MSD Animal Health Nordics, Havneholmen 25, DK-1561 København V, Denmark; University of Copenhagen, Department of Veterinary and Animal Sciences, Section for Animal Welfare and Disease Control, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark.
MSD Animal Health Nordics, Havneholmen 25, DK-1561 København V, Denmark.
Prev Vet Med. 2023 Mar;212:105837. doi: 10.1016/j.prevetmed.2023.105837. Epub 2023 Jan 6.
Lawsonia intracellularis (LI) is an economically important enteric pathogen in pigs with a worldwide endemic prevalence. The objective of this study was to evaluate the effect of an intramuscularly administrated LI vaccine (Porcilis®Lawsonia Vet.) in Danish finisher pigs (30-115 kg) measured on key production figures, antimicrobial (AB) treatments, occurrence of diarrhea and LI shedding. The study was a group-randomized block-trial with parallel groups in two herds, Herd 1 and Herd 2, experiencing a natural subclinical-clinical LI infection in early finisher period. Vaccination occurred at weaning, but the study focused on the first eight weeks in the finisher period. Further, slaughterhouse data were included. In total, 52 and 50 finisher pens comprising 2184 and 2254 finisher pigs were included in each of two herds, respectively. LI vaccination significantly reduced feed conversion ratio (FCR) by 0.05 and 0.09 FU/kg (p = 0.007 and p < 0.001) alongside a significantly increased average daily weight gain (ADWG) by 31 and 43 gr/day (p = 0.001 and p < 0.001) in each of the herds, respectively. In the vaccinated group, less variation was found in ADWG compared to the control group (p < 0.001 in both herds) as an expression of a more uniform growth, which was further confirmed by less variation in lean meat percent in the vaccinated group in one herd (p = 0.007). No significant difference between groups were found in mortality and pigs excluded due to welfare reasons. AB flock treatment against diarrhea was significantly reduced in Herd 1 with all pens treated in the control group compared to 30.8 % in the vaccinated group (p < 0.001). In Herd 2, the difference was non-significant with 68.0 % in the control group compared to 50.0 % in the vaccination group (p = 0.252). Low levels of individual treatments against diarrhea were seen in both herds (≤ 5.0 %) but still significantly reduced in vaccinated pigs compared to control pigs (p < 0.050 in both herds). Mean diarrheic blot counts were significantly reduced in vaccinated pens compared to control pens (p < 0.001 in both herds). In vaccinated pigs, shedding of LI was reduced in both prevalence (p < 0.001 in both herds), excretion level in positive samples (p < 0.001 in both herds) and, in one herd, also in duration (p = 0.003) when compared to control pigs. In conclusion, pigs vaccinated with Porcilis®Lawsonia Vet against LI in both of two high-health and high-productive finisher herds had, compared to non-vaccinated pigs, significantly improved key production figures, and reduced AB treatment, occurrence of diarrhea, LI shedding, and growth variation.
Lawsonia intracellularis (LI) 是一种具有全球流行趋势的、对猪具有重要经济意义的肠道病原体。本研究的目的是评估肌内注射LI 疫苗（Porcilis®Lawsonia Vet.）对丹麦育肥猪（30-115kg）关键生产指标、抗菌（AB）治疗、腹泻和 LI 脱落的影响。该研究是一项在两个群体中进行的随机分组块试验，具有平行组，这两个群体分别为在育肥早期经历自然亚临床-临床 LI 感染的 herd1 和 herd2。疫苗接种在断奶时进行，但研究重点是育肥期的前八周。此外，还包括屠宰场数据。总共，在每个 herd 中，包含 2184 头和 2254 头育肥猪的 52 个和 50 个育肥猪栏分别包含在两个 herd 中。LI 疫苗接种可使每个 herd 的饲料转化率（FCR）分别降低 0.05 和 0.09 FU/kg（p=0.007 和 p<0.001），同时平均日增重（ADWG）分别增加 31 和 43 克/天（p=0.001 和 p<0.001）。在接种组中，与对照组相比，ADWG 的变化较小（在两个 herd 中均为 p<0.001），这表明生长更加均匀，在 herd1 中，接种组的瘦肉百分比变化较小进一步证实了这一点（p=0.007）。在死亡率和因福利原因被淘汰的猪方面，两组之间没有发现显著差异。与对照组所有猪栏均接受治疗相比， herd1 中针对腹泻的 AB 群体治疗显著减少（p<0.001）。在 herd2 中，差异无统计学意义，对照组为 68.0%，接种组为 50.0%（p=0.252）。两个 herd 中均观察到针对腹泻的个体治疗水平较低（≤5.0%），但与对照组相比，接种组的治疗仍显著减少（两个 herd 均为 p<0.050）。与对照组相比，接种组的粪便中 LI 的检出率（p<0.001）、阳性样本中的排泄水平（p<0.001）以及在 herd1 中的持续时间（p=0.003）均显著降低。接种组猪的 LI 脱落率降低，在 herd1 和 herd2 中，LI 脱落的流行率（p<0.001）、阳性样本中的排泄水平（p<0.001）以及持续时间（p=0.003）均显著降低。总之，与未接种疫苗的猪相比，在两个高健康和高生产力的育肥猪 herd 中接种了 Porcilis®Lawsonia Vet 的猪，其关键生产指标显著提高，抗菌（AB）治疗、腹泻、LI 脱落和生长变化减少。
