The Effect of Treated (Spray-Dried) Beef-Tallow Supplementation on Fattening Performance in Japanese Black-breed (WAGYU) Steers

摘要

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 JapaneseBlack 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 weightand BMS No., and the grade of marbling in ribs (M. logissimus thoracis) 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.