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Item Adição de enzimas em dietas de frangos de corte a base de milho de diferentes qualidades(Universidade Federal de Goiás, 2020-03-31) Andrade, Tiago Vieira de; Stringhini, José Henrique; http://lattes.cnpq.br/8505634095383289; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Mascarenhas, Alessandra Gimenez; Arnhold, Emmanuel; Carvalho, Genilson Bezerra de; Fortes, Bruno Duarte AlvesThe nutritional quality of stored corn grains is of paramount importance to formulate more efficient diets, given that corn grains with low nutritional value, trigger metabolic disturbances and consequently negative effects on the performance and use of nutrients in birds. Thus, the objective was to evaluate the effect of the addition of exogenous enzymes in diets of broilers based on corn kernels of different qualities. with 696 birds of the Cobb 500 strain. In experiments 1 and 3, with the purpose of evaluating performance at 1, 7, 21, 35 and 42 days of age and intestinal histomorphometry at 21 and 42 days of age, 600 chicks were used 1 day old males. In experiments 2 and 4, metabolism assays were carried out with 96 14-day old male chicks from experiment 1 and 3 to estimate the metabolizable energy values of corn of different qualities with the inclusion of exogenous enzymes and mycotoxin adsorbent in diets for broilers. In all experiments, a completely randomized design (DIC) was used, distributed in a factorial arrangement (2x2), with experiment 1 and 2 being the addition or not of the XAP enzyme blend (Xylanase, Amylase and Protease) and two types of corn (types 1 and 3), and for experiment 3 and 4 with or without the addition of mycotoxin adsorbent and with or without the addition of the enzymatic blend. It was observed that the birds that consumed type 1 corn with enzyme had higher average weight and better feed conversion. It was observed that the birds that consumed diets containing enzyme showed better digestibility for the values of EMAn, EMA and CMMS in the period of 17 to 21 days. It was observed that birds that consumed type 1 corn with enzyme showed better intestinal development for height of the jejunum and ileum up to 21 days of age. There was a reduction in uric acid and AST for birds that consumed type 1 corn with enzyme. There was a reduction (p <0.05) in LDH for birds that consumed type 1 corn. There was a higher (p <0.05) average weight for birds that consumed diets containing enzyme and adsorbent in the period from 1 to 7 days . In conclusion, it can be said that birds that consumed type 1 corn with enzyme showed good performance, carcass yield, use of nutrients and intestinal development.Item Níveis e fontes de metionina na nutrição de frangos de corte(Universidade Federal de Goiás, 2017-03-20) Carvalho, Genilson Bezerra de; Stringhini, José Henrique; http://lattes.cnpq.br/8505634095383289; Carvalho, Fabyola Barros de; http://lattes.cnpq.br/4936451314440305; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Leandro, Nádja Susana Mogyca; Arnhold, Emmanuel; Laboissiere, Michele; Barbosa, Nei André ArrudaMethionine is an essential amino acid and the first limiting factor in broiler feed. Knowing the bioefficacy of methionine sources and the nutritional requirements of methionine + cystine, as well as their effects on broilers in the different stages and conditions of breeding, is necessary. The objective of this study was to determine the relative bioefficacy of the dietary source of methionine hydroxy analogue calcium salt (MHA-Ca), compared to DL-methionine (DL-met) and methionine + cystine requirement (M + C). Its effect on blood parameters and bed quality in the initial and growth stages of broiler chickens. For this, two experiments (I and II), in the 1 to 21 days and 22 to 42 days of age phases, were performed using a total of 3528 male, oneday-old broilers of the lineage (Cobb-500). In the experiment I, 1728 birds distributed in 9 treatments - (basal diet - without methionine, and four levels of methionine (6 replicates / 32 birds) were used in order to determine the bioefficacy of MHA-Ca compared to DL-Met In the experiment II, in order to determine the Met + Cis requirement, as well as its effect on blood parameters and bed quality, 1800 birds were used in 5 treatments (6 replicates / 30 birds), of which 900 (MHA-Ca, DL-Met) and (DL-Met), respectively, were used in experiments I and II, respectively, in the initial phase and the rest in the growth phase. The mean bioavailability for MHA-Ca for weight gain and feed conversion was 65% and 22% in the 1 to 21 days phase, and 41% and 58% in the 22 to 42 days phase. Of digestible M + C requirement, estimated for the 1 to 21 and 22 to 42 days of age, was 0.764 and 0.716% corresponding to a Met + Cys / lysine ratio of 64% and 68%, respectively. The levels of Met + Cys influenced in some blood parameters (hemoglobin, heterophilic ratio: lymphocytes and monocytes, total leukocytes, hemocytes and hematocrits, uric acid, albumin, PST, total LDL cholesterol and TG) and bed quality And excreted nitrogen) of broiler chickens.Item Efeitos do armazenamento nos parâmetros físicoquímicos e resistência à Salmonella Enteritidis em ovos de ema (Rhea americana)(Universidade Federal de Goiás, 2014-02-12) Cervi, Renato Clini; Araújo, Luciana Batalha de Miranda; Rezende, Cíntia Silvia Minafra e; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Bailão, Alexandre Mello; Andrade, Maria AuxiliadoraThe egg is an animal product with excellent nutritional value used in human food. The Ema (Rhea americana) is an animal of the Brazilian wildlife with potential to produce eggs that differ from other species in its microbiological resistance and percentages of nutrients. In order to obtain information about the chemical composition, resistance to Salmonella Enteritidis, and appropriate forms of storage for preservation of quality, were evaluated five lots of eggs from emus to assess quality in periods of seven , 14 , 21, 28 and 35 days of storage at refrigeration temperature , and three lots on 10 , 20 and 30 days to contamination of Salmonella Enteritidis. According to the results, it can be concluded that the internal quality changes with storage time, remaining viable up to 21 days of storage. The fractions of the egg change with protein degradation, and significant reduction in quality values, expressed in Haugh Unit. The eggs had high resistance to contamination by salmonella Enteritidis in all storage periods. Protein fractions of white and yolk and rheological parameters show differences from chicken egg, providing information to appropriate use of these products by the industry.Item Substituição do cloreto de colina por uma fonte vegetal de colina em dietas de frangos(Universidade Federal de Goiás, 2021-03-02) Dias, Allan Gabriel Ferreira; Stringhini, José Henrique; http://lattes.cnpq.br/8505634095383289; Santin, Ana Paula Iglesias; http://lattes.cnpq.br/2059115299287800; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Mascarenhas, Alessandra Gimenez; Lucca, Érica Crosara Ladir deThe aim of this study was to assess a vegetal source of choline as a replacement of choline chloride and its effects in the animal performance, metabolism and yield of broilers’ carcass. 1120 one day old male Cobb were used, distributed in four treatments with eight repetitions of 35 birds per unit. The treatments were: 1 - control (choline in the form of choline chloride 60%), 2 – 75% of choline chloride and 25% of vegetal choline (Choline-H) as a source of choline, 3 – 50% of choline chloride and 50% of vegetal choline (Choline-H) as a source of choline, and 4 – 100% of vegetal choline (Choline-H) as a source of choline. The animals’ performance was evaluated (weight gain, feed consumption, feed conversion, viability and uniformity), carcass and cuts yield, feathering patterns, serum biochemical profile, liver and locomotor system health, chest muscular anomalies, and zones of growth of the proximal epiphysis of the broilers’ tibias. There were no significant differences in the evaluation of broilers’ performance (weight gain, feed consumption, feed conversion, and viability) in none of the assessed phases (7, 21, 35 and 42 days). The treatment with 100% of vegetal choline provided greater uniformity of the broilers after 35 days to the carcass yield and the percentage of organs also showed no statistical differences. In the feathering score analysis, no difference was found. However, in the percentage of feathers, the treatment combining the two sources of choline had higher percentage of feathers. For the histopathological analysis and the evaluation of locomotor problems, there were no significant differences between treatments. In the serum biochemical analysis, the treatment using only vegetal choline lowered the levels of LDL and cholesterol in 21 days and of LDL in 42 days, not showing any other significant differences to the other assessed parameters (AF, GGT and AST enzymes, triglycerides, HDL and VLDL). It was concluded that the vegetal source of choline can replace choline chloride as a whole in the diet of broilers, without loss of performance and lowering the levels of circulating LDL.Item Avaliação do efeito de variáveis produtivas na conversão alimentar de frangos de corte(Universidade Federal de Goiás, 2015-03-27) Lupatini, Flaviana; Stringhini, Jose Henrique; http://lattes.cnpq.br/8505634095383289; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Arnhold, Emmanuel; http://lattes.cnpq.br/7156945506134934; Café, Marcos Barcellos; França, José Maurício; Carvalho, Fabyola Barros deThe feed conversion is one of the more indexes monitored by poultry agroindustry, in order to keep their production costs within bounds economically viable. The present study was conducted in order to identify which variables productive have the greatest impact on feed conversion of broilers. Was used production data of poultry agroindustry in the central-west of Brazil. The field results were collected from January 2012 to September 2013, a total of 2,978 broilers flocks. The sample is composed of lots of commercial strains Cobb and Hubbard, not sexed. Was made analysis of variance with Tukey Test (P> 0.05), and analysis of variance in mixed model for the following qualitatives variables: year period, commercial strains, hatchery, incubator type, type of poultry house, homogeneity of flock weight at birth. The correlation and regression polynomial for the following quantitative variables: birth weight, weight to 7, 14, 21, 28, 35, 42 days, weight slaughter, slaughter age, mortality, average daily gain and time interval between flocks on the field. Statistical analysis was made through the statistical program R. The sum of squares in the mixed model, the variables that presented the greatest impact on feed conversion were: period of the year with 39.90%, type of poultry house with 35.70% and lineage with 17.80%. Between quantitative variables that had a greater correlation with the feed conversion ratio is the average daily gain,-0.57 (P < 0.01). Each gram in average daily gain results in nine grams in feed conversion. Flocks that showed lower mortality rate, showed greater correlation between average daily gain and feed conversion. Thus, in the present study, the variables that presented the greatest impact on feed conversion were: average daily gain and period of the year.Item Suplementação de glicosaminoglicanos na ração de frangos de corte(Universidade Federal de Goiás, 2018-08-17) Martins, Julyana Machado da Silva; Sgavioli, Sarah; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4717770A4; Café, Marcos Barcellos; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4721288T1; Café , Marcos Barcellos; Faria, Doulglas Emygdio de; Rocha, Fernanda Rodrigues Taveira; Leandro, Nadja Susana Mogyca; Stringhini, José HenriqueTwo experiments were carried out to evaluate performance, hematology and serum biochemistry, locomotor problems, bone and cartilage development, and nutrient metabolizability of broilers supplemented with glycosaminoglycans on ration. The first experiment was conducted in completely randomized design, in a 3 x 3 factorial scheme (three levels of chondroitin sulfate: 0, 0.05, 0.10%, and three levels of glucosamine sulfate: 0, 0.15 and 0.30%), each treatment with six replicates of 30 birds. It was evaluated variables of performance, gait score, valgus and varus, hematology and serum biochemistry, carcass yield, femoral degeneration, tibial dyschondroplasia, macroscopy of tibia and articular cartilage, bone densitometry and strength, bone mineral profile, chondrocyte number, proteoglycans and type II collagen detection tibia articular cartilage, and gene expression of MMP-9 metalloproteinase and its inhibitor in femur articular cartilage. Glucosamine sulfate supplementation increased weight gain at 35 and 42 days old (p = 0.0470 and p = 0.0385, respectively). Chondroitin and glucosamine sulfates reduced the frequency of gait score (p = 0.0067 and p = 0.0001, respectively), and valgus and varus (p = 0.0138 and p = 0.0002, respectively). Glucosamine sulfate reduced frequency of femoral degeneration in the right (p = 0.0139) and left (p < 0.0001) femurs and linearly increased (p = 0.0284) the proliferating cartilage area. Interaction (p < 0.05) was observed of sulfates for leukocytes, lymphocytes, triacylglycerols, very low density lipoprotein (VLDL) and total calcium at 21 days; high density lipoprotein (HDL) and ionic calcium at 21 and 42 days; and for phosphorus, chlorides and sodium at 42 days. Chondroitin sulfate increased linearly (p = 0.0099) albumin and quadratic (p = 0.0140) total serum proteins at 21 days, and linearly (p = 0.0012) calcium blood at 42 days. Glucosamine sulfate linearly reduced (p = 0.0237) the chlorides at 21 days and demonstrated a quadratic effect (p = 0.0450) for albumin at 42 days. There was interaction (p < 0.05) of sulfates for tibial length at 21 days, proximal epiphysis width at 21 and 42 days, and epiphysis distal at 42 days, transverse and medial thickness of articular cartilage of proximal epiphysis at 21 days, and distal epiphysis at 42 days. At 42 days, there was a quadratic effect of glucosamine sulfate levels on tibial length (p = 0.0320) and increasing linear on distal articular cartilage weight (p = 0.0322). There was a higher percentage of calcium (p = 0.0009) and phosphorus (p = 0.0007) on tibia at 21 days with inclusion of glucosamine sulfate, as well as interaction (p < 0.0001) of sulfates for calcium at 42 days. There was interaction (p < 0.05) of sulfates for chondrocytes number, collagen type II and proteoglycans at 21 and 42 days, and for MMP-9 genes expression and its inhibitor at 42 days. The second experiment was performed in completely randomized design, was used in a 2 x 2 factorial scheme (two levels of chondroitin sulfate: 0 and 0.10%, and two levels of glucosamine sulfate: 0 and 0.30%), with eight replicates of 10 birds. Performance, feed nutrient metabolization and intestinal histomorphometry were evaluated. At 21 days old, broilers supplemented with glucosamine sulfate presented greater weight gain (p = 0.0229). There was interaction (p < 0.05) of sulfates for the metabolic coefficients of nitrogen, mineral matter and calcium, and for jejunum villi height. It was concluded that supplementation with glucosamine sulfate in broiler ration increased weight gain and stimulated intestinal histomorphometry and together with the chondroitin sulfate improved the locomotion condition and the bony and cartilaginous development. Sulfates alone promoted greater metabolism of minerals.Item Exposição de ovos de matrizes pesadas à luz monocromática durante a incubação artificial(Universidade Federal de Goiás, 2017-06-01) Mesquita, Mariana Alves; Oviedo-Rondón, Edgar Orlando; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Tanure, Candice Bergmann Garcia e Silva; Minafra, Cibele Silva; Moraes, Dunya Mara Cardoso; Mello, Heloísa Helena de CarvalhoTwo experiments were conducted at North Carolina State University to elucidate the hypothesis that exposing broiler embryos to monochromatic lights during incubation period may influence embryonic growth and development, improving incubation traits and posthatching period. In the first experiment, intermittent green light, continuous green light, intermittent red light and dark were evaluated. In addition, the influence of egg position in the tray was also tested. In the second experiment, monochromatic green light exposure was evaluated during different phases of incubation period. Treatments were: 1) 21d of incubation in the dark; 2) 21d of incubation with green light; 3) dark until E5 and continuous green light until hatch; 4) continuous green light until E5 and dark until hatch; 5) dark until E18 and continuous green light until hatch; 6) continuous green light until E18 and dark until hatch. Machine temperatures were adjusted daily in order to obtain optimal eggshell temperature (99,5 a 100,4°F) during the whole incubation period. In the first trial, embryo mortality in intermediate phase was higher in the group exposed to intermittent green light. Relative proventriculus weight was influenced by light stimuli, and the group that was not exposed to light showed the greatest organ development. Feed intake was also influenced by light treatments at 21 d of age. In the second trial, exposing embryos to continuous green light at different moments during incubation period affected the percentage of hatch and hatch of fertile. In addition, dead pipped was higher in the group exposed to light until E18. Liver weight was higher in chicks incubated in the dark during 21 d. Feed conversion ratio at 35 and 42 days was also influenced by light treatments, and the group that was not exposed to light during the whole incubation period had the lower feed conversion ratio. Significant interaction was observed between light stimuli and sex for breast yield. Male chicks that were light stimulated until E18 had the lowest breast yield. Comparing sexes, the highest breast yield was observed for females that were light stimulated until E18 during incubation. In conclusion, with incubation conditions that were established during the experiments, exposing broiler embryos to monochromatic lights did not promote benefits in incubation traits and also did not influenced chick growth and development in posthatching period.Item Utilização de grãos de milho secos por destilação com solúveis em dietas para frangos de corte(Universidade Federal de Goiás, 2020-02-27) Oliveira, Natiele Ferraz de; Stringhini, José Henrique; http://lattes.cnpq.br/8505634095383289; Santos, Fabiana Ramos dos; http://lattes.cnpq.br/8407012741007007; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Laboissière, Michele; Freitas Neto, Marcondes Dias deThe objective of this study was to evaluate the inclusion of distiller dried grains with soluble (DDGS) in place of soybean meal over zootechnical performance, and the addition of an enzymatic complex composed of amylase, xylanase and protease (AXP) on the metabolizability of nutrients for broilers. Two experiments with birds from the Cobb 500® lineage were conducted. In the first experiment, for the determination of carcass performance and yield and cuts, 600 one-day-old cutting chicks were housed, distributed in a completely randomized design, composed of four treatments (0, 10, 20 and 30% of soybean meal replacement by DDGS) and 10 replicates, containing 15 birds per experimental unit. At the end of the experiment (42 days), a bird per repetition, representing the average of boxing, was slaughtered to evaluate the parameters related to carcass yield and cuts. The data obtained were submitted to variance analysis (ANOVA) and F test. No significant differences were observed (p>0.05) between treatments for carcass performance and performance variables and cuts performed in a bird of each experimental unit at 42 days of age. In the second experiment to determine the metabolizability coefficients of nutrients, the method of total collection of excretes of 108 cutting chicks housed in galvanized steel cages, distributed in a completely randomized design, submitted to treatments: T1 - Reference feed, T2 - Reference feed (60%) + DDGS (40%) without enzyme, T3 - Reference ration (60%) + DDGS (40%) with enzyme and six replications, containing six birds per experimental unit. The data obtained were submitted to variance analysis (ANOVA) and F test. No significant differences were observed (p>0.05) for the metabolizability coefficients of dry matter, protein, crude energy, and also for apparent metabolizable energy and apparent metabolizable energy corrected with the inclusion of the enzymatic complex. It was observed that the addition of DDGS partially replaced soybean meal without affecting the parameters of performance and carcass yield. The use of enzymatic complex in the feed associated with DDGS does not influence the metabolizability of nutrients.Item Complexos enzimáticos em rações para frangos de corte(Universidade Federal de Goiás, 2016-03-17) Santos Neto, Lindolfo Dorcino dos; Carvalho, Fabyola Barros de; http://lattes.cnpq.br/4936451314440305; Stringhini, José Henrique; http://lattes.cnpq.br/8505634095383289; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Laboissière, Michele; Leandro, Nadja Susana MogycaThe objective of study was to evaluate the combination of different enzyme complexes on animal performance, digestibility nutrient based on corn and soybean meal and on the biochemical characteristics of these complexes. The first experiment was used randomized design with 7 treatments and 6 replicates, 30 birds per repetition, a total of 1,260 birds a day old. The treatments were treatment 1: Basal diet; Treatment 2: Basal diet with addition of complex A (phytase, protease, xylanase, beta-glucanase, cellulase, amylase, pectinase) + B complex (protease and cellulase); Treatment 3: Basal diet with addition of complex A + complex B + enzyme (α-galactosidase); Treatment 4: Basal diet with addition of complex A + α-galactosidase; Treatment 5: Basal diet with addition of complex C (xylanase, amylase, protease) + Phytase B and α-galactosidase; Treatment 6: Basal diet with addition of complex C + Phytase C + α-galactosidase; Treatment 7: Basal diet with addition of complex C + Phytase D + α-galactosidase. The performance characteristics and carcass yield and statistical analysis were evaluated with the R software using the Tukey test at 5% probability. The treatments 3 and 5 improvement in the average final weight, weight gain and feed conversion (p <0.05) at seven days of age and the average final weight and gain weight at 14 days of age. There were no significant differences (p> 0.05) in the other stages between the groups and the carcass yield and cuts made in two birds from each experimental unit at 42 days old.The second experiment used 112 birds with 25 days of age, being held the total collection of excreta from 28 to 32 days old. It used the same treatments in the first experiment. Nitrogen analysis was performed, ether extract, crude energy and dry matter. From these data was performed to analyze statistically the R software using the Tukey test at 5% probability. No significant differences were observed (p> 0.05) for the CMMS, CMN, EMAn, BN with the inclusion of enzyme complexes, as for CMEE significant differences (p <0.05), demonstrating the treatments 2 and 4 with greater efficiency in metabolizing ether extract. The third experiment analyzed the samples of each product used in In Vivo experiments were carried out a number of enzymatic assays. These data was performed to analyze statistically the R software using the Tukey test at 5% probability. There were statistically significant differences (p <0.05) for the total protein assay, reducing sugar and β-1,3-glucanase assays, xylanase, CMCase, FPase, amylase, pectinase, acid phosphatase and protease. The complexes A, B, C and the enzyme α – gal shown in most of these assays described the specific and higher enzymatic activity, these results that can be related to the performance results found in the 1 at 7 and 1 at 14 days.Item Ganho de peso compensatório em diferentes fases na criação do frango de corte(Universidade Federal de Goiás, 2021-05-18) Teodoro, Janaina Correia; Mascarenhas, Alessandra Gimenez; http://lattes.cnpq.br/9082632592936909; Leandro, Nadja Susana Mogyca; http://lattes.cnpq.br/3136809931691012; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Carvalho, Fabyola Barros de; Peron, Hugo Jayme Mathias Coelho; Mascarenhas, Alessandra GimenezThis experimental trial was designed with the objective of evaluating a possible compensatory weight gain in broilers at different ages submitted to a quantitative food restriction program. Fully randomized experimental design (DIC), with 5 treatments and 7 repetitions with 32 birds per repetition, totaling 35 experimental plots, totaling 1,120 birds. The treatments consisted of quantitative food restriction of 20% of the expected weekly consumption of the cobb table, separated by week: treatment with food restriction in the second week, treatment with food restriction in the third week, treatment with restriction in the fourth week, treatment with restriction in the fifth week, sixth week with free feeding for all treatments and control treatment without restriction. The collected data were submitted to ANOVA and were evaluated by contrast. In the weekly performance the feed consumption was always low in the treatment of the week restriction when compared to the control treatment, in consequence, the average weight was also lower in the same week, and the conversion was always higher in the week of the restriction. At 42 days, these differences were not observed, suggesting that there was weight recovery, that is, the broiler chicken with a 20% restriction managed to show compensatory weight gain. For organs and tissues, there was a significant difference between treatments in the relative weight for gastrointestinal tract and large intestine, presenting a lower index in the week that the birds went through food restriction. As for intestinal histomorphometry, in general, villus height and crypt depth were higher in treatments that underwent food restriction, since the intestinal epithelium of birds is constantly renewed by mechanisms of intestinal muscosa repair, which can be changed by agent nutrients, which makes them hyperplastic, with deeper crypt depth. For evaluation of woody chest degrees, there was a better result (reduced incidence) for the animals that underwent restriction in the second and fifth week. When examining the means of microscopic lesions of the pectoralis major muscle, a difference is observed only in adipose tissue. It was concluded that birds with a 20% restriction were able to regain weight and present compensatory weight gain. With regard to organs and tissues, there was a decrease in the weight of intestinal organs due to a decrease in peristaltic movements in the face of a period of restriction, requiring less from the intestine and, consequently, decreasing its relative weight. Likewise, the birds' organisms react to food restriction at the cellular level, increasing villus height and crypt depth as a mechanism to improve nutrient absorption and increase tissue repair. With regard to pectoral muscle changes, the restriction applied in this study was able to reduce the incidence of wooden breast.Item Níveis de energia metabolizável em dietas de frango de crescimento lento(Universidade Federal de Goiás, 2020-05-06) Veríssimo, Saulo; Carvalho, Fabyola Barros de; http://lattes.cnpq.br/4936451314440305; Café, Marcos Barcellos; http://lattes.cnpq.br/9860968235125158; Café, Marcos Barcellos; Carvalho, Fabyola Barros de; Leite, Paulo Ricardo de Sá da Costa; Assis, Saullo Diogo deThe aim was to evaluate four levels of metabolizable energy (ME) in the feed of Isa Label broilers, in the first phase on productive performance, carcass composition and energy metabolism. Two experiments were conducted. In triaI I, 240 male and 240 females of the Isa Label lineage, naked neck, were fed with diets containing different levels of ME (2,725, 2,850, 2,975 and 3,100 kcal / kg). The design used was completely randomized in a 4x2 factorial scheme, the treatments was four levels of ME in the initial diet (up to 28 days) combined with two sexes, with six repetitions per treatment, of 20 birds. In the growth phase (29 to 56 days of age) all birds received the same fed. Carcass yield and performance were evaluated. A metabolism trail was carried out with total collection of excreta from 17 to 21 days, with 160 male and 160 females. The design used was completely randomized in a 4x2 factorial scheme, as well as in the first trail, with eight replicates of 10 birds each. The data were submitted to analysis of variance. Polynomial regression analysis was used to study the levels of metabolizable energy in the diet, using the SAS Statistical program. In the phase from 1 to 7 days of age, there was a difference between sexes for feed conversion. At 21 and 28 days there was a difference between sexes for live weight, weight gain and feed consumption. At 28 days there was a quadratic regression effect with a maximum point of 2915.22 for live weight and weight gain and negative linear regression for feed conversion. At 56 days of age, there was a difference between males and females for all variables analyzed and a quadratic regression effect for feed consumption with a minimum point of 2912.5, in addition to interaction between the factors studied (energy x sex) for feed conversion, females responded in a with quadratic regression with a maximum point of 2929.55, males responded in a linear regression. There was no significant regression effect for carcass and fine cuts at 56 days. There was a quadratic regression effect for nitrogen balance and nitrogen metabolizability coefficient, with a minimum point of 2912.5. There was a positive linear regression effect for ether extract balance and quadratic regression effect for the ether extract metabolizability coefficient with a maximum point of 2912.5. For the dry matter metabolizability coefficient, there was a positive linear regression effect. The variables apparent metabolizable energy and the metabolizable energy corrected by nitrogen presented positive linear regression effect. It is recommended to work with diets with levels of 2900-2930 kcal ME / kg, in initial diets from one to 28 days of age.