Effects of feeding raw or reconstituted high tannin red sorghum on nutrient utilisation and certain welfare...

1. A feeding trial was conducted on 360 1-d-old chicks from 0 to 6 weeks of age to assess the effect of processed high tannin red sorghum in the diet of broiler chickens on nutrient utilisation and certain welfare parameters. 2. Each of 9 dietary treatments was allotted to 4 groups (replicates) of chicks in a completely randomised design. The treatments were a maize-soy based standard broiler diet (control, RS(0)) and eight test diets formulated by incorporating either raw red sorghum (RS(25), RS(50), RS(75), RS(100)) or reconstituted red sorghum (RS(25)(R), RS(50)(R), RS(75)(R), RS(100)(R)) replacing 25, 50, 75 or 100% of maize from the control diet. 3. The tannin content was reduced from 23 to 16 g/kg in reconstituted red sorghum. 4. Utilisations of nitrogen, calcium and phosphorus retention were similar in all the dietary groups. 5. The cell-mediated immune response measured as footpad index (FPI) value of birds given raw red sorghum was significantly higher than in control and reconstituted red sorghum groups. Similarly, comparatively better humoral response measured as HA titre value was observed in raw red sorghum based groups than in reconstituted ones. 6. Plasma albumin, globulin, protein, glucose, calcium, phosphorus, SGOT, SGPT and uric acid levels did not differ significantly due to dietary treatments. 7. Mild histopathological changes were observed in liver and kidney tissues of birds given raw red sorghum. 8. From the present study, it is concluded that (1) the reconstitution of high tannin red sorghum resulted in about 30% reduction in its tannin concentration; (2) the feeding of reconstituted sorghum based diets to broiler chickens did not exert any appreciable influence on nutrient utilisation, blood biochemicals and enzymes and gross pathological changes; and (3) the birds fed on raw red sorghum exhibited higher immuno-responsiveness in comparison to their reconstituted counterparts.