Effects of dietary electrolyte balance on performance, energy balance, and expression of genes related to acid-basic balance, absorption, and transport of nutrients in broilers.

The objective of this study was to evaluate the effect of dietary electrolyte balance (DEB) levels on performance characteristics (feed intake, FI; body weight gain, BWG; and feed efficiency, FE), energy balance (retained energy, RE; metabolizable energy ingested, MEI; heat production, HP; and energy retention efficiency, ERE), and the expression of genes related to acid-base balance, nutrient absorption, and transport in broilers from 1 to 21 days of age. A total of 245 male Cobb chickens were used in a completely randomized design with five DEB levels (110, 175, 240, 305, and 370 mEq/kg) and seven replicates of seven birds each. The inclusion of DEB levels influenced FE; 110 mEq/kg provided the better values for this characteristic both in the pre-initial phase and in the initial phase but was different only concerning 175 mEq/kg (1-7 days) and 240 mEq/kg (1-21 days). Birds that ingested diets with a level of 240 mEq/kg of DEB had a higher MEI and HP. This DEB level caused a lesser and greater expression of the SLC12A2 gene in the liver and the ATP1A1 gene in the intestine, respectively. On the other hand, the ATP1A1 gene was less expressed in the liver and kidney of broilers supplemented with 370 mEq/kg compared to a level of 110 mEq/kg. In general, a level of 110 mEq/kg DEB in the ration seems to be the most suitable for good performance, energy balance, and gene expression of broilers from 1 to 21 days of age.

Development of Tenebrio molitor (Coleoptera: Tenebrionidae) on Poultry Litter-Based Diets: Effect on Chemical Composition of Larvae.

In order to investigate a low-cost and sustainable food source, the present study evaluated the use of poultry litter for rearing Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae). The experiment was performed with five diets containing increasing levels of poultry litter (0, 25, 50, 75, and 100%) replacing the control diet and five replicates with 50 larvae per sample unit. Larval growth and development were evaluated and the chemical compositions of diet and T. molitor larvae were determined. Larval development and reproduction efficiency of T. molitor were similar in all treatments. The sole use of poultry litter to feed T. molitor reduced the crude protein of flour by only 8%. Including 50% or more poultry litter in the standard diet is the best-suited formulation for larvae production and incorporation of minerals in the larvae. Mealworm can be grown successfully on diets composed by poultry litter, the diet did not affect survival, growth, and development; however, studies spanning several insect generations should be performed to determine the effects of diet composition on adult fecundity. The knowledge acquired using poultry litter to feed T. molitor will be useful to carry out new research, in addition to evidencing the possibility of low-cost mass rearing of these larvae.

Cottonseed Oil in Diets for Broilers in the Pre-Starter and Starter Phases.

The objective of this study was to evaluate the effect of different levels of crude cottonseed oil in isoenergetic diets, with or without supplementation of ferrous sulfate, on performance variables, relative weight of organs, and blood parameters of broilers, and on the economic viability of diets in the periods from 1 to 7 and 1 to 21 days of age. A total of 600 male birds of the Ross line were distributed in a completely randomized design in a (4×2) factorial arrangement with eight treatments (0, 2, 4, and 6% cottonseed oil with and without ferrous sulfate), and five replicates. The following variables were studied: feed intake, weight gain, feed conversion, weight of organs, blood parameters, and yield of carcass and cuts at 21 days. No effects of the levels of cottonseed oil were found on the performance of animals aged 1 to 7 days, or on the relative weights of the organs. In this same period, the weight gain, and the relative weights of heart, liver, and intestine of the animals that received ferrous sulfate were decreased, and feed conversion was worsened. In the period from 1 to 21 days, weight gain increased linearly with the increase in the levels of cottonseed oil. Blood parameters were not influenced by the diets. Crude cottonseed oil can be utilized in diets for broilers in the periods from 1 to 7 and 1 to 21 days of age at up to 6% of inclusion, and supplementation with ferrous sulfate is unnecessary if the differences in metabolization of the cottonseed oil are considered, with and without, it during the diet formulation process.

Crescimento e desempenho de linhagens de aves pescoço pelado criadas em sistema semi-confinado / Growth and performance of naked neck broiler reared in free-range system

Este trabalho foi realizado para avaliar o crescimento e desempenho de duas linhagens de aves pescoço pelado. Foram utilizadas 400 aves, distribuídas em um delineamento inteiramente casualizado, os tratamentos consistiram de um esquema fatorial 2 x 2 (linhagens x sexo), com cinco repetições de 20 aves cada. Foram utilizadas aves Pescoço Pelado das linhagens Sasso e ISA Label. As aves receberam rações formuladas à base de milho e de farelo de soja para atender às exigências nutricionais. Foi determinado o ganho de peso (GP), o consumo de ração (CR) e a conversão alimentar (CA) aos 28, 56 e 84 dias de idade e o rendimento de carcaça e de partes aos 84 dias de idade. Não foi observada interação entre sexo e linhagem (P>0,05) para nenhuma das variáveis de desempenho analisadas. Para CR e GP houve diferenças significativas (P<0,05) entre as linhagens e entre os sexos nos três períodos. As aves da linhagem Sasso apresentaram desempenho superior à ISA Label. Em relação aos parâmetros descritos da equação de Gompertz, as aves da linhagem Sasso apresentaram maior peso à maturidade (Pm) e tempo em que a taxa de crescimento é máxima (t*) e menor taxa de maturidade (b), indicando que as aves da linhagem ISA Label foram mais precoces para atingir a idade de máximo crescimento. As fêmeas demonstraram melhor aptidão para rendimento de peito e os machos para o rendimento de coxa e de sobra-coxa.

A trial was carried out to evaluate the growth and performance of naked neck birds. Four hundred birds were distributed into four treatments in factorial arrangement (2 strains x 2 genders), with five replicates of 20 birds each. The naked neck strains evaluated were Sasso and ISA Label. The birds were fed a diet formulated with corn and soybean meal according to the nutritional requirements. Food intake, body weight gain and food conversion were determined at 28, 56, and 84 days as well as the yield of carcass and cuts at 84 days. No interaction was observed between gender and strain (P>0.05). Food intake and body weight gain were different (P <0.05) between the strains and between the genders. Sasso strain presented higher performance than ISA Label. The parameters estimated for Gompertz equation, the weigh at maturity (Wm) and time that the growth rate is maximum (t*) were higher and maturity rate (b) was lower for Sasso strain than those of Isa Label strain. These results indicated that the Isa Label was more precocious than Sasso strain. The females showed better breast yield while the males showed better thigh and drumstick yield.