Effects of substituting sow and weaner meal with brewers' spent grains on the performance of growing pigs in Rwanda.

Nutrient composition of brewers' spent grains (BSG) from two industries and sow and weaner meal (SWM) were different (p < 0.05). In completely randomised design (CRD), thirty (30) Landrace x Pietrain crosses 35 to 40 ± 5 kg were randomly allocated to 10 pens each with 3 pigs based on the initial weight. Five diets were assigned to pig, where BSG replaced SWM at 0% (T1), 25% (T2), 50% (T3), 75% (T4) and 100% (T5) on DM basis. Daily feed intake and weekly live weight, feed conversion ratio (FCR) and the net profit were recorded for 42 days. Feed intake increased from T1-T3 and then decreased (p < 0.05). The average daily gains (ADG) were different (p < 0.05), but T1 to T3 were similar (p > 0.05). FCR was similar (p > 0.05) from T1 to T3 but different for T4 and T5 (p < 0.05). Feed cost decreased with the increase in BSG levels. The net return was highest in T3 (50% BSG) than in T1 and T2 but lower in T5. It was concluded that BSG can replace 50% SWM in grower pigs' diets without adverse effect on daily gain with good economic returns.