Weight analyses and nitrogen balance assay in rats fed extruded African breadfruit (Treculia africana Decne) based diets

  • TU Nwabueze
Keywords: African breadfruit (Treculia), extrusion, process optimization, nutritional quality, net protein utilization and protein efficiency ratio


Weight analyses and nitrogen balance assay in adult rats in raw and extruded African breadfruit (Treculia africana) based diets were carried out using response surface methodology in a central composite design. Process variables were feed composition (40 - 100 % African
breadfruit, 0 - 5 % corn and 0 - 55 % soybean, respectively), feed moisture (15 – 27 %) and screw speed (100 – 180 rpm). One hundred and two adult rats weighing 71 – 86 g were housed in stainless steel metabolism cages, and fed different diets comprising 5 (raw), 25 (extruded), standard casein and N-free diets in groups of 6 rats per
cage on the basis of body weight. Data generated were used in calculating nitrogen intakes and balances, biological values, net protein utilization and protein efficiency ratio during the 7-day feeding period. Rats fed the standard raw diet made from casein had the highest
food intake (47.20 g) while those fed diets made from 100 % African breadfruit had the least food intake (29.40 g). Food intake was generally higher in the extruded diets ranging from 35 g in diet containing 70 % African breadfruit, 5 % corn and 25 % soybean to 48.90 g for diets
made from 40 % African breadfruit, 5 % corn and 55 % soybean. Maximum body weight gain, carcass, organ and liver weights were 6.20, 53.80, 13.30 and 3.10 g for rats fed raw diets and 11.60, 93.40, 23.40 and 6.40 g respectively, for those fed extruded diets. Biological
values (0.77 - 0.94), net protein utilization (0.72 - 0.91) and protein efficiency ratio (1.04 - 2.22) for extruded diets were reported. Diet intake was quadratically affected by feed moisture and screw speed.

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eISSN: 0189-7241