Abstract This study reports the use of statistical mixture design as a tool for the simultaneous production of lipase, CMCase, α-amylase, and β-glucosidase by Aspergillus niger under solid-state fermentation. Wheat bran, soybean meal, cottonseed meal, and orange peel were used as substrates, either individually or combined in different formulations, to study their synergistic or antagonistic effects on production of the enzymes. The highest lipase (323 U g-1) and CMCase (10 U g-1) activities were detected after 48 h, while the maximum activities of α-amylase (18 U g-1) and β-glucosidase (15 U g-1) occurred at 72 and 96 h, respectively. Considering the substrate formulation, the ternary mixture of wheat bran (1/3), soybean meal (1/3), and cottonseed meal (1/3) was the most versatile, showing production of CMCase (>5 U g-1) and α-amylase (>8 U g-1) at 24 h, lipase (>320 U g-1) at 72 h, and β-glucosidase (>10 U g-1) at 48 h.

RESUMO. Surgiu recentemente a técnica de produção de silagem de sistemas consorciados de cultura anual e forrageira tropical, na integração lavoura-pecuária, com intuito de minimizar déficit de forragens na entressafra. Sendo assim, objetivou-se avaliar as características fermentativas e valor nutritivo da silagem de sorgo e cultivares de Urochloa brizantha em monocultivo e consorciado em diferentes sistemas de semeadura. O delineamento experimental utilizado foi o de bloco ao acaso, com três repetições, em esquema fatorial 3x2+4, sendo três cultivares de Urochloa brizantha (Marandu, Xaraés e Piatã), consorciadas com sorgo granífero em dois sistemas de semeadura (linha e entrelinha) e quatro monocultivos (Sorgo, Marandu, Xaraés e Piatã). A forma de semeadura dos sistemas consorciados não interferiu nas características fermentativas e químico-bromatológicas das silagens. O mesmo foi obtido para cultivares de Urochloa brizantha. As silagens do consórcio do sorgo com cultivares de Urochloa brizantha apresentaram menores valores de pH, capacidade tampão, N-NH3, ácido acético e butírico e maior ácido lático, além da qualidade superior, quanto aos parâmetros matéria seca, extrato etéreo e nutrientes digestíveis totais. Portanto, silagens dos sistemas consorciados garantem adequado processo fermentativo e qualidade nutricional, constituindo interessantes opções de volumosos suplementar para ser utilizado na entressafra na alimentação animal.

ABSTRACT. Recently it has emerged a technique for silage production of intercropping systems of annual crop with forage through crop-livestock integration, aiming to reduce the deficit forage in the offseason. The study was conducted to evaluate the fermentation characteristics and nutritional value of silage of sorghum and Urochloa brizantha cultivars monocropped or intercropped in different planting systems. The experiment was a randomized block design, with three replications, in a 3x2+4 factorial arrangement, with three cultivars of Urochloa brizantha (Marandu; Xaraes and Piata) intercropped with grain sorghum in two planting systems (row and between rows) and four monocrops (Sorghum, Marandu palisadegrass, Xaraes palisadegrass and Piatã palisadegrass). The planting system of intercropping systems did not interfere with fermentation characteristics and chemical composition of silages. The same was found for Urochloa cultivars. Silages from intercropping sorghum with Urochloa brizantha cultivars had lower pH values, buffering capacity, acetic and butyric acids and higher values of lactic acid, besides showed superior quality, as for the parameters dry matter, ether extract and total digestible nutrient than silages from grasses produced in monocropping system. Therefore, silages of intercropping systems ensure fermentation and nutritional quality, providing interesting supplementary bulky options to be used in the offseason for feeding animals.