Relationships among Neutral Detergent Fiber Content in Feed, Serum Vitamin A Concentration, and Carcass Traits in Japanese Black Cattle

Abstract

Changes in serum total-cholesterol (TC) concentration and carcass traits were studied in Japanese Black beef cattle during the first and middle fattening periods. The animals' feed contained various neutral detergentfibers (NDF). In animals whose feed was high in NDF, serum TC concentrations were significantly higher than in other cattle groups. Furthermore, branch meat weight and sirloin wick areas tended to be large; and perkg unit prices of branch meat were significantly high. Studies were conducted on relations among serum vitamin A (VA) concentrations, beef-marbling standard number (BMS No.), and changes in serum VA concentrations in cattle ranked as A-5, A-4, and A-3. No correlation was recognized between serum VA concentrations and BMS No.on the day following introduction and the day before shipping. At ages of 14 and 15 months, serum VA concentrations in cattle ranked A-5 were significantly lower than those in cattle ranked A-4 and A-3. Keeping serum VA concentrations low during the middle period and giving feed with high NDF levels in the first-middle period may be important to the production of high BMS Nos.and heavy branch meat.