Determination of true metabolizable energy of raw and heat-treated <i>Cassia tora</i> seed meal

Abstract

True metabolizable energy determination of raw and processed C. tora seed meal was undertaken. Fifty (50) arbor acre broiler chicks, reared to 10 weeks were used, out of which fifteen (15) birds were randomly selected for the trial. The birds were weighed, randomly divided into groups A (fed birds) with 12 birds and B (unfed birds) with three birds. Three birds each in group A were randomly assigned to raw and different processes C. tora seed meal viz toasted, boiled and soaked-and-boiled diets, replicated thrice, with one bird per replicate. The birds were placed in individual metabolism cages and fasted for 24 hours. Thereafter each birds in group A were force-fed 25g of raw and processed Cassia tora, returned to their cages and the time recorded, and trays were placed for collection of excreta, after 24 hours. Birds in the control (group B), were subjected to fasting for 48 hours, and their faeces were also collected. All feed and faecal samples were sundried, bulked, milled and analyzed for energy using the adiabatic oxygen bomb calorimetric method. The results showed significant (P<0.05) difference across the mean TME measured between the raw and processed seeds. It was also observed that boiled and soaked-and-boiled processing methods resulted in 92.07% and 91.50% efficiency of energy bioavailability of Cassia tora while toasting method recorded 89.10%. The mean TME values ranged between 2.08Kcal/g for birds force-fed the raw to 2.80 Kcal/g for birds force-fed the soaked-and-boiled seeds. The boiled and soaked-and-boiled seeds had the highest TME values, while the lowest TME value was recorded for raw Cassia tora seeds. In conclusion, processed Cassia tora seeds encouraged better true metabolizable energy than the raw, and are effective, resulting in up to 91% efficiency of energy bioavailability of Cassia tora seeds.