ABSTRACT. The objective of this study was to evaluate productive, nutritional, and economic traits in lactating cows on pasture fed diets with different cation-anion balances (DCAB). Ten lactating – Holstein × ¼ Dairy Gyr cows in the middle third of lactation, at an average age of 70 ± 4.6 months and an average body weight of 400 ± 55.2 kg, were distributed into five treatments in a 5 × 5 Latin square experimental design with two simultaneous squares. Treatments consisted of diets with DCAB of +237, +258, +294, +347, or +419 mEq dry matter (DM). No effects of intake were observed. There was no significant effect of DCAB on milk yield. The milk protein content was not influenced by the DCAB. Body condition score was not significantly affected by the DCAB. The apparent digestibilities of dry matter and nutrients (crude protein, neutral detergent fiber, ether extract, non-fibrous carbohydrates, and total digestible nutrients) were not affected by the DCAB. Marginal rate of return did not show significant differences. Under good conditions of pasture, forage availability, and quality associated with the lactation phases of the cows, all diets were efficient in milk production, dry matter intake, and digestibility. However, in economic terms, the most attractive DCAB was +237 mEq kg-1 DM.

Abstract The shortage of milk at certain times of the year leads to adulteration of buffalo mozzarella, and these frauds alter the composition of milk and buffalo derivatives. This study describes the dynamics of the adulteration on the nutritional quality of mozzarella. Mozzarella was produced from buffalo milk incorporated with cow milk at 0, 10, 20, 30, 40 and 50% (v/v). The chemical composition, fatty acids profile and cholesterol content of the cheeses were evaluated. The results showed that the fat and protein contents of buffalo cheeses decreased with the addition of cow milk. Furthermore, C4:0, C16:0, C22:0 and C16:1 fatty acids decreased while C8:0 and C10:0 acids fatty acids increased. The most dramatic observation was the elevation of the cholesterol content when cow milk was added. The altered content of short-chain saturated fatty acids and cholesterol content, due to the addition of cow milk to buffalo milk for mozzarella production, modified the nutritional indices. The addition of cow milk to buffalo milk for mozzarella production altered the content of short-chain SFA and the cholesterol content, thereby modifying the nutritional indices.

RESUMO. Objetivou-se avaliar a produção e a viabilidade econômica de bovinos de corte confinados no bioma Cerrado do estado do Piauí, Brasil. Cento e cinquenta bovinos - 50 novilhos não castrados (NNC) com peso corporal de 283,0 ± 20,82 kg, aos 30 meses de idade; e100 vacas de descarte (VD) com peso corporal de 296,1 ± 17,80 kg, aos 100 meses de idade - foram utilizados em delineamento inteiramente casualizado. Os indicadores de desempenho animal para a avaliação da viabilidade econômica foram idade inicial (meses), idade de abate (meses), peso corporal inicial (kg), peso corporal final (kg), ingestão diária de alimento (kg animal-1; kg custo de alimentação-1 (R$ kg-1 de dieta), custo por kg produzido (R$ kg-1 produzido) e preço médio do kg de carne para acabamento. Essas variáveis foram obtidas a partir da coleta de dados realizada durante o experimento. As VD consumiram mais silagem e concentrado de sorgo do que os NNC (p < 0,05). Houve diferença entre as categorias (p < 0,05) para a receita bruta, o saldo, o custo de oportunidade e a receita líquida por animal, com maiores valores encontrados para NNC. A categoria de animais não afetou a rentabilidade do sistema, embora os novilhos tenham fornecido menores receitas do que as vacas de descarte.

ABSTRACT. This study was realized to evaluate the production and economic viability of finished beef cattle in feedlot in the Cerrado biome of Piauí State, Brazil. One hundred and fifty cattle -50 bulls (B) with an body weight of 283.0 ± 20.82 kg, at 30 months of age; and 100 cull cows (CC) with an body weight of 296.1 ± 17.80 kg, at 100 months of age- were used in a completely randomized design. The animal performance indicators for the evaluation of economic viability were initial age (months), slaughter age (months), was initial body weight (kg), final body weight (kg), daily feed intake (kg animal-1; kg kg-1 BW), diet cost (R$ kg-1 of diet), cost of kg produced (R$ kg-1 produced), and average price of the kg of meat for finishing (R$). The CC consumed more sorghum silage and concentrate than B (p < 0.05).There was a difference between the categories (p < 0.05) for gross revenue, balance, opportunity cost, and net revenue per animal, with higher values found for the steer category. The animal category did not affect the profitability of the system, although the bulls provided lower revenues than cull cows.

O experimento foi conduzido com o objetivo de avaliar as perdas e o valor nutritivo da silagem de capim-elefante contendo níveis crescentes de torta de algodão. O delineamento experimental utilizado foi o inteiramente casualizado, com cinco tratamentos: 0, 7, 14, 21 e 28% de inclusão de torta de algodão e quatro repetições. O material foi picado e acondicionado em silos de PVC e armazenado por 80 dias. O pH e os teores de matéria seca (MS), proteína bruta, lignina e extrato etéreo das silagens aumentaram linearmente com a adição da torta de algodão, enquanto os teores de nitrogênio insolúvel em detergente ácido, fibra em detergente neutro, fibra em detergente ácido, celulose e hemicelulose reduziram linearmente. A adição de 28% de torta de algodão reduziu o desaparecimento "in situ" da MS (em 48h) a valores inferiores à silagem não-aditivada. Foram reduzidos os teores de nitrogênio amoniacal, as perdas por gases e por efluente. A inclusão de 28% de torta de algodão na ensilagem do capim-elefante contendo 18,4% de MS melhorou as características fermentativas da silagem reduzindo de forma mais eficiente o teor de umidade e perdas por efluente a partir do nível de 7% de inclusão.

The experiment was conducted to evaluate losses and nutritive value of elephant grass silage containing increasing levels of cottonseed meal. The experimental design was completely randomized, with five treatments: 0, 7, 14, 21 and 28% inclusion of cottonseed meal, and four replications. The material was chopped and packed in PVC silos and stored for 80 days. The pH and dry matter (DM), crude protein, lignin and ether extract of the silages increased linearly with the addition of cottonseed meal, while the levels of acid detergent insoluble nitrogen, neutral detergent fiber, acid detergent fiber, cellulose and hemicellulose decreased linearly. The addition of 28% cottonseed meal reduced the in situ disappearance of DM (48h) to values lower than those of silage without additives. The concentration of ammonia nitrogen and the losses from gases and effluent were reduced. The inclusion of 28% cottonseed meal in elephant grass silage containing 18.4% DM improved the fermentation characteristics of silage more efficiently by reducing the moisture content and effluent losses, starting at the 7% level of inclusion.

O objetivo deste trabalho foi avaliar a densidade populacional de perfilhos de pastos de Urochroa decumbens diferidos por 95 e 140 dias, visando determinar a estratégia mais adequada de adubação nitrogenada. Foram estudadas quatro estratégias de adubação no início e no final do verão (0-0, 100-0, 50-50, 0-100 kg ha-1 de N), respectivamente, com quatro repetições. Para os pastos diferidos por 95 dias, as densidades populacionais de perfilhos vegetativos foram maiores (p < 0,05) para a estratégia 0-100. O peso de perfilhos vegetativos por ha, no final do período de diferimento, foi maior para a estratégia 0-100, seguida da estratégia 50-50. As densidades de perfilhos vegetativos, avaliadas nos pastos diferidos por 140 dias, foram maiores (p < 0,05) para as estratégias de adubação 0-100 e parcelados 50-50. No final do período de diferimento, constatou-se maior (p < 0,05) densidade de perfilhos mortos para a estratégia de adubação 0-100, não constatando efeito (p < 0,05) no pós-pastejo. A estratégia de aplicação de 100 kg ha-1 no final do verão, seguida da estratégia de 50 kg ha-1 de nitrogênio parcelado no início e final do verão, promove influência positiva sobre a densidade populacional de perfilhos em pastos diferidos por 140 dias.

The objective of this work was to evaluate the tiller population density in Urochroa decumbens pasture deferred for 95 and 140 days, aiming to determine the best strategy for nitrogen fertilization. Four fertilization strategies at the beginning and end of summer (0-0, 100-0, 50-50, 0-100 kg ha-1 of N) were studied, respectively, with four repetitions. For the pastures deferred for 95 days, the population densities of vegetative tillers were greater (p < 0.05) for the strategy 0-100. At the end of the deferment period, the weight of the vegetative tillers per hectare was greater for the strategy 0-100, followed by the strategy 50-50. The densities of vegetative tillers, evaluated in the pastures deferred for 140 days, were greater (p < 0.05) for the fertilization strategies 0-100 and divided 50-50. At the end of the deferment period, greater density (p < 0.05) of dead tillers was verified for the fertilization strategy 0-100, not proving effect (p < 0.05) in post-grazing. The strategy of application of 100 kg ha-1 at the end of summer, followed by the strategy of 50 kg ha-1 of nitrogen divided between the beginning and end of summer, promoted a positive influence on the tiller population density in pastures deferred for 140 days.

The objective of this study was to evaluate the nutritional and productive characteristics of primiparous lactating cows grazing on tropical pasture, using different levels of crude glycerin in the supplement. The experiment was conducted at Rancho Santana farm, located in Jequié city, Bahia, Brazil, in the period from December 21, 2010 to March 16, 2011. Ten ¾ Holstein × ¼ Dairy Gyr lactating primiparous cows, with 109±24 days of lactation and a mean age of 30±6 months and mean body weight of 426.2±68.29 kg were distributed into five treatments, using two simultaneous 5 × 5 latin squares. Treatments consisted of inclusion levels (0, 94, 191, 289, 389 g/kg dry matter basis) of crude glycerin in the supplement. Intake, digestibility, milk production and composition were measured. Results were statistically analyzed by analysis of variance and regression at 0.05 probability. For all consumption variables no significant differences were found between the levels of crude glycerin. Except for the digestibility of ether extract, all digestibility values were similar between treatments. The fat content and yield showed quadratic effect between treatments. No significant differences were observed for protein, lactose, total solids, nonfat dry extract, fat:protein ratio, milk urea nitrogen and somatic cell count between treatments. For primiparous lactating cows grazing on tropical pasture, up to 389 g of crude glycerin/kg of dietary supplement can be included without nutritional and productive interference.

Este experimento foi conduzido com os objetivos de caracterizar e quantificar as frações que compõem os carboidratos e a proteína de diferentes silagens. Foi utilizado delineamento inteiramente casualizado com quatro tratamentos e cinco repetições: silagem de milho (AG 5011), silagem de sorgo-sudão, silagem de sorgo-forrageiro (BR 601) e silagem de girassol (Rumbsol 91). A silagem de girassol apresentou menor valor de carboidratos totais (CT) e da fração B2 (fração potencialmente degradável da fibra). As silagens de milho, sorgo-sudão e sorgo-forrageiro não apresentaram diferença quanto aos teores de carboidratos totais. A fração C (fração indigestível da parede celular) foi encontrada em maior proporção nas silagens de sorgo-sudão e girassol. Não houve diferenças na fração A da proteína (nitrogênio não-proteico) entre as silagens. A silagem de girassol apresentou maior valor de proteína bruta e nitrogênio total. Não foi observada diferença nos resultados entre as silagens de milho e sorgo, e a fração C foi menor para silagem de milho e sorgo forrageiro. As silagens de sorgo-sudão e sorgo-forrageiro apresentam menor valor nutritivo, devido à maior quantidade de parede celular e ao menor conteúdo de energia em comparação às silagens de milho e girassol.

This experiment was conducted to characterize and quantify the fractions that make up the carbohydrate and protein in silages. The design was completely randomized with four replications and five treatments: corn silage (AG 5011), sorghum-sudangrass silage, forage sorghum silage (BR 601) and sunflower silage (Rumbsol 91). Sunflower silage had the lowest value of total carbohydrates (TC) and B2 fraction (potentially degradable fraction of the fiber). Silages of corn, forage sorghum and sorghum-sudangrass showed no difference in cholesterol levels. Fraction C (indigestible cell wall fraction) was higher in silages of sunflower and sorghum-sudangrass. There was no effect on the protein fraction (non-protein nitrogen) between silages. Sunflower silage showed higher crude protein and total nitrogen. No differences were found between the silages of maize and sorghum, and fraction C was smaller for the corn silage and forage sorghum. Silages of corn, forage sorghum and sorghum-sudangrass presented lower nutritional value due to the greater amount of cell wall and less energy, when compared with silages of corn and sunflower.

Objetivou-se avaliar o efeito da hidrólise da cana-de-açúcar com óxido de cálcio (CaO) sobre o balanço de nitrogênio, as concentrações de ureia na urina e no plasma e a síntese na proteína microbiana em caprinos. Foram utilizados oito caprinos da raça Saanen, machos castrados, com peso corporal médio de 22,6 kg e 4 meses de idade, distribuídos em dois quadrados latinos 4 õ 4, em quatro períodos experimentais de 14 dias. As rações, formuladas para ser isoproteicas, com 14% de proteína bruta (PB), foram compostas de 70% de cana-de-açúcar (tratada com 0; 0,75; 1,5 ou 2,25% de óxido de cálcio na matéria natural e corrigida com 1% de ureia) e 30% de concentrado e fornecidas à vontade. A cana-de-açúcar com óxido de cálcio foi picada em desintegrador estacionário, pesada, acondicionada em baldes plásticos de 50 litros e tratada com o óxido de cálcio para ser fornecida aos animais após 24 horas de armazenamento. O balanço de nitrogênio, as concentrações de ureia na urina e no plasma e as excreções de ureia na urina não foram influenciadas pelo tratamento da cana-de-açúcar com óxido de cálcio. A concentração de alantoína (% das purinas totais) foi maior e a de ácido úrico menor nas dietas com cana-de-açúcar hidrolisada com óxido de cálcio em relação à cana in natura. A produção e a eficiência microbiana não foram afetadas pela adição de óxido de cálcio à cana-de-açúcar em dietas para caprinos em crescimento.

The objective of this work was to evaluate the effect of sugar cane hydrolysis with calcium oxide (CaO) on nitrogen balance, concetrations of urea in the urine and in the plasma and synthesis in microbial protein in goats. Eight castrated male Saanen breed goats, with 22.6 kg average body weight and at four months of age were used distributed in two 4 õ 4 Latin squares, during four 14-day experimental periods. The rations which were formulated to be isoprotein, with 14% crude protein (CP) were composed of 70% sugar cane (treated with 0; 0.75; 1.5 or 2.25% of calcium oxide in natural matter basis and corrected with 1% urea) and 30% of concentrate given ad libitum to animals. Sugar cane with calcium oxide was chopped in a stationary chopper, weighted and stored in 50-L plastic buckets and treated with calcium oxide to be given to the animals after 24 hours of storage. Nitrogen balance, urine and plasma urea concentrations and urine urea excretion were not affected by sugar cane +calcium oxide treatment. Concetration of allantoin (% total purine) was higher and the uric acid concentration was lower in diets with sugar cane hidrolised with calcium oxide in relation to in natura sugar cane. The microbial production and efficiency are not affected by addition of calcium oxide to sugar cane in diets for growing goats.