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Revista Brasileira de Zootecnia, Volume: 44, Número: 12, Publicado: 2015
  • Overcoming dormancy and determining optimal temperature for slender serradella seed germination Forage Crops

    Lopes, Rodrigo Ramos; Souza, Cleber Henrique Lopes de; Bertoncelli, Patricia; Franke, Lucia Brandão

    Resumo em Inglês:

    ABSTRACT The objective of this study was to identify the most efficient method for overcoming coat-imposed dormancy and determine the optimal germination temperature for Ornithopus pinnatus seeds. Treatments to overcome dormancy were: intact seeds; immersion in hot water at 60 ºC, followed by soaking in the same water (unheated)/24 h; immersion in hot water at 90 ºC, followed by soaking in the same water (unheated)/24 h; mechanical scarification; chemical scarification, H2SO4/5 min; and chemical scarification, H2SO4/10 min. Percentages were calculated for germinated, abnormal, dormant, and dead seeds. Optimal germination temperatures were calculated using eight constant temperatures (0, 5, 10, 15, 20, 25, 30, and 35 °C), with 8 h of light and 16 h of darkness. Germination rate, frequency, and synchronization index of germination were used as parameters to establish optimum temperature for germination. A completely randomized experimental design was used, with twelve repetitions of 100 seeds per treatment. Data obtained were subjected to analysis of variance and Tukey's test at a 5% significance level. O. pinnatus seeds exhibit dormancy caused by the seed coat's impermeability to water. Mechanical scarification was efficient in promoting seed germination. The species is stenothermal, meaning it cannot tolerate significant temperature variations. The germination rate of seeds was linearly dependent on temperature. Synchronization of the germination process is greater in the optimum temperature range, established between 15 and 20 °C.
  • Effects of dietary valine:lysine ratios on lactation performance of primiparous sows nursing large litters Non-Ruminants

    Devi, Subramaniam Mohana; Park, Jae Won; Kim, In Ho

    Resumo em Inglês:

    ABSTRACT Eighteen sows were used to determine the effect of dietary valine:lysine (val:lys) ratios on lactation performance in primiparous sows and litter performance. Sows, raised in individual pens, were randomly assigned to 1 of 2 experimental diets containing different standardized ileal digestibility (SID) val:lys ratios of 0.80 or 0.85. Corn-soybean-wheat-based diets were formulated to achieve the dietary treatments (0.86% or 0.87% SID lysine, and 0.69% or 0.74% SID valine). All diets were formulated to have 3,450 kcal metabolizable energy/kg. The experiment lasted 24 d. At the end of the experiment, body weight loss, backfat loss, average daily feed intake, and days to return to estrus were not affected by the different dietary val:lys ratios. Furthermore, no difference was observed in number of piglets weaned, piglet survival rate, weaning litter weight, litter weight gain, piglet weaning body weight, piglet gain, or piglet daily gain between the two dietary treatments. However, increasing the dietary val:lys ratio increased arginine and threonine concentrations in the milk. Dietary val:lys ratios of 0.80 and 0.85 do not affect the lactation performance of primiparous sows nursing large litters, but increase the arginine and threonine concentrations in milk as the dietary val:lys ratio are increased.
  • Feeding behavior and productive performance of steers fed pearl millet grain-based diets containing proportions of babassu mesocarp bran Ruminants

    Alencar, Wanderson Martins; Restle, João; Missio, Regis Luis; Neiva, José Neuman Miranda; Miotto, Fabrícia Rocha Chaves; Freitas, Ithálo Barros de

    Resumo em Inglês:

    ABSTRACT The objective of this study was to evaluate the feeding behavior and feedlot productive performance of dairy-origin steers fed for 84 days ground pearl millet grain-based diets with 0, 120, 240, 360, and 480 g kg-1 of babassu mesocarp bran (BMB) and a standard diet based on ground corn. Thirty Holstein-Zebu steers with average initial body weight of 371.02±27 kg were used. The experimental design was completely randomized, with five replications. Dry matter intake showed better fit with the quadratic regression equation with the inclusion of BMB, reaching a maximum value in diets with 360 g of this by-product. There was no difference for dry matter intake between pearl millet- and corn-based diets. There was no difference in total digestible nutrients intake between diets. The digestibility coefficient of organic matter decreased linearly with the increase in the dietary level of BMB. The digestibility coefficient of organic matter was not different between corn and millet diets. There was no difference in feeding time between diets. Total requirement of metabolizable energy increased linearly with inclusion of BMB. However, total requirements of metabolizable energy did not differ between the corn- and pearl millet-based diets. Average daily gain decreased linearly with the increase in BMB, with adjustment forced by the sharp decline of this variable in diets with 480 g of BMB. There was no difference in average daily gain between corn- and pearl millet-based diets. The inclusion of levels above 360 g of babassu mesocarp bran in pearl millet-based diets reduces the supply of metabolizable energy and the productive performance of feedlot dairy steers.
  • Nutritional evaluation of elephant-grass silages with different levels of by-products from the cashew juice industry Ruminants

    Ferreira, Ana Cristina Holanda; Rodriguez, Norberto Mario; Neiva, José Neuman Miranda; Pimentel, Patrícia Guimarães; Gomes, Silas Primola; Campos, Warley Efrem; Lopes, Fernando César Ferraz

    Resumo em Inglês:

    ABSTRACT This study was conducted to evaluate the intake, apparent digestibility (AD), and degradability in situ of elephant grass (Pennisetum purpureum Schum) silages containing 0, 35.0, 70.0, 105.0, and 140.0 g kg-1 by-product from dried cashew apple (DCBP) (as fed basis). A completely randomized design with four replicates was adopted. For the study of degradability in situ, one adult male cattle was used in a completely randomized design with split plots. Intake and AD of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose, and cellulose were evaluated, and the digestible energy (DE) and nitrogen balance (NB) of the silages were determined. The degradability in situ of DM, CP, and NDF was also determined. Addition of DCBP provided an increase in the intakes of DM, CP, NDF, and ADF. No effects of the levels of addition of DCBP were observed on the coefficients of AD of the silages. Regarding NB, positive values were only detected in the treatment with 105.0 g kg-1 DCBP. In the analysis of the degradability in situ, the incubation periods increased the rates of disappearance of DM, CP, and NDF. However, no effect of the levels of DCBP were observed on the effective degradability of DM. The by-product from dried cashew apple can be included at up to 140.0 g kg-1 in silages of elephant grass, but the high contents of acid detergent insoluble nitrogen may compromise the use and availability of nitrogen to the animals.
  • Development of a cost calculation model and cost index for sheep production Animal Production Systems And Agribusiness

    Raineri, Camila; Stivari, Thayla Sara Soares; Gameiro, Augusto Hauber

    Resumo em Inglês:

    ABSTRACT The objective of this study was to develop a model for calculation and analysis of production costs of lamb and, from that, to elaborate a production cost index. Panel meetings were held in five regions of the state of São Paulo, Brazil, to define technical features of representative properties of lamb production, taken as a basis for the preparation of the cost calculation model. Then the model for production cost calculation was built. The third step consisted of monitoring prices of inputs used, calculating production costs along the studied period, and generating the cost index, by the Laspeyres model. Lastly, questionnaires were applied to sheep producers, to validate the cost index. The model for production cost calculation was planned to be of easy utilization by farmers, and simultaneously faithful to the theoretical principles. The adopted scheme of cost allocation followed the classification of "variable", "fixed operating", and "income of factors". We generated cost indexes for each of the five studied regions, which were then aggregated in a state index, by weighting regional indexes by flock size. More than 97% of the answers to the validation questionnaires were positive, so we considered that the index reached a high level of approval. The application of Economic Theory is essential for the development of cost calculation models. The developed model has potential to generate important information that can help producers to make decisions. It can work in many contexts, and it can even be adapted to other livestock species. The production cost index for lamb was approved and can collaborate with the organization of the sheep agroindustrial system.
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