Holt Peter S, Vaughn Lara E, Moore Randle W, Gast Richard K
U.S. Department of Agriculture Agricultural Research Service Egg Safety and Quality Research Unit, 950 College Station Road, Athens, GA 30605, USA.
Avian Dis. 2006 Sep;50(3):425-9. doi: 10.1637/7519-022706R2.1.
Long-term feed withdrawal has been shown to increase ileocecal intestinal colonization and fecal shedding of Salmonella enterica serovar Enteritidis in challenged hens. Less information is available regarding effects of fasting on crop colonization. Two trials were conducted to compare effects of 14-day feed withdrawal vs. full feed on crop colonization in hens challenged with Salmonella Enteritidis. The levels of Salmonella Enteritidis in the crops of fasted hens were significantly higher than in nonfasted hens on days 3 and 10 and days 3, 9, and 16 postinfection (PI) in trials 1 and 2, respectively. Fecal shedding of Salmonella Enteritidis was significantly increased in the fasted hens on day 10 PI in trial 1. Analysis of crop IgA anti-Salmonella Enteritidis lipopolysaccharide levels in crop lavage samples of hens in trial 1 revealed a humoral response PI in both treatment groups with no significant differences, although peak response for fasted hens occurred 1 wk later. Histologic evaluation of hematoxylin and eosin-stained crop sections from trial 1 birds revealed mild to moderate heterophilic infiltration within the crop lamina propria (LP) or LP and epithelium of nonfasted infected hens at 24 and 96 hr PI. In comparison, heterophils in crops of fasted hens infected at this time point were sparse, indicating a possible diminished heterophil response in the fasted birds. Multifocal areas of tissue inflammation, as indicated by marked heterophil infiltration, with necrosis and sloughing of epithelium, were observed in crops from fasted hens at day 11 PI (14th day of feed withdrawal) but not in the fed groups. This severe heterophilic inflammation was observed in both challenged and nonchallenged fasted hens, suggesting that some factor other than Salmonella Enteritidis was responsible. These results indicate that feed withdrawal can have a dramatic effect on the integrity of the crop and its ultimate response to infection.
长期停喂已被证明会增加受感染母鸡回盲部肠道中肠炎沙门氏菌肠炎血清型的定殖以及粪便中的排出量。关于禁食对嗉囊定殖的影响，相关信息较少。进行了两项试验，以比较14天停喂与正常喂食对感染肠炎沙门氏菌的母鸡嗉囊定殖的影响。在试验1和试验2中，禁食母鸡嗉囊中肠炎沙门氏菌的水平在感染后第3天和第10天以及分别在感染后第3天、第9天和第16天显著高于未禁食母鸡。在试验1中，禁食母鸡在感染后第10天粪便中肠炎沙门氏菌的排出量显著增加。对试验1中母鸡嗉囊灌洗样本中抗肠炎沙门氏菌脂多糖的IgA水平进行分析发现，两个处理组在感染后均出现了体液反应，且无显著差异，尽管禁食母鸡的峰值反应在1周后出现。对试验1中鸟类的苏木精和伊红染色的嗉囊切片进行组织学评估发现，在感染后24小时和96小时，未禁食感染母鸡的嗉囊固有层（LP）或LP及上皮内有轻度至中度嗜异性粒细胞浸润。相比之下，此时感染的禁食母鸡嗉囊中嗜异性粒细胞稀少，表明禁食鸟类的嗜异性粒细胞反应可能减弱。在感染后第11天（停喂第14天），在禁食母鸡的嗉囊中观察到多灶性组织炎症，表现为明显的嗜异性粒细胞浸润，并伴有上皮坏死和脱落，但在喂食组中未观察到。在受挑战和未受挑战的禁食母鸡中均观察到这种严重的嗜异性炎症，这表明除肠炎沙门氏菌外的某些因素是造成这种情况的原因。这些结果表明，停喂会对嗉囊的完整性及其对感染的最终反应产生显著影响。
