Behavior of feed particles during distribution of broilers’ automatic feeders

The mixture of solid particles of different sizes to be transported within the automatic feeders in broiler production tends to segregate. This is due to physical diferences between the particles leading to qualitative and quantitative differences in the composition of the feed along the distribution line. The size and texture of the feed ration are critical in broilers feeding, and birds have difficulty in eating either larger particles or much smaller than the size of their beak. This study was conducted aiming to verify the feed ration homogeneity during the distribution in broilers?automatic feeders. The research was carried out in a commercial broiler farm in Rio Grande do Sul, Brazil. The farm had houses with dimensions of 100 m long and 12 m wide, were equipped with automatic feeders with four route of 90 m, the feed ration used was mashes and the formulation was compatible to the growth phase II. Three samples of 3 kg feed were collected from five points of distribution system, namely: storage silo, hopper, the first dish of feeder, middle and the last dish. The samples of feed were subjected to quantitative analysis of ashes and particle size analysis. The data were subjected to analysis of variance (ANOVA), means separated by Tukey test with p < 0.01, and analysis of linear regression. The amount of ashes sampled in the feed ration and deposited in each site where were collected differed (p <= 0.01) indicating that feeders segregate particles along the feed distribution route. In the four routes of the feed ration distribution results show that there was higher concentration of ashes in the first feed ration dish. In the second dish, there was a decrease as well as in the final feed dish. The particle size deffered (p <= 0.01) and showed the opposite result of ashes, the size of the particles increased as the distance from the feed hopper increases, in the last dish the particle size was bigger than the others four collection points, and these results indicate that a segregation of the components of the feed ration occurs during the distribution according to the granulometry. Limestone, phosphorus bi-calcium, sodium chloride and other sources of macro-minerals are heavier than other components and tend to deposit in the first feeder dishes, and the lower density granules, such as corn and soybean meal, tend to go to the end of the dispensing line. This segregation of the particles as a function of the feed density changes the diet composition and as a consequence alters the ingestion of the nutrients. Results from this study indicate that there is segregation of feed along the distribution within the broiler houses. Further investigation is needed in order to improve the distribution of the feed ration as it is crucial that all broilers receive the same amount of all nutrients for ensuring flock uniform growth.