Edens F W, Parkhurst C R, Casas I A, Dobrogosz W J
Department of Poultry Science, North Carolina State University, Raleigh 27695-7635, USA.
Poult Sci. 1997 Jan;76(1):179-96. doi: 10.1093/ps/76.1.179.
The data that have been presented indicate that the in ovo use of competitive exclusion (CE) agents is feasible for both chickens and turkeys. However, there are many pitfalls that await the use of in ovo application of CE agents, including the use of nonspecies-specific intestinal microbes and the use of harmful proteolytic, gas-producing and toxin-producing intestinal microbes. Of the potential CE agents that have posthatch application, only Lactobacillus reuteri has been shown to be safe and effective in terms of not affecting hatchability and in having a prolonged effect in the hatched chick or poult. Lactobacillus reuteri administration in ovo increases its rate of intestinal colonization and decreases the colonization of Salmonella and Escherichia coli in both chicks and poults. Additionally, mortality due to in-hatcher exposure to E. coli or Salmonella is reduced with in ovo L. reuteri. Use of antibiotics in ovo may preclude the use of co-administered CE agents, but Gentamicin and L. reuteri are a compatible mixture when administered in ovo in separate compartments. Nevertheless, the intestinal morphology can be affected by both the CE agent and by antibiotics. Lactobacillus reuteri both in ovo and ex ovo will increase villus height and crypt depth, and Gentamicin in ovo causes a shortening and blunting of the villus. Both Gentamicin and L. reuteri in ovo suppress potentially pathogenic enteric microbes, but with diminished antibiotic effects shortening and blunting of the intestinal villi does not correct itself. Goblet cell numbers increase significantly on the ileum villus of chicks treated with Gentamicin in ovo, and this is presumably due to the increase in potentially pathogenic bacteria in the intestinal tract. Diminishing antibiotic effects posthatch would then negatively affect the absorption of nutrients and reduce growth at least in a transitory manner. Thus, L reuteri administration in ovo singly or in combination with Gentamicin followed by L reuteri via drinking water or feed appears to have potential to control many enteric pathogens in poultry. Additional work in the use of in ovo CE cultures is mandated because there is a world-wide movement to reduce antibiotic use in poultry due to increased microbial resistance to antibiotics. Use of naturally occurring intestinal bacterial cultures, either in mixed culture or as single well-defined cultures, has potential for immediate use in the poultry industry.
已呈现的数据表明，在鸡和火鸡的胚胎内使用竞争排斥（CE）剂是可行的。然而，胚胎内应用CE剂存在许多隐患，包括使用非物种特异性肠道微生物以及使用有害的蛋白水解、产气和产毒素肠道微生物。在孵化后应用的潜在CE剂中，仅罗伊氏乳杆菌已被证明在不影响孵化率以及对出壳雏鸡或雏火鸡有长效作用方面是安全有效的。胚胎内施用罗伊氏乳杆菌可提高其在肠道的定殖率，并减少雏鸡和雏火鸡中沙门氏菌和大肠杆菌的定殖。此外，胚胎内施用罗伊氏乳杆菌可降低因孵化器内接触大肠杆菌或沙门氏菌导致的死亡率。胚胎内使用抗生素可能会排除同时施用CE剂，但庆大霉素和罗伊氏乳杆菌在胚胎内分室施用时是一种相容的混合物。然而，CE剂和抗生素都会影响肠道形态。胚胎内和孵化后施用罗伊氏乳杆菌都会增加绒毛高度和隐窝深度，而胚胎内使用庆大霉素会导致绒毛缩短和变钝。胚胎内使用庆大霉素和罗伊氏乳杆菌都会抑制潜在的致病性肠道微生物，但随着抗生素作用减弱，肠道绒毛的缩短和变钝不会自行纠正。胚胎内用庆大霉素处理的雏鸡回肠绒毛上的杯状细胞数量显著增加，这可能是由于肠道内潜在病原菌增加所致。孵化后抗生素作用减弱会对营养物质的吸收产生负面影响，并至少在短期内降低生长速度。因此，胚胎内单独施用罗伊氏乳杆菌或与庆大霉素联合施用，随后通过饮水或饲料施用罗伊氏乳杆菌，似乎有潜力控制家禽中的许多肠道病原体。由于微生物对抗生素的耐药性增加，全球范围内都在努力减少家禽抗生素的使用，因此有必要对胚胎内CE培养物的使用进行更多研究。使用天然存在的肠道细菌培养物，无论是混合培养还是单一明确的培养物，都有可能立即应用于家禽业。
