Effect of different dietary levels of carrot pulp on in vitro gas production, nutrients digestibility and rumen fermentation

The aim of the present study was the determination of chemical composition and nutritive value of carrot pulp (CAP), and then evaluating the effects of its different dietary levels on diet digestibility and in vitro rumen fermentation. At first, chemical composition and nutritive value of CAP were compared with wheat straw (WS) and alfalfa. Then, the effect of substituting different levels of CAP (0, 50, 100, 150 and 200 g/kg dry matter [DM]) for forage portion of the diet on in vitro fermentation parameters was assessed. The highest and lowest volume of gas production after 16 and 24 h of incubation as well as constant rate of gas production (c) were observed with incubation of CAP and WS, respectively. However, the highest volume of gas production and potential of gas production (b) were observed for alfalfa, while the lowest amount was observed with WS treatment. The highest amounts of DM and organic matter disappereance, short chain fatty acids and microbial crude protein (MCP) were observed with CAP incubation, while WS resulted in the lowest amounts. With replacing forage portion of the diet with CAP, up to 200 g/kg DM, with exception of ammnia-N concentration and MCP which decreased and increased linearly, other fermentation parameters did not affect with experimental diets. Present results indicated that CAP has favourable chemical composition and nutritive value, and its incorporation as feedstuff in ruminant nutrition, up to 20% of diet, is suggested. However, more experiments, especially in vivo studies, are needed to confirm the present results.