Nutritional stress as a cause of thymic atrophy in broiler chickens.
A study was conducted to examine the effect of nutritional stress on the development of the thymus, bursa, and pancreas of 7-to-14-day-old commercial meat-type chickens. One group of 7-day-old chickens was given access to food for only 30 minutes daily for 7 days. The birds were necropsied, and the thymus, pancreas, and bursa were compared with those of the control chickens fed ad libitum and necropsied at 7 and 14 days of age. The thymuses from birds on the restricted diet were atrophied (0.45 +/- 0.08 g) and congested compared with the thymuses from chickens fed ad libitum (1.32 +/- 0.31 g). The bursae from chickens on a restricted diet were also smaller (0.26 +/- 0.08 g) than the bursae from birds with free access to food (0.74 +/- 0.11 g). The restricted diet did not appear to cause any gross or histological pancreatic changes. The thymic lesions produced by nutritional stress were similar to those observed in the runting/stunting syndrome.
D000818:Animals; D001284:Atrophy / Q000662:veterinary; D001835:Body Weight; D002060:Bursa of Fabricius / Q000473:pathology; D002645:Chickens; D005260:Female; D005508:Food Deprivation; D009929:Organ Size; D010179:Pancreas / Q000473:pathology; D011201:Poultry Diseases / Q000473:pathology*; D013312:Stress, Physiological / Q000662:veterinary*; D013950:Thymus Gland / Q000473:pathology*