Doutorado em Zootecnia (EVZ)

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http://200.137.215.59/tede/handle/tde/223

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Navegando Doutorado em Zootecnia (EVZ) por Assunto "Antimicrobials"

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    Uso de aditivos e adaptação para dietas com alta inclusão de grão de milho inteiro de bovinos confinados
    (Universidade Federal de Goiás, 2017-02-17) Mobiglia, Andrea de Mello; Couto, Victor Rezende Moreira; http://lattes.cnpq.br/4329309889502866; Fernandes, Juliano José de Resende; http://lattes.cnpq.br/7949776443064259; Fernandes, Juliano José de Resende; Silva, Rodrigo Medeiros da; Ribeiro, Marinaldo Divino; Oliveira Júnior, Reinaldo Cunha de; Pádua, João Teodoro
    The objective was to evaluate the effects of antimicrobial additives and the inclusion of roughage during adaptation period in diet containing whole shelled corn (WSC, 85% WSC + 15% pelleted concentrate) on performance of Zebu bulls (Exp. 1). The Exp. 1 was realized in randomized complete block design with 2x2 factorial and five replicates. A hundred bulls were fed for 105 d with diet containing monensin (MON, 30 mg/kg DM) ou virginiamycin (VM, 25 mg/kg DM) and with or without inclusion of sugarcane bagasse as roughage (ROU or NO-ROU) in adaptation period. The Exp. 2 was parallel conducted in randomized design with two treatments (MON, 30 mg/kg DM or VM, 25 mg/kg DM) and five replicates. Ten fistulated steers were used and fed with the same diet than Exp. 1 without inclusion of roughage. A laboratorial experiment (Exp. 3) was realized at Kansas State University and its objective was to evaluate the capacity of Megasphaera elsdenii (ME) strain 41125 metabolizes a range of alternative substrates as carbon source. The experiment was designed in randomized complete blocks with six replicates. Viable cell counting, pH, and optical density were measured in media containing glucose, fructose, galactose, arabinose, xylose, maltose, sucrose, lactose, lactate, trehalose, raffinose, Fructooligosaccharide, potato starch, soy protein, succinate. In Exp. 1 and Exp. 2, antimicrobial additives, MON and VM, added to diet containing 85% WSC and 15% pellet concentrate had equal results for performance, ruminal fermentation, and apparent total tract digestibility of nutrients (P≥0.05). However, lower intake was observed in animals fed with monensin includes on diet (P≤ 0.027). Although the additive used had no effect on performance on Exp. 1, the inclusion of roughage in adaptation period showed tendentiously greater final body weight, average daily gain, and efficiency (P≤ 0.088; P≤ 0.075 e P≤ 0.094, respectively) for adaptation period (1 to 20 d) and entire feedlot period (1 to 105 d). There were no treatment effects and interactions for carcass characteristics as hot carcass weight, dressing percentage, carcass daily gain (P≥0.05). In Exp. 3, Megasphaera elsdenii was able to metabolize alternative substrates as glucose, maltose, lactate, Fructo-oligosaccharide, and fructose. However, ME had greater growth in media containing fructose, but the viable cell counting did not show consistent results with optical density. Investigations must be done to clarify the ME metabolism when fructose is used as carbon source. Accord to results obtained in this study, a roughage sorce might be included on adaptation period in diet contenting 85% whole flint corn plus 15% concentrate pellete to obtain greater animal performance. Thus, Megasphaera elsdenii is able to use alternative substrates as lactate, glucose, fructose, and maltose, maintaining their population in rumen.
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    Atividade antimicrobiana de extratos vegetais em frangos de corte de crescimento lento desafiados com Salmonella Heidelberg
    (Universidade Federal de Goiás, 2019-03-08) Mota, Lorena Cunha; Mascarenhas, Alessandra Gimenez; http://lattes.cnpq.br/9082632592936909; Leandro, Nadja Susana Mojyca; http://lattes.cnpq.br/3136809931691012; Leandro, Nadja Susana Mogyca; Melo, Francislete Rodrigues; Nunes, Romão da Cunha; Café, Marcos Barcellos; Mello, Heloisa Helena de Carvalho
    Two experiments were carried out with the objective of evaluating the antimicrobial activity of native extracts of native species of Brazilian Cerrado. The first experiment was carried out in vitro using seven ethanolic plant extracts native to the Brazilian cerrado (Barbatimão (Stryphnodendron adstringens), Jacaranda (Machaerium villosum), Jenipapo (Genipa americana), Pau-terra (Qualea parviflora), Pau- (Brosimum gaudichaudii), to evaluate the total phenolic compounds, antioxidant activity and antimicrobial activity against Salmonella Heidelberg. The phenolic compounds of the plant extracts were determined by spectroscopy in the visible region, using the Folin-Ciocalteau method. The determination of the antioxidant capacity of the plant extracts was carried out using the ABTS solution free radical sequestration method. The in vitro antimicrobial activity of the seven ethanolic extracts against Salmonella Heidelberg was performed using the disc diffusion method. In the second experiment were performed performance tests, intestinal development, bacteriology and blood biochemistry of slow-growing chickens challenged with Salmonella Heidelberg and treated with woodland plant extract. A total of 432 broiler chickens were used. The roasted red roasted roasted roasted red roasted roe were distributed in six treatments, six replicates and 12 birds per experimental unit. The experimental design was randomized blocks distributed in six treatments: SH + control (birds with challenge + basal ration); SH + EVT (challenged birds + antimicrobial ration), SH + EVPT (control + challenged birds), control (birds without challenge + basal ration), ANT (unchallenged birds + antimicrobial ration) and EVPT challenge + plant extract). Performance, intestinal histomorphometry, specific bacteriology and blood biochemistry were evaluated. The results of the antimicrobial analysis of Salmonella Heidelgerb extracts were submitted to analysis of variance (ANOVA). The data of phenolic compounds and antioxidants were submitted to descriptive analysis. The performance data, histomorphometry and blood biochemistry were submitted to the test of variance. Data from the specific bacteriology were analyzed by descriptive method. The data of phenolic compounds and antioxidants were submitted to descriptive analysis. The ethanolic vegetal extracts varied from 6.48 to 59.81 g EAG / mL of total phenolic compounds and 595 to 1098.33 μmol / L of antioxidant activity. The ethanolic extract of Pau-terra presented moderate antimicrobial activity against Salmonella Heidelberg (halo diameter 9.5%). In the results of the performance evaluation the ANT treatment promoted greater weight gain and higher final weight of the birds and the SH + EVPT treatment influenced in lower weight gain and lower final weight. In the evaluation of the histomorphometry of the segments of the gastrointestinal tract histoformetrium of the chick embryo of slow growth slow crypt depth in the mucosa was higher in the birds submitted to the SH + EVPT treatment and, the lower in the birds submitted to SH + crypt for SH + control birds and reduction in the ratio for SH + EVPT treated birds. The treatments did not influence the studied parameters of the duodenum and jejunum of seven - day - old birds. The SH + EVPT treatment promoted crypt depth increase, and the SH + control treatment reduced crypt depth. In the birds of 42 days of age the treatment promoted EVPT promoted jejunal villus height and SH + control reduced jejunal villus height. In the ilium SH + EVPT treatment promoted villus enlargement and ANT treatment reduced villus height. The SH + control treatment reduced the crypt depth of the ilium and the SH + EVPT treatment increased the crypt depth of the ilium. In bacteriology, 75% of the gastrointestinal tract presented Salmonella Heidelberg at 7 days of age, 58% at 28 days of age and 16.66% at 42 days of age. The concentration of albumin, cholesterol, triglycerides and uric acid was influenced by the treatments. The ethanolic extracts of Barbatimão Jacarandá, Mama-bitch, Jenipapo, Pau-ferro and Murici did not present antimicrobial activity against Salmonella Heidelberg (diameter of halo 5mm). The ethanolic extract of Pau-terra, offered in drinking water, using a concentration of 1: 1000 and supplied once a day to slow-growing chickens does not promote the performance improvement of chickens up to 28 days of age and has no activity antimicrobial activity against Salmonella Heldelberg.