Leg problems of modern broilers as affected by incubation temperature, fluoride and fast growth
Abstract
Fast growing broiler chickens are especially susceptible to bone abnormalities, causing major problems for broiler producers. In this research, the impacts of environmental (incubation temperature), nutritional (Fluoride) and genetic (random-bred population) factors were studied. It would be of great benefit to manipulate the development of leg bone by making simple changes to incubation temperature such that chickens are better able to reduce the incidence of abnormalities. No main effects or interactions between incubation temperature or time and bone abnormalities were detected. However, It is important to note that eggs hatched at different times in our study. As little as 1ºC for 3 days during early incubation ED 4 – 7 affected hatching time and weight, confounding results. Fluoride (F) has been shown to have varying degrees of beneficial effects on bone mineralization and strength, despite its toxic effects on growth and leg disorders. Some studies have demonstrated an increase in bone ash due to F supplementation. Even low levels of F like those used here have the potential to create measurable effects. Experiments were also conducted to test the hypothesis that fast growing (FG) broiler chickens are susceptible to bone abnormalities, causing major leg problems. Growth rate was negatively associated with the twisted legs syndrome and a bone abnormality (TD) in a random-bred population. After all parameters were calculated per unit of final body weight at 6 wks, tibia density and bone ash percent of FG broiler chickens were lower than those of SG broiler chickens.