Effect of dietary crude protein levels on feed intake and nutrient digestibility of Wagyu crossbred cattle

The objective of the experiment was to determine the suitable crude protein level on feed intake and digestible nutrient value of Wagyu crossbred cattle from 13 to 20 months of age. The research included 2 experiments. Experiment 1: five male Wagyu x Zebu crossbred cattle (12.2±0.56 months of age and average live weight of 179±24.2 kg, Mean±SD). Experiment 2: five male Wagyu x Zebu crossbred cattle (16.7±1.05 month’s old and live weight of 276±22.0 kg). Two experiments were Latin square design (5x5) with 5 treatments and 5 periods (21 days per period). The treatments were different crude protein levels at 210, 245, 280, 315, and 350 g per 100 kg live weight (LW) corresponding to CP210, CP245, CP280, CP315, and CP350 treatments, respectively. The basal diet was commercial concentrate (1.2 kg/day), fresh Elephant grass (5.0 kg/day) and ad libitum rice straw. While soybean meal was used to adjust the dietary CP level per 100 kg LW in diets. The result showed that increasing nutrient consumption and metabolism energy (P<0.05) but reduced fiber intakes (P>0.05) by increasing crude protein levels. Experiment 1: the CP digestibility was highest (P<0.05) of CP350 (72.8%) treatment compare to CP210 (58.8%) treatments, while the CP280 (67.2%) treatment was not significant (P>0.05) with CP245 (62.9%) and CP315 (71.7%) treatments. Experiment 2: the highest CP digestibility (P<0.05) of CP350 treatment as compared to CP315, CP280, CP245, and CP210 treatments (80.2, 77.4, 73.1, 70.5, and 65.0%, respectively). As a result, increasing CP levels per 100 kg BW could rise nutrients digestibility and digestible value for Wagyu crossbred cattle. The level of 245 g CP per 100kg live weight in Wagyu crossbred cattle diet from 13 to 20 months of age could be recommended for application.