Thales Marcel Bezerra Filgueira

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.

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.