Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 11, 2006
Publication Date: June 1, 2007
Citation: Rath, N.C., Huff, W.E., Huff, G.R., Kannan, L. 2007. Induction of tibial dyschondroplasia by carbamate and thiocarbamate pesticides. Avian Diseases. 51(1):590-593. Interpretive Summary: Meat-type poultry are affected by a leg problem which leads to lameness. Certain of chemical pesticides have been known to cause these problems. These pesticides are often used to control fungus, insects, pests, and preserve seeds, and wood products those can be used around poultry production. In this study, we screened some of those chemicals to find whether all of them cause leg problem or there are some chemical specificity necessary. By feeding several of these chemicals to broiler chickens for one to two days we find that only those pesticides with specific chemical nature are capable of inducing the leg problems that also show dose related increase in leg problems.
Technical Abstract: Tibial dyschondroplasia (TD) is a major poultry leg problem the natural etiology of which is unknown. Certain dithiocarbamate pesticides such as tetramethyl thiuram disulfide (thiram) have been shown to induce the disease in chickens. Since many different carbamate and thiocarbamate chemicals are used in a number of agricultural, industrial, and house hold applications, the objective of this study was to determine whether all chemicals of these categories induce TD and whether there is a concentration dependent relationship between the ingestion of these chemicals and the incidences and the severity of the disease. Week-old broiler chicks were fed diets containing thiram or other assorted carbamate and thiocarbamate pesticides mixed in feed for 24-48 hr between ages 8 and 10 days. The birds were killed on day 15 and the proximal tibial and tarsometatarsal growth plates were evaluated for the presence and severity of TD lesion. TD was distinguished by broadening of growth plates with histological features of chondrocytes that were shrunken and dead. When compared by including equimolar concentrations of these chemicals in the feed, the dithiocarbamates with more than two sulfide groups such as disulfiram, ferbam, thiram, and ziram were potent inducers of TD, whereas those with two sulfides to no sulfide group appeared ineffective. Both thiram and ferbam also reduced the bird’s body weights. Thiram increased the incidence and the severity of the disease denoted by TD index in a dose dependent manner. These results suggest that inadvertent contamination of feed or litter with some of these or similar chemicals may cause leg problems in poultry.