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Revista Brasileira de Zootecnia, Volume: 42, Número: 9, Publicado: 2013
  • Polyculture of Litopenaeus vannamei shrimp and Mugil platanus mullet in earthen ponds Aquaculture

    Costa, Léa Carolina de Oliveira; Xavier, João Antônio Amaral; Neves, Luis Fernando de Matos; Azambuja, Ana Maria Volkmer de; Wasielesky Junior, Wilson; Figueiredo, Mario Roberto Chim

    Resumo em Inglês:

    The objective of the present study was to evaluate the growth performance of the shrimp Litopenaeus vannamei and the mullet Mugil platanus in earthen ponds (200 m²) located in the Laboratory of Continental Aquaculture of Universidade Federal do Rio Grande (FURG), in both polyculture and monoculture systems. The study consisted of three replicates, as follows: shrimp monoculture (SM), shrimp and mullet polyculture (PO) and mullet monoculture (MM). The stocking density was 10 post-larvae shrimp (PL) m−2 and 0.67 mullet m−2. Fish and shrimp were fed commercial shrimp meal (38% crude protein) once a day. Initially, the amount of feed to shrimp was 20% of their total biomass which was later reduced to 5%. Mullets were fed at 5% of their stocked biomass. The experiment lasted 79 days during the summer of 2007/2008. At harvest, shrimp in monoculture had weight gain (15.59 g), specific growth rate (8.40% day−1), apparent feed conversion (0.88), survival (91%) and production (1.454 kg ha−1) significantly higher than in polyculture (1.039 kg ha−1). Mullets in polyculture had significantly better weight gain (42.72 g) and specific growth rate (3.99 % day−1) than those in monoculture (31.04 g and 3.69% day−1, respectively), while the mullet condition factor was significantly smaller in polyculture (1.06) than in monoculture (1.13). The apparent feed conversion of the mullets did not present significant differences between monoculture (2.50) and polyculture (2.40). The physical and chemical water parameters were not significantly different in any of the experiments, except for the transparency, which was higher in earthen ponds with mullet monoculture. Polyculture of shrimp and mullet reared together in earthen ponds negatively affects the shrimp production and favors the production of mullets.
  • The chemical composition, fermentation profile, and microbial populations in tropical grass silages Forage Crops

    Rigueira, João Paulo Sampaio; Pereira, Odilon Gomes; Ribeiro, Karina Guimarães; Mantovani, Hilário Cuquetto; Agarussi, Mariele Cristina Nascimento

    Resumo em Inglês:

    The objective of this study was to evaluate the fermentation profile, chemical composition and microbial population and losses in the silages of signalgrass and Mombasa grass fertilized with the following levels of nitrogen (N): 0, 30, 60 and 90 kg/ha. The grasses were harvested at 70 days of regrowth, chopped and then ensiled in laboratory silos that had 20 kg of capacity and a snap-top cover and were fitted with Bunsen valves. Before ensiling, samples of the plants were used for the isolation and identification of lactic acid bacteria (LAB) in epiphytic microbiota. The design adopted was a 4 × 2 factorial arrangement, with four doses of N and two forage species, in a completely randomized design, with four replicates. The predominant species of LAB was Lactobacillus fermentum. The interaction between the N dose and forage species affected the dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and water soluble carbohydrates (WSC) of the silages. The pH values and gas losses were influenced only by the forage species, with higher values for the Mombasa grass. For the ammonia (NH3-N) levels and effluent losses, there was an effect of the interaction between the forage species and N doses, and the highest values of NH3-N and effluent losses were found in the Mombasa grass silage fertilized with 60 kg N/ha. Nitrogen fertilization reduces the levels of DM and WSC in the silages and also increases the levels of CP, NH3-N and effluent losses.
  • Growth and productive responses of tropical grass Panicum maximum to nitrate and ammonium supply Forage Crops

    Santos, Jorge Henrique da Silva; Bona, Fabiano Daniel De; Monteiro, Francisco Antonio

    Resumo em Inglês:

    This study was conducted to investigate growth response parameters and forage yield of Panicum maximum Jacq. plants supplied with nitrate (NO3-) and ammonium (NH4+) as N source in a nutrient solution. Six NO3- and NH4+ combinations were tested at the following proportions: 100-0, 85-15, 70-30, 55-45, 40-60 and 25-75%. Grass shoot (number of tillers and leaves and leaf surface area) and root (length and surface area) growth parameters and dry matter production exhibited highest values in P. maximum plants growing in the nutrient solution supplied with NO3-:NH4+ at the proportions ranging between approximately 70-30 and 55-45%. The use of NO3-:NH4+ mixture at the ratio of 55-45% instead of the NO3- solely as N source in the nutrient solution enhanced the production of tillers and leaves and the leaf area surface of P. maximum by about 30, 20 and 30%, respectively. Plants supplied with NO3- and NH4+ mixture (55-45%) showed an increased root length and root surface area by approximately two and six-fold, respectively, compared with P. maximum fertilized with NO3- exclusively in the growth medium. Supplying N in the nutrient solution as NO3- or NH4+ exceeding approximately 70 or 50%, respectively, caused a diminished P. maximum forage yield. Enhanced N-use efficiency associated with P. maximum plants supplied with a NO3- and NH4+ mixture in the growth medium supports the assumption that it is possible to increase plant production by managing N fertilization based on quality (N forms) of N fertilizers applied in pasture systems.
  • Dynamics of forage accumulation in Elephant grass subjected to rotational grazing intensities Forage Crops

    Sousa, Braulio Maia de Lana; Nascimento Júnior, Domicio do; Monteiro, Hélida Christhine de Freitas; Silva, Sila Carneiro da; Vilela, Hélio Henrique; Silveira, Márcia Cristina Teixeira da; Rodrigues, Carlindo Santos; Sbrissia, André Fischer

    Resumo em Inglês:

    We assessed the accumulation dynamics of forage and its components in Elephant grass cv. Napier (Pennisetum purpureum Schum.) that were subjected to three post-grazing height treatments (30, 50, and 70 cm) from February through May 2009 (experiment one) and December 2009 through May 2010 (experiment two). In experiment one, the grazing events started when the light interception by the canopy reached 95%. The same was adopted for experiment two, except for the first grazing event, which was based on the height of the apical meristems of basal tillers. The experimental design for both experiments was a randomized complete block with three replications. The pastures that were managed at a post-grazing height of 30 cm exhibited lower rates of leaf and stem growth, total growth and forage accumulation than those that were managed at 50 or 70 cm, indicating that post-grazing height affects Elephant grass. The pastures that were managed at 50 cm exhibited relatively stable accumulation rates and less stem accumulation. Pastures managed at 70 cm of pos-grazing height presented more leaf and stem accumulation. Most apical meristems of Elephant grass should be removed in the first grazing when they reach the post-grazing target height of 50 cm. The elevation in the residual post-grazing height, especially in the summer, raises the regrowth vigor in the Elephant grass cv. Napier pasture. The post-grazing height of 30 cm reduces the growth of the Elephant grass cv. Napier.
  • Population structure of Nellore cattle in northeastern Brazil Breeding, Genetic And Reproduction

    Barbosa, Ana Carla Borges; Malhado, Carlos Henrique Mendes; Carneiro, Paulo Luiz Souza; Muniz, Lorena Mirelle Santos; Ambrosini, Diego Pagung; Carrillo, José Adrián; Martins-Filho, Raimundo

    Resumo em Inglês:

    The objective of this study was to evaluate the population genetic structure of Nellore cattle in northeastern Brazil. Pedigree information was collected from 175,231 animals born from 1967 to 2007. Probability of gene origin, inbreeding, average relatedness coefficient (AR), completeness pedigree, effective population size and generation interval were calculated. Generation interval was high due to the long period of time animals were used as reproducers. The bottleneck effect was evidenced as a result of intensive use of limited breeders over the last years. Low values were observed in the effective number of founder animals (434) and ancestors (427) comparing with the number on the base (175,231) and reference populations (130,038). Generally, the variability explained by the founders and ancestors is considered low. The average coefficient of inbreeding (0.11%) and AR (0.14%) estimated for this population is considered low and can be partly explained by the increased population effective number in recent periods; however, it may be underestimated by shallow pedigree.
  • Nonlinear models for fitting growth curves of Nellore cows reared in the Amazon Biome Breeding, Genetic And Reproduction

    Marinho, Kedma Nayra da Silva; Freitas, Alfredo Ribeiro de; Falcão, Alencariano José da Silva; Dias, Francisca Elda Ferreira

    Resumo em Inglês:

    Growth curves of Nellore cows were estimated by comparing six nonlinear models: Brody, Logistic, two alternatives by Gompertz, Richards and Von Bertalanffy. The models were fitted to weight-age data, from birth to 750 days of age of 29,221 cows, born between 1976 and 2006 in the Brazilian states of Acre, Amapá, Amazonas, Pará, Rondônia, Roraima and Tocantins. The models were fitted by the Gauss-Newton method. The goodness of fit of the models was evaluated by using mean square error, adjusted coefficient of determination, prediction error and mean absolute error. Biological interpretation of parameters was accomplished by plotting estimated weights versus the observed weight means, instantaneous growth rate, absolute maturity rate, relative instantaneous growth rate, inflection point and magnitude of the parameters A (asymptotic weight) and K (maturing rate). The Brody and Von Bertalanffy models fitted the weight-age data but the other models did not. The average weight (A) and growth rate (K) were: 384.6±1.63 kg and 0.0022±0.00002 (Brody) and 313.40±0.70 kg and 0.0045±0.00002 (Von Bertalanffy). The Brody model provides better goodness of fit than the Von Bertalanffy model.
  • Traditional and alternative nonlinear models for estimating the growth of Morada Nova sheep Breeding, Genetic And Reproduction

    Souza, Laaina de Andrade; Carneiro, Paulo Luiz Souza; Malhado, Carlos Henrique Mendes; Silva, Fabyano Fonseca e; Silveira, Fernanda Gomes da

    Resumo em Inglês:

    In the present study, alternative and traditional nonlinear models to describe growth curves of Morada Nova sheep reared in the state of Bahia, Brazil, were applied. The nonlinear models were: Schnute, Mitscherlich, Gompertz, Logistic, Meloun I Meloun II, III Meloun, Gamito and Meloun IV. The model adjustment was evaluated by using: Adjusted Coefficient of Determination (R²aj), Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Mean Squared Error of Prediction (MEP) and Coefficient of Determination of Prediction (R²p). The selection of the best model was based on cluster analysis, using the evaluators as variables. Six out of the nine tested models converged, while Meloun I and Meloun IV were equally effective in explaining animal growth, without significant influence of sex or type of parturition over the curve parameters. The models Meloun I and IV have the best adjustment and reveal a remarkable reduction of weight gain after 150 days of age, which indicates special attention should be given to feeding at this stage.
  • Intake, digestibility and ruminal parameters of dairy cows fed pelleted diets and treated with lignosulfonate-containing sunflower seeds Ruminants

    Marchi, Francilaine Eloise De; Figueiroa, Fábio José Ferreira; Santos, Geraldo Tadeu dos; Santos, Wallacy Barbacena Rosa dos; Kazama, Daniele Cristina da Silva; Branco, Antonio Ferriani; Leite, Laudí Cunha; Damasceno, Julio Cesar

    Resumo em Inglês:

    The objective of this study was to evaluate intake, in vitro and apparent digestibility and ruminal parameters of Holstein cows that were confined and fed corn silage and concentrate containing: ground sunflower seeds (GS); ground sunflower seeds treated with 5% lignosulfonate (GSL); pelleted sunflower seeds (PS); or ground and pelleted sunflower seeds treated with lignosulfonate (PSL). Four lactating cows with 130±28 days of lactation and body weights of 569±63 kg were used. These animals were distributed in a Latin square design with four diets and four periods of 21 days each. There were no differences in the intakes (% body weight) of dry matter (DM), organic matter (OM), mineral matter (MM), crude protein (CP), neutral detergent fiber (NDF) or acid detergent fiber (ADF). The apparent digestibility of DM, OM, CP, EE, NDF, ADF and NFC were similar for all the diets, with a tendency towards decreased CP digestibility for all the pelleted diets (65.79%) compared with the non-pelleted diets (69.66%). A negative effect of lignosulfonate was observed for the in vitro digestibility (IVD) of DM, and a negative tendency was observed for the IVD of OM. Pelleting decreased the concentration of acetic acid (55.95 × 58.82 mM) in rumen fluid. There was no effect of diet on pH (6.17) or ammonia nitrogen concentration (18.19 mg/dL). Pelleting and lignosulfonate do not promote the protective effect of sunflower seed nutrients as expected, and it may be more feasible to provide ground sunflower seed.
  • Nutritional performance of cattle grazing on low-quality tropical forage supplemented with nitrogenous compounds and/or starch Ruminants

    Lazzarini, Ísis; Detmann, Edenio; Paulino, Mário Fonseca; Valadares Filho, Sebastião de Campos; Valadares, Rilene Ferreira Diniz; Oliveira, Fabrício Albani; Silva, Poliana Teixeira da; Reis, William Lima Santiago dos

    Resumo em Inglês:

    The objective of this work was to evaluate the effects of protein and/or starch supplementation on the nutritional performance of cattle grazing on low-quality tropical forage. Five crossbred steers (Holstein × Gyr) with an average body weight (BW) of 397 kg that were fitted with ruminal and abomasal cannulae were used. The animals were kept in individual signal-grass (Bracharia decumbens) paddocks. Five treatments were evaluated: 1 - control (without supplementation); 2 - supplementation with 1 g of crude protein (CP) per kg of BW; 3 - supplementation with 2.5 g of starch per kg of BW; 4 - supplementation with CP and starch as described for treatments 2 and 3; and 5 - supplementation as described for treatment 4 but replacing the corn starch with a mixture of corn starch and nitrogenous compounds, thereby resulting in an energy supplement of 150 g CP/kg of dry matter. The experiment was performed according to a 5 × 5 Latin square design in a 2 × 2 + 1 factorial arrangement. The forage intake was not affected by any of the factors evaluated in this study. The production of microbial nitrogen in the rumen was not affected by nitrogen or starch supplementation. The apparent nitrogen balance was only increased when both starch and nitrogen were supplied. Supplementation with both starch and nitrogenous compounds for cattle grazing on low-quality tropical forage is characterized by an interactive metabolic effect that increases nitrogen accretion by the animals.
  • Models for estimating feed intake in small ruminants Invited Review

    Pulina, Giuseppe; Avondo, Marcella; Molle, Giovanni; Francesconi, Ana Helena Dias; Atzori, Alberto Stanislao; Cannas, Antonello

    Resumo em Inglês:

    This review deals with the most relevant limits and developments of the modeling of intake of sheep and goats reared intensively and extensively. Because small ruminants are normally fed ad libitum, voluntary feed intake is crucial in feeding tactics and strategies aimed at optimal animal production. The effects of genetic, neuroendocrine, hormonal, feed and environmental factors on voluntary feed intake were discussed. Then, several mathematical models to estimate dry matter intake (DMI) were examined, with emphasis on empirical models for sheep and goats in intensive farm systems or in extensive areas under pasture or rangeland conditions. A sensitivity analysis of four models of prediction of DMI in housed lactating dairy sheep and meat sheep breeds was also presented. This work evidenced a large variability in the approaches used and in the variables considered for housed sheep and goats. Regarding the estimation of feed intake for grazing sheep and browsing goats, the accuracy of estimates based on empirical models developed so far is very low when applied out of the boundaries of the studied system. Feeding experiments indoors and outdoors remain fundamental for a better modeling and understanding of the interactions between feeds and small ruminants. However, there is a need for biological and theoretical frameworks in which these experiments should be carried out, so that appropriate empirical or mechanistic equations to predict DMI could be developed.
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