Com o objetivo de estudar a inclusão de 20, 35, 50, 65 ou 80% de farelo de melancia forrageira (Citrullus lanatus cv. citroides) (FMF) em dietas à base de feno de guandu (Cajanus cajan), foi realizado um ensaio de digestibilidade utilizando-se 20 cordeiros com 6 meses de idade e peso vivo de 11,2 ± 1,2 kg. O experimento constou de 20 dias de adaptação e 5 de coleta total de sobras e de fezes. O farelo de melancia forrageira e o feno de guandu apresentaram 95,3 e 95,75% de matéria seca (MS), 18,7 e 16,8% de proteína bruta (PB) e 38,8 e 64,3% de fibra em detergente neutro (FDN). Os níveis de farelo de melancia forrageira determinaram aumento quadrático nos consumos de MS, MO, PB, FDN, FDA, hemicelulose e carboidratos totais. O consumo de extrato etéreo não foi alterado, mas o consumo de CNF teve aumento linear conforme aumentaram os níveis de farelo de melancia forrageira. Os coeficientes de digestibilidade de MS (58%), PB (69%), FDN (41%) e EE (85%) não foram influenciados pelo nível de farelo de melancia forrageira. As digestibilidades de MO (54 a 62%), FDA (36 a 49%) e carboidratos totais (47 a 58%) variaram linear e positivamente, enquanto a digestibilidade da hemicelulose teve comportamento inverso. As dietas proporcionaram consumo de matéria seca que atendeu a exigência dos animais. Os coeficientes de digestibilidade observados foram satisfatórios. O farelo de melancia forrageira pode ser indicado para compor dietas à base de feno de guandu em níveis de 35 a 66% da matéria seca.
In order to study the inclusion of forage watermelon (Citrullus lanatus var. Citroides) meal (FWM) in pigeon pea hay based diets (Cajanus cajan) (PPH), a digestibility trial in sheep was carried out for testing five levels of FWM (20, 35, 50, 65 and 80%). Twenty lambs with an average age of six months and live weight of 11.2 kg (± 1.2) were used. The experimental period was twenty days for adaptation and five days for total refuses and feces collection. The chemical composition of diet ingredients was determined, being the levels of dry matter (DM) 95.3 and 95.75%, crude protein (CP) 18.7 and 16.8%, neutral detergent fiber (NDF) 38.8 and 64.3% for WFM and PPH, respectively. The water, DM, organic matter (OM), CP, ether extract (EE), NDF, acid detergent fiber (ADF), hemicellulosis (HCEL), non-fibrous carbohydrates (NFC), total carbohydrates (TCOH) intakes, as well as the DM, MO, CP, EE, NDF, ADF, HCEL and TCOH digestibilities were accurately measured. The DM, OM, CP, NDF, ADF, HCEL and TCOH intakes showed a quadratic behavior according to the FMF levels. The ether extract intake remained unchanged, while the NFC intake was linearly positive. The DM (58%), MO (69%), NDF (41%) and EE (85%) digestibility coefficients were not significantly influenced by the forage watermelon meal levels. The OM (54 to 62%), ADF (36 to 49%) and TCOH (47 to 58%) digestibility ranged linear and positively, while the HCEL digestibility showed the opposite behavior. The experimental diets provided dry matter intake enough to meet the animal requirements. The digestibility coefficients observed were satisfactory. The forage watermelon meal can be used in the guandu hay based diets in the levels from 35 to 66% of dry matter.