Methods to Evaluate the Eggshell Quality of Table Eggs

The objectives of this study were to determine the most suitable probe diameter and egg position to perform the eggshell breaking strength test using a texturometer, as well as the most reliable parameter to estimate eggshell quality when no electronic devices are available. Eggshell quality (eggshell breaking strength, eggshell weight, eggshell percentage, eggshell thickness, shell weight per unit surface area) was evaluated as a function of texturometer probe diameter (2, 10, and 75mm), egg type (white and brown) and egg position (horizontal and vertical). In the experiment, 2520 eggs from 60-week-old commercial layers were separated by specific gravity measured by flotation method in saline solution (1.070 to 1.100 g/cm3 with intervals of 0.005 g/cm3).Data were submitted to analysis of variance in a completely randomized design, and means were compared by Tukeys test (p 0.05). Correlations between characteristics were calculated using the Pearsons method. The results showed that the most suitable probe diameter for the analysis of eggshell breaking strength was 75 mm, independently of egg positioning or type egg. White eggs should be positioned vertically in relation to the probe, whereas brown can be placed in any position. When it is not possible to evaluate eggshell quality using electronic devices, the measurement of shell weight per unit surface area is recommended.(AU)

Methods to Evaluate the Eggshell Quality of Table Eggs

The objectives of this study were to determine the most suitable probe diameter and egg position to perform the eggshell breaking strength test using a texturometer, as well as the most reliable parameter to estimate eggshell quality when no electronic devices are available. Eggshell quality (eggshell breaking strength, eggshell weight, eggshell percentage, eggshell thickness, shell weight per unit surface area) was evaluated as a function of texturometer probe diameter (2, 10, and 75mm), egg type (white and brown) and egg position (horizontal and vertical). In the experiment, 2520 eggs from 60-week-old commercial layers were separated by specific gravity measured by flotation method in saline solution (1.070 to 1.100 g/cm3 with intervals of 0.005 g/cm3).Data were submitted to analysis of variance in a completely randomized design, and means were compared by Tukeys test (p 0.05). Correlations between characteristics were calculated using the Pearsons method. The results showed that the most suitable probe diameter for the analysis of eggshell breaking strength was 75 mm, independently of egg positioning or type egg. White eggs should be positioned vertically in relation to the probe, whereas brown can be placed in any position. When it is not possible to evaluate eggshell quality using electronic devices, the measurement of shell weight per unit surface area is recommended.

Production indicators and levels of corticosterone in pullets treated with beak-trimming protocols

The aim of this study was to compare the effects of beak trimming by hot blade or infrared radiation on production indicators and plasma levels of corticosterone in pullets. During the rearing phase, an entirely random delineation was used a 2 x 3 factorial design (two different techniques for beak trimming x 3 strains), a total of six treatments with six repetitions of 20 hens. In the growing phase, the previous treatments were divided into 12, with eight repetitions with seven hens. These treatments were then distributed in a factorial design of 2 x 3 x 2 (two methodologies for beak trimming during rearing phase x three strains x with or without beak trimming at ten weeks of age). In the rearing phase the birds treated by infrared radiation had a lower total consumption and a longer beak length. In the growing phase, the execution of beak trimming at ten weeks of age, led to a lower total consumption and a lower body weight, but a better food conversion, when compared to those hens that did not have beak treatment. Beak trimming at ten weeks did not change the plasmatic levels of corticosterone.(AU)

Production indicators and levels of corticosterone in pullets treated with beak-trimming protocols

The aim of this study was to compare the effects of beak trimming by hot blade or infrared radiation on production indicators and plasma levels of corticosterone in pullets. During the rearing phase, an entirely random delineation was used a 2 x 3 factorial design (two different techniques for beak trimming x 3 strains), a total of six treatments with six repetitions of 20 hens. In the growing phase, the previous treatments were divided into 12, with eight repetitions with seven hens. These treatments were then distributed in a factorial design of 2 x 3 x 2 (two methodologies for beak trimming during rearing phase x three strains x with or without beak trimming at ten weeks of age). In the rearing phase the birds treated by infrared radiation had a lower total consumption and a longer beak length. In the growing phase, the execution of beak trimming at ten weeks of age, led to a lower total consumption and a lower body weight, but a better food conversion, when compared to those hens that did not have beak treatment. Beak trimming at ten weeks did not change the plasmatic levels of corticosterone.

Chicken Meat Submitted to Gamma Radiation and Packed with or without Oxygen

The objective of this study was to evaluate the effects on gamma radiation levels on the physical and microbiological characteristics of chicken breast meat. A completely randomized experimental design in a 4x2x3 factorial arrangement was adopted. Treatments consisted of four radiation concentrations (0, 2, 4, or 8kGy), two package sealing methods (with or without vacuum), and three storage times (01, 07, or 14 days), with ten replicates each, totaling 240 chicken breast fillets. Packaging and radiation had no influence (p>0.05) on chicken breast meat pH, water retention capacity, or presence of Salmonella spp. Breast fillets not submitted to radiation and vacuum packed presented higher water retention capacity (p 0.05) than those radiated at 4kGy and vacuum packed. Drip loss in fillets radiated at 8kGy and not vacuum packed was higher (p 0.05) than in non-radiated and non-vacuum packed fillets; however, both were not different from the other treatments. Coliform presence increased with storage time in non-radiated samples; however, when these were vacuum-packed, their development was slower. The results of the present experiment suggest that the use of a low radiation dose (2kGy), combined with vacuum packing, may minimize the harmful effects of storage on chicken breast fillets.(AU)

Chicken Meat Submitted to Gamma Radiation and Packed with or without Oxygen

The objective of this study was to evaluate the effects on gamma radiation levels on the physical and microbiological characteristics of chicken breast meat. A completely randomized experimental design in a 4x2x3 factorial arrangement was adopted. Treatments consisted of four radiation concentrations (0, 2, 4, or 8kGy), two package sealing methods (with or without vacuum), and three storage times (01, 07, or 14 days), with ten replicates each, totaling 240 chicken breast fillets. Packaging and radiation had no influence (p>0.05) on chicken breast meat pH, water retention capacity, or presence of Salmonella spp. Breast fillets not submitted to radiation and vacuum packed presented higher water retention capacity (p 0.05) than those radiated at 4kGy and vacuum packed. Drip loss in fillets radiated at 8kGy and not vacuum packed was higher (p 0.05) than in non-radiated and non-vacuum packed fillets; however, both were not different from the other treatments. Coliform presence increased with storage time in non-radiated samples; however, when these were vacuum-packed, their development was slower. The results of the present experiment suggest that the use of a low radiation dose (2kGy), combined with vacuum packing, may minimize the harmful effects of storage on chicken breast fillets.

Evaluation of a radiographic method to detect tibial dyschondroplasia lesions in broilers

This study aimed at developing radiographic techniques for the early detection of dyschondroplastic lesions in the tibia of broilers. The experiment was carried out at the facilities of UNIFOR/MG and Formiga and UNIFENAS/ Alfenas with 420 one-day-old male Cobb broilers. At 20 days of age, all birds were radiographed and identified with an alpha-numeric metal ring in the right leg. At 40 days of age, 42 broilers previously selected as a function of bone mineral density and lesion thickness scores were again radiographed and scored, and then sacrificed. Their right tibia was removed for gross and histological examination of the growth plate. The results showed that radiographic techniques are correlated with gross and histological examination and that there was no significant differences among techniques (P>0.05). it was concluded that the use of radiographic examination to identify tibial dyschondroplasia in broilers precludes the use of bone mineral density to diagnose this condition. The non-parametric statistical Chi-square test at 5% significance level was used to analyze the results.(AU)