Resumo Neste trabalho, objetivou-se avaliar a composição química e a degradação in situ das gramíneas do gênero Panicum Massai, Mombaça e Tanzânia nas idades 22, 34 e 46 dias pós-rebrota. Quantificou-se os teores de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA). Na avaliação da degradabilidade in situ foram pesadas 4 g de amostra em sacos de náilon incubados no rúmen de um bovino fistulado, nos tempos 6, 24 e 72 h. Adotou-se delineamento inteiramente casualizado para composição química e em parcela subdividida para degradação in situ, com médias comparadas pelo teste de Tukey a 5%. Houve aumento nos teores de MS (+1,69%) e FDN (+5,06%) (P<0,05) das gramíneas nas maiores idades de corte com redução da fração PB. A degradação potencial (DP) da MS, FDN e PB apresentou redução com o aumento da idade das gramíneas, com o aumento no tempo de colonização (0,69 h) e a taxa de degradação da FDN (1,14%/h). O aumento da idade pós-rebrota das gramíneas Massai, Mombaça, e Tanzânia eleva os teores de fibra em detergente ácido e reduz a proteína bruta, com efeito negativo na degradação da MS, PB e FDN, sendo indicado manejo desses cultivares aos 22 e 34 dias pós-rebrota para se obter forragem com melhor valor nutricional.

Abstract The objective was to evaluate the chemical composition and in situ degradation of Maasai, Mombasa and Tanzania grasses belonging to the genus Panicum, at 22, 34 and 46 days after regrowth. The contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined. For the evaluation of ruminal degradation, 4 g sample were placed in nylon bags and incubated in the rumen of a fistulated animal, for 6, 24 and 72 h. The experiment had a completely randomized design for chemical composition analysis and a split-split plot completely randomized design for in situ degradation, with means compared by Tukey test at 5%. There was an increase in the contents of DM (+ 1.69%) and NDF (+ 5.06%) (P <0.05) of the grasses at the highest cutting ages with reduction in the CP fraction. The potential degradation (PD) of DM, NDF and CP decreased with advancing age of grasses, with an increase in colonization time (0.69 h) and NDF degradation rate (1.14%/h). The increase in the post-regrowth age of the Massai, Mombasa, and Tanzania grasses increases the acid detergent fiber content and reduces the crude protein content, with a negative effect on the degradation of DM, PB and NDF. The management of these cultivars is indicated at 22 and 34 days post-regrowth to obtain forage with better nutritional value.

ABSTRACT This study aimed to evaluate the performance and ingestive behavior of growing goats grazing on Tanzania guinea grass and fed diets containing 40% carnauba or tucum fruits. Twenty-one male castrated goats were distributed into three groups, one exclusively on pasture and the other two on pasture and fed diet supplemented at the level of 1.5% body weight (BW) in a completely randomized design. The intake of the supplements was obtained by difference between the amount supplied and the leftovers, with weighing performed every seven days, while pasture intake was determined using titanium dioxide (TiO2) as external indicator. Ingestive behavior was evaluated for three days. The supplement containing carnauba fruit resulted in a greater intake of neutral detergent fiber (0.137 kg NDF/day), with a reduction of 8.61% in the pasture dry matter (DM) intake of goats. Associated with the intake of pasture nutrients, the tucum fruit diet met the protein (0.103 kg CP/day) and energetic (0.547 kg TDN/day) requirements of goats with intake set at 0.124 kg CP/day and 0.572 kg TDN/day, with higher weight gain (0.111 kg/day) and larger loin eye area (12.76 cm2). The supplementation with fruits influenced the grazing behavior of goats, increasing the idle time by 1 h in relation to animals not supplemented. The supplementation of growing goats grazing on Tanzania guinea grass pasture with a diet containing 40% tucum fruit, in the proportion of 1.5% BW, did not meet the nutritional requirements for gain of 150 g/day; however, it met requirements for maintenance and average gain of 111 g/day. Energy supplementation reduces the grazing time of goats; thus, it is necessary to consider the level and formulation of supplements, with the possibility of increasing the stocking rate and productivity per unit area.

A pesquisa foi realizada para avaliar o desempenho, a digestibilidade e o balanço de nitrogênio e analisar a viabilidade econômica da inclusão de polpa de caju desidratada na alimentação de ovinos em confinamento. Foram utilizados 20 ovinos machos mestiços da raça Santa Inês em confinamento, distribuídos em delineamento de blocos casualisados, com cinco tratamentos (0, 10, 20, 30 e 40% de polpa de caju desidratada - PCD) e quatro repetições. As dietas, isoprotéicas, foram compostas de feno de tifton - 85 moído (Cynodon spp.) como volumoso e concentrado formulado com milho, farelo de soja, polpa de caju desidratada e sal mineral. Os níveis de polpa de caju desidratada na dieta não interferiram no consumo de MS e PB (g/dia) e na conversão alimentar. O consumo de FDN elevou e o ganho de peso diminuiu com o aumento da inclusão da polpa de caju desidratada na dieta. Para ganho médio diário, a polpa de caju desidratada pode ser incluída em proporções de até 30% (nível que proporcionou o melhor retorno econômico). A inclusão de polpa de caju desidratada em rações para ovinos na fase de terminação reduziu a retenção de nitrogênio e afetou negativamente a digestibilidade dos nutrientes (MS, PB, FDN e FDA).

Twenty crossbred male Santa Inês sheep were assigned to a completely randomized block design to evaluate the effects of feeding dried cashew pulp (DCP) on performance, digestibility of nutrients, and nitrogen balance. It was also of particular interest to study the economical viability of adding DCP to diets of feedlot sheep. Diets were isonitrogenous and contained ground Tifton 85 hay (Cynodon spp), corn, soybean meal, salt, and one of the following levels of DCP: 0, 10, 20, 30 or 40%. Increasing the dietary levels of DCP had no significant effect on intakes of DM and CP and also on feed conversion. Neutral detergent fiber intake was increased while an opposite effect was observed for weight gain by adding DCP to the diets. For average daily weight gain is recommended the inclusion of 30% of DCP in the diet because of the greatest economical return rate. Inclusion of DCP in diets of finishing feedlot sheep reduced nitrogen retention and negatively affected total tract digestibilities of DM, OM, CP, NDF and ADF.