Daily Egg-Cycle in Japanese Quail: Serum Biochemistry, Bones, and Oviduct Changes

This study described changes in the serum biochemistry, morphology of genital organs, long bone, and eggshell during the daily egg formation cycle in Japanese quails. Sixty quails (18-wk) were distributed in 6 groups according to hours post-oviposition (POV): 0 hr POV (16h00), 2 hrs POV (egg in magnum), and 4, 8, 14, and 20 hrs POV (egg in uterus). The magnum had higher relative weight before the next ovulation (20 and 0 hr POV), and its tubular glands showed functional variation through periods: abundant eosinophilic, PAS+, and negative Alcian blue secretion at 0 and 2 hrs, empty glands aspect at 4 hrs, and filled again at 20 hrs POV. Serum albumin and total Ca had the highest value in the 2 hrs group, and the lowest in 8 and 14 hrs groups. Egg-cycle period affected the Ca% of the medullar bone of the femur and tibiotarsus, with the lowest mean at 14 hrs POV (06h00), and the highest mean after oviposition (0 hr POV), showing the recovery of Ca stores in long bones for the next egg cycle. Analysis of the eggshell using scanning electron microscopy evidenced that palisade layer formation starts during the night (8­14 hrs POV), and most parts are secreted during the day period. In conclusion, eggshell secretion in light periods, high magnum activity and medullary bone Ca deposition during midday and afternoon, as well as the ovulation/oviposition in the afternoon, are the main characteristics of the distinct physiological aspects of the egg cycle in quails.(AU)

Effect of Thermal Embryonic Manipulation on the Quality of Male and Female Broiler Meat Submitted to Thermal Stress Pre-Slaughter

Adverse environmental conditions during rearing may negatively affect productivity and meat quality of the modern fast-growing broiler strains. Temperature manipulation during sensitive embryonic development periods may affect broilers' physiological responses to environmental conditions during rearing on commercial farms. The objective of this trial was to evaluate the effect of temperature manipulation during incubation and breeder age on the meat quality of male and female broilers submitted to heat stress during the pre-slaughter period. In this experiment, 1280 broiler chicks were distributed according to a completely randomized experimental design in a 2x2x2 factorial arrangement. Treatments consisted of two breeder ages (30 and 60 weeks), two temperature programs applied in the last four days of incubation (standard or high temperature), and sex (male and female). Birds were submitted to 32 °C for 48 hours before slaughter, on day 46.Meat quality parameters (pH, temperature, color, and weight loss) were evaluated. There was significant effect (p 0.05) of sex on meat redness (a*) and fat percentage, with females presenting higher values than males in both measurements. Males incubated at the higher temperature presented higher (p 0.05) meat weight loss by pressure than females. The thermal manipulation applied during the final stage of incubation did not affect the meat yield or meat quality of broilers submitted to heat stress.

Effect of Thermal Embryonic Manipulation on the Quality of Male and Female Broiler Meat Submitted to Thermal Stress Pre-Slaughter

Adverse environmental conditions during rearing may negatively affect productivity and meat quality of the modern fast-growing broiler strains. Temperature manipulation during sensitive embryonic development periods may affect broilers' physiological responses to environmental conditions during rearing on commercial farms. The objective of this trial was to evaluate the effect of temperature manipulation during incubation and breeder age on the meat quality of male and female broilers submitted to heat stress during the pre-slaughter period. In this experiment, 1280 broiler chicks were distributed according to a completely randomized experimental design in a 2x2x2 factorial arrangement. Treatments consisted of two breeder ages (30 and 60 weeks), two temperature programs applied in the last four days of incubation (standard or high temperature), and sex (male and female). Birds were submitted to 32 °C for 48 hours before slaughter, on day 46.Meat quality parameters (pH, temperature, color, and weight loss) were evaluated. There was significant effect (p 0.05) of sex on meat redness (a*) and fat percentage, with females presenting higher values than males in both measurements. Males incubated at the higher temperature presented higher (p 0.05) meat weight loss by pressure than females. The thermal manipulation applied during the final stage of incubation did not affect the meat yield or meat quality of broilers submitted to heat stress.(AU)

Influence of european quail breeders age on egg quality, incubation, fertility and progeny performance

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.

Influence of european quail breeders age on egg quality, incubation, fertility and progeny performance

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.(AU)

The effect of dietary phytase on broiler performance and digestive, bone, and blood biochemistry characteristics

The dietary inclusion of phytase increases nutrient and energy bioavailability for broilers. The effect of phytase increases nutrients and energy bioavailability for either the objective of this experiment was to evaluate the influence of nutrient and energy reduction in diets supplemented with phytase on the performance, gastrointestinal pH, organ and bone composition, and blood biochemistry of broilers between eight and 21 days of age. In the study, 1.120 male Cobb 500(r) broilers, with 161±1g average weight, were used. At eight days of age, birds were distributed according to a completely randomized experimental design with seven treatments in a 3x2+1 factorial arrangement with eight replicates of 20 broiler each. Treatments corresponded to reduction of calcium (Ca) and phosphorus (P), amino acids and energy, or reduction of Ca, P, amino acids and energy; supplementation or not of phytase; and a positive control treatment. Broiler fed the diet with reduced Ca and P levels and phytase supplementation presented the best performance of all groups. The diet with reduced amino acid and energy levels and phytase addition reduced gizzard and proventriculus pH. Dietary Ca and P reduction increased relative liver and heart weights, as well as albumin blood levels. The bones of broilers fed phytase-supplemented diets presented higher ash content.

The effect of dietary phytase on broiler performance and digestive, bone, and blood biochemistry characteristics

The dietary inclusion of phytase increases nutrient and energy bioavailability for broilers. The effect of phytase increases nutrients and energy bioavailability for either the objective of this experiment was to evaluate the influence of nutrient and energy reduction in diets supplemented with phytase on the performance, gastrointestinal pH, organ and bone composition, and blood biochemistry of broilers between eight and 21 days of age. In the study, 1.120 male Cobb 500(r) broilers, with 161±1g average weight, were used. At eight days of age, birds were distributed according to a completely randomized experimental design with seven treatments in a 3x2+1 factorial arrangement with eight replicates of 20 broiler each. Treatments corresponded to reduction of calcium (Ca) and phosphorus (P), amino acids and energy, or reduction of Ca, P, amino acids and energy; supplementation or not of phytase; and a positive control treatment. Broiler fed the diet with reduced Ca and P levels and phytase supplementation presented the best performance of all groups. The diet with reduced amino acid and energy levels and phytase addition reduced gizzard and proventriculus pH. Dietary Ca and P reduction increased relative liver and heart weights, as well as albumin blood levels. The bones of broilers fed phytase-supplemented diets presented higher ash content.(AU)