Improving Rumen Fermentation Characteristics and Nutrient Digestibility by Increasing Rumen Degradable Protein in Ruminant Feed using Tithonia diversifolia and Leucaena leucocephala

Abstract

The aim of this research was to discover the effect of increasing rumen degradable protein in ruminant diet using Tithonia diversifolia and Leucaena leucocephala on rumen fermentation characteristics, microbial protein synthesis, protozoa population, methane production, and nutrient digestibility. The in vitro method was used in this research in randomized block design with three treatments and five replications. Three diets were formulated containing 50, 55 and 60% rumen degradable proteins (RDP) and were represented as 50, 55 and RDP60. The RDP50 diet contained RDP 50% of crude protein. The 55 and RDP60 diet contained RDP 55 and 60% of crude protein, respectively. The results showed Total Volatile Fatty Acid (100mM vs 98.93mM and 95.60mM) and microbial protein synthesis (88.86mg/100mL vs 84.03mg/100mL and 81.20mg/100mL) were higher in RDP55 diet (P<0.05). Decreasing protozoa population and methane production were observed with increasing RDP in diet (P<0.05). NH3 production (15.30-16.15mM) and protein digestibility (62.52-66.12%) increased with the rising of RDP level (P<0.05). Beside that, higher dry matter (64.56% vs 61.58% and 58.20%), organic matter (66.67% vs 63.89% and 60.69%), crude fiber (65.37% vs 62.07% and 60.78%), and nitrogen-free extract (66.45% vs 62.87% and 60.57%) digestibility were observed in RDP55 diet (P<0.05). Our study revealed that diet containing RDP 55% of crude protein in ruminant feed using T. diversifolia and L. leucocephala improved rumen fermentation characteristics and nutrient digestibility. Further research is needed to discover the effect of the in vivo feeding trial on animals.