RESUMO -O objetivo neste trabalho foi estudar o perfil de crescimento e a deposição de nutrientes nos órgãos (coração, fígado, moela, intestino e proventrículo) de frangos de corte das linhagens Ross e Cobb de ambos os sexos. Foram utilizados 1.920 pintos de 1 dia alojados em boxes de galpão experimental em piso. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2 × 2, composto de dois sexos (machos e fêmeas) e duas linhagens (Ross e Cobb), com quatro repetições de 120 aves. As aves foram alimentadas com rações formuladas de acordo com suas exigências nutricionais em cada fase de criação. Os pesos dos órgãos e de seus componentes (água, cinzas, proteína e gordura) foram obtidos semanalmente, com os parâmetros estimados pela equação de Gompertz e as taxas de crescimento determinadas por meio das derivadas das equações. Não houve influência da linhagem nas taxas de crescimento e deposição de nutrientes no coração. As aves Ross foram mais precoces no crescimento e na deposição de água e cinzas no fígado, portanto apresenta maior atividade metabólica na digestão e síntese de nutrientes. A linhagem Cobb foi mais precoce no desenvolvimento do intestino e crescimento e na deposição de nutrientes no proventrículo. Os machos são mais precoces que as fêmeas na taxa de crescimento e deposição de proteína, gordura e água na moela.Palavras-chave: Cobb, equações de predição, fêmeas, Gompertz, machos, Ross Growth and nutrients deposition on organs of two commercial strains of broiler chickensABSTRACT -This work was carried out with the objective of studying the growth profile and the nutrients deposition on organs (heart, liver, gizzard, intestine and proventricle) of male and female broiler chickens from Ross and Cobb lineages.It was used 1,920 chicks at the age of one day placed in experimental shed boxes on the floor. The experimental design was completely randomized in a 2 × 2 factorial model composed of 2 sexes (mates and females) and two strains with 4 repetitions of 120 broilers each. The broilers were fed formulated diets to supply the nutrient requirements according to each breeding phase. After 24 hours of fasting, the broilers were weighed and slaughtered (1 to 56 days) every week. The weight and components of the organs (water, ash, protein and fat) were weekly obtained, with parameters estimated by the equation ofGompertz and the growth rates were determined by the derived of the equations. There was no influence of the strains on the deposition of nutrients on the heart. Ross chicks were more precocious on growth and on the deposition of water and ashes in the liver, therefore it presents a greater metabolic activity in digestion and nutrient synthesis. Cobb strain was more precocious in the development of the intestine and the growth and deposition of nutrients on the proventricle. Males are more precocious than females on the growth rate and on the protein, fat and water deposition in the gizzard.

The objective of this work was to study growth and body nutrient deposition profiles of male and female Cobb and Ross broilers using Gompertz equations. A total number of 1,920 one- to 56-day-old broilers were used. A randomized experimental design in a factorial arrangement (2 strains x 2 sex), with 4 replicates of 120 birds each, was applied. Diets were formulated to supply the nutrient requirements recommended by the genetic companies. A sample of birds was weekly weighed and sacrificed after 24 hours fasting. Carcasses were de-feathered and weighed again. The parameters of the Gompertz equation for body weight and its components (water, ashes, protein, and fat) were estimated. An interaction (p<0.05) between sex and breed was observed for mature weight (Wm) (kg), growth rate (b) (daily) and time at maximum growth rate (t*) (day) of body weight, and body water and ash. Cobb was presented earlier growth and body protein and ash deposition. Ross strain was superior in body water deposition

RESUMO -Foram utilizados 520 pintos de corte machos da linhagem Cobb ® com 1 dia de idade alimentados com dietas à base de milho, farelo de soja e farelo de arroz desengordurado com o objetivo de avaliar o efeito da suplementação de fitase sobre o desempenho e a digestibilidade dos nutrientes. Foi adotado delineamento inteiramente casualizado, com cinco tratamentos e oito repetições de 13 aves por repetição. A composiçãos percentual dos tratamentos foi: controle positivo (CP) -3.000 kcal de energia metabolizável por quilo (EM/kg); 21,4% de proteína bruta (PB); 0,42% de fósforo disponível (Pd) e 0,96% de cálcio (Ca); e controle negativo (CN) -2.940 kcal EM/kg; 21,2% PB; 0,27% Pd e 0,90% Ca. Avaliaram-se três níveis de suplementação de Fitase 5000 Ouro Fino na dieta CN: 500, 750 ou 1.000 unidades de fitase/kg ração (uft/kg) e seus efeitos na uniformidade, no consumo de ração, no ganho de peso, na conversão alimentar, na digestibilidade da matéria seca (MS), da proteína bruta (PB), do Ca, P, da energia digestível (ED), %MS e %MN, nas concentrações de Ca e P e na resistência óssea nas tíbias dos frangos aos 20 dias de idade. A digestibilidade do P das dietas com menores níveis nutricionais foi inferior à da ração controle positivo. A suplementação com fitase melhorou a digestibilidade do P e da ED, uma vez que os coeficientes melhoraram com a adição de 1.000 uft/kg. A redução nos níveis nutricionais da dieta prejudicou o desempenho e a mineralização e resistência óssea das tíbias das aves, no entanto, a suplementação com fitase melhorou estas características. As características do osso das aves alimentadas com ração CN suplementada com 750 uft de fitase foram semelhantes às obtidas com a dieta controle positivo.Palavras-chave: cálcio, cinza óssea, digestibilidade ileal, fósforo, resistência óssea, tíbia Effect of phytase suplementation on performance and nutrient digestibility in diets of broilers ABSTRACT -A total of 520 1-d old male broiler chicks (Cobb) was fed a corn-soy-fat-free rice meal diet to evaluate the effect of phytase suplementation on performance and nutrient digestibility. The experiment was analyzed as a completely randomized experimental design with five treatments, eight replications of 13 broilers per replication. The percentage composition of the experimental diets were: positive control (PC) with 3000 kcalME/kg; 21.4% CP; 0.42% Pd and 0.96% Ca and negative control (NC) with 2940 kcalME/kg; 21.2% CP; 0.27% Pd and 0.90% Ca. Three levels of supplementation of Fitase 5000 Ouro Fino to NC diets: 500, 750 and 1,000 phytase units/kg of diet (ftu/kg) and their effects on uniformity, feed intake, weight gain, feed conversion, digestibility of dry matter, crude protein, Ca, P and energy digestible (DE), %DM and % as fed, and the concentration of Ca and P and bone resistance in tight of broilers at 20 days of age. The P digestibility of the diets with lower nutritional levels was inferior to the PC diets. The phytase supplementation improved P and DE digestibility, since the coefficients improved with the...

The objective of this work was to compare the growth and chemical composition of the main body parts of males and females of the Ross and Cobb broiler strains available in Brazil. In total, 1,920 chicks were raised in 16 floor pens, from which 4 birds of each strain and sex were sampled weekly for the required measurements. The strains and sexes were reared in separate pens, using 4 replications of 120 birds each. Four feeds, based on corn and soybeans, were used during the trial: feed 1 from 1 to 7 d, feed 2 from 8 to 28 d, feed 3 from 29 to 49 d, and feed 4 from 50 to 56 d of age (all of the birds were given the same feed for each time interval). All of the birds were weighed weekly and the 4 birds sampled from each strain and sex were weighed, fasted for 24 h, reweighed, killed, eviscerated, and dissected. The breast, drums, thighs, and wings were weighed, packed into identified plastic bags, and stored in a freezer to later be thawed and minced. They were then freeze-dried to obtain the water content, after which they were again milled before analyzing for protein, lipid, and ash using AOAC procedures. The Gompertz equation was fitted to the weights of the body parts as well as to the protein weights of the components. Using data from each individual chicken that was sampled, allometric regressions were fitted to the weights of the physical and chemical components, with ln body protein weight being the independent variable and ln component weight being the dependent variable. Although some of the allometric relationships between the various body parts and body protein weight differed statistically between strains and sexes, these differences were of little commercial significance, suggesting that the relative growth rates of the different body components of the genotypes tested in this trial have not been changed substantially by genetic selection.

The aim of this work was to compare the efficiency of total (TC) or partial (PC) collection excreta methods to determine metabolizable energy in poultry feeds. A number of 180 12- to 21-day-old broilers were distributed into two treatments of six replicates of 10 birds each. A reference-diet was formulated to supply broiler requirements, and the test-diets consisted of 60% of reference diets and 40% of corn or soybean meal. Celite was added at 1% to the diets as a marker. Excreta and diet samples were analyzed for dry matter, energy, nitrogen, and acid-insoluble ash (AIA). AME of corn determined by partial collection (PC) was higher (3544 kcal/kg) as compared to total collection (TC) (3133 kcal/kg). However, no difference were observed for soybean meal (1797 vs. 1821 kcal/kg) between both methods. Marker recovery rates in the excreta were 101, 111, and 96% for the basal-diet, and the test-diets with corn or soybean meal, respectively. This result indicates the importance of marker recovery rate in the excreta to evaluate feed AME and digestibility

1. The objective of this study was to estimate growth parameters of carcass components (wing, thighs and drumsticks, back and breast) and organs (heart, liver, gizzard and gut) in males and females of one meat-type quail strain (Coturnix coturnix coturnix) and two laying strains (Coturnix coturnix japonica) designated either yellow or red. 2. A total of 1350 quail from 1 to 42 d old were distributed in a completely randomised design, with 5 replicates of each strain. The carcass component weights and body organs were analysed weekly and evaluated using the Gompertz function; growth rates were evaluated through derivative equations. 3. The meat-type strain presented the highest growth rates in carcass components and organs. Across strains, females showed the highest weight of internal organs at maturity compared to males. 4. Females had greater growth potential in breast, wings and back than males for both yellow and red laying quail.

ABSTRACT. This study aimed to evaluate liver and breast muscle insulin-like growth factor I (IGF-I) and growth hormone receptor (GHR) gene expression between broilers fed different methionine levels and sources. Broiler chicks were 22 to 42 days old, distributed in 5 treatments (control diet, DL1 -0.08% DL-methionine, DL2 -0.24% DL-methionine, MHA-FA1 -0.11% methionine hydroxy analoguefree acid, and MHA-FA2 -0.33% methionine hydroxy analogue-free acid). The broilers were euthanized by cervical dislocation. RNA was extracted from liver and breast muscle, followed by cDNA synthesis and amplification using qRT-PCR. DL2 methionine supplementation provided best animal performance results. GHR and IGF-I gene expression in the muscle tissue was not affected by methionine supplementation. IGF-I gene expression in the liver was higher in animals fed methionine supplementation than in animals fed control diet. IGF-I mRNA levels in broilers fed DL2 were greater than DL1 (1.56 vs 0.97 AU) and greater than MAH-FA1 and MAH-FA2. Broilers 6415 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 12 (4): 6414-6423 (2013) Gene expression in broilers fed DL2 increased significantly GHR gene expression in the liver than animals fed the control diet. Addition of methionine improved animal performance by stimulating synthesis and release of growth factor.

-An experiment was conducted to estimate the parameters of the Gompertz, Brody, Logistic, and Von Bertalanffy equations through Bayesian inference and evaluate the potential for growth in terms of weight and body composition of laying female quail (Coturnix coturnix japonica). The weights and body compositions of the birds were obtained weekly (1-119 days), allowing the adjustment of the four equations by Bayesian inference. The parameters mature weight (β1), integration constant (β2), maturity rate (β3), and their credibility intervals in four models on body weight and body components were properly estimated by Bayesian inference to describe the body growth in laying quail. The inflection point was determined by the 1st and 2nd derivatives of the Gompertz equation for body weight and body components (fat, protein, ash, and water). Based on Deviance Information Criterion (DIC) for the studied and analyzed variables, there is a model that fits best as a result of its better performance to achieve the DIC value. The Von Bertalanffy model proved to be very versatile, not obtaining good fit of data only for fat. The study shows that other models can also be used in several data sets as an alternative to Gompertz, which, due to its adequate biological interpretation and desirable characteristics in a curve growth, is generally the most used.