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Search Results: 1 - 10 of 78666 matches for " Roberta Gomes Mar?al Vieira; "
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Características agron micas, morfogênicas e estruturais do capim "Panicum maximum" cv. Momba a sob desfolha o intermitente Characteristics agronomic, morphogenic and structural of the “Panicum maximum” cv. Momba a grass under intermittent defoliation
Carlos Henrique Oliveira Macedo,Emerson Alexandrino,Adriano Jakelaitis,Roberta Gomes Maral Vieira Vaz
Revista Brasileira de Saúde e Produ??o Animal , 2010,
Abstract: Avaliou-se o efeito de dois períodos de descanso sobre as características morfogênicas, estruturais e o acúmulo de forragem do Panicum maximum cv. Momba a estabelecido na Amaz nia Legal. Os tratamentos foram dispostos em delineamento em blocos ao acaso, com quatro repeti es. Os períodos avaliados foram de 36 e 48 dias de rebrota o, com 25 cm de altura do corte. Para as características agron micas avaliadas, apenas a produ o de matéria seca de lamina foliar n o foi incrementada com o prolongamento do período de descanso. A produ o de matéria seca total n o variou entre os períodos de descanso, o que demonstra que, no menor período de descanso (36 dias), a menor produ o por corte foi compensada pelo maior número de cortes. O período de descanso n o influenciou sobre nenhuma variável morfogênica avaliada, com exce o para o filocrono, e a maior média obtida no menor período de descanso. Para as características estruturais do relvado, foi detectado efeito do período de descanso para o comprimento de lamina foliar, número de folhas mortas e rela o folha colmo. O prolongamento do período de descanso n o altera as características morfogênicas da forragem, n o obstante, altera a estrutura do pasto e aumenta a produ o de matéria seca total. The effect of rest periods during seasons was evaluated on morphogenetic and structural characteristics and herbage accumulation of Panicum maximum cv. Mombaca established in Amazonia. We used a completely randomized design, with four replicates per treatment. Rest periods were 36 and 48 days, and height of cut was 25 cm. Leaf blade dry matter production did not increase as rest period increased. Dry matter production did not modify between rest periods, showing that in the lowest rest period lower production was compensated by higher number of cuts. Rest period did not influence the morphogenetic variable evaluated, except phyllocrono as higher average was obtained in lower rest period. For structural characteristics, effect of rest period was observed for leaf blade length, death leaves number and leaf-stem ration.
Evolution of the biomass and the profile of organic reserves during regrowth of “Brachiaria brizantha” cv. Marandu submitted to levels of nitrogen Evolu o da biomassa e do perfil da reserva organica durante a rebrota o da "Brachiaria brizantha" cv. Marandu submetida a doses de nitrogênio
Emerson Alexandrino,Paulo Roberto Mosquim,Domício do Nascimento Júnior,Roberta Gomes Maral Vieira Vaz
Revista Brasileira de Saúde e Produ??o Animal , 2008,
Abstract: The regrowth of forage plants is supported by organic compounds synthesized by them. In this way, the objective was to evaluate the nitrogen (N) effect on dry biomass evolution and the profile of organics compounds on the botton of Brachiaria brizantha cv. Marandu represented by non structural carbohydrates and nitrogen compounds. Treatments were distributed in a randomized blocks design, under factorial scheme (3 x 6), with three levels of N (0, 20 e 40 mg /dm3 soil/week N) and six dates of regrowth (0, 2, 4, 8, 16 e 32 days after the uniformization cut) in a greenhouse with three repetitions for each treatment. N had positive effect (P<0.05) on the evolution of the biomass of the plants during the regrowth. Non structural carbohydrates content reduced after defoliation, which was stimulated by N levels. From the compounds that contributed to non structural carbohydrates, the reduced sugars were more sensible followed by starch and non reduced sugars which decreasing of 84, 40 and 14% respectively. N level increased the nitrogen compounds content and the highest reduction of the content after cut was showed by plants that did not received N. A rebrota o das forrageiras é mantida pelos compostos organicos sintetizados por elas. Dessa forma, objetivou-se avaliar o efeito do nitrogênio (N) sobre a evolu o da biomassa seca e do perfil dos compostos organicos da base do colmo da Brachiaria brizantha cv. Marandu, representados pelos carboidratos totais n o-estruturais e compostos nitrogenados. Foi utilizado o delineamento em blocos casualizados, em esquema fatorial 3 x 6, sendo três doses de N (0, 20 e 40 mg /dm3 de solo/semana de N) e seis tempos de rebrota o (0, 2, 4, 8, 16 e 32 dias após o corte de uniformiza o), em casa-de-vegeta o, com três repeti es para cada tratamento. O N teve efeito significativo (P<0,05) e positivo sobre a evolu o da biomassa das plantas durante a rebrota o. O conteúdo de carboidratos totais n o-estruturais reduziu após a desfolha o, sendo estimulado com o aumento das doses de N. Dos compostos que formam os carboidratos totais n o-estruturais, os a úcares redutores foram os mais sensíveis, seguidos do amido e a úcares n o-redutores, com redu o de 84, 40 e 14%, respectivamente. O N estimulou a recupera o dos a úcares redutores e incrementou a redu o do amido após a desfolha o. O aumento na dose de N incrementou o conteúdo dos compostos nitrogenados, e a maior redu o do conteúdo após o corte foi encontrada em plantas que n o receberam N.
Equa es de predi o da energia metabolizável da torta de baba u para frangos de corte Predictive equations for metabolizable energy content of babassu for broilers
Jefferson Costa de Siqueira,Dáphinne Cardoso Nagib Nascimento,Roberta Gomes Maral Vieira Vaz,Rubens Fausto Silva
Revista Brasileira de Saúde e Produ??o Animal , 2011,
Abstract: Objetivou-se elaborar equa es de predi o dos valores de energia metabolizável aparente (EMA) e aparente corrigida para o balan o de nitrogênio (EMAn) da torta de baba u (Orbignya martiana) para frangos de corte. Uma revis o da literatura foi realizada para identificar trabalhos que avaliaram a composi o química (matéria seca, proteína bruta, e extrato etéreo,) e os valores energéticos (energia bruta, EMA e EMAn) da torta de baba u para aves. Foram calculados os coeficientes de correla o de Pearson para estudar a associa o entre os componentes químicos e os valores energéticos. Posteriormente, os dados foram submetidos à análise de regress o linear simples e múltipla. Utilizou-se a técnica Stepwise e considerou-se um nível de significancia igual ou inferior a 5%. As equa es recomendadas para corrigir o conteúdo energético da torta de baba u em fun o da sua composi o química, na matéria natural, s o: EMA (kcal/kg) = -3517,25 + 79,78 EE + 1,157 EB (R2 = 0,926; P = 0,019) e EMAn (kcal/kg) = -2909,80 + 71,707 EE + 0,979 EB (R2 = 0,973; P = 0,005). As equa es foram avaliadas mediante cálculo dos coeficientes de correla o (r) entre os valores de EMA e EMAn preditos e aqueles observados em ensaios de metabolismo com aves, de forma que foram observadas altas correla es entre os valores determinados e aqueles preditos para a EMA (r = 0.97) e para a EMAn (r = 0,95). This study aimed to develop equations to predict the values of apparent metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen balance (AMEn) of babassu (Orbignya martiana) for broilers. A literature review was performed to identify studies that evaluated the chemical composition (dry matter, DM; crude protein, CP; ether extract, EE) and energy values (gross energy, GE, AME and AMEn) the babassu for birds. We calculated the correlation coefficients of Pearson, to check the association between chemicals components and the energy values. Subsequently, data were analyzed by simple and multiple linear regressions using the Stepwise technique, considering a significance level equal or inferior to 5%. The equations recommended to correct the energy content of babassu depending on their chemical composition, on wet matter basis, are: AME (kcal / kg)= -3517.25 + 79.78 EE + 1.157 CE (R2 = 0.927; P = 0.019) and AMEn (kcal/kg) = -2909.80 + 71.707 EE + 0.979 CE (R2 = 0.973; P = 0.005). The equations were evaluated by calculating the correlation coefficients (r) between the values predicted and those observed in metabolism trials with birds. Were observed high correlations be
Níveis de lisina digestível em ra??es para frangos de corte de 22 a 42 dias de idade, mantidos em ambiente de termoneutralidade
Lana, Sandra Roselí Valerio;Oliveira, Rita Flávia Miranda de;Donzele, Juarez Lopes;Gomes, Paulo Cézar;Vaz, Roberta Gomes Maral Vieira;Rezende, Wilkson de Oliveira;
Revista Brasileira de Zootecnia , 2005, DOI: 10.1590/S1516-35982005000500024
Abstract: two trials were conducted to evaluate the effects of increasing dietary digestible lysine levels, maintaining or not the amino acid relation, on performance of broilers from 22 to 42 days old on thermoneutral environment. two hundred and ten male broilers (averaging initial weight of 662.5 g) and 168 broilers (averaging initial weight of 623.7 g) were assigned to a completely randomized experimental design in trials 1 and 2, respectively. in trial 1, the broilers were allotted to five treatments (digestible lysine levels in conventional diets) and six replicates of seven broilers. in trial 2, the broilers were allotted to four treatments (digestible lysine levels in diet maintaining amino acid relation) and six replicates of seven broilers. in both trials, linear effect of digestible lysine levels on body weight gain and feed:gain ratio were observed. in trial 1, the increasing dietary digestible lysine levels increased linearly absolute carcass weight. there was no effect of lysine levels on relative carcass weights and on absolute and relative weichts of abdominal fat. in trial 2, absolute and relative breast and thigh weights increased linearly, while the absolute drumstick data increased quadraticly up to 0.955% digestible lysine level. no treatment effects on relative drumstick weight and absolute and relative weights of abdominal fat was observed. it was concluded that male broilers, avian farms, in the period from 22 to 42 days old, require at least 1.015 and 1.075% digestible lysine in conventional diet or in a diet maintaining the amino acid relation, respectively. this corresponds to an intake of 28 g digestible lysine for birds on a thermoneutral environment.
Níveis de metionina + cistina para pintos de corte mantidos em ambiente termoneutro
Oliveira Neto, Adhemar Rodrigues de;Oliveira, Rita Flávia Miranda de;Donzele, Juarez Lopes;Cecon, Paulo Roberto;Vaz, Roberta Gomes Maral Vieira;Gasparino, Eliane;
Revista Brasileira de Zootecnia , 2005, DOI: 10.1590/S1516-35982005000600020
Abstract: the experiment was conducted to determine the effect of dietary methionine + cystine (met + cys) requirement of 1-to-21-day-old broiler chicks on thermoneutral environment. four hundred avian farm male broiler chicks were assigned to a randomized experimental design with five treatments (0.756, 0.810, 0.866, 0.920, and 0.976% of met + cys), eight replicates of ten birds. weight gain (wg), feed:gain ratio, met + cys intake, protein deposition of absolute weights of liver, gizzard, and lung and relative weights of lung were affected by the increasing dietary met + cys levels. no effect of met + cys levels on feed intake, fat deposition, absolute weights of carcass, proventriculus, heart, and intestine or relative weights of heart, liver, gizzard, proventriculus, lung and intestines was verified. the best wg was observed at 0.866% met + total cys (0.790% met + digestible cys calculated) level, corresponding to 69% met + cys/total lys ratio (72% for digestible) and the best feed:gain ratio value was observed at 0.894% met + total cys (0.822% digestible calculated) level, corresponding to 72% met + cys/ digestible lys total ratio (74% met + cys/digestible lys ratio), for broiler chicks on thermoneutral environment.
Exigências de treonina digestível para leitoas mantidas em ambiente termoneutro dos 30 aos 60 kg
Saraiva, Edilson Paes;Oliveira, Rita Flávia Miranda de;Donzele, Juarez Lopes;Ferreira, Aloízio Soares;Vaz, Roberta Gomes Maral Vieira;Oliveira, Will Pereira de;
Revista Brasileira de Zootecnia , 2007, DOI: 10.1590/S1516-35982007000800020
Abstract: this study was carried out to evaluate the requirement of digestible threonine in diets of gilts from 30 to 60 kg, maintained thermoneutral environment. seventy crossbreed gilts with an initial weight of de 30.0 ± 0.61 kg were used in a randomized blocks design, with five treatments (levels of digestible threonine), seven replicates and two animals per experimental unity. the treatments corresponded of the levels of 0.50; 0.53; 0.56; 0.60; and 0.63% of digestible threonine. no effect was observed of digestible threonine level on daily weight gain of animals. feed:gain ratio improved in a quadratic way with the digestible threonine level, and the linear response plateau model estimated in 0.52% the level of amino acid, from which the feed conversion did not change. daily feed intake was reduced with the increase of digestible threonine intake. fat deposition linearly reduced, while protein deposition did not change with the increase of digestible threonine. the absolute and relative weight of kidneys and the absolute of intestine increased in a quadratic way with the digestible threonine levels, however, the relative weight of intestine increased in a linear way. it was concluded that the calculated level of 0.52% of digestible threonine, corresponding to a daily intake of 9.18 g and a relation with the digestible lysine of 63% provided better feed:gain ratio for gilts maintained in a thermoneutral environment from 30 to 60 kg.
Efeito da temperatura ambiente sobre o desempenho e as características de carca?a de frangos de corte dos 22 aos 42 dias
Oliveira, Gisele Andrade de;Oliveira, Rita Flávia Miranda de;Donzele, Juarez Lopes;Cecon, Paulo Roberto;Vaz, Roberta Gomes Maral Vieira;Orlando, Uislei Antonio Dias;
Revista Brasileira de Zootecnia , 2006, DOI: 10.1590/S1516-35982006000500020
Abstract: this study was conducted to evaluate the effect of environmental temperature on performance and carcass characteristics of male broilers in the period from 22 to 42 days old. three hundred and thirty-six male avian farm broilers, averaging 624 g were allotted to a randomized experimental design, with four treatments (temperatures of 16, 20, 25 and 32oc). the treatment 1 consisted of 12 replicates and the others of 24 replicates, all with four birds per experimental unity. the treatments affected weight gain, feed intake and metabolizable energy intake that quadractly increased until the estimated temperatures of 24.4, 19.1 and 19.1oc, respectively. feed:gain ratio also changed in a quadratic way, increasing until the estimated temperature of 26.3oc. the treatments influenced the carcass and breast yield that changed in a linear way as the temperature increased from 16 to 32oc. thigh yield changed in a quadratic way, increasing until the estimated temperature of 19.4oc. the absolute weights of heart, kidney and gizzard and the relative weights of heart and gizzard were affected by the environmental temperatures and were higher in cold environment (16oc) and smaller in the hot environment (32oc). the relative weight of kidney linearly increased as the temperature increase from 16 to 32oc. however, no treatment effect on absolute and relative weights of proventriculus was observed. it was concluded that the best results of weight gain and absolute weights of carcass, breast and thigh are obtained when the birds are reared on environmental temperatures from 22.3 to 24.7oc. environmental temperatures bellow or above these values affect negatively weight gain and absolute weights of carcass, breast and thigh.
Níveis de lisina digestível em ra??es, em que se manteve ou n?o a rela??o aminoacídica, para frangos de corte de 1 a 21 dias de idade, mantidos em estresse por calor
Valerio, Sandra Roseli;Oliveira, Rita Flávia Miranda de;Donzele, Juarez Lopes;Albino, Luiz Fernando Teixeira;Orlando, Uislei Antonio Dias;Vaz, Roberta Gomes Maral Vieira;
Revista Brasileira de Zootecnia , 2003, DOI: 10.1590/S1516-35982003000200015
Abstract: two trials were conducted to evaluate the effects of digestible lysine levels in diets maintaining or not the relationship of amino acids, on performance of broilers from 1 to 21 days, kept under heat stress. a completely randomized experimental design was used in both trials. in the trial 1, the broilers were allotted in five treatments (0.92; 0.98; 1.04; 1.10 and 1.16% of lysine in conventional diets), eight replicates and ten broilers per replicate. in the trial 2, the broilers were allotted in four treatments (1.04; 1.10; 1.16 and 1.22% of lysine in diet maintaining the relationship of amino acids), eight replicates and ten broilers per replicate. in the trial 1, the digestible lysine levels influenced quadraticly the weight gain and the feed intake that increased up to 1.14 and 1.09%, respectively. although feed:gain ratio had changed by linear way, the lrp model adjusted better to the data, estimating in 1.097% the lysine level where occurred a "plateau". there was no effect of treatments on absolute weights of heart, liver and intestines, while the absolute weight of gizzard increased linearly. the absolute weight of carcass increased while the relative weights of heart and liver reduced quadraticly. in the trial 2, the treatments influenced in a crescent linear way the weight gain and the feed:gain ratio while the feed intake was not influenced. the treatments influenced linearly the absolute weight of carcass while the absolute and relative weights of the organs were not influenced. it was concluded that male broilers, in the period from 1 to 21 days of age, kept under heat stress, require at least 1.14 and 1.22% of digestible lysine in conventional diet and in diet maintaining the relationship of amino acid, respectively.
Níveis de proteína bruta e suplementa??o de aminoácidos em dietas para leitoas mantidas em ambiente de alta temperatura dos 60 aos 100 kg
Orlando, Uislei Antonio Dias;Oliveira, Rita Flávia Miranda de;Donzele, Juarez Lopes;Ferreira, Rony Antonio;Vaz, Roberta Gomes Maral Vieira;
Revista Brasileira de Zootecnia , 2007, DOI: 10.1590/S1516-35982007000500012
Abstract: this experiment was conduced to determine the level of cp with amino acid supplementation in diets to gilts under high environmental temperature in finishing phase. thirty-five crossbreed gilts (landrace x large white) with an average initial weight of 60.3 kg were allotted in a randomized experimental design with five diets (17.3, 16, 14.7, 13.4, and 12.1% cp) seven replications and one animal by experimental unity. the experimental diets were supplied ad libitum until the end of the experiment when the animals reached the average weight of 100.3 kg. the average temperature inside the room was kept in 30.6oc and the relative humidity in 71%. the black globe humidity index calculated in the period was 81. not effect was observed for the reduction of cp level of the diet on the studied performance characteristics (feed intake, weight gain and feed gain ratio). the carcass characteristics (carcass length; loin eye area; backfat thickness and yield of carcass, lean meat, fat and ham) also were not influenced by the cp reduction in the diets. the cp levels and supplementation of amino acids in the dieta influenced the relative and absolute weight of intestine. smaller values were observed in animals fed diet with smaller level of cp (12.1%). the reduction of cp level in the diet from 17.3 to 12.1% did not harms the performance of gilts maintained in a high environmental temperature from 60 to 100 kg since the diets are properly supplemented with limiting essential amino acids.
Níveis de metionina + cistina total para frangos de corte de 22 a 42 dias de idade mantidos em ambiente termoneutro
Oliveira Neto, Adhemar Rodrigues de;Oliveira, Rita Flávia Miranda de;Donzele, Juarez Lopes;Barreto, Sergio Luiz de Toledo;Vaz, Roberta Gomes Maral Vieira;Gasparino, Eliane;
Revista Brasileira de Zootecnia , 2007, DOI: 10.1590/S1516-35982007000600019
Abstract: the experiment was carried out to determine the requirement of methionine + cystine (met + cys) for broilers from 22-to-42-day-old kept under thermoneutral environment (23.5°c). a total of 240 avian farm male broilers, with 827 g average initial weight were distributed in a randomized experimental design with five levels of met + cys (0.659, 0.704, 0.750, 0.796, and 0.841%), six replications and eight birds per experimental unit. the increase of met + cys level influenced positively feed: gain ratio, met + cys intake, drumstick absolute weigh and thigh relative weight. no effect of met + cys levels was observed on the final weight, weight gain, feed intake, breast, carcass and abdominal fat absolute and relative weight, thigh absolute weight, and drumstick relative weight, or for relative and absolute weight of the organs (heart, liver, gizzard, proventriculus, lung and intestines). the level 0.727% met + total cys (0.661% digestible met + cys), corresponding to the ratio met + cys/total lys of 70% (72% for digestible lys) gave the best feed: gain ratio for male broilers kept in thermoneutral environment.
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