Sergio Luiz de Toledo Barreto

Efeito dos níveis de triptofano digestível em dietas para codornas japonesas em postura

O nivel dietetico adequado (0,12; 0,16; 0,20; 0,24 e 0,28%) de triptofano digestivel foi avaliado em 400 codornas japonesas de 21 a 30 semanas de idade, fase de postura. As codornas foram alojadas em gaiolas de 125 cm2/ave, com peso inicial de 158,50 g e producao media de ovos de 84,50%. O delineamento experimental foi em blocos casualizados, constituido por oito blocos, cinco tratamentos, oito repeticoes de dez aves/repeticao e tres periodos experimentais de 21 dias cada. Foram avaliados os parâmetros de desempenho das aves, consumo de racao (g/ave/dia), consumo de triptofano (mg/ave/dia), producao de ovos (%/ave/dia), peso medio dos ovos (g), massa de ovos (kg/ave/dia) e conversao alimentar (kg de racao/kg de ovos e por duzia de ovos). Somente as variaveis consumo de triptofano e producao de ovos apresentaram efeitos significativos dos niveis de triptofano nas dietas. As respostas de desempenho das codornas, respeitando o ajuste estatistico obtido por meio de modelos de regressao linear e do modelo descontinuo LRP, e a interpretacao biologica permitem concluir que, para se obter o melhor desempenho produtivo, as dietas de codornas devem conter o nivel de 0,21% de triptofano digestivel, o que resulta no consumo diario de 45,0 mg/ave de triptofano, correspondendo a relacao triptofano: lisina digestivel de 21%.

Dietas de diferentes densidades energéticas mantendo constante a relação energia metabolizável: nutrientes para codornas japonesas em postura

The aim of this experiment was to evaluate the effects of energetic density reduction in diets in the performance of Japanese quail, keeping constant the metabolizable energy (ME) to nutrients ratio. A total of 400 Japanese quails with 155 g ± 5.5 g and 76 to 160 days old were distributes to a complete randomized experimental design with five energetic density, eight replicates and ten birds per experimental unit. Five energetic density in the diets was evaluated (2,900, 2,800, 2,700, 2,600, and 2,500 kcal ME/kg of diet) keeping constant the metabolizable energy to nutrients ratio. The birds were fullfed during all experimental period. It was observed difference for feed intake, feed conversion per egg mass and feed conversion per egg dozen related to energy level in the diet. However, the diets did not influence the intakes of energy, crude protein, lysine, methionine+cystine, threonine, egg production, commercial egg production, egg mass, energy efficiency per egg mass, energy efficiency per egg dozen, weight gain and quail viability. For Japanese quail in posture, diets with 2,900 and 2,800 kcal ME/kg provided better feed conversion per egg mass and feed conversion per egg dozen, respectively, when the metabolizable to nutrients ratio is kept.

Níveis de treonina digestível em dietas para codorna japonesa em postura

The experiment was carried out to estimate the level of digestible threonine for laying japanese quail during 63 days. A total of 400 japanese quails, with inicial age of 57 days were allotted to a complete randomized experimental design with five treatments, eight replicates and ten birds per experimental unit. The basal diet, deficient in threonine and with 20% C, 2,910kcal ME/kg, was supplemented with five levels of L-threonine 98% (0.018, 0.074, 0.128, 0.183, and 0.239%), corresponding to digestible threonine: digestible lysine ratios 0.65, 0.70, 0.75, 0.80, and 0.85, respectively, to compose the experimental treatments. The characteristics evaluated were: feed intake, threonine intake, egg production, production of commercial eggs, egg weight, egg mass, feed conversion per egg mass, feed conversion per egg dozen, egg quality (yolk, albumen and shell), egg length and width and specific gravity. Linear effect was only observed in the threonine intake. In conclusion, to provide the best performance results and of the quality of eggs, the Japanese quail does not require more than 0.65% of digestible threonine for a intake of 149.2 mg of digestible threonine/day or a daily intake of 14.34 mg of digestible threonine/g egg, corresponding to the digestible threonine: digestible lysine ratio of 0.65.

Níveis de lisina digestível em rações para poedeiras no período de 24 a 40 semanas de idade

The objective of this study wast to determine the requirement of digestible lysine for light-weight laying hens 24 to 40 weeks of age. Two hundred and sixteen Hy-Line W36 light-weight laying hens were allotted to a randomized complete blocks with six treatments, six blocks and six hens per experimental unit. The treatments consisted of a basal diet, with 14.54% crude protein, deficient in digestible lysine (0.545%), supplemented with six levels of L-lysine HCl (78%) 0.00; 0.059; 0.118; 0.177; 0.237 and 0.295%. Considering the digestibility of the lysine to be 97.6%, the amount of L-lysine. HCl added in each diet supplied 0.00; 0.045; 0.090; 0.135; 0.180 and 0.225 digestible lysine, respectively, resulting in diets with 0.545; 0.590; 0.635; 0.680; 0.725 and 0.770% digestible lysine. Feed intake, lysine intake, egg production, average egg weight, egg mass, feed conversion (kg feed/egg dozen), albumen index and final weight gain of the chickens showed a linear response with increase in the digestible lysine levels. There was a quadratic effect for the levels of digestible lysine on feed conversion/egg mass but no significant effect on Haugh Units, yolk index and egg components was detected. The digestible lysine requirement was estimated to be at least 0.770% of the diet, corresponding to the intake of 759 mg of lysine digestible/hen/day.

Levels of phosphorus and calcium in diets of laying Japanese quails

An experiment was conducted with the objective to verify the effect of different levels of available phosphorus (aP) and of calcium (Ca) in the diet on the performance, the quality of eggs and the nutritional status of the bone tissue of japanese quails during the initial laying phase. A total of 700 japanese quails, with 61 days of age, distributed in 70 experimental units with 10 birds each were used. A completely randomized experimental design was use, in a 5 × 2 factorial arrangement with five levels of aP (0.15; 0.25; 0.35; 0.45 e 0,55%) and two levels of Ca (2.5 e 3.2%), with seven replicates per treatments. The experimental diets were isoproteicas (20.0% CP), isocaloricas (2.900 kcal ME/kg) and isoaminoacids. The levels of aP influenced by a quadratic form, the height and the average diameter of the eggs, the Ca egg shell content and percentage of Ca (2.5% Ca) and P (3.2% Ca) in the bones. There was a linear improvement for the commercial egg production and percentage of P in the bones (lower level of tested Ca), up to the level of 0.31% and of 0.51% P, respectively, in the diet. As aP levels increased in the diet, the conversion for dozen of eggs linearly decreased and the percentage and yolk weight reduced up to the levels of 0.40 and 0.25% of aP, respectively, in the diet. The shell weight, percentage and thickness, specific weight, shell Ca content and percentage of Ca in the bones were influenced by the Ca levels in the diet. There was no influence of the Ca and a aP levels on eggs production, ration consumption, egg mass, feed conversion per eggs mass, viability, final average weight of the birds and percentage and weight of albumen in the eggs. Dietary levels of 2.5 and 0.31% aP are enough to provide good productive performance and satisfactory maintenance of the quality of eggs and nutritional status of bone tissues of Japanese quails during the initial laying period.

Níveis de sódio em dietas para codorna japonesa em pico de postura

An experiment was carried out to verify the effect of different dietary Na levels on the performance and egg quality of laying Japanese quail during the peak of production (69 to 132 days old). A total of 300 laying Japanese quails aged 69 days was allocated to 30 experimental units with ten birds each. The quails were assigned to a completely randomized design, with five treatments, six replicates. The Na levels studied were 0.017, 0.083, 0.149, 0.215, and 0.281% corresponding to 0.000, 0.166, 0.332, 0.499, and 0.665%, respectively, of salt inclusion in the diets. The experimental diets were isoproteic (20.0% CP), isoenergetic (2,900 kcal ME/kg) and isocalcium (3.2% Ca). It was observed linear increase of egg production, feed conversion by egg mass, albumen and yolk percentage and egg specific gravity with the increase of Na in the diet. Quadratic effect was observed for feed intake, weight egg, egg mass/bird.day, final body weight, eggshell thickness and Haugh unit. No effect of Na levels was observed of on feed conversion of dozen-egg, eggshell percentage, viability and moisture in the excreta of birds. Diets containing 0.281%Na, corresponding to a daily intake of 69.1 mg Na/hen, increased performance and egg quality of laying Japanese quail during the peak of production. However, a satisfactory performance, based on production of egg/hen.day and commercial egg production can be obtained with birds fed diet containing 0,149% de Na.

Efeito da redução da densidade energética de dietas sobre as características do ovo de codorna japonesa

The aim of this study was to evaluate the effects of reduction of energetic density of the diet on the quality of Japanese quail eggs, keeping the same metabolizable energy (ME):nutrients relationship. It was used 400 Japanese quails from 76 to 160 days of age, distributed in a complete random design, with five treatments, 10 replicates and 8 birds per experimental unity. It was used five diets with different energetic densities (2,900; 2,800; 2,700; 2,600; and 2,500 kcal ME/kg), keeping constant the relationship between metabolizable energy and nutrients of the diet, which had 2,900 kcal ME/kg. Diet was fed ad libitum during all the experimental period. There was a significant difference only on the ration intake and on the egg specific weight. It was not observed significant difference among diets for the following parameters: metabolizable energy intake, crude protein and amino acids, egg weight, egg mass, yolk weight, yolk percentage, albumen height, albumen percentage, shell weight, shell percentage, egg diameters and egg height. Diets with 2,800 and 2,900 kcal ME/kg, by keeping constant metabolizable energy:nutrients ratio, provide the same egg quality.

Utilização de aditivos em rações formuladas com milho normal e de baixa qualidade para frangos de corte

Foi conduzido um experimento com 2.112 pintos de corte, machos da linhagem Ross, para avaliar a influencia da utilizacao de aditivos nao-nutrientes (antibiotico, prebiotico e simbiotico) sobre o desempenho e as caracteristicas de carcaca de frangos de corte. As aves foram distribuidas em delineamento inteiramente casualizado, em arranjo fatorial 2 × 6 (milho × aditivo), totalizando 12 tratamentos, com oito repeticoes e 22 aves por unidade experimental. As racoes foram formuladas a base de milho e farelo de soja, utilizando-se, na metade dos tratamentos, milho de qualidade normal (T1, T2, T3, T4, T5 e T6) e na outra metade, milho de baixa qualidade (T7, T8, T9, T10, T11 e T12). Os tratamentos foram: T1 e T7 = racao basal (RB); T2 e T8 = RB + antibiotico; T3 e T9 = RB + simbiotico; T4 e T10 = RB + prebiotico 1 (0,5kg/t); T5 e T11 = RB + prebiotico 1 (1,0 kg/t); e T6 e T12 = RB + prebiotico 2 (1,0 kg/t). Para aumentar o desafio sanitario, alem da cama reutilizada, os bebedouros nao foram lavados periodicamente, com o objetivo de piorar a qualidade da agua de bebida. Aos 21 e 42 dias de idade, foram avaliados ganho de peso, consumo de racao e conversao alimentar. Aos 23 dias de idade, foram avaliadas as caracteristicas fisicas do figado e a presenca de petequias no peito e na coxa e aos 42 dias, as caracteristicas de carcaca e o peso relativo do figado. Verificou-se efeito do aditivo somente para ganho de peso aos 21 dias e para ganho de peso e consumo de racao aos 42 dias. Nao foi observado efeito dos aditivos sobre as demais caracteristicas avaliadas. Os prebioticos a base de mananoligossacarideos e o simbiotico podem substituir o antibiotico avilamicina nas racoes para aves, pois nao promoveram perdas no desempenho das aves. O uso de milho de baixa qualidade piorou o desempenho, provocando perdas no rendimento e na qualidade de carcaca de frangos de corte.

Efeito da suplementação de enzima fitase sobre o metabolismo de nutrientes e o desempenho de poedeiras

The effect of the addition of phytase enzyme on performance and metabolism of laying hens was evaluated. Three hundred and sixty Bovans Goldline hens were allotted to a completely randomized design, with 12 replicates of 6 birds per unit and 5 experimental treatments as follows: T1 = positive control (PC), T2 = Negative control (NC by 0.15% phosphorus available), T3 = NC + 200 FTU of phytase, T4 = NC + 400 FTU of phytase, T5 = NC + 600 FTU of phytase. The positive control diets were formulated to contain adequate nutrient levels according to recommendations of the Brazilian Tables. Diet of treatments 2, 3, 4 and 5 (Negative Control) were calculated with reduced contents of nutrients present in the nutritional contribution of the enzyme complex evaluated according with recommendations from the manufacturer. The parameters evaluated were: feed intake, egg production, egg weight, egg mass and feed:gain ratio (per g of egg mass and per dozen of egg). In the metabolism trial, feed consumption and total excreta production per replicate were measured to determine the metabolizable energy values (apparent ME and apparent nitrogen corrected ME), metabolizability coefficients of gross energy and nitrogen retention and P and Ca balance of the experimental layer diets. The addition of phytase (200, 400 and 600 FTU) to the negative control diet resulted in layers with egg mass production, feed:gain ratio per egg mass similar to layers fed the positive control diet. The egg components parameters were not affected by treatments, except the eggshell weight, which increased with the addition of phytase in the diets. The addition of 600 FTU of phytase improve the metabolism of nutrients in nutritionally deficient diets.

Avaliação do desempenho e da qualidade dos ovos de codornas de corte de dois grupos genéticos

An experiment was conducted with the objective to evaluate the performance and quality of eggs from meat quails from two genetic groups during 84 days of experiment. A total of 98 birds averaging 258 kg and 40 days old was assigned to a completely randomized design with two genetic groups (A and B) and seven replications of seven birds each. The evaluated characteristics were: diet consumption (g/bird/d), average egg weights (g), laying per bird per day (%) and per lodged bird (%), percentage of viable eggs produced, percentage of viable eggs/bird/d, egg mass (g/bird/d), conversion by egg mass (kg/kg), conversion by egg dozen (kg/dz), specific gravity (g/cm3), egg yolk weight (g), albumen and shell, percentage of yolk, albumen and shell, height and diameter of eggs (mm), viability of birds (%), initial and final weight (g) and weight gain (g). The genetic group B showed lower initial weight at 40 days old, higher weight and percentage of shell and better specific gravity of eggs. The other characteristics did not differ between the genetic groups. Both evaluated genetic groups have satisfactory performance in the period from 40 to 124 days old.