the feed efficiency was not improved by addition of BT in the present experiment. Plasma triglyceride (TG) level was relatively steady along with their growth in the control group, but a little high in the BT-supplemented group at an early stage of the experiment. The plasma cholesterol level tended to be higher(P<0.05) in the BT-supplemented group as compared with that in control at 0, 1 and 3 months after the initiation of experiment. The moisture content of the carcass decreased (P<0.05) after feeding BT diet as compared with that after feeding control diet, and, on the contrary, the contents of crude fat tended to increase in lambs fed the BT diet. As a result, the meat (such as the loin) tended to contain more fat in lambs fed the diet with BT than in control. These findings indicate a possibility that the BT treatment, such as spray-drying as in this study, can be used as an energy source to stimulate fat deposition in the muscles of fattening sheep.

No abstract

The effect of dietary supplementation of treated (spray-dried) beef tallow (BT: 3% of concentrate during 350 days of latter part of fattening) on the lipid metabolism and carcass quality (marbling) during fattening was investigated using ten Japanese Black breed (WAGYU) steers. The feed intake (both concentrate and roughage) was slightly lower in the BT-supplemented group than in the control group, but the difference was not significant (P>0.05).The daily gain (DG) during the period tended to be higher in the BT-supplemented group than in the control, and the feed conversion ratio during the latter part of fattening was significantly lower (P<0.05) in the former than in the latter. Fattening performances, e. g., growth rate, dressed carcass weight and BMS No., and the grade of marbling in ribs (M. logissimus thoracic) were also similar in both groups. The concentration of triglyceride (TG) in blood plasma was not different between the two groups. The concentration of cholesterol in blood plasma was significantly higher (P<0.05) in the BT-supplemented group than in the control group, particularly in the latter part of fattening period.There were no clear differences between the BT-supplemented and the control groups in the chemical composition and fatty acid composition of meat. These findings suggest a possibility that the BT used in this study improves feed efficiency and fat nutrition in the beef cattle when supplemented at the later stage of fattening.