Kretzschmar-McCluskey V, Curtis P A, Anderson K E, Kerth L K, Berry W D
Department of Poultry Science, Auburn University, AL 36849, USA.
Poult Sci. 2008 Oct;87(10):2146-51. doi: 10.3382/ps.2007-00433.
The objective of this study was to determine if increasing hen age and 3 different molting treatments influenced the total microflora counts or the prevalence of Salmonella spp. on the exterior of the egg shell, within the interior shell, or in the contents. Eggs from Hy-Line W-98 and Bovans White layer strains were sampled approximately every 28 d from 70 to 114 wk of age, with the molting period from 66 to 70 wk of age. Layers were utilized from the 35th North Carolina Layer Performance and Management Test and managed under identical husbandry practices. This study consisted of nonfasted, nonmolted, and feed-restricted treatments with the use of 135 eggs per layer strain, for a total of 270 eggs sampled per period. The exterior, interior shell, and contents were spiral plated onto plate count agar to calculate the total aerobic counts. Additional preenrichment, enrichment, conformational, and biochemical procedures were performed to test for the presence of Salmonella spp. Hen age and molting treatment significantly (P < 0.05) affected the microbial loads on all 3 egg components. Exterior, interior, yolk, and albumen counts increased during the molt period to as much as 1 log unit higher than the highest countable plate, which was 10(5). Exterior, interior, and contents counts significantly increased (P < 0.05) during period 15, with a significant increase (P < 0.05) in the interior also in period 14, and in the contents in periods 14 and 17. There were a total of 360 egg pools, and of those, 4 were positive Salmonella samples. Both the interior and exterior shell components and 2 of the 3 molting treatments had positive samples. Of these positives, 4 were confirmed as Salmonella Braenderup. Three positives were associated with the interior component, whereas 1 positive was associated with the exterior shell component. Three of the 4 samples were related to the nonfasted treatment, whereas the remaining positive was found in the non-molted treatment.
本研究的目的是确定母鸡年龄的增加和3种不同的强制换羽处理是否会影响蛋壳表面、壳内或蛋内容物中的微生物总数或沙门氏菌的流行率。来自海兰W-98和博万斯白鸡种鸡的鸡蛋在70至114周龄期间大约每28天采样一次，强制换羽期为66至70周龄。这些母鸡来自第35届北卡罗来纳州蛋鸡生产性能与管理试验，并在相同的饲养管理条件下饲养。本研究包括非禁食、非强制换羽和限饲处理，每个鸡种使用135枚鸡蛋，每个时期共采集270枚鸡蛋。将蛋壳表面、壳内和蛋内容物螺旋接种到平板计数琼脂上，以计算需氧菌总数。进行了额外的预增菌、增菌、鉴定和生化程序，以检测沙门氏菌的存在。母鸡年龄和强制换羽处理对所有3个蛋组分的微生物负荷有显著影响（P < 0.05）。在强制换羽期，蛋壳表面、壳内、蛋黄和蛋清中的菌数增加，比最高可计数平板（10⁵）高出多达1个对数单位。在第15期，蛋壳表面、壳内和蛋内容物中的菌数显著增加（P < 0.05），在第14期壳内菌数也显著增加（P < 0.05），在第14期和第17期蛋内容物中的菌数显著增加。总共采集了360个鸡蛋样本池，其中4个是沙门氏菌阳性样本。壳内和蛋壳表面组分以及3种强制换羽处理中的2种有阳性样本。在这些阳性样本中，4个被确认为布伦德鲁普沙门氏菌。3个阳性样本与壳内组分相关，而1个阳性样本与蛋壳表面组分相关。4个样本中的3个与非禁食处理有关，而其余阳性样本在非强制换羽处理中发现。
