Visscher Christian, Kruse Anne, Sander Saara, Keller Christoph, Mischok Jasmin, Tabeling Robert, Henne Hubert, Deitmer Ricarda, Kamphues Josef
Institute for Animal Nutrition, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hanover, Germany.
Boehringer Ingelheim Veterinary Research Center GmbH & Co. KG, Bemeroder Str. 31, 30559, Hanover, Germany.
Acta Vet Scand. 2018 Apr 12;60(1):22. doi: 10.1186/s13028-018-0378-4.
Lawsonia intracellularis is one of the most economically important pathogens in swine production. This study tested the hypothesis that the composition of diets for pigs has an impact on the excretion of L. intracellularis in a natural infection model.
Fifty boars (~ 90 kg BW) from a SPF-farm with a strict hygiene and management regime for reducing the spread of an L. intracellularis infection up to the beginning of the final fattening period were transported, regrouped and randomly allotted to groups of five animals each at the research facility. After a 1-week acclimatisation period groups were fed one of five diets 4 weeks before slaughter. These were either a finely ground pelleted diet (FP) or a coarsely ground meal diet (CM), both consisting of wheat (40.0%), barley (39.3%), soybean meal (16.0%), soybean oil (2.0%) and minor components. In the other meal diets parts of wheat, barley and soybean meal were substituted either with 22% cracked corn (CORN), 16.9% dried whey (WHEY) or 30% raw potato starch (RPS). The animals had a comparable serological status in a blocking-ELISA immediately before the start and at the end of the feeding experiment. Values increased significantly during the trial. In all subgroups (FP/CM/CORN/WHEY/RPS), shedding was detected in week 0 (genome equivalents = GE; log GE L. intracellularis/g faeces: 2.46 ± 2.64/3.58 ± 2.54/3.43 ± 2.37/2.30 ± 3.16/2.58 ± 2.73). The average number of L. intracellularis microbes in faeces during the trial period did not differ between the groups (log GE L. intracellularis/g faeces: 3.40 ± 1.53/3.01 ± 1.41/3.80 ± 1.71/3.98 ± 2.20/4.08 ± 2.13). In animals fed the WHEY-diet, significantly lower counts of L. intracellularis were found in the caecal content. The acetate content in the caecum was negatively correlated with the serological results at the end of the trial (r = - 0.36; P = 0.010). Butyrate concentrations in the caecal content were negatively correlated with the number of L. intracellularis in the caecum (r = - 0.32; P = 0.023).
Therefore, this study provides preliminary evidence that there might be specific dietary effects on the course of a L. intracellularis infection.
胞内劳森菌是养猪生产中经济影响最为重大的病原体之一。本研究在自然感染模型中检验了猪的日粮组成对胞内劳森菌排泄有影响这一假设。
来自一个具有严格卫生和管理制度以减少胞内劳森菌感染传播直至育肥期末期的无特定病原体猪场的50头公猪（体重约90千克）被转运至研究设施，重新分组并随机分配到每组5头动物的组中。经过1周的适应期后，在屠宰前4周给各组饲喂五种日粮之一。这些日粮要么是细磨颗粒日粮（FP），要么是粗磨粉料日粮（CM），两者均由小麦（40.0%）、大麦（39.3%）、豆粕（16.0%）、大豆油（2.0%）和少量成分组成。在其他粉料日粮中，小麦、大麦和豆粕的部分分别被22%的碎玉米（CORN）、16.9%的干乳清（WHEY）或30%的生马铃薯淀粉（RPS）替代。在饲喂试验开始前和结束时，动物在阻断ELISA中的血清学状态相当。试验期间数值显著增加。在所有亚组（FP/CM/CORN/WHEY/RPS）中，在第0周检测到排菌（基因组当量=GE；每克粪便中胞内劳森菌的log GE：2.46±2.64/3.58±2.54/3.43±2.37/2.30±3.16/2.58±2.7%）。试验期间各组粪便中胞内劳森菌微生物的平均数量无差异（每克粪便中胞内劳森菌的log GE：3.40±1.53/3.01±1.41/3.80±1.71/3.98±2.20/4.08±2.13）。在饲喂乳清日粮的动物中，盲肠内容物中胞内劳森菌的数量显著较低。试验结束时，盲肠中的乙酸盐含量与血清学结果呈负相关（r=-0.36；P=0.010）。盲肠内容物中的丁酸盐浓度与盲肠中胞内劳森菌的数量呈负相关（r=-0.32；P=0.023）。
因此，本研究提供了初步证据，表明日粮可能对胞内劳森菌感染过程有特定影响。
