The objective of this study was to evaluate the effects of monensin supplementation on animals receiving warm-season grass with limited supplementation. In Exp. 1, treatments were a factorial combination of 2 stocking rates (1.2 and 1.7 animal unit [AU] [500 kg BW]/ha) and supplementation with monensin (200 mg/d) or control (no monensin) distributed in a complete randomized design with 3 replicates. Thirty Angus × Brahman crossbred heifers (Bos taurus × Bos indicus) with initial BW of 343 ± 8 kg were randomly allocated into 12 bahiagrass (Paspalum notatum) pastures and supplemented with 0.4 kg DM of concentrate (14% CP and 78% TDN) daily for 86 d. Herbage mass (HM) and nutritive value evaluations were conducted every 14 d, and heifers were weighed every 28 d. There was no effect (P ≥ 0.97) of monensin on HM, herbage allowance (HA), and ADG; however, animals receiving monensin had greater (P = 0.03) plasma urea nitrogen (PUN) concentrations. The stocking rate treatments had similar HM in June (P = 0.20) and July (P = 0.18), but the higher stocking rate decreased (P < 0.01) HM and HA during August and September. Average daily gain was greater (P < 0.01) for the pastures with the lower stocking rate in August but not different in July and September (P ≥ 0.15). Gain per hectare tended to be greater on pastures with the higher stocking rate (P ≤ 0.06). In Exp. 2, treatments were 3 levels of monensin (125, 250, and 375 mg/animal per day) and control (no monensin) tested in a 4 × 4 Latin square with a 10-d adaptation period followed by 5 d of rumen fluid collection and total DMI evaluation. Blood samples were collected on d 4 and 5 of the collection period. Ground stargrass (Cynodon nlemfuensis) hay (11.0% CP and 52% in vitro digestible organic matter) was offered daily. The steers received the same supplementation regimen as in Exp. 1. Total DMI was not different among treatments (P = 0.64). There was a linear increase (P ≤ 0.01) in propionate and a tendency for decreased acetate (P ≤ 0.09) concentrations in the rumen with increasing levels of monensin; however, there was no effect (P ≥ 0.19) of monensin levels on ruminal pH and ruminal concentrations of butyrate and ammonia. In addition, there was no effect (P ≥ 0.73) of monensin levels on plasma concentrations of glucose, insulin, IGF-1, and PUN. In summary, monensin supplementation effects were not detected at either stocking rate and may not be effective in increasing performance of beef cattle grazing low-quality warm-season grasses with limited supplementation.

RESUMO -Objetivou-se avaliar os efeitos da inclusão de torta de dendê na dieta sobre o consumo, a digestibilidade das dietas e o desempenho de novilhas leiteiras. Utilizaram-se 16 novilhas leiteiras mestiças Holandês × Zebu, com média de 13 meses de idade e peso vivo inicial de 183,4±32,5 kg, distribuídas em delineamento inteiramente casualizado, com quatro níveis de torta de dendê (0; 11,9; 22,9 e 34,2% da matéria seca total), cada um com quatro repetições. Avaliaram-se os consumos de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), carboidratos não-fibrosos (CNF), extrato etéreo (EE) e nutrientes digestíveis totais (NDT) e as digestibilidades aparentes da MS, PB, FDN, CNF e EE. Houve redução linear no consumo de MS, PB, FDN, CNF e NDT. A digestibilidade aparente da MS e FDN reduziu com a inclusão da torta de dendê na dieta, enquanto a de PB e dos CNF sofreu efeito quadrático. A inclusão de torta de dendê nas dietas promoveu aumento linear da digestibilidade aparente do extrato etéreo. O ganho de peso reduziu linearmente com a inclusão de torta de dendê na dieta, sendo observados valores de 1,06; 0,99; 0,89 e 0,54 kg/dia para as dietas contendo 0; 11,9; 22,9 ou 34,2% de torta de dendê na dieta total, respectivamente. A conversão alimentar não foi afetada pelos níveis de inclusão de torta de dendê na dieta. A inclusão de torta de dendê na dieta reduz o consumo de nutrientes e o desempenho de novilhas leiteiras em crescimento, porém, quando utilizada em níveis de até 24,6% da dieta total, proporciona ganho de peso compatível com os obtidos em programas de recria visando à parição aos 24 meses de idade.Palavras-chave: biodiesel, Elaeis guineensis, ganho de peso vivo, subproduto, subprodutos do biodiesel, valor nutritivo Intake, nutrient digestibility and performance of dairy heifers fed diets containing palm kernel cake ABSTRACT -The objective was to evaluate the effects of inclusion of palm kernel cake in the diet on intake, digestibility and performance of dairy heifers. Sixteen dairy Holstein-Zebu crossbred heifers with average age of 13 months and average weight of 183.4±32.5 kg were distributed to four treatments in a completely randomized design with four levels of palm kernel cake (0, 11.9, 22.9 and 34.2% from total dry matter), each one with four replicates. The intake of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), non-fibrous carbohydrates (NFC), ether extract (EE) and total digestible nutrients (TDN), and the apparent digestibility of DM, CP, NDF, NFC and EE were evaluated. There was linear reduction in DM, CP, NDF, NFC, and TDN intake. The apparent digestibility of DM and NDF reduced with the inclusion of palm kernel cake in the diet, while the apparent digestibility of CP and NFC showed quadratic effect. The inclusion of palm kernel cake in the diets resulted in linear increase in the apparent digestibility of ether extract. Weight gain decreased linearly with the inclusion of palm kernel cake in the diet, with values of 1.06, 0.99, 0.89 and 0.54 kg/day ...

Stockpiling warm‐season perennial grasses for winter grazing is an important management practice for beef cattle production systems in tropical and subtropical regions. Limpograss [Hemarthria altissima (Poir.) Stapf et C.E. Hubb.] has greater digestibility at late maturity than other commonly used warm‐season perennial grasses; however, decreased crude protein (CP) concentration may limit livestock performance. The objective of this study was to evaluate the in situ dry matter (DM) and CP ruminal disappearance kinetics of stockpiled limpograss herbage. Forage for the in situ study derived from a 2‐yr field experiment in which treatments were the factorial combinations of three cultivars (‘Kenhy’, ‘Gibtuck’, or ‘Floralta’) and three stockpiling periods (8, 12, or 16 wk) distributed in three replicates of a randomized complete block design. Effective degradability of DM was greater for Kenhy and Gibtuck compared with Floralta (614 and 611 vs. 575 g kg−1), and it declined linearly as stockpiling period increased from 8 to 16 wk (623 vs. 586 g kg−1). Herbage CP concentration (48–32 g kg−1 DM) also declined linearly from 8 to 16 wk, but rumen‐unavailable CP increased during stockpiling (257–438 g kg−1 CP), causing effective CP degradability to decrease (637–489 g kg−1 CP). Limpograss is a good option for stockpiled forage, and both new releases outperformed Floralta; however, concentration and availability of CP must be considered when defining a supplementation strategy.

A existência de variabilidade espacial nas propriedades do solo influencia na produção da forrageira. O trabalho teve como objetivo determinar a distribuição espacial das propriedades químicas do solo relacionando-a com a produção e a preferência de forragem por animais em pastejo de Urochloa brizantha cv. Marandu (Syn. Brachiaria brizantha) sob lotação contínua. Para caracterização da área de pastagem, foram realizadas medições de 108 pontos com distribuição em malha irregular, com coletas de solo para determinação dos atributos químicos (pH, matéria orgânica, P, K, Ca, Mg, Al, H+Al) e densidade do solo, produção de forragem, altura do dossel forrageiro, índice SPAD e intensidade de pastejo, no período das águas de 2012. Realizou-se o teste de normalidade, seguido de análise descritiva dos dados e análise geoestatística. As características químicas e densidade do solo, bem como a produção e altura do pasto, apresentaram dependência espacial, com mesmo padrão de resposta, inferindo que tais respostas são interrelacionadas. Os fatores que causam a variabilidade nas características do solo também interferem nas relacionadas ao pasto influenciando em parte no pastejo animal. Os atributos químicos do solo, densidade, massa seca, altura e intensidade de pastejo, ajustaram-se ao modelo exponencial. A estimativa da variabilidade espacial dos atributos do solo juntamente com avaliação da disponibilidade do pasto e os pontos de preferência do pastejo animal são ferramentas importantes para estabelecer critérios de uso e manejo diferenciado dentro de uma mesma área de pastagem, na perspectiva de evitar degradação do solo e do pasto.

The objective of the present study was to assess the effect of different dietary inclusion levels of palm (Elaeisguineensis L.) kernel cake (PKC) for lactating dairy cows on feed intake, nutrient digestibility and milk production. Diets containing 0, 113, 228, 342g of PKC/kg dry matter were formulated and fed to eight crossbred (Holandês x Zebu) dairy cows with mean weight of 382kg at 60-90 days of lactation. The cows were used in a double 4 x 4 Latin square design. Each experimental period lasted for 15 days, with 11 days adaptation and four days sampling. Increasing the levels of PKC in the diet reduced the intake of dry matter (DM), crude protein (CP), hemicellulose, non-fibrous carbohydrates (NFC) and total digestible nutrients (TDN). The NDF intake was higher at the 113g/kg PKC inclusion level compared to other treatments. There was linear decreasing effect on fat corrected milk with the inclusion of PKC. There was linear reduction in digestibility of dry matter(DM) and total carbohydrate (TC), but no effect was observed on the NDF and ADF digestibility. Linear increase was observed on crude protein (CP), NFC and ether extract (EE) digestibility. The digestibility of these nutrients probably increased because of the longer retention time of the digest in the rumen caused by reduced DM intake. The addition of PKC decreased the nutritive value of the diets, which subsequently reduced linearly milk production. Key words: Biodiesel, by-products, milk production, palm kernel cake, digestibility, Elaeis guineensis L ResumoO objetivo do presente trabalho foi avaliar o efeito da inclusão (0.0; 113,4; 227,8 e 341,7 g/kg de matéria seca) da torta de dendê (TD) em dietas para vacas leiteiras lactantes sobre o consumo, digestibilidade aparente da matéria seca e dos nutrientes e produção de leite. Foram utilizadas oito vacas mestiças Holandês x Zebu, primíparas, com peso médio de 382 kg, entre 60 e 90 dias de lactação, distribuídas em duplos quadrados latinos 4 x 4. Cada período experimental teve duração de 15 dias, sendo 11 dias para adaptação e quatro para coletas. Avaliou-se o consumo, expresso em kg/dia, g/kgpv0,75 e g/kg PV, a digestibilidade aparente da matéria seca ( MS), proteina bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose (HEM), carboidratos não fibrosos (CNF), extrato etéreo (EE) e nutrientes digestíveis totais (NDT) e a produção de leite corrigida para gordura (PLCG). A inclusão de níveis crescentes de TD na dieta acarretou redução linear no consumo de MS, PB, HEM, CNF e NDT. O consumo de FDN apresentou efeito quadrático e os maiores valores foram observados com o nível de inclusão de TD de 113,4 g/kg MS. Houve efeito linear decrescente sobre a PLCG com a inclusão da TD. Houve redução linear da digestibilidade da MS e dos CT, porém não se observou efeito sobre a digestibilidade da FDN e FDA. Observou-se ainda aumento linear da digestibilidade da PB, CNF e EE. O aumento da digestibilidade destes nutrientes provavelmente ocorreu devido ao maior tempo de re...

-The objective of the study was to assess the effects of including 0, 79.8, 159.8, and 240.0 g kg -1 crude glycerin in the total diet dry matter on the 84 days feedlot performance, nutrient digestibility, blood parameters, and carcass characteristics of crossbred dairy steers. Experimental diets were composed of 98.5 g kg -1 of sorghum silage and 901.5 g kg -1of concentrate. Twenty-four crossbred dairy steers (337.3±39.8 kg body weight and 15 months of age) were distributed in a completely randomized design with four treatments and six replicates. The intake and digestibility of the dry matter and nutrients were not altered by including crude glycerin in the diet. Crude glycerol levels did not affect the final weight (430.2 kg), daily weight gain (1.38 kg day -1 ), total weight gain (97.2 kg), hot carcass weight (218.9 kg), cold carcass weight (215.2 kg), hot carcass yield (0.50 kg 100 kg -1 BW), longissimus dorsi area (62.86 cm²), subcutaneous fat thickness (4.05 mm), and carcass physical composition. Concentrations of serum glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol, and creatinine were not altered by including crude glycerin in the diet. Crude glycerin can be added to high concentrate diet up to 240 g kg -1 without changing the animal performance, apparent digestibility of nutrients, the main carcass characteristics, and blood parameters of finishing crossbred dairy steers.

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