| Abstract |
Introduction and Objective
Structural carbohydrates in roughage are resistant to the ruminant’s digestive enzymes. Increasing the efficiency of rumen microbiota which degrades fiber meaning to increase energy available and decrease feed cost. Therefore, the objective of this study was investigated the use of exogenous fibrolytic enzyme (EFE) to improve fiber digestibility and feed efficiency of in ruminants.
Methods
In vitro experiment: This study was conducted by using an in vitro gas technique at various incubation time intervals to study the level of enzyme supplements that are suitable to improve feed efficiency of rice straw in ruminants. Four dietary treatments were diets without (control) and with exogenous fibrolytic enzyme supplementation at 250, 500 and 750 g/ton DM, respectively.
In vivo experiment: Two each of rumen-fistulated of dairy crossbreds cattle (>75% HF), beef crossbreds, and Thai swamp buffaloes, were randomly assigned to receive a sequence of dietary treatments in a switch-back design. Animals were fed at 2% of BW on a basal diet (concentrate: roughage=50:50). Rice straw was used as a roughage source. The dietary treatments were non supplementation and exogenous fibrolytic enzyme (EFE) supplementation at 500 g/ton dietary DM.
Results
In vitro experiment, the IVDMD and IVOMD at 24 h. after incubation of exogenous fibrolytic enzyme (EFE) supplementation at 500 g/ton DM diets was higher than control group, while EFE supplementation at 250 g/ton was lower and at 750 g/ton was not different. This result demonstrated that EFE enhances fiber utilization. In vivo experiment, total dry matter intakes (kg, kg/%BW and g/BW0.75), nutrients intake and nutrient digestibility were not significantly different among treatments (P>0.05). Ruminal pH, NH3-N and blood urea nitrogen (BUN) concentrations were similar in all treatments with no difference (p>0.05) between dietary treatments and species. However, ruminal pH of all treatment means were within the normal range regarded as optimal activity for microbial digestion of fiber. The different responses of exogenous fibrolytic enzyme supplementation between the in vitro and in vivo experiments are discussed.
Conclusion
The present investigation found that EFE supplementation at 500g/ton dietary DM resulting in increase IVDMD and IVOMD at 24 h. after incubation. |
Publication
Journal Publication
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