Effect of fibre and digestible energy levels on retail cuts, gut characteristics and morphology of growing rabbits

The retail cuts, gut characteristics and morphology of rabbits fed with varying dietary fibre and digestible energy (DE) levels were measured in a 70-d feeding trial using 135 weaner rabbits. The experiment was designed as a 3 × 3 factorial arrangement of treatments having 3 levels of dietary fibre (low, optimum and high) and 3 levels of DE (low, optimum and high). The rabbits were allotted to 9 dietary groups consisting of 15 rabbits each. Main effect of fibre and DE showed that dressing out percentage (P < 0.05), chilled carcass weight (P < 0.05) and reference carcass weight (P < 0.01) increased with increasing inclusion levels of fibre. Rabbits fed with (430 – 456 g/kg NDF, 249 - 253 g/kg ADF) had the highest (P < 0.05) weights of thoracic cage, loins, hind part, small intestine, empty caecum and highest (P < 0.05) villus height in the duodenum and jejunum. Rabbits fed (10.5 – 11 MJ/kg) diets had the least (P < 0.05) chilled and reference carcass weight. Interaction effect of fibre and DE showed that rabbit fed (445.70g/kgNDF, 252.10g/kgADF and 8.01MJ/Kg) diet recorded the highest (P < 0.05) chilled carcass weight. Rabbit fed with low fibre (249 – 258 g/kg NDF, 149 - 157 g/kg ADF) diets not withstanding the level of DE had low (P < 0.05) chilled and reference carcass weight. The villus height of the duodenum and crypt depth of the jejunum increased (P < 0.05) with increasing level of dietary fibre irrespective of the level of digestible energy. In conclusion, feeding of (440.41 g/kg NDF, 250.09 g/kg ADF, 10.52MJ/kg) diets to rabbits favoured improved retail cuts, gut characteristics and gut morphology.Keywords: Weaner rabbits; Carcass yield; Organ weights; Gut characteristics; Gut morpholog

Effect of fibre and digestible energy levels on growth performance, apparent nutrient digestibility and caecal fermentation of growing rabbits

A seventy-day feeding trial was conducted to investigate the effect of dietary fibre and digestible energy (DE) level on growth performance, apparent nutrient digestibility and caecal fermentation of growing rabbits. The experiment was laid out in a 3 × 3 factorial arrangement of 3 levels of fibre (low (249 – 258 g/kg NDF, 149 - 157 g/kg ADF), optimum (349 – 381 g/kg NDF, 188 - 193 g/kg ADF) and high (430 – 456 g/kg NDF, 249 - 253 g/kg ADF)) and 3 levels of DE (low (8 – 8.5 MJ/kg), optimum (10.5 – 11 MJ/kg) and high (12 – 12.30 MJ/kg)). A total of one hundred and thirty five weaner rabbits were allotted to 9 dietary groups of 15 rabbits each. Main effect of fibre showed that the final live weight and weight gain of rabbits increased (P < 0.01) while Ca retention reduced (P < 0.001) with increasing dietary fibre level. Rabbits fed (249 – 258 g/kg NDF, 149 - 157 g/kg ADF), had the worst (P < 0.05) feed to gain ratio. Rabbits fed (349 – 381 g/kg NDF, 188 - 193 g/kg ADF) had the highest apparent dry matter (P < 0.05), ether extract (P < 0.05), NDF (P < 0.001), ADF (P < 0.001) and organic matter digestibility (P < 0.001). Main effect of DE showed that rabbits fed high DE recorded the highest (P < 0.05) weight gain. Highest (P < 0.01) apparent dry matter, crude protein, ash, NDF, ADF, organic matter digestibility and Ca retention were recorded with rabbits fed optimum DE diet. Rabbits(445.70g/kgNDF, 252.10g/kgADF and 8.01MJ/Kg) recorded the highest (P < 0.001) final live weight, weight gain and feed intake (P<0.05) while rabbits fed (249 g/kg NDF, 149 g/kg ADF and 8.17MJ/Kg) had the least (P < 0.001) final live weight, weight gain, apparent dry matter digestibility, NDF and ADF digestibility. Highest (P<0.001) NDF digestibility was obtained with rabbits fed (370.79 g/kg NDF, 189.61 g/kg ADF and 10.84MJ/kg). Not withstanding the DE level of the diets, rabbits fed with (430 – 456 g/kg NDF, 249 - 253 g/kg ADF) recorded the highest (P<0.05) total VFA and acetic acid concentration. Rabbits fed (445.7g/KgNDF, 250.09g/KgADF and 10.52MJ/kg) recorded the best growth performance, improved caecal fermentation with no adverse effect on apparent nutrient digestibility.Keywords: Growing rabbits; Dietary fibre; Digestible energy; Caecal fermentatio

Short Communication: Visual assessment, proximate composition and cost analysis of three differently processed discarded vegetable-bovine blood-rumen content mixtures

With increased search for least-cost alternative feed resource in animal production, this study was conducted to determine the visual properties, chemical composition and cost analysis of three differently processed discarded vegetable-bovine blood-rumen content mixture as potential alternative feed resource. These mixtures were obtained by mixing whole bovine blood, discarded vegetable and rumen content at ratio 1:1:1 under different processing methods. The processed mixtures obtained were in three categories: discarded vegetable-fresh bovine blood-fresh rumen digesta (D1), discarded vegetable-ensiled bovine blood-fresh rumen digesta (D2) and discarded vegetable-fresh bovine blood-ensiled rumen digesta (D3). The mixtures were cooked and sun-dried to constant moisture content and thereafter were subjected to particle size reduction. Chemical composition of the products indicated a good potential nutritional quality with metabolizable energy and crude protein contents ranging from 9.66 to 10.49 MJ/kg and 40.79 to 50.21, respectively. Crude fibre concentrations were relatively low (8.39-13.14) for most of the products compared to conventional protein sources. Visual assessment of processed mixtures revealed D1 to be brownish in colour while D2 and D3 tend towards grey. In terms of odour, all three test mixtures were strongly pungent. Processed mixture D1 had an intermediate texture (it was neither finely ground nor coarse) where D2 and D3 had a finely ground texture. Cost analysis revealed a lower production cost for the three processed mixtures indicating its adequacy to replace soybean and other plant and animal protein sources in terms of their cost/kg inclusion in diet. Processed mixtures can serve as suitable replacements for soybean meal in terms of chemical constituents and reduced cost/kg feed for animal.Keywords: Bovine blood, rumen digesta, discarded vegetable, visual assessment, proximate composition, cost analysis