Journal of Animal Science and Veterinary Medicine

The use of non-conventional feed resources either as replacement or as a supplement in the nutrition of livestock cannot be overemphasised. The shortage of feed resources for livestock and poultry feeding diverted the majority of research in the field of animal nutrition to look into possibilities to overcome this crisis; however, a possible and perhaps the most viable proposition could be the inclusion of non-conventional feed resources in livestock rations with suitable and complete feed technology that can utilise the feed sources with maximum efficiency. Therefore, this study was carried out to estimate the protein quality of raw and processed sorrel (Hibiscus sabdariffa L.) seed, and how well the protein is digested, absorbed and utilised in Wistar rats, before it can be utilised and applied in feeding rabbits. Thirty 3-4-week-old weanling Wistar rats weighing 67.00 ± 0.7 g were randomly allotted into six dietary treatments of five rats each and fed the experimental diets for 28 days. The dietary layout was: T₁ = (control) casein, T₂ = raw sorrel seed, T₃ = boiled sorrel seed, T_{4 =} soaked sorrel seed, T₅ = fermented sorrel seed, T₆ = nitrogen-free diet. Growth performance, protein quality indices, serum biochemical indices and relative organ weights were assessed. The results showed that the average daily weight gain value (1.73 g) recorded in the casein-based diet (Control) was similar to the values recorded in boiled (1.18 g), soaked (1.34 g), and fermented sorrel seed meal (1.26 g) when compared with rats fed raw sorrel seeds (0.68 g) and that of the nitrogen-free diet groups (-1.36 g). Feed conversion ratio and protein efficiency ratio, however, showed a similar trend for both rats on the control and processed sorrel seed-based groups. There were, however, no significant differences (p>0.05) in the values recorded for crude protein digestibility, biological value, Net protein ratio and nitrogen retention of the casein-based diet and that of the soaked sorrel seed meal group. The total protein recorded in rats fed the casein-based diet did not differ significantly (p>0.05) from the rats fed the processed sorrel seed meal groups. In addition, albumin and globulin values showed a similar trend. The Aspartate Amino Transferase (AST), Alanine Amino Transferase (ALT), Alkaline Phosphatase (ALP) and Urea levels recorded in rats fed casein-based diets did not differ significantly (p>0.05) from the values recorded in rats fed processed sorrel seed meal. The relative organ weights of Wistar rats fed a casein-based diet, raw, processed sorrel seed and a nitrogen-free diet on kidney, spleen, liver, lungs and heart were recorded. However, there were no significant (p>0.05) differences in the values recorded in liver and lungs, while the values obtained for the kidney, spleen and heart differed significantly (p<0.05) among the treatment groups. It was concluded that rats fed soaked sorrel seed meal gave similar results to the control (casein-based diet) because it enhanced average daily weight gain, crude protein digestibility, biological value, and net protein utilisation.