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Objetivou-se com este estudo avaliar a produtividade e o valor nutritivo das gramíneas forrageiras tropicais: Brachiaria brizantha cvs. Piatã, Xaraés e Marandu, Panicum maximum cv. Mombaça e B. ruziziensis cv. Kennedy, em sistema de integração lavoura-pecuária (ILP), na segunda safra, buscando novas alternativas de produção de forragem para alimentação animal no outono-inverno. Utilizou-se delineamento experimental de blocos ao acaso em esquema de parcelas subsubdivididas, com quatro repetições. Os tratamentos das parcelas corresponderam às cinco forrageiras, às subparcelas corrresponderam a três sistemas de cultivo (monocultivo, consórcio com milho sem supressão e consórcio com milho com supressão), e às sub-subparcelas, quatro intervalos de corte das forrageiras (50, 90, 125 e 195 dias após a emergência, DAE). O experimento foi conduzido no período de fevereiro a setembro de 2014. As produtividades de matéria seca, obtidas aos 195 DAE, referentes aos três sistemas de cultivo (monocultivo, consórcio sem supressão e com supressão), foram de 18,45; 7,15 e 3,05 t ha-1, respectivamente, e os teores de proteína bruta da lâmina foliar das forrageiras decresceram linearmente entre os intervalos de corte, de 50 a 195 DAE, de 19,95 % para 9,70%. O cultivo de forrageiras tropicais em sistemas integrados na segunda safra produz forragem de alta qualidade e quantidade para o outono-inverno. As gramíneas tropicais Panicum maximum cv. Mombaça e Brachiaria brizantha cvs. Xaraés e Piatã apresentaram maior produtividade de folhas e proteína bruta, em comparação às demais forrageiras em estudo. Em termos de valor nutritivo, Brachiaria ruziziensis cv. Kennedy foi superior aos capins Mombaça e Xaraés, porém apresentou menores produtividades de matéria seca total, folha e proteína bruta. De maneira geral, os capins Xaraés, Piatã e Mombaça são os mais indicados para o cultivo na segunda safra em sistema de ILP visando a produção de forragem para alimentação animal.

The aim of the current study is to assess three integrated systems presenting different eucalyptus tree densities due to animal and forage production. The following integrated systems were assessed: crop-livestock-forest with 357 eucalyptus trees ha-1 (ICLF1); crop-livestock-forest with 227 eucalyptus trees ha-1 (ICLF2); and crop-livestock with 5 remnant native trees ha-1 (ICL). The randomized block experimental design was applied in a split-plot scheme with four replicates. The Average Daily Gain (ADG, g animal-1day-1) and the live-weight gain per area (LWG, kg ha-1) were applied to analyze animal performance, which was set by weighing the animals every 28 days (the animals previously fasted for 16h). Forage yield was higher in ICL during fall and winter; in summer, it did not differ from ICLF2. There was no forage yield difference between the ICL and ICLF2 systems in any of the assessed seasons; summer was more productive in ILPF1 than other seasons. The highest leaf crude protein contents (CP) in summer was recorded in systems ICLF1 and ICLF2, and the highest value recorded in fall was found in ILPF1; the lowest was found in ILP. On the other hand, the highest leaf NDF contents in summer were found in ILP. The highest ADG were found in summer. The highest LWG values recorded for the ICL and ICLF2 systems were collected in summer and fall; there was no difference in any of the three systems in winter. The LWG was higher in all system in summer. The ICLF2 emerged as the system (with trees) most appropriate for beef cattle production. Despite the shading interference on forage production, such condition is compensated by the best nutritional contents such as CP. The ICLF2 system allowing an annual LWG of 83% in relation to the ICL system during the fifth year of establishment of the systems.

The goal was to evaluate the chemical composition and fermentation pattern of elephant grass (Pennisetum purpureum Schum. cv. Roxo) silage with different levels of soybean hulls or rice bran. Two trials were conducted, comprising of a completely randomized design, with four replicates each. Treatments consisted on the addition of 0%, 5%, 10%, and 15% of soybean hulls or rice bran to unwilted green elephant grass forage. Large PVC silos were used adopting a density of 600 kg of green mass m-3. The silos were opened 40 days after ensiling. The results revealed that the inclusion of 10% soybean hulls increased elephant grass forage dry matter (DM) content to 31%, but did not alter the water soluble carbohydrate (WSC) content or buffering capacity. The resultant silages exhibited good fermentation patterns in terms of pH (less than 3.97) and NH3-N (4.07% total N) levels. The inclusion of rice bran increased both DM and WSC content in the forage, improving the fermentation pattern of silages (P < 0.05). This too was verified by a pH lower than 3.92 and a maximum NH3-N of 4.23% of the total N. The inclusion of 10% rice bran to the elephant grass improved the nutritional value of the forage to be ensiled and, hence, of the produced silage.