| The objective of this study was to evaluate the use of oat hulls (OH) to substitute traditional fiber in the diets of fattening rabbits by examining on its effect on the growth performance, coefficient of total tract apparent digestibility (CTTAD) of nutrients, gastrointestinal tract development, caecum fermentation and carcass traits. A total of 160 mixed sex Hyla commercial meat rabbits (40 per treatment) were used to study the effects of including OH in the diet from 30 to 80 days of age. A control diet based on rice hulls and mugwort and Folium Artemisiae Argyi Powder containing 175.2 g crude fiber and 169.7 g crude protein/kg was included. Growth performance and CTTAD of nutrients were recorded from d 30 to 70 and d 68 to 70 respectively, while gastrointestinal tract development, caecum fermentation and carcass traits were determined at d 70. Increasing concentrations of OH in the diet decreased ADFI (P=0.0018), but have no effects on ADG and feed conversion ratio (FCR)(P>0.05). The CTTAD of crude fiber decreased with the inclusion of OH (P<0.05). No effects of CTTAD of NDF, ADF, ADL, dry matter and gross energy were observed (P>0.05). Moreover diet composition significantly affected the relative weight of caecal content (P=0.0474), but did not affect other gastrointestinal organs. The concentrations of total VFA, acetic and butyric acids were greater in rabbits fed the lower levels of OH (0 g/kg,50 g/kg) compared to higher rate (100 g/kg,150 g/kg; P<0.05). However, the proportions of acetic, propionic and butyric acids were not affected by treatments (P>0.05). Furthermore, no significant effect on the ratios of acetic/(Propionic+butyric) was observed (P>0.05). Hot carcass weight, dressing percentage, pH (45 mins,24 h), lightness, redness, yellowness,24 h drip loss of longissimus lumborum (LL) muscles were not affected by diet OH (P>0.05). It is concluded that OH can satisfactorily replace rice hull in diets for growing-fattening rabbits. |
PDF Full Text Request