ABSTRACT The effect of replacing wheat bran with spineless cactus (0, 25, 50, 75, and 100%) in sugar cane-based diets on the intake of nutrients, feeding behavior, and rumen digestibility of steers was assessed using digested samples collected from the omasum. Five crossbred steers (1/2 Holstein-Zebu) were fitted with cannulas in the rumen and then assigned to a 5 × 5 Latin square design. Samples of omasal digesta were collected for three days. Rumen was evacuated via the rumen cannula to determine the rumen pool of dry matter (DM), neutral detergent fiber (NDF), indigestible NDF (iNDF), intake (ki), passage (kp) and degradation (NDF) rates, and the passage of iNDF (kpi). Nutrient intake displayed a quadratic effect, with maximum intakes of DM (5.73 kg d−1), non-fiber carbohydrates (NFC, 4.63 kg d−1), and digestible organic matter (DOM, 3.45 kg d−1) estimated at the replacement levels of 54.63, 60.00, and 43.17%, respectively. The replacement levels showed no effect on feeding, rumination, or idle times. There was a linear increase in the total apparent and ruminal digestibility of CP as the spineless cactus content in the diet was increased. There was no effect on total and partial digestibilities of OM and NDF or on intestinal digestibility of CP. No effect was observed on the rumen pool of DM, NDF, or iNDF. Furthermore, ki, kp, NDF degradation, and iNDF passage rates displayed a quadratic effect, with higher concentrations estimated for replacement levels of 56.07, 56.12, 59.00, and 55.20%, respectively. Replacing 55% wheat bran with spineless cactus in sugar cane-based diets is recommended.

O objetivo deste trabalho foi avaliar o efeito da substituição do fubá de milho pelo gérmen integral de milho, sobre a digestibilidade dos nutrientes na dieta e sobre o desempenho e características de carcaça de ovinos Santa Inês. Quarenta animais, com peso inicial de 17,0±2,5 kg, foram confinados em baias individuais, em delineamento de blocos ao acaso, com cinco tratamentos e oito repetições. As taxas de substituição foram: 0, 25, 50, 75 e 100%. Ao abate, foram obtidos os pesos de carcaça quente e de trato digestivo cheio e vazio, a área de olho de lombo, a espessura de gordura subcutânea e o rendimento de cortes comerciais. A substituição do fubá de milho pelo gérmen integral reduziu linearmente o consumo de matéria seca e os coeficientes de digestibilidade de: matéria seca, matéria orgânica, proteína bruta, fibra em detergente neutro e extrato etéreo. A conversão alimentar não foi afetada pelos tratamentos. O ganho médio diário, o peso vivo final, a área de olho de lombo, a espessura de gordura e os rendimentos de carcaça quente e de cortes comerciais diminuíram linearmente com o aumento nos níveis de substituição. A substituição do fubá de milho pelo gérmen integral de milho, nas dietas de ovinos, prejudica o desempenho e as características de carcaça dos animais.

The objective of this work was to evaluate the effect of replacing corn meal by corn germ meal on nutrient digestibility in the diet, and on the performance and carcass characteristics of Santa Inês lambs. Forty animals, with 17,0±2.5 kg average initial live weight, were housed in individual pens in a randomized block design with five treatments and eight replicates. The replacing rates were 0, 25, 50, 75, and 100%. Hot carcass weight, full and empty digestive tract weight, ribeye area, fat thickness, and yield of commercial cuts were obtained at slaughter. Corn meal replacement by corn germ meal linearly reduced the dry matter intake and the coefficients of apparent digestibility of: dry matter, organic matter, crude protein, neutral detergent fiber, and ether extract. Feed conversion was not affected by the treatments. Average daily gain, final live weight, loin eye area, fat thickness, and yields of hot carcass and retail cuts decreased linearly with the increasing replacement levels. Replacing corn meal by corn germ meal, in lamb diets, negatively affects the performance and carcass characteristics of the animals.

A casca da mamona, coproduto da extração do óleo da mamona, por apresentar em sua composição elevados teores de matéria seca e fibra, surge como fonte alternativa de volumoso na alimentação de ovinos, podendo diminuir os custos com alimentação, uma vez que outras fontes são comercializadas a preços superiores. Avaliou-se o efeito da substituição do feno de capim Tifton 85 pela casca de mamona em 0, 33, 66 e 100% na dieta de ovinos sobre as características de carcaça, os pesos e rendimentos dos cortes comerciais e a morfometria da carcaça. Vinte e oito animais não castrados, com 7 ± 1,4 meses de idade e peso inicial médio de 19,5 ± 4,3 kg, foram abatidos após 70 dias de confinamento. Houve efeito linear decrescente (P≤0.05) para o peso corporal ao abate, peso de corpo vazio, peso de carcaça quente, peso de carcaça fria e área de olho-de-lombo, de acordo com os níveis crescentes de substituição. O decréscimo linear (P≤0,05) no peso de todos os cortes comerciais e o efeito quadrático do rendimento do pescoço (rendimento mínimo de 9,84% quando a substituição foi de 56,9%) também foram verificados com o aumento percentual da casca de mamona. Não houve efeito (P > 0,05) sobre os rendimentos dos demais cortes, mas o perímetro do tórax, da perna e da garupa e o índice de compacidade da carcaça decresceram linearmente (P≤0,05) com a substituição. A substituição do feno de capim Tifton 85 pela casca de mamona para ovinos diminui o peso corporal ao abate, os pesos de carcaça quente e fria, os pesos dos cortes comerciais e as medidas morfométricas.

Castor bean hulls (CBH), co-products of castor oil extraction, are high in dry matter (DM) and fiber and are emerging as alternative roughage in sheep feed. This could reduce feed costs since other sources of roughage can be more expensive. The effects of replacing Tifton 85 hay with CBH at 0, 33, 66 and 100% in the diet of sheep on the carcass characteristics, weights and yields of retail cuts and carcass measurements were studied. Twenty-eight non-castrated sheep averaging 7 ± 1.4 months of age with an initial weight of 19.5 ± 4.3 kg were slaughtered after 70 days of confinement. There was a linear decline (P ≤ 0.05) in slaughter body weight, empty body weight, hot and cold carcass weight and longissimus muscle area (LMA) as the percentage of dietary CBH increased. A linear decrease (P≤0.05) of the weights of all retail cuts and a quadratic effect (minimum yield of 9.84% with the replacement of 56.9%) of the neck yield were also detected as the percentage of CBH increased. No treatment effects (P > 0.05) on the yield of the other cuts were observed, but there was a linear decline (P ≤ 0.05) in the perimeters of the thorax, leg and rump and the carcass compactness index. Replacing Tifton 85 hay with CBH in sheep diets is not recommended because it decreases the slaughter body weight, cold and hot carcass weight, retail cut weights and morphometric measurements.