Nutritive value evaluation of roughages and Non-forage fiber sources using in vitro gas production technique

Abstract

The objectives of this experiment were to evaluate nutritive values and to compare digestibility, kinetics of gas production, and the value of metabolizable energy between forages and non-forage fiber sources using an in vitro gas production technique. The treatments were divided into two groups of feed sources. The first group included nineteen forage fiber sources (FFS) into tree sub-group 1.1 Alternative forage (ALT), sub-group 1.2 Grass forage (GRS) and sub-group 1.3 Legume forage (LEG). The second group included thirteen non-forage fiber sources (NFFS). The experimental design was arranged into a randomized complete block design with 4 replications. Three Holstein-Friesian bulls, with an average body weight 200 kilograms, were the sources of stomach fluid, an inoculum. Crude protein of FSS and NFFS was vary among 2.92-13.73% and 1.72-50.32%, respectively, EE was vary among 0.30-3.14% and 0.38-27.11%, respectively and NDF was vary among 44.32-79.98% and 23.25-76.03%, respectively. The value of in vitro organic matter digestibility (IVOMD), of the group NFFS was higher than that of FFS and GRS (P<0.01), but did not differ from the ALT and LEG. The value of in vitro neutral detergent fiber digestibility (IVNDFD) of the NFFS group was higher than that of FFS and ALT (P<0.01), but did not differ from GRS and LEG. Kinetics of gas production; potential of gas production (A+B) of NFFS was lower than FFS, ALT and GRS (P<0.01), but did not differ from LEG. Rate of gas production (C) of NFFS did not differ from FFS and ALT, but higher than GRS (P<0.01) and LEG (P<0.05). Metabolizable energy (ME) of NFFS was higher than FFS (P<0.05) and GRS (P<0.01), but did not differ from ALT and LEG. These results indicated that some NFFS had a high potential to be used as CP and energy sources.