-The objective of this study was to evaluate the effect of the presence of roosters on welfare and egg production of laying hens reared in an alternative system. Two breeding systems were established: barn 1 -laying hens reared without roosters (4500 birds); and barn 2 -laying hens reared with roosters (4500 layers and 250 roosters). In the poultry facilities, microclimate, egg production, mortality rate, and bird behavior were evaluated. Microclimate analysis showed that the birds were subjected to periods of constant heat stress, except for the morning hours. However, even under these conditions, egg production results and mortality rate were consistent with the indices recommended in the Isa Brown management guide in the barn with roosters; the indices obtained were even better and were characterized by higher egg production and lower mortality rates. In addition to productivity benefits, the presence of roosters broadened the behavioral repertoire of the birds due to the introduction of reproductive behaviors. Moreover, there was a significant decrease in the tolerance-reflex behavior, which is associated with the impossibility of displaying reproductive behaviors. This alternative egg production system proved to promote animal welfare since it provides and stimulates the display of behaviors considered important for birds.

No abstract

The use of amino acids from alternative sources to reduce costs and increase or maintain poultry production levels is crucial to succeed in competitive industry. This study investigated the alternative methionine effects obtained from soybean compared to synthetic DL-methionine-99 % on the broilers performance in the production periods of 1-21 and 1-42 days of age. A total of 720 pullets were included in a completely randomized design with four treatments and six replicates of 30 birds. They received water and food ad libitum throughout the production phase. Diets consisted of T1-reference diet formulated with synthetic methionine (DL-methionine-99 %); T2-diet replacing 100 % of synthetic methionine with alternative methionine; T3-diet replacing 110 % of synthetic methionine with alternative methionine, and T4-diet replacing 120 % of synthetic methionine with alternative methionine. At 1-21 days of age, there was a significant difference (p<0.05) among treatments in daily gain weight (DWG), live weight (LW), and feed intake (FI). However, no differences were observed (p>0.05) in feed conversion (FC) and mortality rates. At 42 days of age, a significant difference (p<0.05) in DWG, LW, and FC parameters was observed among treatments, but there were no differences in FI and mortality. Broilers supplemented with alternative methionine showed significantly lower DWG, LW, FI, productive efficiency index (PEI), and flock uniformity (FU) and showed higher FC compared to animals supplemented with synthetic methionine. The synthetic methionine replacement resulted in lower broiler performance. More researches are necessary to promote better alternative diets for this system.

The aim of this study was to assess the bromatological quality and the content of essential amino acids in maize grains produced using two different cropping systems: organic and conventional. The experimental area was four hectares, divided into two hectares per system. In the conventional management, agrochemicals from conventional maize production were used. In the organic management, inputs permitted by the current Brazilian legislation on organic production were used. For each system, 10 plots of 9 m² each were established, from which experimental samples were harvested. A significant difference was found in the bromatological quality of maize grains. The conventional management provided greater crude protein content. Significant changes were also found in the following amino acids: methionine, threonine, arginine, isoleucine, leucine, valine, histidine, and phenylalanine, which showed lower levels in the organic management. The results confirm the need to determine food composition before diet formulation, since using preestablished food compositions probably leads to differences between what was formulated and what was actually given to poultry. The type of management influenced the quality of maize grains. The management of plant nutrition in the organic system should be refined to adequately supply nitrogen, thus improving bromatological and amino acid quality of the grains.

No abstract