A consorciação com espécies hibernais vem sendo utilizada como alternativa para aumentar a produtividade de entressafra (outono/inverno) das pastagens irrigadas. Este trabalho foi conduzido no período de maio a outubro de 2009, no município de Icaraíma, Estado do Paraná, com o objetivo de avaliar a produtividade e a composição morfológica do capim Tifton 85 com sobressemeadura de forrageiras de inverno em sistema irrigado. O delineamento utilizado foi de blocos casualisados com quatro repetições e com medidas repetidas no tempo. As parcelas experimentais foram implantadas por meio de cinco tratamentos, sendo três na forma de sobressemeadura de aveia, utilizando os genótipos Iapar 61, IPR 126, e FMS2 em pastagem de capim Tifton 85 e, um na forma de sobressemeadura de aveia em consórcio com centeio (IPR 126 + IPR 89), também em capim Tifton 85 e, por fim, um tratamento testemunha com apenas capim Tifton 85 sem sobressemeadura. A sobressemeadura com aveia IPR 126 obteve a maior produtividade acumulada, igual 4.102 kg MS ha-1, com razão folha/colmo superior ao capim Tifton 85 exclusivo, iguais 1,77 e 1,08, respectivamente. No entanto, as sobressemeaduras de forrageiras de inverno não aumentaram a produtividade total da pastagem.

Intercropping with cool season species has been used as an alternative to increase productivity off-season (fall/winter) of irrigated pastures. This study was conducted from May to October 2009 in Icaraíma, Paraná State, to evaluate the productivity and morphological composition of the Tifton 85 grass overseeded with winter forage in irrigated system. The experiment was a randomized block design with four replicates and repeated measures over time. The experimental plots consisted of five treatments, three as oats overseeding using the genotypes IAPAR 61, IPR 126, and FMS2 on Tifton 85 pasture and one as overseeding of oats combined with rye (IPR 126 + IPR 89) also on Tifton 85 grass and, finally, a control with only Tifton 85 without overseeding. The overseeding of IPR 126 oats achieved the highest cumulative productivity, 4102 kg DM ha-1, with leaf/stem ratio higher than that of exclusive Tifton 85 exclusive, 1.77 and 1.08, respectively. However, overseeding of winter forages did not increase the overall productivity of the pasture.

The experiment was carried out to evaluate the structural characteristics, biomass accumulation, chemical composition and in vitro digestibility of dry matter and crude protein of white oat (Avena sativa L. IPR 126) under different management systems. Grazing, cut at two heights (15 and 20 cm) and free growth were all evaluated in three periods (July, August and September) with a 28-day average interval between evaluations. In the free growth system, samples at 15 and 20 cm were also taken at the intervals chosen for cutting and grazing. The experimental design was in randomized blocks with three replications, arranged in a 3 × 2 factorial split plot design over time; systems of management and heights were the factors of plots, and time was taken as subplot. There was higher straw production under free growth, but, with decreased chemical quality from the first to the second period and from the second to the third one, with 236.4, 172.5, and 91.4 g/kg crude protein values, respectively. Regarding cutting and grazing systems, they showed structural changes in tillering, which was favored by the cut, but with some reduction in the periods. Nutritional quality values were close to cutting and grazing with high crude protein content (216.6 g/kg), adequate neutral detergent fiber (535.4 g/kg) content and high in vitro digestibility of dry matter (826.3 g/kg). Management heights promoted few changes in the characteristics evaluated. After the third period, cutting and grazing systems showed no suitable residual straw for ground covering and set a summer crop under no-tillage system, with 738.39 kg/ha of residual dry matter on average.

Foram conduzidos dois ensaios de digestibilidade, objetivando-se estudar o valor nutricional de quatro diferentes milhetos (BN2, COMUM, IAPAR e IAPAR-REPASSE) processados em moinhos com três tipos de peneiras (diâmetros de furo de 3, 2 e 1 mm). Os coeficientes de digestibilidade (CD) da energia bruta (CDEB) e o coeficiente de metabolizabilidade (CM) da energia bruta (CMEB) relativos à peneira de 3 mm foram: 63,09 e 61,20% (COMUM); 71,57 e 69,66% (IAPAR) e 67,39 e 65,60% (BN2). Os CD e CM da energia do COMUM foram inferiores ao IAPAR e ambos foram semelhantes ao BN2. O IAPAR-REPASSE apresentou CDEB de 70,62% e CMEB de 68,49%, semelhante ao IAPAR. O IAPAR-1 mm apresentou maior CDEB e CMEB (84,61 e 81,41%) que o IAPAR-3 mm (70,59 e 68,71%) e o IAPAR-2 mm (77,73 e 75,46%). Os valores de energia digestível (ED) e energia metabolizável (EM) para o IAPAR (3 mm) foram de 3.030 kcal/kg e 3.001 kcal/kg, respectivamente. Verificou-se ED de 3.083 e 3.355 kcal/kg e EM de 2.993 e 3.228 kcal/kg para o IAPAR (2 e 1 mm). O IAPAR-REPASSE apresentou valores de 2.849 kcal/kg (ED) e 2.763 kcal/kg (EM), enquanto o COMUM (3 e 2 mm), de 2.574 e 3.022 kcal/kg (ED) e 2.497 e 2.932 kcal/kg (EM), e o BN2 (3 e 2 mm), de 2.692 e 3.047 kcal/kg (ED) e 2.620 e 2.966 kcal/kg (EM). As diferentes variedades de milheto apresentaram variações em sua composição química que resultaram em diferenças no valor nutricional, sendo o milheto IAPAR o que apresentou melhor valor, seguido pelo BN2 e o COMUM.

Two digestibility trials were carried out, to study the nutritional value of four types of pearl millet (BN2, Comum, Iapar and Iapar-Repasse), grounded through 3, 2, and 1 mm screen. The digestibility coefficient (DC) of gross energy (GEDC) and gross energy metabolization coefficient (GEMC) relative to 3 mm screen were: 63.09 and 61.20% (Comum); 71.57 and 69.66% (Iapar) and 67.39 and 65.60% (BN2). The GEDC and GEMC of COMUM were lower than IAPAR and both were similar to BN2. The IAPAR-REPASSE showed GEDC (70.62%) and GEMC (68.49%) similar to the Iapar. The Iapar- 1 mm (84.61 and 81.41%) showed higher GEDC and GEMC than Iapar-3 mm (70.59 e 68.71%) and Iapar-2 mm (77.73 e 75.46%). The values of digestible energy (DE) and metabolizable energy (ME) for the Iapar (3 mm) were 3,030 kcal/kg and 3,001 kcal/kg, respectively. The IAPAR (2 and 1 mm) showed DE of 3,083 and 3,355kcal/kg and ME of 2,993 and 3,228 kcal/kg. The Iapar-Repasse showed the values of: 2,849 kcal/kg (DE) and 2,763 kcal/kg (ME). The COMUM (3 and 2 mm) showed values of: 2,574 and 3,022 kcal/kg (DE) and 2,497 and 2,932 kcal/kg (ME). The BN2 (3 and 2 mm) showed values of: 2,692 and 3,047 kcal/kg (DE); 2,620 and 2,966 kcal/kg (ME). The different pearl millets showed variations in chemical composition. The differences result in variations on nutritional values. The Iapar pearl millet, showed the best values, followed by BN2 and Comum.

O objetivo deste trabalho foi avaliar o ganho em peso de novilhos em crescimento e terminação, o ganho de peso vivo por hectare e a qualidade da forragem em diferentes sistemas de produção a pasto, no inverno e verão. No inverno, foram avaliados sistemas de produção em pastagem de aveia preta (PAV) ou em grama estrela roxa (GER). No verão, foram avaliados sistemas de produção em pastagem de milheto (MIL), capim-Mombaça (MOM) ou grama estrela roxa (GER) e o efeito do sistema de produção utilizado no inverno sobre o desempenho animal no verão. No inverno, o sistema PAV propiciou maiores peso final (PF 381 kg), ganho médio diário (GMD 0,64 kg/dia) e ganho de peso vivo/ha (GPV/ha 233 kg), quando comparado ao sistema GER (PF 332 kg, GMD -0,01 kg/dia e GPV/ha -1,38 kg). Os animais mantidos no sistema PAV no inverno apresentaram menor desempenho no verão. Para os animais em crescimento, o sistema PAV no inverno e MIL no verão resultou em maior peso vivo final (447 kg) em relação aos sistemas PAV no inverno e MOM no verão (414 kg) e GER no inverno e MOM no verão (397 kg). Para os animais em terminação, não houve diferença no peso vivo final, no rendimento de carcaça e no peso de carcaça quente entre os sistemas avaliados. No inverno, a PAV e a GER apresentaram média de 15 e 5% de proteína bruta (PB), 51 e 81% de fibra em detergente neutro (FDN), 31 e 51% de fibra em detergente ácido (FDA) e 81 e 45% de digestibilidade in vitro da matéria seca (DIVMS). No verão, a GER, o MOM e MIL apresentaram média de 9, 9 e 18% de PB, 65, 64 e 54% de FDN, 40, 39 e 32% de FDA e 55, 60 e 80% de DIVMS.

The aim of this work was to evaluate the weight gain of growing and finishing steers, the life weight gain per hectare, and the forage quality in different grass production systems in the winter and summer. In the winter, the black oat pasture (BOP) and star grass (SGA) production systems were evaluated. In the summer, the millet (MIL), Mombaça (MOM), and star grass (SGA) production systems were evaluated and the effect of the production systems used in the winter on the animal performance in the summer was evaluated too. In the winter, the BOP system resulted in higher final body weigh (FW 381 kg) higher average daily gain (ADG 0,64 kg/day) and higher life weight gain/ha (LWG/ha 233 kg) when compared with SGA system (FW 332 kg, ADG -0,01 kg/day and LWG/ha -1,38 kg). The animals kept on BOP system in the winter had lower performance in the summer. For the growing animals, the BOP in the winter and MIL in the summer resulted in higher final body weigh (447 kg) when compared with BOP in the winter and MOM in the summer (414 kg) and SGA in the winter and MOM in the summer (397 kg). For the finishing steers, there was no difference between the systems evaluated. In the winter, the BOP and SGA presented means levels of 15 and 5% of crude protein (CP), 51 and 81% of neutral detergent fiber (NDF), 31 and 51% of acid detergent fiber (ADF), and 81 and 45% of in vitro dry matter digestibility (IVDMD). In the summer, the SGA, MOM and MIL presented means levels of 9, 9, and 18% of CP, 65, 64, and 54% of NDF, 40, 39, and 32% of ADF, and 55, 60, and 80% of IVDMD.