Feed restriction and realimentation on performance and carcass characteristics of growing rabbits in a humid environment
Pertanika Journal of Tropical Agricultural Science
Department of Animal Production and Health, College of Animal Science and Livestock Production, Federal University of Agriculture, P.M.B 2240 Abeokuta, Ogun State, Nigeria
The effects of feed restriction for three weeks followed by a four-week realimentation on performance and carcass characteristics were investigated in growing rabbits in a derived savannah vegetation zone of South West Nigeria. Thirty (30) growing rabbits of mixed breeds and sexes with an average weight range of 750 - 800g were randomly distributedinto five restriction regimes which served as the study treatments. The rabbits were divided into five groups of six rabbits each. Each treatment was replicated three times with two rabbits per replicate. The experiment was carried out using the completely randomized design (CRD). The rabbits in Treatment 1 (T1) (control) were fed ad libitum, whereas those in Treatment 2 (T2) and Treatment 3 (T3) were restricted to 80% and 60% of ad libitum respectively throughout the 7-week study period. Meanwhile, the rabbits in Treatment 4 (T4) were restricted to 80% of ad libitum for three weeks and later fed ad libitum for the remaining three weeks, whereas those in Treatment 5 (T5) were restricted to 60% of ad libitum for three weeks and later fed ad libitum for the remaining four weeks. The trial lasted for 7 weeks after which the rabbits were starved overnight and slaughtered. Weight gain over the entire period, average daily gain and average daily feed intake over the 49 days of experimental period were significantly (P<0.05) influenced by the feeding regime employed. The least average daily weight gain over the entire period of the experiment was observed on the rabbits subjected to 60% of ad libitum feeding throughout the experimental duration. The rabbits in Treatment 4 (which were restricted to 80% of ad libitum feeding for 3 weeks followed by 4 weeks of ad libitum feeding showed a consistent similarity in performance with the rabbits on ad libitum feeding (Control). Feed restriction regimes significantly influenced (P<0.05) dressed weight and dressing out percentage (DOP); however, there were no effects (P>0.05) on the forelimb, loin, hind limb and thoracic cage weights of the rabbit carcasses. In terms of overall performance, the rabbits in Treatment 4, however, required less feed to gain a unit weight as compared to the rabbits in other treatments. Based on the findings of this study, it was concluded that feed restriction did not significantly influence carcass yield and relative organs investigated. It is recommended that growing rabbits can be subjected to a three-week feed restriction of not more than 20% provided at least four weeks of ad libitum feeding is allowed for compensatory growth. © Universiti Putra Malaysia Press.