Glutamic acid improves body weight gain and intestinal morphology of broiler chickens submitted to heat stress

The objective of this study was to evaluate the effects of 1% dietary glutamic acid on the body weight, intestinal morphometry, and anti-Newcastle antibody titers of broiler chickens submitted to heat stress. One-d-old male broiler chicks (n=120) were distributed according to a 2 x 2 factorial design with two environmental temperatures (thermoneutral or heat stress) and two diets (with 0 or 1% glutamic acid). Heat stress temperature was constantly maintained (24h/day) 5 ºC higher than the thermoneutral temperature. Diets supplied the nutritional requirements of broilers in the pre-starter (1 to 7d) and starter (8 to 21d) phases. Birds were vaccinated against Newcastle disease on d 7 via eye drop. On days 5, 10, 15, and 20, individual body weight was determined, serum samples were collected from five birds, and duodenum samples were collected from four birds per treatment. Serum anti-Newcastle antibody titers were determined by enzyme immunoassay and transformed into log10. Villus height, crypt depth, and villus: crypt ratio were measured in the duodenum. Data were analyzed by ANOVA. Chronic heat stress negatively affected body weight and intestinal morphometry during the pre-starter and starter phases, but had no effect on antibody titers. Dietary glutamic acid supplementation (1%) improved body weight and intestinal integrity of birds submitted to heat stress when compared with non-supplemented and heat-stressed birds.(AU)

Glutamic acid improves body weight gain and intestinal morphology of broiler chickens submitted to heat stress

The objective of this study was to evaluate the effects of 1% dietary glutamic acid on the body weight, intestinal morphometry, and anti-Newcastle antibody titers of broiler chickens submitted to heat stress. One-d-old male broiler chicks (n=120) were distributed according to a 2 x 2 factorial design with two environmental temperatures (thermoneutral or heat stress) and two diets (with 0 or 1% glutamic acid). Heat stress temperature was constantly maintained (24h/day) 5 ºC higher than the thermoneutral temperature. Diets supplied the nutritional requirements of broilers in the pre-starter (1 to 7d) and starter (8 to 21d) phases. Birds were vaccinated against Newcastle disease on d 7 via eye drop. On days 5, 10, 15, and 20, individual body weight was determined, serum samples were collected from five birds, and duodenum samples were collected from four birds per treatment. Serum anti-Newcastle antibody titers were determined by enzyme immunoassay and transformed into log10. Villus height, crypt depth, and villus: crypt ratio were measured in the duodenum. Data were analyzed by ANOVA. Chronic heat stress negatively affected body weight and intestinal morphometry during the pre-starter and starter phases, but had no effect on antibody titers. Dietary glutamic acid supplementation (1%) improved body weight and intestinal integrity of birds submitted to heat stress when compared with non-supplemented and heat-stressed birds.

Influence of environmental temperature and electrolyte balance on the performance of quails (Coturnix Coturnix Coturnix)

High environmental temperatures have a negative effect on the production efficiency of poultry reared in hot climates. This study evaluated the efficiency of electrolyte supplementation under high environmental temperature conditions by manipulating water and feed electrolyte balance (EB) on the survival and performance of European quails. In experiment 1, a completely randomized experimental design was applied in a 4 x 2 factorial arrangement. Treatments consisted in four feed EB values (0, 120, 240, 360 mEq/kg), and two environmental temperatures (25 and 34 ºC). Feed electrolyte balance was manipulated by the addition of sodium bicarbonate and ammonium chloride. In experiment 2, birds were randomly distributed according to a 5 x 2 factorial arrangement. Treatments consisted in five BE values in the drinking water (0, 30, 60, 90, 120 mEq/L) and two environmental temperatures (25 and 34 °C). Only sodium bicarbonate was added to the water to obtain the different BE values. The experiments were carried out simultaneously in environmental chambers at constant temperatures with 20- to 37-d-old quails. Most evaluated parameters were influenced by temperature in both experiments. In experiment 1, EB affected water intake and intestinal length. In experiment 2, EB values influenced (p 0.05) water intake and heart and liver relative weights. Electrolyte balance values of 120 mEq/kg of feed and of 30 mEq/L of drinking water are recommended to increase water intake of grower European quails reared under hot temperature.

Influence of environmental temperature and electrolyte balance on the performance of quails (Coturnix Coturnix Coturnix)

High environmental temperatures have a negative effect on the production efficiency of poultry reared in hot climates. This study evaluated the efficiency of electrolyte supplementation under high environmental temperature conditions by manipulating water and feed electrolyte balance (EB) on the survival and performance of European quails. In experiment 1, a completely randomized experimental design was applied in a 4 x 2 factorial arrangement. Treatments consisted in four feed EB values (0, 120, 240, 360 mEq/kg), and two environmental temperatures (25 and 34 ºC). Feed electrolyte balance was manipulated by the addition of sodium bicarbonate and ammonium chloride. In experiment 2, birds were randomly distributed according to a 5 x 2 factorial arrangement. Treatments consisted in five BE values in the drinking water (0, 30, 60, 90, 120 mEq/L) and two environmental temperatures (25 and 34 °C). Only sodium bicarbonate was added to the water to obtain the different BE values. The experiments were carried out simultaneously in environmental chambers at constant temperatures with 20- to 37-d-old quails. Most evaluated parameters were influenced by temperature in both experiments. In experiment 1, EB affected water intake and intestinal length. In experiment 2, EB values influenced (p 0.05) water intake and heart and liver relative weights. Electrolyte balance values of 120 mEq/kg of feed and of 30 mEq/L of drinking water are recommended to increase water intake of grower European quails reared under hot temperature.(AU)

Substituição de minerais inorgânicos por orgânicos na alimentação de poedeiras semipesadas / Substitution of inorganic minerals for organic minerals in the diet of semi heavy layers

Avaliou-se o efeito da suplementação dietética de fontes orgânicas de microminerais para galinhas poedeiras sobre o desempenho e a qualidade do ovo. Foram utilizadas 216 aves de linhagem comercial, distribuídas num delineamento inteiramente ao acaso, com quatro tratamentos e nove repetições, com seis aves por parcela. O experimento teve duração de 140 dias, divididos em cinco ciclos de 28 dias. Os tratamentos consistiram de uma dieta basal formulada para atender às exigências nutricionais das aves, suplementada com minerais na forma inorgânica ou porcentagens de minerais orgânicos: T1 - Basal + 100% minerais inorgânicos; T2 - Basal + 100% minerais orgânicos; T3 - Basal + 66% minerais orgânicos; T4 - Basal + 33% minerais orgânicos. A produção de ovos, peso do ovo, massa de ovo, conversão alimentar por massa e dúzia de ovo, porcentagem de albúmen, gravidade específica, espessura de casca e margem bruta relativa apresentaram melhores resultados quando os minerais inorgânicos são substituídos em 66% pelos orgânicos.(AU)

This study evaluated the effect of the supplementation with organic microminerals on performance and egg quality of semi-heavy layers. Dekalk Brown layers (n=216) were distributed according to a completely randomized design into four treatments, nine repetitions and six birds per repetition. The experiment lasted 140 days and was comprised of five 28 day cycles. The basal diet was formulated to fulfill the nutritional requirements and was supplemented with organic or inorganic minerals, resulting in four treatments: T1 - basal + 100% inorganic minerals; T2 - basal + 100% organic minerals; T3 - basal + 66% organic minerals; T4 - basal + 33% organic minerals. Egg production, egg weight, egg mass, feed conversion for dozen and mass, albumen percentage, specific gravity, shell thickness and relative gross margin have better results when the inorganic minerals are replaced with 66% organic.(AU)

Estudo comparativo da proteína do feno de maniçoba em relação à proteína do feno de alfafa na ração de coelhos / Comparative study of maniçoba hay crude protein in relation to alfafa hay crude protein in the diet of rabbits

O presente experimento foi conduzido com o objetivo de avaliar a substituição parcial da proteína bruta (PB) do feno da alfafa (FA) pela PB do feno de maniçoba (FM) na alimentação de coelhos em crescimento, bem como o valor nutricional da proteína bruta do feno de maniçoba. Foram estudados os parâmetros de desempenho, digestibilidade, rendimento de carcaça e dos cortes nobres submetidos às dietas experimentais. Os tratamentos consistiram em quatro níveis de substituição (0, 25, 50 e 75%) da proteína do feno de alfafa pelo feno de maniçoba. A substituição crescente dos níveis de feno maniçoba resultou em um aumento linear no consumo de ração e no ganho de peso de forma quadrática aos 83 dias, mostrando que esse ingrediente pode ser utilizado como substituto ao feno de alfafa na dieta de coelhos. A proteína do feno da alfafa pode ser substituída parcialmente pela proteína do feno de maniçoba.(AU)

The experiment was conducted to evaluate the nutritional value and the partial substitution of crude protein (CP) of alfalfa hay (FA) with CP hay maniçoba (FM) in diets for growing rabbits. The performance, digestibility, carcass yield and prime cuts parameters submitted to experimental diets were studied. Treatments consisted of four levels (0, 25, 50 and 75%) of protein alfalfa hay and maniçoba hay. The increasing substitution levels of maniçoba hay resulted in a linear increase in feed intake and weight gain quadratically at 83 days, showing that this ingredient can be used as a substitute for alfalfa hay in the diet of rabbits. The protein of alfalfa hay can be partially replaced by the maniçoba protein hay.(AU)

Effect of heat exposure on the thermoregulatory responses of selected naked neck chickens / feito da exposição ao calor na resposta termorregulatória de aves de pescoço pelado selecionadas

The variation in cloacal temperature, body weight loss and expression of the 70 kDa heat shock protein (Hsp70) in three naked neck broiler genotypes during heat stress were studied. Twelve birds of each genotype (Na/Na, Na/na and na/na) were reared to market weight (approximately 2.1kg) at thermoneutral temperature. Six birds from each group served as controls and the remaining six underwent gradual heat stress (from 28oC to 36oC). Cloacal temperature and body weight were measured before and after exposure to heat. Liver samples were collected and Hsp70 levels were quantified using western blotting with monoclonal anti-chicken Hsp70 antibody. Heterozygous (Na/na) birds had a significantly lower cloacal temperature variation and less body weight loss during heat stress than the other genotypes. There was no significant difference in the Hsp70 levels among the genotypes. Heterozygous birds (Na/na) appeared to have a slight advantage over the other genotypes during gradual heat stress, perhaps because of a heterotic effect.(AU)

Estudaram-se o efeito do estresse térmico sobre a temperatura cloacal, a perda de peso corporal e a expressão da proteína de estresse de 70 kDa (Hsp70) em três genótipos de galinhas de pescoço-pelado. Foram usadas 12 aves de cada genótipo (Na/Na, Na/na e na/na), com peso corporal médio de 2,100kg e criadas em temperatura termoneutra. Seis aves de cada grupo serviram como controle e as seis restantes foram submetidas a estresse térmico gradativo (28oC 36oC). A temperatura cloacal e o peso das aves foram avaliados antes e depois do estresse. Amostras de fígado foram coletadas e os níveis de Hsp70 foram quantificados por "western blotting" com anticorpo monoclonal específico para Hsp70 de galinha. As aves heterozigotas (Na/na) tiveram variação de temperatura cloacal significativamente menor e menor perda de peso corporal durante o estresse térmico do que as dos outros genótipos. Não foi observada diferença significativa (P>0,05) para o aumento de Hsp70 no fígado. Aves heterozigotas parecem ter pequena vantagem sobre os outros genótipos durante estresse térmico gradativo, talvez devido ao efeito de heterose.(AU)