Performance and carcass characteristics of growing rabbits fed bacterial protein meal

Abstract

In an 84 days feeding trial, the effect of feeding bacterial protein meal (BPM) either as a replacement for fish meal or for groundnut cake meal in growing rabbits was examined. A total of 20 growing rabbits having an initial body weight of 617.2 (standard error 25) g were randomly assigned to five dietary treatments. A control diet based mainly on agro-industrial by-product palm kernel meal was formulated to meet the nutrient requirement of growing rabbits. Other conventional protein and energy rich ingredients such as maize, groundnut cake (GNC) and fish meal (FM) were included as composite at levels up to 17% of the weight. Bacterial protein meal (Streptomyces sp., species not specified by the manufacturer) with a crude protein, fat and fibre content of 70, 6.5 and 4.1%, respectively was added to the control diet (diet I) either as a replacement for FM at 0, 20 and 40 g/kg in diets I, II and III or as a replacement for GNC at 34 and 68 g/kg in diets IV and V, respectively. Each diet was offered to four rabbits housed individually in raised metal hutches with wire screen floors with each hutch representing an experimental unit. The rabbits were individually weighed on a weekly basis until the end of the experiment. Water and feed were supplied ad libitum and daily voluntary feed intake was monitored. Growing rabbits responded non-significantly (p> 0.05) in feed intake, body weight gain and feed conversion to BPM as a replacement for either FM or GNC over the 84 days of experiment. Six rabbits (3 rabbits from each treatment) on diet I (zero inclusion of BPM) and diet V (highest level of BPM inclusion) were slaughtered at 12 weeks
to determine carcass composition. The inclusion of BPM in diet V reduced the skin weight significantly (p<0.004) and kidney fat weight (p<0.067), while dressing percentage and other carcass indices were not significantly (p>0.05) affected. It was concluded that BPM can completely (to 100 %) replace FM and GNC in the diet of growing rabbits. BPM also reduced kidney fat content (which is an index of carcass fatness). BPM can be fed (up to 6.8% of the total diet) to 5 - 6 weeks old rabbits through finishing with no adverse effect on growth or carcass characteristics.

Key words: Rabbit, feedstuff, microbes, carcass, performance