Effects of Feed Restriction on Performance, Carcass Yield, Relative Organ Weights and Some Linear Body Measurements of Weaner Rabbits

Abstract

Effects of feed restriction on performance, carcass yield, relative organ weights and some linear body measurements were investigated in weaner rabbits in a sub-humid environment in north central Nigeria. Twenty four weaner rabbits of mixed breeds and sexes with an average initial weight of 804.17±71.20g were used for the study which lasted six weeks. There were three dietary treatments consisting of diet A, ad libitum (24 hrs) feeding (control), diet B, 8 hrs per day feeding (7.00 a.m-3.00 p.m) and diet C, skip-a-day feeding. This feeding arrangement was carried out within the first five weeks of the experiment, after which all the animals in the three treatment groups were fed ad libitum for one week. Animals were fed pelletized commercial grower`s feed supplemented with Centrosema pubescens. Drinking water was also supplied ad libitum throughout the duration of the experiment. Each treatment group was replicated four times while each replicate comprised two rabbits housed in the same cage. The initial and final body weights, feed conversion ratio, mortality, fasted weight, slaughter weight, carcass weight and dressing percentage were not significantly (p>0.05) affected by feed restriction. However, average weekly feed intake (454.94, 356.36 and 331.48g) and average weekly body weight gains (1137.50, 1127.50 and 1007.50g) were significantly (p<0.05) influenced; with higher values recorded among rabbits fed   ad libitum compared to those on 8 hrs feeding per day and skip-a-day feeding respectively. There were no significant differences (p>0.05) in relative weights of liver, kidneys, spleen and heart among the treatment groups. Significant difference (p<0.05) was found in the relative weight of lungs, with rabbits on 8 hrs feeding per day and those on skip-a-day feeding having an edge over those fed ad libitum (0.61 versus 0.50). There were no significant differences (p>0.05) in heart girth, body length, face length and ear length among the dietary treatments studied. The present results have indicated that feed restriction could be exploited in the feeding regimen of rabbits, especially in periods of inadequate supply of concentrates and forages.