Effects of cassava chip supplementation on ruminal fermentation, methane and milk production, and nutrient digestibility of crossbred lactating goat in the tropical region
Abstract:
The objective of this study was to determine cassava chip supplementation on feed efficiency, ruminal fermentation, blood metabolites, milk production and composition and in vitro gas production technique (IVGPT). Twelve crossbred dairy goats (Saanen x Native) with initial body weight of 29 kg and 35 d in milk were randomly assigned to a 2x2 crossover design. The experiment was 2 periods with the first 14 d for adaptation and the last 7 d for data collection. Two dietary treatments were composed of pangola hay and cassava chip at the ratios of 100:0 and 79:21 for T1 and T2, respectively. The pangola hay was fed ad libitum while the cassava chip in T2 was given about 0.5 %body weight (BW). Body weight, feed intake, milk yield, feces and urine were collected for analyze feed efficiency. Samples were determined their chemical compositions. Blood sample was analyzed for blood metabolites and non-esterified fatty acid. Ruminal fluid was collected to analyze volatile fatty acid (VFA) composition and gas production by IVGPT. The methane concentrations from IVGPT were determined by gas chromatography. Comparing T1 and T2, there were no significant differences in %BW change, feed intake, N balance, digestibility, VFA composition, blood metabolites (protein, triglycerides, blood urea nitrogen (BUN) and NEFA) milk yield and milk composition (protein, fat, total solids (TS), solid not fat (SNF) and 4%fat corrected milk (FCM)). Goats fed with T2 had higher blood glucose and milk lactose than those fed with T1 (p<0.05). Nevertheless, T2 had higher gas production at 24 and 48 hours, metabolizable energy, net energy lactation and methane composition than T1 (p<0.05). In conclusion, supplementation of cassava chip can be used as a carbohydrate and energy source for dairy goats fed on pangola hay without adverse effects on feed efficiency and ruminal fermentation. However, it was not suitable for raising dairy goats that aimed to enhance production and reduce methane emission at the same time