Nutrient digestibility and growth performance of ruminants fed with mulberry (Morus alba L.) at different cutting intervals

Four studies were conducted to determine the feeding value of mulberry as a protein supplement for goats. Study I determined the effects of different cutting intervals at 30, 45, 60 and 90 d on forage yield and chemical composition of mulberry. Study 2 examined the effects of different cutting intervals on in sacco digestibility of mulberry using three each of rumen-fistulated carabao, cattle and goat. In study 3, the effects of mulberry as replacement of concentrate on the growth performance of goat were evaluated using 4 dietary treatments as follows: Napier grass 100%, Napier grass 70% + Concentrate 30%, Napier grass 70%+ Concentrate 15%+ Mulberry 15%, and Napier grass 70% + Mulberry 30%, respectively. Study 4 evaluated the effects of mulberry on rumen condition of 3 fistulated native goats fed 100% Napier grass, 50% Napier grass + 50% Mulberry and 100% Mulberry in a 3 x 3 Latin Square design experiment. The percentage of crude protein (CP) was highest in mulberry harvested from 30 to 60 d, while the concentration of dry matter (DM), fiber fractions and ash increased with longer cutting intervals. Forage production was highest at 90 d cutting interval. Using the nylon bag technique, the soluble fraction (a) of mulberry DM was highest at 30 d and decreased with longer cutting intervals in rumen of carabao and cattle, but not in the rumen of goats. The potential degradable fraction (b) of mulberry DM significantly increased with increasing cutting intervals. The rate of degradation (c) of mulberry DM significantly decreased with increasing cutting intervals in carabao but not in cattle and goat. Degradability of the soluble fraction (a) of CP was significantly highest at 30 d and decreased with increasing cutting intervals in rumen of carabao and goat but not in the rumen of cattle. Insoluble fraction (b) value of mulberry CP, increased with increasing cutting intervals in rumen of carabao and goat. The rate of degradation (c) of mulberry CP at 90 d was significantly lowest in rumen of carabao but not in the rumen of cattle and goat. These results indicate differences in microbial digestions of mulberry among the three ruminant species. Replacement of concentrate with mulberry improved total feed intake, DM and neutral detergent fiber digestibility and average daily grain (p0.05). No significant differences were found in CP digestibility and feed conversion ratio when compared with goats that were fed with Napier grass only. Feeding mulberry at 50% and 100% of the diet has no significant effects on ruminal pH and total volatile fatty acid, but significantly increased rumen NH sub 3-N concentration (p0.05). This results indicate that mulberry is a potential replacement of concentrate or as a supplement to low quality roughage in ruminants by improving rumen function and consequently the performance of animal.