摘要：Background and Objective: The aim of this experiment was to examine the supplementation of cassava leaves in a cow diet utilizing ammoniated rice straw and synchronized the release of N-protein and energy in the rumen to obtain the best digestion nutrients and the best urine allantoin concentration, plasma progesterone and BUN (blood urea nitrogen) level in the blood of the cow. Materials and Methods: By a randomized block design of a 2×3 factorial, two diet treatments, either without (R1) or with the cassava leaves supplementation (R2), were offered to twelve cows of different breeds, namely, the local cow (Pesisir cow) and Bali and Simmental cows. Results: There was no significant effect of the interaction between the breed and diet treatments on all of the parameters. Even so, the R2 diet showed a relatively higher nutrient digestion and feed efficiency. It not only had a relatively lower BUN level but also had a lower urine allantoin concentration compared to that of R1, whereas the BUN level of the Bali and Pesisir cows was higher than that of Simmental cow (p<0.05). The Simmental cow, however, showed a relatively higher feed efficiency and allantoin concentration in the urine and a relatively lower nutrient digestion and BUN level than those of the Pesisir and Bali cows. Conclusion: It is concluded that the supplement of 3.0% cassava leaves in the cow diet with ammoniated rice straw, having a synchrony index of 0.567, produced a good production performance and had no effect on the plasma progesterone level in the cow. Moreover, the highest plasma progesterone level was in the Bali cow followed by the Pesisir cow and Simmental cow.
关键词：Ammoniated rice straw; cassava leaves; cow diet; progesterone; synchrony index
