Activated Charcoal Affects the Bioavailability of Cyanide in Weaned Pigs: Growth Performance, Nutrient Retention and Cyanide Degradability in Various Segments of the Gastro-Intestinal Tract

Sixty-four weaned pigs (Large White-Landrace, age = 8 weeks) were assigned to eight groups with eight pigs per group, and each pig was a replicate. A set of four diets formulated, contained cassava root meal (CRM) at 0%, 25%, 50% and 75% replacing maize such that they were without activated charcoal while the next set of four diets had activated charcoal (AC) at 40g/kg diet as a supplement. Thus, making eight diets. The experiment was a 2 x 4 factorial arrangement in a completely randomised design. The result indicated that the interaction effect differs significantly (p< 0.05) for Live Weight (LW), Daily Weight Gain (DWG), Daily Feed Intake (DFI), Feed-Gain ratio (F:G) and Hydrogen Cyanide (HCN) intake. Diets with activated charcoal supplementation (ACS) differed significantly (p<0.05) for LW such that the control group had a higher value (29.06kg) which is similar to that of groups 2 (28.25kg) and 3(28.63kg). Diets with ACS (0% and 50% CRM) for DWG recorded the highest value (0.35kg/day) (p<0.05). The least F:G was observed in diet with 50% CRM with ACS. Cyanide intake increased with increasing CRM with or without AC supplementation. Apparent digestibility of CP, EE, CF, NFE and HCN were significantly affected (p<0.05) (i.e by both varying levels of CRM and activated charcoal supplementation) except for nitrogen-free-extract at 25% CRM level where charcoal supplementation had no effect. Digestibility of HCN improved significantly (<0.05) across the CRM levels. The interaction effects of CRM and ACS differ (p<0.05) for cyanide degradability in the stomach, caecum and large intestine. It can be concluded that weaned pigs fed 50% CRM with ACS had higher DWG and F:G. Diets without ACS had significantly better nutrient digestibility at 0% level (control) except for CP and ash at 50% CRM. ACS significantly (p<0.05) influenced HCN degradability but more in the stomach and caecum at 25% CRM level. For improved weight and feed conversion, 50% CRM replacement for maize with ACS is recommended.