MUSCLE ATROPHY INDUCED IN BROILER CHICKS BY PARTS OF SENNA-OCCIDENTALIS SEEDS

Senna occidentalis (formerly Cassia occidentalis) is a common contamin ant of agricultural commodities. It is toxic to cattle and poultry, re portedly being responsible for skeletal myodegeneration in these anima ls. All parts of the plant present toxicity, but the seeds are the mos t toxic. The toxin(s) responsible for the myodegeneration have not bee n definitively identified, nor is it known which part of the seeds is most toxic. Intoxication by this plant leads to weight loss with consi derable economic repercussions. The effects of the whole seed and of p arts of S. occidentalis seeds (1% in commercial feed) were compared on the pectoralis major muscle of broiler chicks intoxicated from birth until 22 days of life. There were severe clinical signals and reduced body weight in birds that received the external tegment of the seed, w hereas no adverse effects were observed in birds that received the who le seed or other parts of the seed. Histological and morphometric stud ies showed an intense muscle fibre atrophy (both type 1 and type 2 fib res were affected) in the group that received 1% external tegment. Thi s study may be the first step to identifying: the substance(s) involve d in this pathological process.