Fulton Richard M
A Diagnostic Center for Population and Animal Health and Department of Pathobiology and Diagnostic Investigation College of Veterinary Medicine, Michigan State University, 4125 Beaumont Road Lansing, MI 48910.
Avian Dis. 2017 Sep;61(3):289-295. doi: 10.1637/11556-120816-RegR.
In a large population of animals, it is normal to have some die each day from causes not related to disease, which is often referred to as natural causes. In poultry production, this phenomenon is commonly referred to as daily mortality. In egg-producing chickens, many of the natural causes of death are associated with making an egg. The causes of normal mortality in commercial egg-laying chicken flocks have been described very little to date. A commercial chicken egg farm, housing approximately two million single-comb white leghorn chickens (Gallus gallus domesticus) in 16 egg-producing flocks, was visited on a monthly basis to monitor bird health, body conditioning, skeletal integrity, and causes of daily mortality in an attempt to provide early detection of health abnormalities. A representative sample of daily mortality from each flock was necropsied to determine the cause of death. Reported herein is a summary of visits for a period of 38 mo from June 2011 to July 2014. The top 15 causes of normal mortality, in rank order of prevalence, were determined to be the following: egg yolk peritonitis, hypocalcemia, gout, self-induced molt, salpingitis, caught by spur, intussusception or volvulus (twisted intestine), cannibalism (pick out), tracheal plug, septicemia, fatty liver syndrome, internal layer, layer hepatitis, persecution, and prolapsed vent. Other causes noted were hyperthermia (during summer), trauma, coccidiosis, ovarian neoplasia, being egg bound, urolithiasis, peritonitis (not egg yolk induced), leg fracture, caught in the structure, tumor (other than ovarian origin), wing fracture, exsanguination, and cardiomyopathy.
在大量动物群体中，每天都会有一些动物因与疾病无关的原因死亡，这通常被称为自然原因。在家禽生产中，这种现象通常被称为日死亡率。在产蛋鸡中，许多自然死亡原因与产蛋有关。迄今为止，关于商业产蛋鸡群正常死亡率的原因描述甚少。一家商业鸡蛋养殖场饲养了约200万只单冠白来航鸡（家鸡），分16个产蛋鸡群饲养，每月对其进行走访，以监测鸡的健康状况、身体状况、骨骼完整性和日死亡率原因，试图早期发现健康异常情况。对每个鸡群的日死亡率代表性样本进行尸检以确定死亡原因。本文报告了2011年6月至2014年7月为期38个月的走访总结。按患病率排序，正常死亡率的前15个原因如下：蛋黄性腹膜炎、低钙血症、痛风、自发型换羽、输卵管炎、被距抓伤、肠套叠或肠扭转（肠道扭曲）、同类相食（啄癖）、气管堵塞、败血症、脂肪肝综合征、内寄生虫、产蛋鸡肝炎、受迫害和泄殖腔脱垂。其他注意到的原因包括体温过高（夏季期间）、外伤、球虫病、卵巢肿瘤、产蛋困难、尿石症、腹膜炎（非蛋黄性引起）、腿部骨折、被困在鸡舍结构中、肿瘤（非卵巢起源）、翅膀骨折、失血和心肌病。
