I. de A. Nääs

Use of vitamin D to reduce lameness in broilers reared in harsh environments

In tropical poultry-producing countries, poultry houses usually have little environmental control. This study investigated the effect of dietary vitamin D on the incidence of leg abnormalities of a fast-growing broiler strain reared under harsh conditions. In this study, 300 one-day-old male broilers were distributed in two treatments with three replicates of 50 birds each. One group was fed a placebo and the other group was fed 25-hydroxycholecalciferol (25-OH-D3) in a soluble form. The environmental variables were weekly recorded during until birds were 49 days old. Birds were weekly gait scored, and their walking speed and vertical force while walking were assessed. Post-mortem examination was performed and skeletal lesions were assessed. Control birds presented more leg problems than those that ingested 25-OH-D3. These results suggest that dietary vitamin D is effective in decreasing the severity of lameness by reducing tibial dyschondroplasia and other leg abnormalities.

The Influence of Side-Curtain Color on Broiler Chick Behavior

Brazilian poultry production is prospering, and negative-pressure broiler houses are increasingly used to improve environmental control. One important issue is the color of the side curtains used in such houses due to the influence of colors on broiler behavior. This study aimed at evaluating the influence of different curtain color on the welfare of 7-day-old broilers, considering luminosity and other environmental parameters. Chicks were housed in three different negative-pressure broiler houses either with black (T1), blue (T2), or yellow (T3) side curtains. House environment (luminosity, dry-bulb temperature, air relative humidity, air velocity, and gas emissions) and the behavior of chicks on day 7 after housing were evaluated in three consecutive flocks in the morning and in the afternoon. Data were submitted to multivariate analysis, Kruskal-Wallis’ test, and Pearson’s correlation test. Luminosity and ITU were influenced by curtain color, and some of the evaluated behaviors were associated with luminosity or other environmental parameter.