Digestible Lysine Requirements the Performance, Carcass Traits and Breast Meat Quality of Slow-Growing Broilers

ABSTRACT Three experiments were conducted to estimate the digestible lysine requirements of slow-growing broilers on their performance, carcass traits, and breast meat quality. Different broilers were evaluated in each experiment. In Experiment 1, broilers were evaluated from 29-49 days of age (grower phase I), in Experiment 2, from 50 to 69 days old (grower phase II), and in Experiment 3, from 70-84 days old (finisher phase). A completely randomized design with five treatments of four replicates each was applied in all experiments. The following dietary digestible lysine values were investigated: 0.871, 1.011, 1.151, 1.291 and 1.431% in Experiment 1; 0.803, 0.943, 1.083, 1.223 and 1.363% in Experiment 2; and 0.766, 0.906, 1.046, 1.186 and 1.326% in Experiment 3. In all three experiments, digestible lysine values quadratically affected feed intake, weight gain, and feed conversion ratio. Lysine intake linearly increased with increasing digestive lysine values, whereas lysine utilization efficiency linearly decreased. Lysine requirements for maximum feed intake (1.298, 1.109, 1.150%), weight gain (1.183, 1.199, 1.162%), and feed conversion ratio (1.203, 1.162, 1.126%) were estimated in Experiments 1, 2 and 3. Digestible lysine requirement for carcass yield were estimated as 1.162, 1.068 and 1.107% in experiments 1, 2 and 3, respectively. Lysine influenced the physical-chemical parameters broiler breast meat. Digestible lysine levels of 1.203, 1.162 and 1.126% are recommended in the diets of Redbro Plume broilers during the phases 29-49, 50-69 and 70-84 days of age to optimize feed conversion ratio.

Control of the Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) with entomopathogenic fungi

The beetle Alphitobius diaperinus (Panzer), considered a worldwide pest in the poultry industry, is difficult to control and it is a vector for pathogens. The objective of this study was to evaluate the biological control of the lesser mealworm, by strains of fungi Beauveria bassiana, Cladosporium sp. and Trichoderma sp. Larvae and adults of the A. diaperinus were inoculated with suspensions of conidia in the concentration of 10(7) conídia.mL-1. The B. bassiana isolate caused higher insect mortality as compared to Cladosporium sp. and Trichoderma sp. isolates, with the larvae being more susceptible than adults. The entomopathogenicity of B. bassiana was further evaluated with 200 larvae and 200 adults of A. diaperinus inoculated with suspensions 10(6), 10(7), and 10(8) conidia.mL-1, and observed for ten days. Larvae mortality started at the fourth day at the lowest concentration, and the adult mortality was only observed on the sixth day at the concentration of 10(8) conidia.mL-1.

Internal quality of conventional and omega-3-enriched commercial eggs stored under different temperatures

The internal quality of conventional and -3 enriched commercial eggs stored at different temperatures was evaluated. Eggs derived from Isa Brown layers fed two different diets. In Group 1, 432 hens were fed throughout their productive life with a diet based on corn and soybean meal (production of conventional eggs). In Group 2, starting at 22 weeks of age, other 432 hens were fed a diet containing 1.5% of marine algae substrate and 1.8% of fish oil (production of -3 enriched eggs). The following parameters were evaluated: Haugh unit, yolk index, albumen pH, and yolk pH. There were no significant differences between conventional and enriched with -3 eggs as to internal quality parameters. Only the interaction between storage time and temperature was significant, and therefore their effects were evaluated, independent of egg type (conventional eggs and -3 enriched eggs). Eggs stored at 25ºC presented lower Haugh units and yolk index, and higher albumen pH and yolk pH as compared to those kept at 5ºC. In addition, internal quality was reduced when eggs were stored for 7, 14, and 21 days, particularly when maintained at 25ºC. It was concluded that conventional and -3 enriched eggs have good internal quality; however, to maintain this quality, eggs must be stored under refrigeration.

Internal quality of conventional and omega-3-enriched commercial eggs stored under different temperatures

The internal quality of conventional and -3 enriched commercial eggs stored at different temperatures was evaluated. Eggs derived from Isa Brown layers fed two different diets. In Group 1, 432 hens were fed throughout their productive life with a diet based on corn and soybean meal (production of conventional eggs). In Group 2, starting at 22 weeks of age, other 432 hens were fed a diet containing 1.5% of marine algae substrate and 1.8% of fish oil (production of -3 enriched eggs). The following parameters were evaluated: Haugh unit, yolk index, albumen pH, and yolk pH. There were no significant differences between conventional and enriched with -3 eggs as to internal quality parameters. Only the interaction between storage time and temperature was significant, and therefore their effects were evaluated, independent of egg type (conventional eggs and -3 enriched eggs). Eggs stored at 25ºC presented lower Haugh units and yolk index, and higher albumen pH and yolk pH as compared to those kept at 5ºC. In addition, internal quality was reduced when eggs were stored for 7, 14, and 21 days, particularly when maintained at 25ºC. It was concluded that conventional and -3 enriched eggs have good internal quality; however, to maintain this quality, eggs must be stored under refrigeration.

Control of the Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) with entomopathogenic fungi

The beetle Alphitobius diaperinus (Panzer), considered a worldwide pest in the poultry industry, is difficult to control and it is a vector for pathogens. The objective of this study was to evaluate the biological control of the lesser mealworm, by strains of fungi Beauveria bassiana, Cladosporium sp. and Trichoderma sp. Larvae and adults of the A. diaperinus were inoculated with suspensions of conidia in the concentration of 10(7) conídia.mL-1. The B. bassiana isolate caused higher insect mortality as compared to Cladosporium sp. and Trichoderma sp. isolates, with the larvae being more susceptible than adults. The entomopathogenicity of B. bassiana was further evaluated with 200 larvae and 200 adults of A. diaperinus inoculated with suspensions 10(6), 10(7), and 10(8) conidia.mL-1, and observed for ten days. Larvae mortality started at the fourth day at the lowest concentration, and the adult mortality was only observed on the sixth day at the concentration of 10(8) conidia.mL-1.