RESUMO. Avaliou-se o efeito da inclusão de 0; 33; 67 e 100% do farelo de mamona destoxificado (FMD) em substituição ao farelo de soja em dietas para ovinos em terminação sobre o metabolismo dos compostos nitrogenados, em delineamento de blocos ao acaso em parcelas subdivididas (tempos de coleta líquido ruminal e sangue), com cinco animais por tratamento. Não houve efeito (p > 0,05) sobre os parâmetros de metabolismo de nitrogênio, N ingerido , N fecal , N urinário , N absorvido e N retido (g dia -1 ), relação N fecal /N ingerido e N urinário /N ingerido (%), N fecal /N urinário (g g -1 ) e balanço de nitrogênio (%), com médias 26,70 ± 5,50; 8,73 ± 1,79; 2,17 ± 0,71; 17,96 ± 3,98; 15,78 ± 3,17; 32,90 ± 2,82; 7,89 ± 2,55; 5,08 ± 1,61 e 59,19 ± 4,68, respectivamente. As dietas influenciaram (p < 0,05) os valores de pH e N-NH 3 no líquido ruminal (LR) e ureia no soro sanguíneo, com interação (p < 0,05) dos níveis de inclusão de farelo de mamona nas dietas x tempos de coleta de LR e sangue apenas para os teores de N-NH 3 ureia no soro sanguíneo. O farelo de mamona destoxificado pode ser utilizado em substituição ao farelo de soja em dietas para ovinos em terminação, por não influenciar o metabolismo do nitrogênio, com estabilidade do pH ruminal, da concentração de N-NH 3 no líquido ruminal e de ureia no soro sanguíneo em relação aos intervalos fisiológicos normais para a espécie ovina. Neste caso, o nível de inclusão deste coproduto na dieta de ovinos deve ser realizado de acordo com a viabilidade econômica da substituição.Palavras-chave: balanço de nitrogênio, líquido ruminal, nitrogênio amoniacal, Ricinus communis, valor nutritivo.ABSTRACT. Nitrogen metabolism in sheep fed diets containing detoxified castor bean meal. The study evaluated the effect of levels 0, 33, 67 and 100% of detoxified castor bean meal (DCBM) to replace soybean meal on nitrogen metabolism in diets for finishing sheep. The experimental design was randomized blocks in a split plot design (plot = levels of DCBM, and subplot = four collection times of ruminal liquid or blood: 0, 2.5, 5 and 7.5h), with five animals per treatment. No effect (p > 0.05) was verified on nitrogen metabolism parameters: N intake , N faeces , N urinary , N absorbed and N retained (g day -1 ), N faeces /N intake , N urinary /N intake (%) and N fecal /N urinary (g g -1 ) ratio and nitrogen balance (%), with means 26. 70 ± 5.50, 8.73 ± 1.79, 2.17 ± 0.71, 17.96 ± 3.98, 15.78 ± 3.17, 32.90 ± 2.82, 7.89 ± 2.55, 5.08 ± 1.61 and 59.19 ± 4.68, respectively. The diets influenced (p < 0.05) pH and N-NH 3 in ruminal fluid (RF) and blood urea concentrations, with interaction (p < 0.05) levels of inclusion of castor bean meal x collection times of RF and blood only for N-NH 3 and urea concentrations. Detoxified castor bean meal can be used to replace soybean meal in diets for finishing sheep, as it has no influence on nitrogen metabolism, with stable rumen pH, concentration of N-NH 3 in ruminal fluid and urea in blood serum in relation to normal physiological values for sheep. In this...

SUMMARY The objectives of this research were to determine the effects increasing levels of concentrate on nutrients digestibility, performance, economic viability of diets and ingestive behavior of lambs. Fifteen crossbred lambs were used in a randomized complete block design according to initial body weight and age. Lambs were penned individually during 55 days, being 10 days for adaptation of diets and 45 days for data collection. The treatments consisted in three isonitrogenous diets with increasing levels of concentrate: 40, 60, or 80%, in dry matter basis. No effect (P>0.05) were observed on dry matter intake, crude protein intake, crude protein digestibility and neutral detergent fiber digestibility, whereas the dry matter digestibility was lower (P<0.01) for lambs fed diets with 40% of concentrate. The addition of 80% concentrate decreased (P<0.05) neutral detergent fiber intake, however this treatment provided higher average daily gain, followed by 60 and 40% of concentrate. In relation to feeding behavior, the animals fed80% concentrate spent more time with feeding (P<0.05) compared to the other treatments. It is concluded that supplementation of concentrate between 60 to 80% improves dry matter digestibility and performance of crossbred lambs without relevant affect dry matter intake and ingestive behavior. A diet with 80% concentrate provides positive gross margin of profit.

Twenty crossbred lambs (21.6 ± 3.5 kg BW) were used in a completely randomised design to determine the effects of babassu mesocarp flour (BMF) on performance and ingestive behaviour. The treatments were defined by the increase in concentrations (0, 10, 20 or 30%, in DM basis) of BMF in the diet. When significant treatments effects were found, orthogonal polynomials for treatment responses were determined by linear and quadratic responses (p < .05). To determine the in situ ruminal degradability of the diets used in performance trial, one rumen-fistulated Santa Inês male sheep (63 kg BW) was used in a completely randomised design in a split splot arrangement with three replications (three periods of incubation) in times 3, 6, 24 and 72 h. Data from potential degradability (PD), dry matter (DM) and crude protein (CP) degradability for diets and the incubation time were compared by t-test (p < .05). Negative quadratic effect was observed upon nutrients intake, except for neutral detergent fiber (NDF) intake. The average daily gain, body condition score, feeding efficiency of DM and time spent in feeding decreased linearly with BMF addition. The BMF decreased the soluble fraction (a) potentially degradable fraction (b) PD, effective degradability of DM and CP and the NDF degradability. The addition of BMF in diets of sheep had negative effects on performance, feed efficiency of DM and degradability of DM, CP and NDF. However, the BMF can be used in diets, during the conventional grains off-season, at concentration up to 10.5% as alternative feed. HIGHLIGHTS The mesocarp produced from industrialization of the babassu coconut has a great content of fiber and lignin. The great content of fiber associated to decrease in degradation of fiber and potential degradability in DM and CP reduced the performance of lambs. Although the reduction of the performance, BMF can partially replace the corn in diets of lambs in periods that the price of this ingredient is great.

-The objective of this work was to evaluate the quality of pasture and enteric methane (CH 4 ) emission of Curraleiro Pé-duro x Nellore cattle in a pasture of Megathyrsus maximus 'Mombaça', both in full sun and in a consortium with babassu palms (Attalea spp.) in the Amazonian biome. The experimental design was completely randomized, with six steers per system, and the evaluations were done during the dry period (2015) and rainy period (2016). In comparison to forage in the full sun system, forage in the silvopastoral system showed, in the dry period, higher levels of crude protein, ether extract, total digestible nutrient, and in vitro digestible organic matter, and lower levels of dry matter, neutral detergent fiber, and total carbohydrate (TCHO). In the rainy period, forage in the silvopastoral system showed higher levels of crude protein and a reduction of nonfibrous carbohydrate and TCHO. The CH 4 emissions were similar in both systems within the same period, and ranged from 44.0 to 74.2 kg per year per animal. During the dry period, the emission per kilogram of dry ingested matter and the loss of gross energy as methane were lower in the silvopastoral system. During the rainy period, the emissions were similar in both systems. The silvopastoral system yields forage with good quality in the dry period, and considering both periods, it is more efficient (emission of CH 4 per daily weight gain) than the system in full sun. Index terms: CH 4 , Curraleiro Pé-duro, greenhouse gases, livestock farming, Nellore. Metano entérico de bovinos em pastagem a pleno sol e em sistema silvopastoril na AmazôniaResumo -O objetivo deste trabalho foi avaliar a qualidade da pastagem e a emissão de metano (CH 4 ) entérico de bovinos Curraleiro Pé-duro x Nelore, em pastagem de Megathyrsus maximus 'Mombaça', tanto a pleno sol como em consórcio com palmeiras de babaçu (Attalea spp.), no bioma Amazônia. O delineamento experimental foi inteiramente casualizado, com seis novilhos por sistema, e as avaliações foram realizadas nos períodos seco (2015) e no chuvoso (2016). Em comparação à forragem no sistema a pleno sol, a forragem no sistema silvopastoril apresentou maiores teores de proteína bruta, extrato etéreo, nutrientes digestíveis totais e digestibilidade in vitro da matéria orgânica, e menores teores de matéria seca, fibra em detergente neutro e carboidratos totais (CHOT). No período das águas, o sistema silvopastoril apresentou maiores teores de proteína bruta e reduções de carboidratos não fibrosos e CHOT. As emissões de CH 4 foram semelhantes entre os sistemas, tendo variado de 44,0 a 74,2 kg por animal por ano. No período seco, a emissão por quilograma de matéria seca ingerida e a perda de energia bruta por metano foram menores no sistema silvopastoril. No período chuvoso, as emissões foram similares entre os tratamentos. O sistema silvopastoril oferece pastagem de boa qualidade na seca e, considerando-se o ciclo com ambos os períodos, é mais eficiente (emissão de CH 4 pelo ganho de peso diário) do que o sistema a ...

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