Abrahamsson P, Fossum O, Tauson R
Swedish University of Agricultural Sciences, Uppsala, Sweden.
Acta Vet Scand. 1998;39(3):367-79. doi: 10.1186/BF03547785.
Mortality and health were studied in laying hens kept in an aviary system on a practical scale. All management inputs were done by university staff. Five batches of birds (trials) during a period of 6 years with approximately 4,700 birds per trial were included in the study. The aviary was a three-tiered "Marielund" system divided into 4 pens. Three hybrids, reared on litter with access to perches, were used; Lohmann Selected Leghorn (LSL), Lohmann Brown (LB) and an experimental cross (SLU-1329). The hens were not beak-trimmed. The stocking density was 17 hens/m2 ground floor. Mortality varied between pens and between batches, ranging from normal rates of 3.4% to 7.8%, except in LSL in Trial 2 and LB in Trial 3 where it was much higher (15.6% and 20.9%, respectively). The dominating causes of total mortality were salpingitis and cannibalism. Coccidiosis and lymphoid leucosis contributed significantly to mortality in Trial 2. An infestation with fowl mites (Dermanyssus gallinae) occurred in Trial 1. Feather loss was most severe in LB. Keel bone deviations were recorded at increasing levels by age. Foot abscesses occurred more frequently at 35 weeks than at 55 weeks. LSL was more severely affected than LB and SLU-1329.
在实际规模的禽舍系统中对蛋鸡的死亡率和健康状况进行了研究。所有管理工作均由大学工作人员完成。该研究纳入了6年期间的五批鸡（试验），每次试验约有4700只鸡。禽舍是一个三层的“玛丽隆德”系统，分为4个栏。使用了三种在垫料上饲养且有栖木的杂交品种；罗曼精选来航鸡（LSL）、罗曼褐壳蛋鸡（LB）和一个实验杂交品种（SLU - 1329）。母鸡未进行断喙处理。底层的饲养密度为每平方米17只母鸡。不同栏和不同批次之间的死亡率有所差异，正常死亡率在3.4%至7.8%之间，但试验2中的LSL和试验3中的LB死亡率要高得多（分别为15.6%和20.9%）。总死亡率的主要原因是输卵管炎和同类相食。球虫病和淋巴细胞性白血病在试验2中对死亡率有显著影响。试验1中发生了鸡螨（鸡皮刺螨）感染。LB的羽毛损失最为严重。龙骨弯曲随着鸡龄增长而记录到的水平不断增加。脚垫在35周龄时比55周龄时更频繁出现。LSL比LB和SLU - 1329受到的影响更严重。
