Concentration of Partial VFA and Methane Production of Beef Cattle Rument Fluid which Red Dragon Fruit Skin (Hylocereus costaricensis) and Guava Leaf (Psidium guajava L.) in Ammoniated Rice Straw Based Ration

The research aimed to examine the effect of red dragon fruit skinand guava leavessupplemented into beef cattlefeed onthe concentration of partial VFA and methane gas production. The in vitro study was conducted ina completely randomized design (CRD)with3 treatments,namely P0: 50 % concentrate + 50 % ammoniated straw (Control),P1: 50 % concentrate + 50 % ammoniated straw + 5 % red dragon fruitskinflour,and P2: 50 % concentrate + 50 % ammonia straw + 5 % red dragon fruit skinflour + 2.5 % guava leaf flour. The concentrate consistedof 2 parts of rice bran and 1 part of coconut meal. The ratio of concentrat and ammoniated rice straw was 50:50. Each treatment was repeated 6 times. The results showed that the concentration of acetic acid, butyrate and methane gas decreased while the concentration of propionate increased with the addition of red dragon fruit and guava leaves. The research concluded that the addition of 5 % red dragon fruit skinflourcombined with 2.5 % guava leavesflourin beef cattle feed couldfurther reduce the concentration of acetic acid, butyric acid and the production of methane gas,but increase the concentration of propionic acid. It issuggested that defaunated agents of red dragon fruit skinand guava leavescould reduce the production of methane gas in the rumen of beef cattle.