KASIMA, J. S.MUGONOLA, B.ALIRO, T.NDYOMUGYENYI, E. K.2025-09-082025-09-082021-06Kasima, J. S. Mugonola, B. Aliro, T. and Ndyomugyenyi, E. K. 2021. Effect of substituting a commercial grower diet with fermented sweet potato vine-cassava tuber-based diet on the performance of growing pigs. African Journal of Rural Development 6 (2):44-52.24152838http://hdl.handle.net/20.500.14270/647In Uganda, the major limitation to pig production is the high cost of quality feeds. Consequently, smallholder farmers resort to using non-conventional feedstuffs within their surroundings, which are seasonal and do not solely meet the nutritional requirements of the pigs. In order to reduce feed costs, this study assessed the performance of growing pigs fed on a mixture of a commercial diet and a fermented composite of commonly used local feedstuffs namely sweet potato vines (SPV), cassava tubers (CT) and rice bran (RB). A completely randomised block design with two treatments (diets), each replicated three times was adopted for the study. The diets were; commercial diet (control), and a 1:1 mixture of commercial diet and fermented sweet potato vine-cassava tuber-rice bran composite. The chemical composition of SPV, CT and RB varied, with SPV having the highest crude protein (10.8%), CT having the highest digestible energy (3032 Kcal/kg) and RB having the highest crude fibre (20.3%). The crude protein content of the commercial feed was higher (16.5 %) than that of the mixture (13.33 %), while the mixture had a higher crude fibre content (11.6 %) than the commercial feed (6.3 %). However, the fat content and digestible energy content of the two diets did not differ. Grower pigs fed on the commercial diet registered higher daily weight gains and better feed conversion ratio (p<0.05) than those fed on the 1:1 mixture of the commercial diet and fermented composite. Therefore, feeding the 1:1 mixture of commercial and fermented SPV-CT-RB feeds to pigs lowered the performance of grower pigs and did not meet the goal of reducing feeding costs. Further research should be conducted at different levels of substitution of the commercial with the mixed feed to establish the combination that can reduce feeding costs without compromising the performance of the pigs.enCommercial dietfeeding costsfermentationnon-conventional feedstuffspig productionArticle