Metabolic Profile of Japanese Black Breeding Cattle Herds: Its Usefulness in the Detection of Abnormal Metabolism Resulting from High Protein Diets

Metabolic profile tests (MPTs) in Japanese Black (JB) breeding cattle from 45 herds with poor reproductive performance revealed that one herd with an abnormal metabolic profile was fed excessive protein diet during parturition. The fullness rate of CP was 229%; as a feed quality improvement measure, the CP was reduced by 1 kg/day (equivalent to 202% of CP requirement). We performed another MPT six months later on a total of 10 cows, and compared the results before and after feed improvement, postpartum day open period, and occurrence of reproductive disorders. The occurrence and developmental conditions of diseases in the calves were also compared. Blood urea nitrogen (BUN), total protein (TP), and albumin (Alb) levels were within the reference range, but glucose level (Glu) was lower and 3-hydroxybutyric acid (3-HB) level was higher than the reference range before dietary intervention (n=9). After dietary intervention (n=10), BUN, TP, and Alb levels were within the reference range, but TP level increased significantly (P<0.01). Additionally, Glu level increased significantly (P<0.01) and 3-HB level decreased significantly (P<0.05), returning to the reference range. The postpartum days open tended to decrease after feed improvement. The number of reproductive treatments and treatment expenses for the mothers decreased after feed improvement, but there was no significant difference among the calves before and after feed improvement; there was no significant difference in the mean body weight of calves. Excessive protein feeding might result in a low energy state adversely affecting the reproductive performance. These results show that optimization of dietary energy and protein can improve the reproductive performance and economic efficiency of JB cattle.