Gabriel da Silva Viana

Calcium levels and calcium: available phosphorus ratios in diets for white egg layers from 42 to 58 weeks of age

The experiment was conducted to determine the nutritional requirement of calcium and the best calcium:available phosphorus ratio for commercial layers at the post-laying peak. A total of 324 Hy-Line W-36 laying hens were utilized in the period from 42 to 58 weeks of age, distributed in a completely randomized design in a 3 × 3 factorial arrangement, composed of three levels of calcium (39, 42 and 45 g/kg) and three calcium:phosphorus ratios (12.12:1; 10.53:1; and 9.30:1), totaling nine treatments with six replications and six birds per experimental unit. There was no significant effect from the calcium levels × calcium:phosphorus ratio interaction for any of the variables studied. The calcium levels and the calcium:phosphorus ratios did not affect the variables performance or egg and bone quality. At the evaluation of the calcium:phosphorus balance, as the levels of calcium of the diet were raised, the intake of calcium and phosphorus and the contents of mineral matter and calcium in the excreta increased linearly, and the retention of calcium by birds decreased linearly. With the reduction of the calcium:phosphorus ratios of the diet, intake, retention and excretion of phosphorus by layers increased. Diets containing calcium at 39 g/kg and a calcium:phosphorus ratio of 12.12:1, corresponding to an increase in calcium of 3.51 g/bird/day and available phosphorus of 289 mg/bird/day, meet the requirements of calcium and available phosphorus of white egg layers in the period from 42 to 58 weeks of age.

Determination of digestible isoleucine: lysine ratio in diets for laying hens aged 42-58 weeks

Two hundred and fifty-two Hy-Line W36 laying hens were allotted in a completely randomized design with 6 treatments, 7 replicates and 6 hens per experimental unit in order to determine the ideal ratio of isoleucine (Ile) in relation to lysine (Lys) to laying hens aged 42-58 weeks. Experimental diets contained digestible Ile at different levels, resulting in different Ile:Lys ratios (0.73:1; 0.78:1; 0.83:1; 0.88:1; 0.93:1 and 0.98:1). A basal diet was formulated to provide Isoleucine in levels below recommendations. This diet was supplemented with L-isoleucine to make up the 6 diets. Each diet was made isonitrogenous by varying the dietary contents of glutamic acid and isocaloric by adjusting the contents of cornstarch. All essential amino acids were provided proportionally to lysine. Egg production, egg weight, egg mass, feed conversion ratio, albumen, yolk and eggshell contents were recorded and compiled at every 28-day period. No differences were observed in the performance over a wide range of dietary isoleucine concentrations from 5.76 to 7.73 g/kg corresponding to 0.73:1 to 0.98:1 Ile:Lys ratios. The lowest Ile:Lys ratio (0.73:1) was sufficient to ensure satisfactory performance of birds, corresponding to the consumption of 534 mg of isoleucine and 731 mg of lysine/day.

Proteína bruta e energia metabolizável para codornas de corte de um a 14 dias de idade

Aiming to evaluate the effect of different levels of crude protein and metabolizable energy for quails from 1 to 14 days of age, a study was conducted using 840 quails, mixed. The birds were distributed in a factorial arrangement (2x5) consisting of 10 treatments (two levels of metabolizable energy - 2,800 and 3,000kcal/kg and 5 levels of crude protein - 22.0, 24.0, 26.0, 28.0 and 30.0%), 7 repetitions with 12 birds each. We evaluated the following parameters: feed intake, weight gain at 7 and 14 days of age, feed conversion at 14 days and viability. It was found that quail fed diets with the lowest energy level, 2,800kcal/kg, showed higher consumption. Birds fed diets with lower energy level had greater weight at 7 days of age regardless of the level of crude protein used. The weight at 14 days of age showed a quadratic response with the addition of crude protein in feed, showing that diets containing 28.86% CP provide better gain regardless of the level of energy used. The feed showed better results with the increased level of dietary CP, regardless of level of metabolizable energy used. There were no significant effects of protein and energy levels or their interaction on viability. Diets with 30.0% crude protein and 2,800 or 3,000kcal/kg metabolizable energy provide satisfactory performance results for quails from 1 to 14 days of age.

Ideal digestible isoleucine: digestible lysine ratio in diets for laying hens aged 24-40 weeks

Two hundred fifty-two Hy-Line W36 laying hens were allotted in a randomized block design with 6 treatments, 7 replicates and 6 hens per experimental unit in order to determine the ideal digestible isoleucine: digestible lysine (Ile:Lys) ratio for laying hens aged 24-40 weeks. Experimental diets contained 5.92, 6.33, 6.73, 7.14, 7.54 and 7.95 g/kg of digestible isoleucine, resulting in different Ile:Lys ratios (0.73:1, 0.78:1, 0.83:1, 0.88:1, 0.93:1 and 0.98:1). Experimental diets were isonitrogenous, with different dietary contents of glutamic acid, and made isocaloric by adjusting the levels of cornstarch. All essential amino acids were provided proportionally to digestible lysine. Feed intake, egg production, egg weight, egg mass, feed conversion ratio per egg mass, feed conversion ratio per dozen eggs, albumen, yolk and eggshell content were assessed. Feed intake, egg production, egg mass and feed conversion ratio were influenced by Ile: Lys ratios quadratically. The egg weight was not affected by Ile: Lys ratio. No differences were observed in the egg quality according to Ile: Lys ratios. The data indicates that the optimum digestible isoleucine: digestible lysine ratio for laying hens aged 24-40 week is 0.84:1, corresponding to the consumption of 681 mg of isoleucine and 811 mg of lysine/hen day-1.

Optimum Digestible Valine to Lysine Ratio for Meat-Type Quails from 15 to 35 Days of Age

This study was conducted to estimate the dig. valine to lysine (Val:Lys) ideal ratio for meat-type quails from 15 to 35 d of age. A total of 385, 15-day-old not sexed quails, were randomly assigned to five treatments, each one seven times replicated with eleven quails per experimental unit. Experimental treatments consisted of five dig. Val:Lys ratios (0.65; 0.70; 0.75; 0.80 and 0.85). Ideal dig. Val:Lys ratio was estimated using polynomial regression and linear broken-line regression model. Significant effect was considered when p≤0.05. Feed conversion ratio was not affected by dig. Val:Lys ratios in any of the assessed phases. From 15 to 21 d of age Val:Lys ratios increased linearly feed intake, weight gain and body weight. From 15 to 28 d of age, weight gain and body weight were both optimized by the Val:Lys ratio of 0.77. A linear effect of dig. Val:Lys ratios was observed on weight gain and final body weight from 15 to 35 d of age. From 15 to 35 d of age, according to linear broken-line regression model, the dig. Val:Lys ideal ratios for optimum final body weight and weight gain were 0.77 and 0.76, respectively. Based on the results the estimated dig. Val:Lys ratio for optimum meat-type quail performance from 15 to 35 d of age is 0.77

Relação treonina: lisina digestíveis na dieta de poedeiras leves de 42 a 58 semanas de idade

This study was conducted to determine the ideal ratio of digestible threonine: lysine in diets for laying hens at 42 to 58 weeks of age. Two hundred forty Hy Line W-36 laying hens were used at 42 weeks of age for 16 weeks. The treatments were distributed in a completely randomized design with eight replicates and six birds each. The experimental diets were formulated with five levels of digestible threonine (0.461; 0.515; 0.569; 0.622 and 0.676%) providing the five ratio of digestible threonine: lysine (60; 67; 74; 81 and 88%) studied. The variables analyzed were: egg production; feed intake; lysine intake; threonine intake; mass egg; average egg weight; lysine use efficiencies by mass and produced eggs; feed conversion per mass and dozen eggs; Average weights yolk, albumen and shell; weight gain and final body weights of birds; and nitrogen balance. The digestible threonine: lysine ratio in the diet did not influence the analyzed variables except consumption of threonine which showed a linear effect. The ideal ratio of digestible threonine: lysine in diets for white laying hens at 42 to 58 weeks of age is 60%, which corresponds to the level of 0.461% of digestible threonine in the diet and daily intake of digestible threonine 446mg/bird.

The Effect of Calcium and Available Phosphorus Levels on Performance, Egg Quality and Bone Characteristics of Japanese Quails at End of the Egg-Production Phase

Calcium (Ca) and available phosphorus (avP) requirements for egg production are different between the beginning and the end of the egg-production cycle. The objective of this study was to estimate the Ca and avP requirements of Japanese quails at end of the production phase. In total, 256 Japanese quails with 48 weeks of age were randomly distributed in 2 x 2 factorial arrangement consisting of two Ca levels (29 and 38 g/kg) and two avP levels (1.5 and 3.0 g/kg), totaling four treatments with eight replicates of eight hens each. The variables evaluated were feed intake (FI); egg production (EP); marketable egg production (MEP); egg weight (EW); egg mass (EM); feed conversion ratio per egg mass (FCRM); feed conversion ratio per dozen eggs (FCRD); livability (L); yolk weight (YW), albumen weight (AW), eggshell weight (SW); yolk percentage (YP), albumen percentage (AP), eggshell percentage (SP), specific egg weight (SEW); bone calcium percentage (BCa), bone phosphorus percentage (BP), bone ash weight (Bash) and bone ash percentage (PBash). There was no interaction between Ca and avP levels for any of the evaluated parameters, except for SEW. Quail performance was not influenced by the treatments, except for MEP. Bone characteristics were not influenced by the tested dietary Ca and avP levels. However, SW and SP increased and AP decreased as dietary Ca level increased. The dietary supplementation of 38 g Ca/kg and 3.0 g avP/kg may increase marketable egg production and the egg quality of Japanese quails at end of the production cycle.

Qualidade de ovos de codorna submetidos ou não a tratamento superficial da casca armazenados em diferentes ambientes

With the aim of evaluating the quality of eggs of Japanese quail treated superficially, by immersion in mineral oil or propolis solution, simultaneous experiments were conducted in two environments, without refrigeration (Experiment 1) and with refrigeration (Experiment 2). For each experiment, were selected 360 intact eggs distributed in a completely randomized design in factorial 3 x 5 (untreated eggs; eggs immersed in propolis or eggs immersed in mineral oil, evaluated for five storage times: 7; 14; 21; 28 and 35 days), each treatment consisted of four replicates of six eggs each. The eggs had increased weight loss, decrease in specific gravity and growth the weight and the pH of the yolk, besides the reduced the pH of the albumen and their respective weight with advancing storage time in the absence of cooling (Experiment 1), whether treated or not in the shell. However, the surface treatment with mineral oil promoted protection against progressive loss of weight and decreased specific gravity, making them less intense with advancing the storage period without refrigeration. In the Experiment 2, the immersion of eggs in mineral oil promoted less weight loss, higher specific weight, greater weight of the yolk and the albumen during storage under refrigeration. The quality of quail eggs submitted of treatment superficial on shell by immersion in mineral oil is preserved for up to five weeks under different environments, with and without refrigeration.

NÍVEIS DE SÓDIO PARA CODORNAS DE CORTE DE 1 A 14 DIAS DE IDADE

A trial was carried out on Aviculture Sector of the Federal University of Vicosa. The objective of this present trial was to determinate the nutritional requirements of meat quails from one to fourteen days of age. Four hundred and twenty quails, one day old, were housed. The birds were distributed in a completely randomized design with five treatments, seven replicates and twelve birds per experimental unit. The experimental diets consisted of increasing sodium levels: 0.10; 0.17; 0.24; 0.31 and 0.38%. The variables analyzed were feed intake (g/bird), weight gain (g/bird), final weight (g), feed conversion ratio (g/g), viabilitty (%) and sodium intake (g). The results were statistically analyzed using the SAEG UFV. The regression analysis was performed using the linear and quadratic effects to estimate the sodium requirements, considering the significance level, determination coefficient value, and the biological response of the birds. All of the variables analyzed from one to seven days old were not affected (P>0.05) by the diets, except sodium intake. In both phases, one to seven days old and one to fourteen days old sodium intake presented a linear increase (P 0.05) by the treatments. The nutritional requirement of sodium for quails from one to fourteen days old is 0.10%.