The objective of this study was to evaluate the processing of millet grain provided at two supplementation frequencies for grazing beef cattle during the dry season on nutritional parameters. Five rumen-cannulated crossbred steers, with 24 to 26 months of age and average body weight of 428.6±26.06 kg, were assigned to a Latin square design (5 × 5) in a 2 × 2 + 1 factorial arrangement, as follows: two forms of millet grain (whole grains - or ground; WG - GG), two strategies of concentrate supplementation (daily distribution - 7X; or three times a week - 3X) and a control treatment (mineral mixture - MM). Animals were kept in five paddocks of 0.24 ha each with Marandu grass pastures. Concentrate supplements were supplied at 2.00 and 4.66 kg/animal/day for treatments 7X and 3X, respectively. The concentrate supplementation enhanced the intake of total dry matter (DM) and organic matter (OM) and nutrients compared with mineral supplementation. No differences were found between dry matter intake and forage organic matter intake. The values of digestibility coefficients of DM, OM, ether extract, total carbohydrates and non-fiber carbohydrates were increased by concentrate supplementation. Regarding concentrations of rumen ammonia nitrogen, the interactions among time × treatment × day and day × treatment had effects on the measurements of ruminal pH. Plasma urea nitrogen, urinary urea excretion and urinary urea N excretion differed only between MM treatment and the others, with no interference of grain physical form and supplementation frequency on those variables. The millet grain processing does not alter forage intake, but improves digestibility. Daily supplementation increases digestibility of dry matter and neutral detergent fiber.

The objective of this study was to evaluate the effects of total digestible nutrient (TDN) levels in supplements on rumen pH, ruminal ammonia nitrogen concentration, intake and digestibility, nitrogen balance and microbial efficiency in beef cattle grazing on Marandu grass during the rainy season. The supplements comprised a mineral mixture, ground corn grain, soybean hulls, roasted soybeans and urea:ammonium sulfate. The mineral mix (MM) and supplements were supplied at 800, 1,600 and 2,400 g/animal/day, contained 500, 1,000 and 1,500 g of TDN, respectively, and were termed S500, S1000 and S1500. Supplemental crude protein (CP) was fixed at 300g animal/day for all supplementing strategies. Four crossbred rumen-fistulated steers, with an average weight of 512kg, were utilized. The animals were distributed in a 4×4 Latin square in four paddocks of 0.25 ha. The rumen nitrogen concentration was increased by 63% after four hours of supplementation. Supplements with increased TDN levels did not alter the total dry matter and forage intakes, although the TDN levels linearly increased the non-fibrous carbohydrates intake. Additionally, most supplements did not alter the digestibility of the diet nutrients.The nitrogen balance was similar in all treatments. However, supplements with the highest TDN levels linearly improved the microbial efficiency of finishing beef cattle that were pasture-grazed during the rainy season. Supplements with in creasing TDN levels improve the microbial efficiency during the rainy season.

Objetiva-se com essa revisão abordar os aspectos relevantes à utilização da cana-de-açúcar na alimentação de ruminantes. A cana-de-açúcar é uma forrageira que apresenta elevada produtividade de massa por área, o que representa a principal vantagem de sua utilização. Entretanto, o corte diário é um empecilho para sua adoção em muitas propriedades. Opções como o tratamento químico da cana-de-açúcar in natura ou a ensilagem são válidas, mas possuem limitações. A cana-de-açúcar sempre foi considerada uma forrageira de baixa qualidade nutricional. Nesta revisão serão tecidas considerações para interpretar essas limitações nutricionais com um novo aspecto. E por fim serão apresentados trabalhos científicos que mostram o potencial de uso da cana-de-açúcar como volumoso para ruminantes.

The objective of this review is to highlight the important aspects of the usage of sugar cane to feed ruminants. Sugar cane is forage that presents high productivity body per area, meaning the main advantage of its usage. However, its daily cut accounts in hindrance. Chemical treatment of sugar cane in natura or silage are alternative options but there also limitations. Sugar cane is considered forage of low nutritional value. This review aims at bringing about new interpretations for these nutritional limitations considering new aspects. Finally, scientific works will be presented to demonstrate the potential usage of sugar cane as roughages.

Objetivou-se avaliar o processamento do grão de milheto inteiro ou triturado em suplementos fornecidos diariamente ou três vezes por semana para bovinos de corte em pastejo e seus efeitos sobre o desempenho produtivo e econômico e o comportamento ingestivo diurno durante o período da seca. Utilizaram-se 25 bovinos nelores não-castrados, com peso inicial de 350,92±31,7 kg, mantidos em cinco piquetes com área unitária de 1,45 ha formados por B. brizantha cv Marandu. Os animais foram distribuídos em delineamento inteiramente casualizado em esquema fatorial 2 × 2 + 1, composto de duas formas físicas do grão de milheto (inteiro ou triturado), duas frequências de suplementação (diária ou três vezes por semana) e um tratamento controle (mistura mineral). A suplementação concentrada promoveu ganho de peso, enquanto a suplementação apenas com minerais acarretou perdas de peso de 0,16 kg/animal/dia. A moagem do grão de milheto proporcionou maiores ganhos (0,36 e 0,38 kg/animal/dia nos grupos com suplementação 3 e 7 vezes por semana, respectivamente), em comparação ao fornecimento de grão inteiro (0,22 e 0,24 kg/animal/dia, 3 e 7 vezes por semana, respectivamente), enquanto as frequências de suplementação estudadas não promoveram diferenças nestas variáveis. Foi encontrado efeito significativo da interação dia × tratamento para tempo gasto com consumo de suplemento, pastejo e hidratação. Para o tempo em ócio, foi encontrada diferença entre o grupo controle e os demais. Maior retorno econômico foi obtido quando se ofertou milheto triturado e em menor frequência de suplementação (R$ 22,70/animal). A utilização de suplementos múltiplos, assim como o processamento do grão de milheto, possibilita maiores ganhos de peso, independentemente da frequência de suplementação estudada, sendo que o fornecimento de suplemento 3 vezes por semana reduz os custos da suplementação.

The objective was to evaluate the processing of the grain of millet in supplements given daily or three times a week to grazing beef cattle on productive performance, economic and diurnal intake behavior during the drought period. Twenty-five non-castrated Nelore cattle with initial body weight of 350.92±31.7 kg were kept in five paddocks with unit area of 1.45 ha formed by B. brizantha cv. Marandu. The animals were distributed in a completely radomized design in a 2 × 2 + 1 factorial arrangement, as follows: two physical forms of the grain of millet (whole or ground), two frequencies of supplementation (daily or three times a week) and the control treatment (mineral mix). It was found that the concentrate supplementation promoted weight gains, while sole mineral supplementation resulted in weight loss of 0.16 kg/animal/day. Grinding the millet grain promoted higher gains (0.36 and 0.38 kg/animal/day for 3 and 7 times a week, respectively) when compared with the whole grain (0.22 and 0.24 kg/animal/day for 3 and 7 times a week, respectively), with no differences between the frequencies of supplementation. Significant effect of the day × treatment interaction was found for time in the trough, grazing and drinking water. For the resting time difference was found between the control treatment and the others. Greater economic return was achieved when ground millet was supplied at lower supplementation frequency (R$ 22,70/animal). The use of multiple supplements, as well as the processing of millet grain, enabled greater weight gain, regardless of the supplementation frequency studied. Providing supplement 3 times a week reduces the costs with supplementation.

O objetivo deste trabalho foi avaliar o efeito da suplementação na resposta produtiva, no pH e no nitrogênio amoniacal ruminal, e no custo de produção de ovinos em pastagem de capim-marandu no período da seca. O experimento teve a duração de 84 dias. Utilizaram-se 20 cordeiros não castrados com idade e peso corporal inicial médios de quatro meses e 24,20 kg, respectivamente, para avaliação do desenvolvimento, distribuídos em cada um dos tratamentos que são os suplementos, mineral, energético, proteico e múltiplo, com cinco animais por tatamento, em área de 0,1 ha. Para avaliação dos parâmetros nutricionais, foram utilizados quatro ovinos fistulados no rúmen com 12 meses e 55 kg de peso corporal foram distribuídos em quatro piquetes de 0,1 ha. Avaliaram-se os suplementos mineral, energético, múltiplo e proteico. Os ganhos de peso foram de 0,017, -0,008, 0,024 e 0,077 kg por dia para os suplementos mineral, energético, múltiplo e proteico, respectivamente. Quatro horas após suplementação, os valores de pH ruminal foram de 6,30, 6,40, 6,18 e 6,24 para os suplementos mineral, energético, múltiplo e proteico, respectivamente. Os valores para nitrogênio amoniacal do líquido ruminal foram de 10,57, 7,36, 21,58 e 24,50 mg dL-1 para os suplementos mineral, energético, múltiplo e proteico, respectivamente. Os suplementos mineral e proteico produziram o ganho de peso com o menor custo. O uso de suplemento energético para cordeiros submetidos à forragem com baixo teor de proteína reduz o ganho de peso.

The objective of this work was to evaluate the effect of supplementation on the productive response, ruminal pH and ammoniacal nitrogen, and production cost of sheep grazing marandu grass in the dry season. The experiment lasted 84 days. Twenty noncastrated lambs with average age and initial body weight of four months and 24.2 kg, respectively, were used for performance evaluation, and were distributed in the following treatments which are, mineral salt, energetic, multiple and proteic supplements, with five animals per treatment, in area of 0.1 ha. For nutritional parameters evaluation, four rumen fitted sheep with 12 months of age and 55 kg of weight were distributed in four paddocks of 0.1 ha. Mineral salt, energetic, multiple and proteic supplements were evaluated. Weight gains were 0.017, -0.008, 0.024 and 0.077 kg per day for mineral salt, energetic, proteic and multiple supplements, respectively. Four hours after supplementation, ruminal pH values were 6.30, 6.40, 6.18 and 6.24 for mineral salt, energetic, multiple and proteic supplements, respectively. Values for ammoniacal nitrogen in the rumen fluid were 10.57, 7.36, 21.58 and 24.50 mg dL-1 for mineral salt, energetic, multiple and proteic supplements, respectively. Mineral salt and proteic supplements produced weight gain with the lowest cost. The use of energetic supplement for lambs grazing lower protein content forage reduces weight gain.