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.

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.

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.

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.

Effect of heat exposure on the thermoregulatory responses of selected naked neck chickens

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