Effect of feeding Asystasia gangetica weed on intake, nutrient utilization, and gain in Kacang goat

Abstract

A high concentration of nitrate and total nitrogen (N) in Chinese violet (CV) weed (Asystasia gangetica) has a potential benefit as a digestible protein source for ruminant production in humid tropical regions. We conducted a study using twelve Kacang goats in a crossover design to investigate the effect of CV weed on intake, nutrient utilization, and growth. Four dietary treatments were tested: Guinea grass (Panicum maximum) ad libitum (GG), GG ad libitum and CV (1% live weight, LW) (GG + CV), CV ad libitum (CV), and CV ad libitum plus cassava chip (1% LW) (CV + CC) (dry matter, DM basis). No sign of nitrite toxicity was observed when the goat fed CV diet while intake, N retention, and LW gain was higher than goats on the GG and GG + CV diets (P < 0.001). Digestibility of DM was similar to the goats on the GG + CV diet but higher than the goats on the GG diet (P < 0.001). However, the goats on the CV diet had a higher urinary N loss compared to the goats on GG and GG + CV diets (P < 0.001). The cassava supplementation (CV + CC) increased DM digestibility and lowered urinary N loss (P < 0.001). Hence, the CV weed could be fed as a sole diet or as a supplement to the Kacang goat fed a low-quality forage for improvement of nutrients intake, digestibility, and gain, while the urinary N loss could be lowered by cassava supplementation.