Replacement of Soybean Meal with Cassava Pulp Mixed with Urea Gelatinizes (Caspurea) in Concentrate Diets of Beef Cattle

This experiment aimed to study the effects of cassava pulp mixed with urea Gelatinizes (Caspurea) on productive performance of Thai native x Brahman beef cattle. Four yearling Thai native x Brahman beef cattle with average live weight of 154.7 +/- 26.8 kg were used in a 4x4 Latin square arrangement of treatments with 4 periods, each period consisted 21 days. The treatments were levels of Caspurea replacement for soybean meal in concentrate at 0, 25, 50 and 75%. Concentrates were formulated to contain 14% CP and were fed at 2.0% BW. All animals were fed ad libitum urea treated rice straw as roughage. The results showed that total dry matter intake (5.5, 5.5, 5.2, 5.3 kgDM day(-1); p>0.05) was not significantly different among dietary treatments. DM digestibility (71.2, 72.1, 71.2, 67.7%; p<0.01) was lowest in 75% replacement diet. DM digestibility decreased linearly (p<0.01) and quadratically (p<0.01) as the level of Caspurea increased. Ruminal ammonia-N concentration (8.5, 8.8, 9.5, 13.3% mg; p<0.01) was highest in 75% replacement diet and increased linearly (p<0.01) and quadratically (p<0.01) with increasing the level of Caspurea. Moreover, linearly (p<0.01) and quadratically (p<0.01) decreases in TVFAs (127.4, 123.6, 119.8, 96.4 mM L-1; p<0.01) observed were (total volatile fatty acid) reflecting increases in level of Caspurea. Increase in level of Caspurea caused linearly (p<0.01) decrease in bacteria (2.6, 2.5, 2.5, 2.4 (x10(10) cell mL(-1))) and protozoa populations (2.2, 2.2, 2.1, 1.9 (x 10(5) cell mL(-1))). Nitrogen absorption (65.5, 64.7, 60.6, 57.7 g day(-1)) were also lowest in 75% replacement diet (p<0.01), however, among 0, 25 and 50% replacement groups were not differ. With increasing the level of Caspurea, N absorption was decreased. Nitrogen retention (%N intake) (24.1, 23.6, 25.3, 13.6 % N intake) tended to increase in 50% replacement diet (p = 0.05) while, in 0, 25 and 50% replacement diet groups were not differ, moreover, N retention tended to decreased linearly (p = 0.08) as the level of Caspurea increased. Blood urea nitrogen (22.5, 23.2, 23.3, 24.6% mg; p<0.01) was highest in 75% replacement diet and BUN increased linearly (p<0.01) with increasing the level of Caspurea. These results indicated that 50% replacement diet by Caspurea for soybean meal in concentrate has positive effects on Thai native x Brahman crossbred beef cattle production.