SURVEY OF SALMONELLA-ENTERITIDIS IN SPENT HENS AND ITS RELATION TO FARMING STYLE IN HOKKAIDO, JAPAN

In order to estimate the distribution of Salmonella including Salmonel la enteritidis (SE) and SE-antibodies in commercial layer hen flocks i n Hokkaido, the northern prefecture of Japan, a survey of spent layer hens was performed, from August 1996 to January 1997. From the three s pent hen processing plants, samples of intestines and sera were collec ted from 740 birds presented for slaughter from 37 flocks of 22 layer hen farms. Intestines from each birds were cultured for Salmonella inc luding Salmonella enteritidis. Serum from each bird was examined for S E-antibody with the enzyme-linked immunosorbent assay (ELISA). Salmone lla (any serotype) and Salmonella enteritidis were isolated from 50 (6 .8%) and three (0.4%) of 740 birds, respectively, and SE-antibody posi tive values were recorded from seven birds (0.9%). SE-antibody positiv e birds did not always indicate isolation of Salmonella enteritidis, h owever SE-antibody positive hens were demonstrated only from Salmonell a enteritidis positive flocks. Salmonellae were isolated from the bird s of ten layer hen farms, all of these hens were raised in houses with out windows and with automatic feeders. No isolations of salmonella we re made from birds raised in houses with windows. From the windowless houses, Salmonellae were isolated from 46 (21.8%) of 260 birds in hous es with four to six cages piled up vertically, and from six (2.5%) of 240 samples from the houses with four to five cages piled in a slantin g manner. (C) 1997 Elsevier Science B.V.