The ratio of nitrogen released from terminalia leaves to organic matter released from the cassava peel between 4
and 12 h of incubation ranged from 1:54 to 1:63 and was 1:51 at 24 h. Based on the ratio of 25 g of nitrogen per kilogram of degraded organic matter (1:40) as the optimal ratio of synchronization proposed by Sinclair et al. (1993), terminalia would still not be a suitable supplement. Therefore, if terminalia leaves were fed as the sole nitrogen supplement with a cassava peel-based diet to sheep, the organic matter from the peel may not be efficiently utilized, due to inadequate nitrogen release from the leaves. However, the long lag phase and slow rate of degradation make terminalia leaves a potential by-pass protein source. Conversely, the release of nitrogen from the chaya leaves was too rapid compared to the release of organic matter from the cassava peel. If chaya leaves and cassava
peel were fed together, rumen microbes may not get enough energy from the organic matter released to make
efficient use of the nitrogen from the chaya leaves. The ratio of nitrogen released from chaya leaves to organic matter
released from the cassava peel was 1:16 or less during the entire 96 h of incubation. A rapid release of nitrogen not
matched to the release of organic matter from the carbohydrate source could lead to a high absorption of ammonia
from the rumen. In that regard, ammonia not captured in the rumen is absorbed and converted into urea in the liver.
Invariably, most of the excess nitrogen from chaya leaves would be lost in the urine, resulting in energetically inefficient use of nitrogen (Kennedy and Milligan, 1980).During the first 8 h of the degradation of ficus leaves
the ratio of nitrogen released to organic matter fermented ranged from 1:32 to 1:30. This ratio decreased to 1:25
at 12 h. It was therefore apparent that based on its high nitrogen content (3.1%,DM basis) and fermentation characteristics, only ficus leaves would be a suitable supplement in terms of supplying adequate nitrogen, and in synchrony with the fermentation of organic matter in sheep feed cassava peel-based diets.