This experiment studied the effect of four calcium (3.0, 3.5, 4.0, and 4.5%) and four available phosphorus levels (0.25, 0.30, 0.35, and 0.40%) in the diet of semi-heavy commercial layers after molting. Hisex Brown® layers between 90 and 108 weeks of age were distributed in a completely randomized experimental design with a 4x4 factorial arrangement with 16 treatments of five replicates of eight birds each. mortality, egg production, feed intake, egg mass, average egg weight, calcium and phosphorus intake, feed conversion ratio (per dozen eggs and per kg eggs), eggshell percentage and thickness, eggshell strength, eggshell weight per surface area (ESWSA), yolk percentage and color, albumen percentage, albumen and yolk heights, and blood and excreta calcium and phosphorus concentrations. There was no interaction (P>0.05) between dietary Ca and avP for any of the studied parameters. There were linear increases in Ca intake (P<0.01), eggshell percentage (P<0.05); ESWSA (P<0.05); yolk color (P<0.05); Ca concentration in the blood (P<0.05) and excreta (P<0.01) as dietary Ca level increased. The intake of avP linearly increased (P<0.01) with dietary avP levels. The remaining parameters were not influenced (P>0.05) by dietary Ca and avP levels. The diet containing 4.5% calcium improved feed conversion ratio per dozen eggs and eggshell quality. The lowest avP level fed (0.25%) is sufficient to maintain the performance and the egg quality of semi-heavy commercial layers after molting

Aiming at evaluating the influence of cyclic temperatures on the performance and egg quality of Japanese quails an experiment was carried out with 480 birds after egg production peak. Birds were housed in a bioclimatic chamber with automatic temperature control that contained two rooms, one maintained at thermoneutral temperature (21 ºC) and the other adjusted for the tested cyclic temperatures (24, 27, 30, 33 and 36 ºC at a time). Each room had a battery of five floors and ten cages, with a capacity of 24 birds per cage, totaling 240 birds per battery. Birds were fed iso-nutritious and iso-caloric diets. Data obtained under the tested cyclic temperatures were compared with those obtained under thermoneutral temperature. At the end of each experimental period (14 days) performance and egg quality parameters were evaluated. A completely randomized experimental design with two treatments (thermoneutral temperature and tested temperature) and ten replicates of 24 birds each. Cyclic increases of 27 ºC and higher in environmental temperature negatively affected bird performance, with reduced feed intake and consequent reductions in egg weight and mass. A cyclic increase of the environmental temperature to 36 ºC reduced the percentage of saleable eggs and egg production

This study evaluated the effect of dietary calcium levels and limestone particle size distribution on first-cycle layer performance and egg quality. A completely randomized experimental design in 4x3 factorial arrangement (four Ca levels -3.0, 3.5, 4.0, 4.5%; and three limestone particle size distributions -100% fine, 50% fine and 50% coarse, 30% fine and 70% coarse) was applied, totaling 12 treatments with six replicates of eight birds each. The treatments did not influence the most of evaluated performance and internal and external egg quality parameters. However, limestone particle size distribution quadratically affected with percentage of defective eggs, with the lowest percentage obtained with the distribution 61.75% fine limestone and 38.25% coarse limestone. Increasing dietary Ca levels significantly increased eggshell weight per surface area and the percentage of Ca excreted in the feces. It was concluded that the combination of the highest dietary Ca level (4.5%) with 50% replacement of fine-particle limestone by coarse limestone results in better eggshell and increases the number of marketable eggs.

This study assessed the effect of different cage stocking densities on the performance of Italian quails in the laying period. Two hundred and sixty four quails with 30 weeks of age and 280g mean body weight were used. Birds were randomly assigned to 96 x 33 x 16 cm cages and distributed in a randomized block design with 4 treatments (12, 15, 18 and 21 quails per cage or 264, 211, 176 and 151 cm² per quail, respectively) and 4 replicates. Birds were given feed and water ad libitum and submitted to the same experimental conditions. The experimental diet was formulated based on NRC (1994) recommendations. There were no significant differences among treatments for feed conversion per egg mass (kg:kg), percentage of broken eggs and mortality. There was a linear reduction (p<0.05) in egg weight, feed consumption, percentage of production, egg mass and feed conversion per dozen with the increase in stocking density. The gain per house per day was better at the cage density of 151 cm² per bird. However, the density of 211 cm² per bird provided the best gain per bird per day, because this stocking density had better productive indexes when compared with the other treatments

This experiment aimed at evaluating the effects of the supplementation of different vegetable oils at different levels to the diet of commercial layers on egg cholesterol levels and nutritional composition (proteins, total solids, lipids, and ashes) for 112 days. Birds were distributed according to a completely randomized experimental design with 10 treatments (T1-control; T2-inclusion of 2.5% rapeseed oil; T3-inclusion of 2.5% canola oil; T4-inclusion of 2.5% soybean oil; T5-inclusion of 5% rapeseed oil; T6-inclusion of 5% canola oil; T7-inclusion of 5% soybean oil; T8-inclusion of 2.5% rapeseed oil + 2.5% soybean oil; T9-inclusion 2.5% canola oil + 2.5% soybean oil; T10-inclusion of 2.5% rapeseed oil + 2.5% canola oil) of six replicates of eight birds each, totaling 480 birds. Yolk cholesterol levels and nutritional composition were determined on days 20, 60 and 112 days of the experimental period. Data obtained during the experimental period were submitted to analysis of variance. Egg yolks produced by layer fed oils presented lower cholesterol levels after 20 days of inclusion in the experimental diets. On days 60 and 112, cholesterol levels were higher. It was concluded that supplementing layer diets with vegetable oils rich in polyunsaturated fatty acids does not change the nutritional composition of egg yolks. The supply of diets containing oils rich in polyunsaturated fatty acids does not reduce yolk cholesterol content.

Beak Trimming Methods and Their Effect on the Performance and Egg Quality of Japanese Quails (Coturnix japonica) During Lay

A total of 405 23-week-old ISA ® Brown layers were distributed in a completely randomized experimental design in a factorial arrangement with nine treatments consisting of three dietary calcium levels (3.5, 3.75, and 4.5%) and three limestone particle sizes (100% fine limestone (FL), 70% FL + 30% coarse limestone (CL) and 50% (FL) + 50% (CL)), with nine replicates of five birds per cage. The following parameters were evaluated: percentage of lay, defective eggs, egg weight, egg mass, feed intake, feed conversion ratio (per kg eggs and per dozen eggs), and mortality. Dietary Ca levels significantly affected lay, with birds fed diets containing 4.5% calcium producing less eggs as compared to those fed 3.0 and 3.75% Ca. Egg production linearly decreased as dietary Ca levels increased, but blood Ca levels (mg/L) increased in 28-week-old birds. The interaction of dietary Ca levels and limestone particle sizes resulted in a reduction in tibial ash Ca content as dietary Ca levels increased and as fine limestone was replaced by coarse limestone. It is concluded that a dietary Ca level of 3.75% and 100% fine particle limestone are required to maintain adequate egg production and available Ca blood level. INTRODUCTIONCalcium is the mineral with the highest concentration in the body of poultry, consisting of 1.5% of its body weight. It is more than one third of total mineral body content of an adult bird (Klasing, 1998) and represents one third of eggshell components.During lay, structural bone loss (medullary and cortical) and the subsequent development of osteoporosis are associated to the medullary bone. Medullary bones in females are shaped in response to estrogen. The role of these bones in mineral homestasis is more important than their structural skeletal function, and it is associated to bone mineralization and eggshell formation. Studies on layer skeleton using fluorochrome (Cransberg et al., 2001) showed that there is no formation of medullary or cortical bone during eggshell formation; only the shape of medullary bones are changed. However, the high mobilization of minerals for eggshell deposition may result in osteoporosis and consequently, in bone fragility.Calcium has an essential role in nutrition and calcium turnover determines the optimal calcium level for bone formation, including the tíbia, but the relationship between calcium turnover and the development of osteoporosis is still not clear (Cransberg et al., 2001

campus, and aimed at evaluating the effect of the inclusion of flavonoids along with mannan oligosaccharides (MOS) as compared to other additives on the performance, carcass and parts yields, and meat quality of broilers reared from 1 to 42 days of age. A total number of 1500 Cobb broilers were distributed according to a completely randomized experimental design into five treatments, with six replicates of 50 birds each. Treatments consisted of a control group, probiotic 1, probiotic 2, antibiotic, and flavonoids+MOS. For the period of 1 to 42 days of age, there were no differences among treatments as to daily weight gain, feed intake, mortality, and final body weight, but a significant difference was found for feed conversion ratio for the flavonoids+MOS treatment. Carcass and parts yields were not significantly influenced by the treatments. Tbars number, which indicates meat fat oxidation index, was significantly different in both refrigerated and frozen meat. The lowest oxidation index was obtained with the flavonoids+MOS treatments. Under the conditions of the present study, the supplementation of broiler diets with flavonoids+MOS was effective.