Effect of ursodeoxycholic acid supplementation on growth, carcass characteristics, and meat quality of Wagyu heifers (Japanese Black cattle).

Ursodeoxycholic acid (UDCA), which is used as a hepatic and digestive medicine in humans and domestic animals, was added to the diet of Wagyu beef cattle to investigate its effects on growth, carcass characteristics, and meat quality. The study involved 20 Japanese Black heifers. Animals were divided into the following 2 groups, a control group and a UDCA group (diet supplemented with UDCA), with each group containing 10 animals. The UDCA was administrated at a dose of 2.5 g/(animal/d) to each heifer 24 times over a period of 7 mo in the finishing period. The heifers were slaughtered at 29 mo of age, and carcass characteristics and meat quality were determined. Both the UDCA group and the control group showed similar (P > 0.1) final BW, fattening periods, and daily BW gain. Supplementation of UDCA significantly increased meat quality grade (P < 0.05) and marbling (P < 0.01) and but did not show a significant (P > 0.1) effect on dressing percentage, fat thickness, rib thickness, or ribeye area. The percentage of ether extract in the LM was significantly greater (P < 0.05) in the UDCA group (43.2%) than in the control group (37.8%), whereas the percentage of moisture was significantly less in the former than the latter (P < 0.05).The L* (lightness) values of the muscles were greater (P < 0.05) in the UDCA group than in the control group. No significant differences (P > 0.1) were observed between groups in water-holding capacity, fatty acid composition, and vitamin E content of the LM or in intermuscular fat characteristics. Supplementation of the diet with UDCA can increase marbling without causing growth defects and can improve carcass characteristics in Wagyu cattle.