Resumo: O objetivo deste trabalho foi avaliar três espécies de gramíneas tropicais quanto à produção de metano (CH4) in vitro e à degradabilidade da matéria orgânica, para determinar as relações entre a qualidade nutritiva das gramíneas e a produção de CH4. O capim-colonião (Megathyrsus maximus), o capim-braquiarão (Urochloa brizantha) e o capim-decumbens (Urochloa decumbens) foram avaliados. O capim-braquiarão apresentou os maiores teores de matéria orgânica, fibra em detergente neutro, fibra em detergente ácido e lignina, e o menor teor de proteína bruta. O capim-decumbens apresentou os maiores teores de hemicelulose e de nitrogênio em fibra de detergente neutro, além do menor teor de celulose. O capim-colonião e o capim-decumbens apresentaram maior produção total de gases do que o braquiarão. Além disso, o capim-colonião apresentou maior produção de CH4, e o capim-braquiarão, menor degradabilidade verdadeira da matéria orgânica e reduzido fator de partição, em comparação ao capim-decumbens. Maior produção de CH4 foi verificada em casos em que os valores de hemicelulose e fator de partição foram menores. A qualidade nutricional e a produção de CH4 das forragens avaliadas podem ser utilizadas como parâmetros a serem empregados, que visem a sustentabilidade da produção de ruminantes.

Abstract: The objective of this work was to evaluate three tropical forage species for their in vitro methane (CH4) production and organic matter degradability, in order to determine the relationships between forage grass nutritive quality and CH4 production. Guinea grass (Megathyrsus maximus), palisade grass (Urochloa brizantha), and signal grass (Urochloa decumbens) were evaluated. Palisade grass showed the highest organic matter, neutral detergent fiber, acid detergent fiber, lignin, and lower-crude protein content. Signal grass had the highest values for hemicellulose and neutral detergent fiber-nitrogen, and the lowest-cellulose content. Guinea grass and signal grass showed a higher-total gas production than palisade grass. Besides, Guinea grass showed an increased CH4 production, and palisade grass showed lower value for truly degraded organic matter, and reduced partitioning factor, in comparison to signal grass. An increased CH4 production was observed in cases of lower hemicellulose and paratitioning factor. The nutritive value and CH4 production of forages may be employed as parameters, aiming at the sustainability of ruminant production.

ABSTRACT The aim of this study was to evaluate the effect of three different grazing systems: isolated, alternate and simultaneous, on feed intake, performance and carcass characteristics of sheep. About 5.2 ha area of Tanzania grass (Panicum maximun Jacq cultivate Tanzania) was divided into 13 paddocks. This area was used as a stocking rate of two animal units (AU) per ha for 7 days’ occupation and 21 days rest. A total number of 58 animals were used consisting of 12 heifers and 30 Santa Ines lambs with the addition of 16 adult ewes that were used to stabilize grazing pressure in the isolated system. The sheep were fed on 200 g per head per day of concentrate and cattle 2 kg per head per day. The parameters determined were the following: weekly weight (WW), total live weight gain (LWG) and mean daily weight gain (MDW). Also dry matter intake was estimated 84 days after the start of the experiment using external indicators (Purified and Enriched Lignin) in addition to carcass traits and composition which were also estimated. The result obtained for carcass composition revealed that the muscle:bone ratio and bone percentage were better in the alternate system. Moreover, the simultaneous and isolated systems showed higher lamb performance than the alternate system, while there was no effect on dry matter intake. Furthermore, there was no difference of the different systems on carcass traits and feed intake of sheep. Nevertheless, the simultaneous grazing system showed better sheep performance than the alternate grazing system.

Objetivou-se com este experimento avaliar os efeitos de métodos alternativos de suplementação de cordeiros em aleitamento sobre seu desempenho e sobrevivência. Foram utilizados 84 cordeiros Santa Inês, 50 % machos e 50 % fêmeas, de partos simples e gemelares. Os animais foram divididos em três tratamentos: A (controle), B (200 mL de leite de vaca/animal/dia) e C (200 mL de leite de vaca, mais 20g de mistura múltipla/animal/dia). O experimento se inciou às três semanas de idade dos cordeiros e terminou ao desmame (2 meses). O peso dos ovinos ao desmame (PD) foi 10,90, 13,20 e 13,59 kg, para os tratamentos A, B e C respectivamente, e o ganho médio diário (GMD) foi de 126, 163 e 168 g/animal/dia, respectivamente. A taxa de mortalidade foi maior (P< 0,05) no grupo A em relação aos grupos B e C. O sexo dos animais influenciou significativaente (P<0,05) o GMD e PD. GMD e PD foram menores para os ovinos que morreram em comparação aos que sobreviveram: 7,94 kg contra 13,51 kg e 77 g contra 165g, respectivamente. Os gêmeos apresentaram GMD e PD menores (P<0,05) que os de parto simples. A suplementação com ou sem a mistura múltipla se mostrou eficiente, podendo aumentar a produtividade do sistema de produção.

The objective of this experiment was to evaluate the effect of alternative methods of feeding on the performance and mortality rate of suckling lambs. Eighty-four Santa Inês lambs, twins and singles, half male and half female, were used. The animals were divided into three groups: A (control), B (bovine milk) and C (bovine milk plus Multi-mixture). The experiment began when lambs were three weeks old and finished at weaning at 2 months of age. Each animal from group B received 200 mL of bovine milk daily; group C received 200 mL of bovine milk plus 20g of Multi-mixture daily. Weaning Weight (WW) was 10.90, 13.20 and 13.59 kg, respectively for groups A, B and C. Daily Weight Gain (DWG) was 126, 163 and 168 g.day-1 respectively. The mortality rate was higher (p<0.05) in group A than in group B and C. Gender influenced significantly (p<0.05) the DWG and WW. DWG and WW were lower for the animals that died compared to the animals that survived: 7.94 kg against 13.51 kg (WW) and 77 g against 165 g (DWG) respectively. The twins had lower (P<0.05) WW and DWG when compared to the singles. The use of milk-replacers with or without Multi-mixture is effective and it can increase the productivity of the system.