Effects of particle size of corn and stocking densities on the performance, carcass traits and gastrointestinal tract development of Muscovy ducks in housing.

The current investigation was conducted to investigate the effects of different particle sizes of corn and stocking densities on performance, carcass traits and gastrointestinal tract (GIT) development of Muscovy ducks in housing. 200 Muscovy ducks were distributed in a factorial scheme (2 × 2) where the treatments were constituted by two stocking densities (2 or 3 birds/m2) and two particle sizes of corn (6 or 8 mm), with five replicates of 10 birds each. At 1, 35, 70, and 90 days old, Muscovy ducks were slaughtered to evaluate the development of heart and GIT. Muscovy ducks managed in the density of 3 birds/m2 presented higher (P < 0.05) GIT development, performance and carcass traits regardless of age evaluated. In the same way, Muscovy ducks fed diets using a particle size of corn of 6 mm (Mean Geometric Diameter (MGD) = 781 µm) presented higher (P < 0.05) GIT development, performance and carcass traits regardless of age evaluated. Conclusively, the stocking density of 3 birds/m2 and the particle size of corn of 6 mm (MGD = 781 µm) were considered ideal recommendations for Muscovy ducks, providing higher GIT development, which resulted in better performance and carcass traits.

Effect of in ovo injection of DL-methionine on hatchability, embryo mortality, hatching weight, blood biochemical parameters and gastrointestinal tract development of breeder chicks.

The current investigation was conducted to test the potential effects of in ovo feeding of DL-methionine (MET) on hatchability, embryonic mortality, hatching weight, blood biochemical parameters and development of heart and gastrointestinal (GIT) of breeder chick embryos. 224 Rhode Island Red fertile eggs were randomly distributed into seven experimental treatments: untreated egg (control), buffered saline (0.5% NaCl), and five solutions containing increased levels of MET (0.5, 1.0, 1.5, 2.0 and 2.5%) + 0.5% NaCl, being separated into four groups/replicates (each one with 8 eggs), totaling 32 eggs/treatment. All embryos submitted to in ovo injection with MET presented a decrease in the hatchability results and an increase in the results of intermediary embryonic mortality. Chicks hatched from eggs injected with until to 1.0% MET were heavier and presented better development of the heart and GIT, especially important organs and regions for digestion and nutrient absorption. Conclusively, the in ovo feeding using MET showed positive impacts on hatching weight and GIT development of breeder chicks. However, caused negative impacts on hatchability when used at high levels.

In ovo feeding of creatine monohydrate increases performances of hatching and development in breeder chicks.

The current investigation was conducted to test the potential effects of in ovo feeding of creatine monohydrate (CMH) on hatchability, embryonic mortality, hatching weight, and development of heart and gastrointestinal tract (main organs and regions) of breeder chick embryos. Rhode Island Red fertile eggs were randomly distributed into seven experimental treatments: untreated egg (control), a sterile buffered solution (0.50% NaCl), and five solutions containing increased levels of CMH (0.50, 1.00, 1.50, and 2.00%) + 0.50% NaCl, being separated in four groups/replicates (three with 15 eggs and one with 16 eggs), totaling 61 eggs/treatment and a total of 427 fertile eggs used. All-in ovo injected groups with CMH decreased the hatchability and increased the intermediary embryonic mortality. At hatching, all-in ovo injected groups with CMH also increased the hatching weight and stimulated the development of the heart and the total length of the gastrointestinal tract, especially important organs for digestion of nutrients (yolk sac, pro-ventricle and gizzard) and regions for nutrient absorption (jejunum + ileum and colon + rectum). Conclusively, the in ovo feeding using CMH showed positive impacts on hatching weight and the development of gastrointestinal tract of chicks. However, caused negative impacts on hatchability.