Cláudia de Castro Goulart

Determinação da exigência nutricional de treonina para poedeiras leves e semipesadas

An experiment was carried out to determine the nutritional threonine requirement for white-egg and brown-egg laying hens, during a period from 21 to 36 weeks. Five hundred and seventy six laying hens, 288 from white-egg and 288 from brown-egg, were used during four experimental periods of 28 days each. A complete randomized blocks design in a fatorial arangement (level x trademarks), with six replicates (eight birds/replicate), was used. The treatments consisted on a basal diet with 14.2% crude protein supplemented with 0.025, 0.050, 0.075, 0.100, and 0.125% of L-threonine providing a total of 0.510, 0.535, 0.560, 0.585, 0.610, and 0.635% of threonine. The productive performance and internal egg quality were evaluated. Feed intake, egg production, egg mass and weight gain were superior for the brown-egg laying hens. Egg production and internal egg quality, feed: gain ratio, body weight gain were not influenced by the used threonine levels. The level of 0,510% of threonine, that correspond to 515 mg/hen·day (0,423% of digestible threonine) and 535 mg/hen·day (0,440% of digestible threonine), was sufficient to meet the performance and to the internal egg quality for the studied characteristics of both white-egg and brown-egg laying hens, respectively.

Suplementação da fitase em rações com diferentes níveis de fósforo disponível para frangos de corte

The study was carried out with the objective of evaluating the effect of phytase supplements in feeds with different levels of available phosphorus on the performance of broilers from 22 to 42 days of age. We used 1080 Cobb-500 chickens distributed in a completely randomized design, in a 3 x 4 factorial scheme, with three levels of available phosphorus (0.30; 0.40 and 0.50%) and four levels of phytase (0; 500; 1,000 and 1,500 UF), totaling 12 treatments, each with six replications of 15 birds. The variables evaluated were: feed intake, live body weight, weight gain, feed conversion and carcass characteristics. Live body weight and weight gain were not influenced by the levels of available phosphorus or adding phytase to the diet. There was interaction between the levels of available phosphorus and phytase levels for feed intake and feed conversion. Better feed conversion was seen in birds fed on diets containing 0.30% available phosphorus at 1,500 UF kg-1. The available phosphorus levels affected the development of the thigh and the back, where the best results were from 0.30% and 0.40% respectively. The use of a diet containing 0.30% phosphorus, supplemented with 1500 UF kg -1 is recommended.

Nutritional potassium requirement for laying Japanese quails

The objective of this study was to evaluate the potassium requirement for laying Japanese quails. Two hundred and forty quails were distributed in a randomized block design, with five treatments and six replicates, with eight birds each. The treatments consisted of a basal diet deficient in potassium (K) (2.50 g/kg), supplemented with potassium carbonate, to replace the inert, to reach levels of 2.50, 3.50, 4.50, 5.50 and 6.50 (g/kg) of K in the diet. There was a quadratic effect of K levels on feed intake, egg production, egg mass and feed conversion per egg mass and per egg dozen, estimating the requirements of 4.26, 4.41, 4.38, 4.43 and 4.48 (g/kg) of K diet, respectively. There was no significant effect on the levels of K in the diet on egg weight, albumen weight, percentage of yolk or shell and yolk color. However, yolk and shell weights reduced and the albumen percentage increased linearly with increasing levels of K in the diet. Despite the reduction of shell weight, the increased levels of K did not influence the specific gravity and shell thickness. The use of 4.41 g/kg of potassium is recommended in the diet for laying Japanese quails.

Exigência de cálcio para codornas japonesas (Coturnix coturnix japonica) machos na fase de 1 a 21 dias de idade

Objetivou-se, com esta pesquisa, determinar a exigencia de calcio de codornas japonesas machos, no periodo de 1 a 21 dias de idade. Foram utilizadas 280 codornas com peso medio de 8 ± 2 g na fase inicial. As variaveis estudadas foram consumo de racao (CR), ganho de peso (GP) e conversao alimentar (CA). O delineamento experimental utilizado foi o inteiramente ao acaso, constituido de sete niveis de calcio para cada fase, com quatro repeticoes de dez aves por unidade experimental. Os niveis de calcio foram 0,85; 1,00; 1,15; 1,30; 1,45; 1,60 e 1,75%. As suplementacoes de calcio foram realizadas atraves do calcario calcitico da racao. Verificou-se que o CR, o GP e a CA apresentaram efeito quadratico com o aumento dos niveis de calcio na dieta. Recomenda-se dieta contendo 1,24% de calcio para codornas japonesas machos no periodo de 1 a 21 dias de idade.

Características de Carcaça de Codornas Europeias Alimentadas com Diferentes Níveis Protéicos

Objetivou-se avaliar o rendimento de carcaca de codornas europeias (Coturnix coturnix coturnix) no 42° dia de idade, alimentadas com dietas isoenergeticas contendo cinco diferentes niveis de proteina bruta (16, 19, 22, 25 e 28%). Trezentas codornas europeias de 22 a 42 dias de idade foram distribuidas em um delineamento inteiramente casualizado com cinco tratamentos e seis repeticoes de dez aves por unidade experimental. As variaveis observadas foram rendimento de carcaca (%), rendimento da coxa+sobrecoxa (%), rendimento de peito (%), rendimento da gordura corporal (%) e rendimento de visceras comestiveis (figado, moela e coracao). Observou-se efeito quadratico (P<0,01) da dieta sobre rendimento de carcaca, peito e moela e efeito linear (P<0,01) sobre o rendimento de coxa mais sobrecoxa e gordura corporal. DOI:10.15528/2176-4158/rcpa.v12n1p53-55

Cottonseed meal in broiler diets with or without enzyme supplements

This experiment was carried out with the aim of evaluating diets containing cottonseed as a substitute for soybean meal protein, with or without enzyme supplements, on performance and carcass characteristics in broilers. A total of 350 chicks were distributed in a completely randomised experimental design, in a 2 x 2 + 1 factorial scheme (2 levels of substitution: 10% or 20% x with or without enzyme supplementation + control diet), giving a total of five treatments with seven replications. When compared to the control diet, in the pre-initial phase, the chicks submitted to the diets containing cottonseed meal showed higher feed intake and weight gain. However, when the periods, from 1 to 21 days and from 1 to 42 days, were evaluated, the performance of the birds was similar. Over the total breeding period, there was an effect from the level of substitution and the enzyme supplement, where a substitution of 20% and the addition of enzymes resulted in better weight gain. For carcass characteristics, it was found that a diet with 10% substitution and the addition of enzymes increased thigh weight in comparison to the control diet, and a substitution of 20%, gave greater yield of the upper thigh. Greater thigh weight was also found with the addition of enzymes. It can be concluded that cottonseed meal can be used as a substitute for 20% of the soybean meal protein in broiler diets supplemented with the enzymes phytase and xylanase.Este experimento foi conduzido com a finalidade de avaliar dietas contendo farelo de algodao em substituicao a proteina do farelo de soja, com ou sem suplementacao enzimatica sobre o desempenho e caracteristicas de carcaca de frangos de corte. Foram utilizados 350 pintos distribuidos em delineamento experimental inteiramente casualizado, em esquema fatorial 2 x 2 + 1 (2 niveis de substituicao: 10 ou 20% x suplementacao ou nao com enzimas + dieta controle), totalizando cinco tratamentos, com sete repeticoes. Quando comparados a dieta controle, na fase pre-inicial, os pintos submetidos as dietas contendo farelo de algodao apresentaram maior consumo de racao e ganho de peso. No entanto, quando avaliados os periodos de 1 a 21 e 1 a 42 dias, o desempenho das aves foi semelhante. No periodo total da criacao, houve efeito do nivel de substituicao e da suplementacao enzimatica, em que a substituicao de 20% e a adicao de enzimas resultaram em melhor ganho de peso. Nas caracteristicas de carcaca, verificou-se que a dieta com 10% de substituicao com adicao de enzimas aumentou o peso da coxa, em comparacao a dieta controle e a substituicao de 20% em maior rendimento de sobrecoxa. Tambem foi verificado maior peso de coxa com a adicao das enzimas. Conclui-se que o farelo de algodao pode ser utilizado em substituicao de 20% da proteina do farelo de soja em dietas com suplementacao das enzimas fitase e xilanase para frangos de corte.

Rendimento de Carcaça de Frangos de Corte em Dietas com Redução Proteica Suplementadas com Lglutamato

Com o objetivo de avaliar o efeito da reducao proteica e a suplementacao de L-Glutamato sobre o rendimento de carcaca de frangos de corte aos 42 dias de idade, 540 pintos de corte machos da linhagem Cobb 500 foram distribuidos em um delineamento inteiramente casualizado com seis tratamentos, seis repeticoes de quinze aves por unidade experimental. O primeiro tratamento consistiu de uma racao Controle formulada em funcao do atendimento das exigencias dos aminoacidos essenciais limitantes para cada fase de criacao com suplementacao de lisina, metionina e treonina. Alem da suplementacao dos aminoacidos citados anteriormente, a L-valina foi suplementada no segundo tratamento e a reducao de proteina forneceu o proximo aminoacido limitante para formular o terceiro tratamento, que no caso foi a L-isoleucina. De forma semelhante, no quarto tratamento ocorreu a suplementacao de L-arginina. Para os tratamentos 5 e 6, as racoes foram suplementadas com a Lglutamato em quantidades suficientes para atender os requerimentos minimos de proteina para cada uma das fases. As variaveis avaliadas foram: rendimento (%) da carcaca, de peito e de coxa, peso absoluto (g) e relativo (%) da gordura abdominal. Os dados finais da racao Controle apresentaram melhores resultados para pesos de carcaca e peito. DOI:10.15528/2176-4158/rcpa.v14n2p184-187

Chlorine requirement for Japanese laying quails

The objective of this study was to determine the chlorine nutritional requirement of Japanese Quails during the laying phase, based on performance and egg quality parameters. A total of 240 Japanese quails were distributed according to a randomized block design, with five treatments and six replicates, with 8 birds each. The experiment lasted 84 days, divided in four cycles of 21 days each. Treatments consisted of a basal diet formulated to meet the nutritional requirements, except for chlorine, and four supplementation levels with ammonium chloride, generating the levels 0.8; 1.6; 2.4; 3.2 and 4.0 g/kg. The parameters evaluated were: feed intake (g/bird/day), egg production (egg/bird/day), egg weight (g), egg mass (g), egg mass conversion (g/g), conversion per dozen eggs (kg/dz), weight of yolk (g/100 g of egg), albumen (g/100g of egg) and shell (g/100 g of egg), specific gravity (g/cm3) and shell thickness (mm). As a result of this study, feed intake, egg weight, weights of albumen, yolk, shell and specific gravity were not affected by treatments. There was a quadratic behavior for egg production, egg mass, egg mass conversion, conversion per dozen eggs and shell thickness according to the chlorine levels in the diets, with the requirements for those parameters established at 1.54; 1.37; 1.39 and 2.78 g/kg, respectively. The recommendation is 1.39 g/kg of chlorine and 244.22 mEq/kg of electrolyte balance in diets for Japanese quails.