Carlos Eduardo Braga Cruz

Limestone particle size and artificial light for laying hens in the second laying cycle

The experiment was conducted to evaluate the effects of limestone particle size and the use of artificial light for laying hens in the second laying cycle. We used 240 Hisex White laying hens at 82 weeks of age in a completely randomized design in a 5 × 2 factorial arrangement, resulting in 10 treatments with 4 replicates of 6 birds. The variables were the five particle sizes obtained by increasing the proportion of thick limestone (0, 25, 50, 75 and 100%) compared with thin limestone and two lighting programs: with and without artificial light. Limestone particle size and light did not affect performance or egg quality. However, there were changes in bird feeding schedule throughout the day as a response to the lighting program. Bone quality, density and mineral content of the tibia were not affected by the treatments, but limestone particle size had a quadratic effect of on bone deformity and strength, obtaining maximum inclusion points with 63% and 59% of thick limestone, respectively. The use of large particles of limestone in the diet and the use of a lighting program does not influence the performance and quality of the eggs of laying hens in the second production cycle, but the use of a proportion of 63.3 g of average particle size (0.60 mm) replacing the fine limestone (0.23 mm) per 100 g of total limestone added to the diet improves bone quality in these birds.

Fibra na ração de crescimento e seus efeitos no desempenho de poedeiras nas fases de crescimento e postura

Objetivou-se com esta pesquisa avaliar os efeitos dos niveis de fibra em detergente neutro (FDN) das racoes oferecidas para as aves entre a 7a e 17a semanas de idade sobre o desempenho, o desenvolvimento dos sistemas digestorio e reprodutor, bem como os efeitos na maturidade sexual, no desempenho e na qualidade dos ovos na fase de postura.Foram distribuidas 1.296 aves em delineamento inteiramente casualizado em esquema fatorial 3 × 2, composto de tres niveis de FDN e duas linhagens, com quatro repeticoes de 54 aves. Foram testados os niveis de 14,5; 16,5; e 18,5% de FDN em aves leves e semipesadas. Ao final da fase de crescimento, as aves foram transferidas para o galpao de postura, mantendo o mesmo delineamento, composto por 14 aves por parcela. Nao houve interacao entre os niveis de FDN e as linhagens para as variaveis avaliadas. Na fase de crescimento, o aumento do nivel de FDN reduziu o ganho de peso e o peso final, piorou a conversao alimentar e aumentou o peso dos intestinos. Na fase de postura, os niveis de FDN nao influenciaram o desempenho das aves nem os constituintes e a qualidade dos ovos. Na fase de crescimento, as aves semipesadas apresentaram maior consumo, ganho de peso e peso final, melhor conversao alimentar, peso maior da moela e menor do figado e do ovario. Na fase de postura, as aves leves foram mais precoces, apresentaram menor peso e massa de ovos, pior conversao alimentar, ovos com mais gema, menos albumen, maior densidade especifica e menores unidades Haugh. Independentemente da linhagem, o aumento do nivel de FDN em racoes para crescimento pode influenciar o desempenho das frangas, resultando em aves menos pesadas, sem influenciar a maturidade sexual, o desempenho e a qualidade dos ovos na fase de postura.

Fiber level for laying hens during the growing phase

Feeding management of laying hens has been focused on the direct influence of nutrient intake on weight gain, especially at growing phase. This study evaluates nutrient digestibility, performance, development of the digestive tract, body composition, and bone quality of two strains of laying hens fed with different levels of neutral detergent fiber (NDF) during the growing phase from the 7th to the 12th week of age. A total of 1,296 birds were distributed in a completely randomized design in a 2 x 3 factorial arrangement (two strains x three levels of NDF) with four replicates of 54 birds per treatment. Semi-heavy (Hy Line Brown) and light-strain (Lohman LSL) pullets were allotted to dietary treatments consisting of 14.50, 16.50, and 18.50% NDF. An interaction between strains and NDF levels was observed only for feed/gain ratio and light-strain pullets had lower performance with 18.50% NDF. The increasing levels of NDF in the diet reduced the coefficients of digestibility of dry matter, nitrogen and gross energy, and the values of metabolizable energy. Higher levels of NDF in the diet increased the relative weight of liver and intestines and reduced gizzard weight. It was also observed differences between bone quality and composition of the femur and tibia of light and semi-heavy hens. The increase in NDF level in ration for growing phase laying hens above 14.50% decreases the nutrient digestibility and the metabolizable energy of the diet; however, it does not affect the carcass composition, bone quality, feed intake, and weight gain, although it may impair feed conversion of light-strain pullets.

Bone quality of laying hens fed different levels of fiber in the growth phase (7 to 17 weeks of age)

The effects of neutral detergent fiber levels (NDF) (145, 165, 185 g/kg) were assessed on the bone quality of light-weight and medium-weight laying hens. Eight hundred and forty laying hens were distributed in a completely randomized design in a 2 × 3 factorial arrangement (two strains and three NDF levels) with four replications of 35 birds. At the end of the growth phase, birds were transferred to a laying shed in the same experimental design and each experimental plot consisted of 14 birds. For bone assessment, two birds were selected per plot in the 17th week and one bird in the 35th week for slaughter. After slaughter, drumstick and thigh (legs) were removed and after deboning of the femur and tibia, taken to measurement of their length, weight, Seedor index, resistance, deformity, dry matter, mineral residue and crude protein. The data analysis showed no significant interaction between the factors NDF level and strain for any of the variables assessed at the different phases. The NDF level in the diet did not significantly influence bone growth, quality and composition at the end of the growing and laying phases. Medium-weight birds presented larger and heavier femur and tibia, with a greater Seedor index and less deformity, ash content and protein than the light-weight birds. Resistance did not vary significantly among the strains. A diet intended for laying hens at the growth phase can contain up to 185 g/kg NDF without causing problems in bone development and quality of laying hens.

Parboiled rice bran in japanese quail diets at growing phase and residual effect at laying period

Rice is the second largest cereal crop in the world and the by-products resulting from rice processing for human consumption are potential feedstuffs to compose poultry diets. In this sense, it was evaluated the influence of parboiled rice bran (PRB) in diets for Japanese quails in growing phase on the performance and digestibility, besides of residual effects and characteristics of egg quality in laying phase. A total of 324 Japanese quails with 7 days of age were distributed in a completely randomized design, with 6 treatments and 6 replicates of 9 birds. The treatments consisted of 6 isonutritives diets, being a control diet without PRB and the others containing 5, 10, 15, 20 and 25%. At the end of growing phase the birds were allotted in cages and fed the same diet without PRB at laying phase. At growing phase, the inclusion of PRB up to 5% promoted linear reduction in dry matter and gross energy digestibilities of diet; however a linear increase in metabolizable energy was noted. Feed intake, weight gain and final weight were reduced but not altering feed:gain ratio and body composition. At laying phase, the inclusion of PRB increased the age at first egg production but no influence was verified at age to reach 50% of egg production. No effect was verified at laying percentage, feed intake, weight and egg mass and feed:gain ratio. In economical evaluation, the inclusion of up to 25% of parboiled rice bran provided best economical indexes. The inclusion of PRB Japanese quails diets at growing phase can be recommended in levels up to 25%, without incurring future losses at laying phase.

Performance of broiler chickens reared at two stocking densities and coir litter with different height

The objective of this study was to evaluate the performance of broiler chickens reared at two stocking densities and coir litter with different height. A total of 522 one-day male chicks were distributed in a completely randomized design in a 3×2 factorial arrangement, with three litter height (5, 10 and 15 cm) and two densities (10 and 13 birds/m2), with six triplicates. The experimental period lasted 42 days, evaluating pH and litter moisture; performance; carcass traits; bone quality; and intensities of breast, hock and footpad lesions in the birds. Regarding the effect of density, a significant influence was observed only on performance, wherein the birds reared at the density of 13 birds/m2 showed lower intake and weight gain and better feed conversion than those reared at the density of 10 birds/m2. Irrespective of the rearing density and litter height, the hock and footpad lesions were frequent, and with severe intensity. It is concluded that coir with 5 cm height can be used to housing up to 13 birds/m2; however, the high rate of hock and footpad lesions makes the use of coir in the evaluated form unfeasible.

Blood parameters and enzymatic and oxidative activity in the liver of chickens fed with calcium anacardate

The aim of this research was to evaluate the inclusion of calcium anacardate (CAC) as a source of anacardic acid in the diet of broiler chickens on blood parameters, and enzymatic and oxidative activity in the liver. A total of 840 male chicks, one day old, were kept in a completely randomised experimental design, with six treatments and seven replications of 20 birds, totalling 140 birds per treatment. The treatments consisted of feed without the addition of growth promoter (GP), feed with GP, and feed with no GP and the addition of CAC at levels of 0.25, 0.50, 0.75 and 1%. The biochemical blood variables to be analysed were uric acid, total cholesterol, HDL, LDL, creatinine, AST, ALT, triglycerides, total erythrocytes, haemoglobin, haematocrit, mean corpuscular volume, corpuscular haemoglobin concentration, total plasma protein, total leukocytes, heterophils, lymphocytes, platelets and heterophil/lymphocyte ratio. The concentrations of superoxide dismutase, glutathione peroxidase and malondialdehyde were analysed for the enzymatic and oxidative parameters in the liver. There were no significant differences between treatments in the blood parameters or the enzymatic and oxidative activity in the liver of the chickens, demonstrating that the use of calcium anacardate as a source of anacardic acid is non-toxic, and does not affect these parameters.

Effect of Syzygium cumini leaves on laying hens performance and egg quality

The aim of this study was to evaluate the effect of Syzygium cumini leaves (SCL) in laying hens diets on productive performance, egg quality and lipid oxidation of yolk. A total of 108 Hysex White laying hens were distributed in a completely randomized design with three treatments and six replicates of six birds each. The treatments consisted of SCL inclusion at dietary levels of 0, 5 and 10 g/kg. There was no significant effect of SCL inclusion on feed intake, laying percentage, weight and egg mass, feed conversion ratio, Haugh units, specific gravity, percentage of yolk, albumen and egg shells and shell thickness. However, the inclusion of SCL significantly influenced the yolk color and yolk lipid oxidation measured by TBARS values. Yolk color increased and TBARS values ​​decreased with the inclusion of SCL. The inclusion of SCL in laying hens diets improves pigmentation and lipid stability of yolk.

Farelo da castanha de caju na alimentação de poedeiras marrons

The use of alternative foods to replace conventional foods is becoming a source of research for many researchers. The cashew nut meal (CNM) has high energy and protein value, may be a partial substitute for corn and soybean meal for poultry feed. In this context, this research was conducted to evaluate the effect of inclusion of CNM on the utilization of nutrients in the ration for laying hens, as well as the performance and characteristics of the eggs. The study used 180 Dekalb Brown laying hens 27 weeks of age, distributed in a completely randomized design with six treatments and five replicates of six birds. Treatments consisted of a control diet without CNM and others with the inclusion of this food at levels of 5, 10, 15, 20 and 25%. Upon regression analysis, a linear increase in nitrogen metabolism, crude energy and apparently metabolizable energy was seen. The dry matter digestibility and metabolizable energy corrected for rations were not affected by the inclusion of the CNM. Feed intake and egg weight were not affected by the inclusion of the CNM; however, egg production, egg mass, feed conversion, and yolk color worsened linearly with inclusion of CNM. Compared to control diet, the inclusion of CNM worsened the egg mass and feed conversion from 15%, and yolk color from 20%. As a result, it is recommended the inclusion of the CNM in the diet of laying hens at a maximum level of 10%.