Abstract

Despite being abundantly available and nutritious, corn stover and Ceara rubber tree leaves are rarely used as livestock feed. However, these agriculture byproducts contain hard to digest nutrients to be used as feed for livestock. This study evaluates the fermentation characteristics (pH levels, ammoniacal nitrogen (N-NH₃), and total volatile fatty acid (VFA) production and nutrient digestibility (dry matter digestibility_DMD, organic matter digestibility_OMD) of a silage-based diet composed of a mixture of corn stover and Ceara rubber tree leaves in Etawa crossbred goats in vitro. The hay, based on corn stover and Ceara rubber tree leaves, is supplemented with a concentrate comprising bran, pollard, coconut meal, tapioca waste, molasses, and urea. The research design employs a Randomized Complete Block Design with four treatments and four replications. The four treatments are as follows: T1 (60% forage silage with 60% corn stover, 30% Ceara rubber tree leaves, and 10% ground corn + 40% concentrate), T2 (60% forage silage with 65% corn stover, 27.5% Ceara rubber tree leaves, and 7.5% ground corn + 40% concentrate), T3 (60% forage silage with 70% corn stover, 25% Ceara rubber tree leaves, and 5% ground corn + 40% concentrate), and T4 (60% forage silage with 75% corn stover, 22.5% Ceara rubber tree leaves, and 2.5% ground corn + 40% concentrate). Data analysis involves variance analysis, and differences between treatments are tested using Duncan's Multiple Range Test. The results indicate that different combinations of corn stover and Ceara rubber tree leaves significantly impacted the N-NH₃ level but did not significantly affect the pH, VFA total, DMD and OMD. This study concludes that combining both fermented ingredients creates a normal in vitro fermentation ecosystem capable of supporting the growth and activity of microorganisms in breaking down nutrients with high efficiency. Based on the results of the study, it proves that the implementation of fermentation technology on high fiber and low crude protein feed ingredients combined with ingredients containing nitrogen sources such as Ceara rubber tree can improve the nutrient content of silage from agricultural by-products.

Keywords:
fermentation; nutrient digestibility; in vitro; Etawa crossbreed