Evaluation of some by-Products using In situ and In vitro Gas Production Techniques

Abstract

Food by-products in Iran are produced in high levels. In this study, in situ and in vitro gas production techniques were used to describe nutritive value of apple pomace, tomato pomace and noodle waste. For this purpose two ruminal fistulated sheep were used. Nylon bags which were approximately (6×12 cm) containing 5 g samples (2 mm screen) were incubated in duplicate in the rumen of fistulated sheep for 0,2,4,6,8,12,16,24,36 and 48 h. The gas production was recorded after 2, 4, 6, 8, 12, 16, 24, 36 and 48 h of incubation and the equation of P = A (1-e^-ct) was used to describe the kinetics of gas production. The data was analyzed using completely randomized design. DM and CP disappearance were significantly different among feedstuffs (p<0.05). After 48 h of incubation DM disappearance in noodle waste was highest and in tomato pomace was lowest. Regarding to the results, at the most incubation times tomato pomace had lower CP disappearance among feedstuffs (p<0.05). Potential gas production (A) and rates of gas production (c) differed among feedstuffs. Apple pomace showed higher potential gas production (A) (305.1 mL g^-1 DM) and tomato pomace had higher rate of gas production (c) (0.09 h^-1) than the other feedstuffs. According to gas production volume, the value for the ME, OMD and SCFA ranged from in 8.87 noodle waste to 9.76 in apple pomace, 56.1 in tomato pomace to 64.3 in apple pomace and 0.919 in noodle waste to 1.168 in apple pomace, respectively. Partitioning factor in noodle waste was highest and in tomato pomace was lowest. In the present study, feeds composition significantly affected the degradation parameters.