RESUMO: Com o objetivo de avaliar o efeito dos níveis de energia metabolizável (EM) sobre o desempenho de codornas de corte de 15 a 35 dias de idade, foi conduzido um experimento com 560 aves aos 15 dias de idade, distribuídas em delineamento inteiramente casualizado com cinco tratamentos (2.850; 2.950; 3.050; 3.150 e 3.250kcal de EM kg-1 de ração), oito repetições com 14 aves por unidade experimental. Verificou-se redução linear (P<0,01) no consumo de ração, de proteína, de lisina e na conversão alimentar, com o aumento dos níveis de EM da ração. O consumo de energia metabolizável, o peso corporal, o ganho de peso, viabilidade das aves não foram influenciados (P>0,05) pelos níveis de EM utilizados. Os níveis de EM das dietas não influenciaram (P>0,05) a matéria seca, o teor de umidade e a proteína nas carcaças. Foi observado efeito quadrático (P<0,04) dos níveis de EM sobre o teor de gordura nas carcaças. Conclui-se que o nível de EM de 3.250kcal kg-1 de ração, correspondendo à relação de energia metabolizável:proteína bruta de 139,24, possibilita melhor desempenho das codornas de corte.

ABSTRACT: This trial was carried out to evaluate the effects of dietetic metabolizable energy levels on performance and carcass traits of meat quails from 15 to 35 days old. Five hundred sixty, 15-d old, meat quails were randomly assigned to five treatments (2.850; 2.950; 3.050; 3.150 e 3.250kcal of ME kg-1 of diet), with eight replicates and fourteen birds per experimental unit. Feed intake, protein and lysine intake and feed conversion decreased linearly as the metabolizable energy content of diets increased (P<0.01), whereas metabolizable energy intake, body weight, weight gain and viability were not affected (P>0.05) by the treatments. Diets did not influence (P>0.05) carcass traits as dry matter, moisture and protein content in carcass. However a quadratic effect (P<0.04) were observed on carcass fat content. Based on these results, the adequate metabolizable energy level to ensure better meat quails' growth is 3.250kcal of ME kg-1 diet, that corresponds to a metabolizable energy: crude protein ratio of 139,24.

Two-hundred sixteen white laying hens were used to assess the ideal ratio of digestible threonine:lysine in diets for laying hens at 24 to 40 weeks of age. Birds were assigned to a randomized block design, with six treatments, six replicates per treatment and six birds per experimental unit. The cage was used as the blocking criterion. Experimental diets contained different digestible threonine:digestible lysine ratios (65, 70, 75, 80, 85 and 90%) with 142 g/kg of crude protein. Experimental diets were formulated to be isonitrogenous and isocaloric with different contents of L-glutamic acid. Feed intake (g/hen/d), egg production (%), egg weight (g), egg mass (g/hen/d), feed conversion ratio (kg/dozen and kg/kg egg), eggshell weight (g), albumen weight (g), yolk weight (g) and body weight gain (g) were assessed. The maximum egg production was observed at 78% digestible threonine:digestible lysine ratio, while the best values of feed conversion ratio (kg/dozen egg) and feed conversion ratio (kg/kg of egg) were observed at 77.6% and 75%, respectively. Feed intake, egg mass and egg contents (yolk, albumen and eggshell) were not affected by treatments. The estimated digestible threonine:digestible lysine ratio of Hy-Line W36 laying hens at 24 to 40 weeks of age is 78%, corresponding to 5.70 g/kg of dietary digestible threonine.

The objective of this study was to estimate the digestible lysine requirement of Japanese quails in the egg-laying phase. A total of 336 female Japanese quails (Coturnix coturnix japonica) of average initial age of 207 days were distributed in a completely randomized experimental design, composed of 6 treatments (lysine levels) with 7 replicates and 8 birds per experimental unit, with duration of 84 days. Experimental diets were formulated from a basal diet, with corn and soybean meal, with 2.800 kcal ME/kg and 203.70 g/kg crude protein, showing levels of 9.50; 10.00; 10.50; 11.00; 11.50; and 12.00 g/kg digestible lysine; diets remained isoprotein and isocaloric. The following variables were studied: feed intake (FI); lysine intake (LI); egg production per bird per day (EPBD); egg production per bird housed (EPBH); production of marketable eggs (PME); egg weight (EW); egg mass (EM); utilization efficiency of lysine for egg mass production (UELEM); feed conversion per mass (FCEM); feed conversion per dozen eggs (FCDZ); bird availability (BA); percentages of yolk (Y), albumen (A) and shell (S); specific egg weight (SW); nitrogen ingested (NI); nitrogen excreted (NE); and nitrogen balance (NB). Significant effect was only observed for LI, EW, EM, UELEM, FCEM, Y, A and SW. The digestible lysine level estimated in diets for laying Japanese quails is 11.20 g digestible lysine/kg diet, corresponding to an average daily intake of 272.23 mg lysine.

Four trials were conducted to determine the requirements of available phosphorus (aP) of female broiler chicks from 1 to 10 (exp.1), 11 to 21 (exp.2), 22 to 33 (exp.3), and from 34 to 46 (exp.4) days of age, keeping the calcium:available phosphorus ratio equal to 2:1. In each trial, 480 Cobb broilers were randomly allotted in a completely randomized design with 6 treatments, 8 replicates and 10 birds per pen. The levels of aP ranged from 2.0 to 5.5 g/kg (Exp. 1), 1.9 to 5.4g/kg (exp. 2), 1.8 to 5.3 g/kg (exp. 3) and 1.7 to 5.2 g/kg of diet (exp. 4), in increments of 0.7 g/kg. The experimental diets were formulated using corn and soybean meal and the available phosphorus was considered 33% of total phosphorus. The characteristics evaluated were body weight gain, feed intake, feed conversion ratio and bone parameters. For female broiler chicks from 1 to 10; 11 to 21; 22 to 33; and from 34 to 46 days of age, the levels of available phosphorus and calcium recommended are 4.59 and 9.18; 3.88 and 7.76; 3.58 and 7.16; and 2.56 and 5.12 g/kg of diet, respectively.