Comparison of techniques for tibial dyschondroplasia assessment in broiler chickens

Icl Almeida Paz,Rr Quinteiro,J Moreira,Lc Vulcano,Aa Mendes,Fs Wechsler,Pc Guerra,K Pelícia,Ts Takita,Rg Garcia,Cm Komiyama,Se Takahashi

doi:10.1590/s1516-635x2005000100005

Abstract

This study was carried out at Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu, SP, Brazil, with the objective of evaluating the efficacy of four techniques in the assessment of tibial dyschondroplasia lesions in broiler chickens. Four hundred Cobb male chicks were reared from 1 to 39 days of age. At 39 days, forty birds were selected and tibial dyschondroplasia status was assessed by four different techniques: evaluation using the lixiscope, macroscopic examination, histological examination and bone mineral density assessment using optical radiographic densitometry. The efficacy of each technique to assess dyschondroplasia lesions in the tibial growth plate was determined in comparison to histology, which was considered to be 100% efficient. The correlation results between lixiscope analysis and histology were poor. Macroscopic scores and densitometry readings were highly correlated with histology scores, and it is considered that these techniques reliably reproduce the status of the growth plate.

Highlights

Bone marrow calcification in the growth plate is a progressive process associated to chondrocyte maturation
At 39 days, forty birds were selected and tibial dyschondroplasia status was assessed by four different techniques: evaluation using the lixiscope, macroscopic examination, histological examination and bone mineral density assessment using optical radiographic densitometry
Macroscopic scores and densitometry readings were highly correlated with histology scores, and it is considered that these techniques reliably reproduce the status of the growth plate

Summary

Introduction

Bone marrow calcification in the growth plate is a progressive process associated to chondrocyte maturation. Since the growth rate of the tibia is much faster than the growth rate of other long bones in broiler chickens, a metabolic disease called tibial dyschondroplasia might occur, which is characterized by the presence of an abnormal cartilage mass in the epiphyseal growth plate. This cartilage is the pre-hypertrophic cartilage that did not undergo calcification, because the blood vessels from the metaphysis have not invaded the hypertrophic zone. Macroscopic examination of only one section of affected bones is not the most adequate method to evaluate the incidence and severity of dyschondroplasia, and histology is necessary to distinguish between the lesions caused by dyschondroplasia and other diseases that affect the epiphysis growth plate

Methods

Results

Conclusion