In vitro Fermentation and Bacterial Protein Synthesis in the Different Diets Supplemented with Lerak Extract plus Mineral (Ca, P, Mg, S)

Abstract

Bacterial protein supply is usually low in animals fed with high forage ration because of the lack of sources of minerals in the rumen. The aim of this study was to evaluate the use of lerak extract plus mineral (Ca, P, Mg, S) on fermentation and bacterial protein synthesis in the in vitro fermentation with different ratios of forage and concentrate. The design of experiment was factorial block design (3x3) with 2 factors which were: ratio of forage and concentrate (70:30, 50:50, 30:70) as the first factor and the type of supplements (0, 1mg/ml lerak extract and 1mg/ml lerak extract + minerals) as the second factor. Total volatile fatty acid (VFA), NH3 concentration, population of protozoa, and bacterial protein synthesis were measured at 4 h incubation. Dry matter and organic matter digestibility were evaluated after 48 h incubation. The result showed that there was no interaction effect between ratio of forage to concentrate and the type of supplements. The different ratios of forage and concentrate had no effect on dry matter and organic matter digestibility, and NH3 concentration. The increase of concentrate ratio in the diet reduced population of protozoa, but increased total VFA and bacterial protein synthesis. The addition of 1 mg/ml lerak extract without minerals significantly decreased (P<0.05) population of protozoa and increased (P<0.05) bacterial protein synthesis but no effect on dry matter and organic matter digestibility, NH3 concentration, and total VFA production compared to the control. However, the addition of lerak extract plus mineral (Ca, P, Mg, S) had no effect on all parameters measured. In conclusion, bacterial protein synthesis increased by supplementation of lerak extract without mineral addition.