RESUMO. Este trabalho foi realizado para avaliar o efeito de suplementos múltiplos contendo palma forrageira enriquecida com ureia (0, 1, 2 e 3% na matéria seca - MS) em substituição a um suplemento tradicional (controle) sobre os parâmetros ruminais e síntese de proteína microbiana em novilhos mestiços. Cinco novilhos canulados no rúmen (½ Holandês x Zebu), com peso corporal inicial de 240 ± 22,1 kg foram utilizados em um Quadrado Latino 5 × 5. Efeito quadrático foi observado para o consumo de MS e retenção de N, com valores máximos de 6,97 kg d-1e 50,9 g d-1com a inclusão de 1,8 e 2,1% de ureia, respectivamente. Concentrações máximas de 16,2; 23,2 e 24,3 mg dL-1 de N-NH3 foram registradas nos animais alimentados com palma forrageira enriquecida com 1, 2 de 3% de ureia. Houve efeito quadrático sobre o pH ruminal, com valor de 6,45 às 4,08 horas após alimentação. Síntese de proteína microbiana de 103 g de proteína bruta kg-1de nutrientes digestíveis totais foi obtida com a inclusão de 1,6% de ureia. Recomenda-se a utilização de suplementos múltiplos contendo palma forrageira enriquecida com 1,6 a 1,8% de ureia em substituição ao suplemento tradicional para bovinos.

ABSTRACT. This study was realized to evaluate the effect of the ‘multiple supplements’ containing spineless cactus enriched with urea (0, 1, 2 and 3% on dry matter basis - DM) as a replacement to a traditional supplement (control) on ruminal parameters and microbial protein synthesis in crossbred steers. Five steers(½ Holstein x Zebu) can nulated in the rumen, with an average initial body weight of 240 ± 22.1 kg were used in a 5 × 5 Latin square. A quadratic effect was observed for DM intake and N retention, with maximum values of 6.97 kg d-1 and 50.9 gd-1 with the inclusion of 1.8 and 2.1% urea, respectively. Maximum concentrations of 16.2, 23.2 and 24.3 mg dL-1of N-NH3were recorded in animals fed spineless cactus enriched with 1, 2, and 3% of urea. There was a quadratic effect on ruminal pH, with a value of 6.45 at 4.08 hours after feeding. Microbial synthesis efficiency of 103 g CPkg-1 TDN was obtained with the inclusion of 1.6% urea. Multiple supplements containing spineless cactus enriched with 1.6 up to 1.8% urea in replacement of a traditional supplement is recommended for cattle.

ABSTRACT The objective of this study was to evaluate the effect of different concentrate levels (40, 50, 60, and 70% on dry matter basis) on intake, digestibility of nutrients, and performance of heifers fed sugarcane bagasse as exclusive roughage. Twenty Girolando heifers, with an average body weight of 198±25.6 kg were assigned to a completely randomized design, established according to body weight. The intake of dry matter (5.12 to 7.73 kg d-1), organic matter (4.72 to 7.32 kg d-1), crude protein (0.71 to 1.05 kg d-1), and digestible organic matter (3.09 to 4.77 kg d-1) linearly increased with the inclusion of concentrate in the diets. The final weight (238 to 299 kg d-1), body weight gain (0.50 to 1.20 kg d-1), and total weight gain (35.2 to 83.6 kg d-1) linearly increased with the concentrate levels. Considering the occurrence of the first calving at 24 months, a 50:50 ratio of sugarcane bagasse to concentrate seems to be the most appropriate for crossbred heifers.

Resumo Objetivou-se avaliar as características estruturais, a produção de massa seca e a composição bromatológica de cultivares de Brachiaria e Panicum. O estudo foi conduzido em casa-de-vegetação, em delineamento em blocos casualizados, com cinco tratamentos, sendo três cultivares de Brachiaria (B. decumbens cv. Basilisk, B. brizantha cv. Marandu e cv. Xaraés) e dois cultivares de Panicum (P. maximum cv. Mombaça e cv. Tanzânia), com quatro repetições. De modo geral, maior número de folhas, comprimento laminar e perfilhos foram verificados nas cultivares Mombaça, Tanzânia e Basilisk. As cultivares Tanzânia e Mombaça se destacaram na produção de massa seca, em relação a cv. Marandu, com as outras cultivares com posição intermediária, enquanto a cultivar Xaraés apresentou a maior relação lâmina/colmo. Não houve diferenças nos teores de proteína bruta entre as cultivares, enquanto os teores de fibra em detergente neutro e fibra em detergente ácido foram inferiores para Marandu e Xaraés. Com base nos resultados, todas as cultivares poderiam ser recomendadas, atendendo-se às suas diferentes exigências nutricionais,

Abstract The aim of this study was to evaluate the dry matter production and the structural and bromatological characteristics of Brachiaria and Panicum cultivars. The study was conducted in a greenhouse in a randomized complete block design with five treatments, three cultivars of Brachiaria (B. decumbens cv. Basilisk, B. brizantha cv. Marandu and cv. Xaraes) and two cultivars of Panicum (P. maximum cv. Mombaça and cv. Tanzania), with four replications. Higher number of leaves, greater laminar length and tillers were observed in Mombaça, Tanzania, and Basilisk cultivars. Tanzania and Mombaça cultivars showed higher production of dry mass in relation to Marandu, and Xaraes cultivar showed higher leaf/stem ratio. There was no difference in crude protein content among cultivars, while neutral detergent fiber and acid detergent fiber content was lower for Marandu and Xaraes. We recommend all the cultivars considering their different nutritional requirements.

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.

ABSTRACT - The objective of this study was to evaluate the effect of replacing wheat bran by spineless cactus (0, 25, 50, 75, and 100%) in sugar cane-based diets on intake and nutrient digestibility and ruminal parameters of sheep. Five sheep (Santa Inês; average initial weight of 34.0±3.6 kg) were fitted with cannulas in the rumen and then assigned to a 5 × 5 Latin square design. The maximum dry matter (DM; 1414 g d−1), digestible organic matter (658 g d−1), and neutral detergent fiber corrected for ash and protein (NDFap; 425 g d−1) intakes were estimated by replacing 80.2, 89.9, and 50.5% of wheat bran. Dry matter and crude protein digestibility increased by 0.60 and 0.85 g kg-1 of DM. With the replacement of 57.1 and 62.2% of wheat bran, a maximum rate of NDF ingestion (0.70 h−1) and NDF ruminal pool (7.31 g) was obtained. Rumen pH increased with the inclusion of spineless cactus, while the maximum concentration of ammonia N (33.3 mg dL−1) and total volatile fatty acids (57.7 μmol mL−1) were estimated at the levels of 72.3 and 63.7% of replacement of wheat bran. It is recommended to replace 63% of wheat bran by spineless cactus in sugar cane-based diets, to promote better animal performance.

RESUMO O estudo foi realizado para avaliar o perfil metabólico de cabras lactantes alimentadas com dietas contendo farelo de manga integral em substituição ao milho. Foram avaliados quatro níveis de substituição (0; 33; 66 e 100%) em dietas com relação volumoso:concentrado de 60:40. Oito cabras mestiças Saanen, multíparas e lactantes (48.72 ± 1.99 kg de peso corporal) foram introduzidas no experimento aos 48 dias pós-parto e mantidas até 124 dias de lactação. Utilizou-se como delineamento experimental dois Quadrados latinos 4x4, com quatro tratamentos, quatro períodos e quatros animais por quadrado. Não houve efeito (P>0,05) dos níveis de farelo de manga integral sobre os consumos de matéria seca (1890 g/dia), PB (278 g/dia) e FDN (959 g/dia). Contudo, os consumos de carboidratos não fibrosos e nutrientes digestíveis totais reduziram (P<0,05) 27,9 g/dia e 0,082 kg/dia respectivamente, à medida que aumentava o teor farelo de manga integral nas dietas. As concentrações de ureia, creatinina, gama glutamil transferase, aspartato aminotransferase, albumina, proteínas totais, glicose, triglicerídeos, colesterol total e magnésio não foram alteradas pelos níveis de substituição, com valores médios de 54,52 mg/dl, 0,71 mg/dl, 52,59 UI, 77,37 UI, 4,69 g/dl, 9,32 g/dl, 74,44 mg/dl, 40,10 mg/dl, 39,39 mg/dl e 11,09 mg/dl, respectivamente. Considerando o perfil metabólico, o farelo de manga pode substituir totalmente o milho em dietas de cabras lactantes.

SUMMARY The work was conducted to evaluate the metabolic profile of lactating goats fed diets containing integral mango meal as a replacement for corn. Four levels of replacement (0, 33, 66 and 100%) were evaluated in diets with forage:concentrate ratio of 60:40. Eight crossbred multiparous lactating Saanen goats (48.72 ± 1.99 kg of BW) were introduced in the experiment 48 days postpartum and maintained up to 124 days of lactation. It was used a double Latin Square (4x4) experimental design, with four treatments, four periods and four animals per square. There was no effects (P>0.05) for the integral mango meal level on the intake of DM (1890 g/day), CP (278 g/day) and NDF (959 g/day). However, the intake of NFC and TDN decreased (P<0.05) 27.9 g/day and 0.082 kg/day, respectively, as the dietary integral mango meal increased. The concentrations of urea, creatinine, gamma glutamyl transferase, aspartate aminotransferase, albumin, total protein, glucose, triglycerides, total cholesterol, and magnesium were not altered (P>0.05) by replacement levels, with average values of 54.52 mg/dl, 0.71 mg/dl, 52.59 UI, 77.37 UI, 4.69 g/dl, 9.32 g/dl, 74.44 mg/dl, 40.10 mg/dl, 39.39 mg/dl, and 11.09 mg/dl, respectively. Considering the metabolic profile, mango meal whole can totally replace corn in diets of dairy goats.

The objective of this study was to assess the effect of applying N and K2O at different times after harvest on the structure and production characteristics of Marandu and Xaraés cultivars of Brachiaria brizantha. Two greenhouse 4 × 2 factorial experiments using a randomized block design with eight treatments and four replicates were carried out. In experiment 1, the plants in pots were fertilized weekly with 50 mg/dm³ of N and K2O until a week before a uniformity cut, for a total of four applications. After cutting, plants were fertilized with 50 mg/dm³ of N and K2O at 0, 3, 6, and 9 days. Cultivars were evaluated after 44 days of regrowth. In experiment 2, a single 50 mg/dm³ dose of N and K2O was applied a week before the uniformity cut, and 100 mg/dm³ of N and K2O were applied at 0, 4, 8, and 12 days after cutting; cultivars were evaluated after 39 days of regrowth. In experiment 1, the leaf/stem ratio and dry matter yield were influenced by the time at which fertilizers were applied. In the second experiment, the total number of leaves, expanded leaves, dead leaves, and the leaf lamina accumulated length and dry matter production were influenced by the time at which fertilizers were applied. Marandugrass had more leaves and tillers than cv. Xaraés, which, in turn, had greater height, dry matter yield and regrowth vigor. Applying nitrogen and potassium fertilizer immediately after cutting improves the structural characteristics, while the dry matter yield is maximized by applying fertilizers immediately after cutting by using lower doses of N, or at 4.5 days after cutting by using higher doses of N.

Avaliaram-se a produtividade de matéria seca (MS), proporção de lâminas e composição bromatológica de Brachiaria spp., colhidas com 42 dias de rebrotação, em Diamantina, MG. Para a determinação dos teores de MS, PB, FDN, FDA e lignina utilizaram-se o esquema em parcelas subsubdivididas, no DIC, com quatro repetições. Nas parcelas foram distribuídas as cultivares Basilisk, Marandu, Xaraés, Llanero e B. humidicola comum; nas subparcelas, dois cortes, e, nas subsubparcelas, dois anos experimentais. A produção de MS total e a proporção de lâminas foram analisadas em esquema de parcelas subdivididas, com espécies/cultivares nas parcelas e anos nas subparcelas. A produção de MS no segundo ano (3 cortes) foi mais alta que no primeiro (2 cortes), destacando-se as cultivares Basilisk, Xaraés e Llanero. De modo geral, as cultivares apresentaram teores satisfatórios de PB, mais altos no segundo ano. Os teores de FDN foram mais baixos no segundo ano e os de lignina mais baixos no primeiro ano. As cultivares Xaraés e Marandu destacam-se pela elevada proporção de folhas e apresentam composição bromatológica semelhante a da cultivar Basilisk. Associando-se a composição bromatológica com a produtividade de MS, recomendam-se as cultivares Xaraés e Basilisk para as condições do Alto Vale do Jequitinhonha.

Dry matter production, proportion of leaf blades and chemical composition of Brachiaria spp. harvested at intervals of 42 days of regrowth, in Diamantina, MG were evaluated. The DM, CP, NDF, ADF and lignin contents were analyzed in a split-split plot completely randomized design, with four replicates. Five cultivars of Brachiaria were distributed in the plots, two cuts in the split-plot, and two experimental years in the split-split plot. The dry matter production and the proportion of leaf blades were analyzed in a split plot completely randomized design, with cultivars in the plots and years in the subplots. The dry matter production in the second year (3 cuts) was higher than in the first (2 cuts), especially with the cultivars Basilisk, Xaraés and Llanero. Generally, the cultivars presented satisfactory levels of CP, with higher values in the second year. The contents of NDF were lower in the second year and the lowest levels of lignin were in the first year. Cultivars Xaraés and Marandu stand out for the high proportion of leaves and presented chemical composition similar to the Basilisk cultivar. Based on the chemical composition and dry matter production, Xaraés and Basilisk cultivars are recommended for cultivation in the Jequitinhonha High Valley.

Objetivou-se estudar o efeito do tamanho da presa, com ou sem adição de ração na larvicultura do pacamã (Lophiosilurus alexandri), espécie nativa da bacia do Rio São Francisco ameaçada de extinção. As larvas foram cultivadas em aquários por 16 dias e alimentadas com zooplâncton natural, selecionado em malhas de 650 e 1.300 µm, com ou sem ração. A oferta de zooplâncton de maior tamanho resultou em melhor desenvolvimento das larvas de pacamã, comprovando a vantagem do fornecimento de partículas alimentares maiores para o potencial de crescimento da espécie. O aumento na quantidade de ração não influenciou o desempenho das larvas, evidenciando a baixa ou falta de capacidade das larvas em digerir a ração ofertada. O fornecimento de ração diminuiu o pH e aumentou a condutividade elétrica, prejudicando a qualidade da água, o que não afetou o desempenho das larvas.

The effect of prey size selection and feeding on pacamã Lophiosilurus alexandri larvae culture (native specie of San Francisco basin classified as threatened of extinction) was evaluated. The larvae were cultivated in aquariums during 16 days and fed with natural zooplankton, screened in 650 and 1300 µm sieve, with and without ration. The offer of zooplankton of largest size provided a better development of the pacamã larvae, demonstrating the need of alimentary particles larger for the growth potential of the species. The increase of the amount of ration did not affect the performance of the larvae, evidencing low or lack of capacity in digesting the offered ration. The ration fed reduced the pH and increased the electric conductivity, worsening water quality, which did not affect the performance of the larvae.