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Enteric diseases have never left the limelight. Infection of the intestinal tract is as relevant now as ever due to the effect on nutrient absorption and growth rate and the weight variation that goes with it.

Probably the most common enteric problem in pigs isileitis, or proliferative enteropathy. Caused by Lawsonia intracellularis (LI), ileitis is a worldwide disease that can kill pigs on the finishing floor and rob them of their genetic potential.

While most diseases affect only a portion of animals within a group, recent surveys across Europe have shown that 80 percent or more of pigs seroconvert to LI during finishing.¹

Field studies demonstrate how carcass uniformity is achieved by preventing ileitis – prevention through Enterisol® Ileitis, an oral vaccine on the market since 2001 in the United States, and now available in over 30 countries worldwide.

A study presented at last year’s American Association of Swine Veterinarians annual meeting looked at ileitis vaccination and market weight consistency in three case studies. Doctors Harm Voets and Torsten Hardge of Boehringer Ingelheim Animal Health, Germany, provided the results.

The researchers noted that pigs are not affected with ileitis at the same time or to the same degree. Some pigs will show more severe reduction in growth rate and feed conversion, which might be due to varying immunity levels and/or the fact the disease is not affecting each animal of a group at the same time.

The following three field studies compared carcass weight uniformity of pigs vaccinated with Enterisol Ileitis and unvaccinated pigs.

Case No. 1 – Germany
A total of 833 pigs from two successive farrowings on a 6,000-sow farm were studied side by side. There were three groups – one received an oral 2 mL dose of vaccine by drench*; the second was vaccinated orally via drinking water. The third control group received saline solution by drench. Pigs were vaccinated at 7 weeks of age.

Results showed variation in carcass weight was less in vaccinated pigs than non-vaccinated (Table 1). Individual carcass weight and percent lean was also better in the vaccinated groups.

The lower percentage of pigs outside the optimal weight window and the lower percentage of lightweight pigs avoided market discounts and earned a better price per pound carcass weight. Feed intake and feed conversion were also better in vaccinated groups of the same age.

Case No. 2 – Belgium
This trial involved a multi-site farrow to finish farm with 360 sows. Vaccination via drinking water was performed in the common nursery at 10 days after weaning. Finishers were housed at two sites, each of which received both vaccinated and non-vaccinated pigs.

A serological profile of the sites showed initial Lawsonia infection at 10 weeks of age and diarrhea around 13 weeks of age in the non-vaccinates, which became chronically infected.

At site one, carcass weight rose from 205.30 lbs. in the non-vaccinated group (1,506 pigs) to 213.80 lbs. in the vaccinated (1,398 pigs) group. At site two, the mean carcass weight rose from 194.90 lbs. in non-vaccinates (1,356 pigs) to 211.20 lbs. in vaccinates (1,349 pigs). Vaccinates in both finishing sites had greater uniformity after vaccination, and there were fewer lightweight pigs in the vaccinated group.

Case No. 3 – The Philippines
A 2,500-sow farrow to finish farm was chosen for this study. In total, 942 pigs were divided into three groups.

One received a 2 mL dose at 22 days of age via drench*; a second group was vaccinated upon reaching 56 days of age via drinking water delivered through regular waterlines and drinking bowls over a 4-hour period. The third group served as a control, but received continuous feed antimicrobials, including chlortetracycline, valnemulin, tylosin and trimethoprim-sulfonamide.

Body weights and feed intake were recorded in all three groups from birth to market. Animals on the farm are routinely classified into one of three categories, which indicate the effect of a treatment on uniformity. Results clearly demonstrated that vaccinated animals were not only better performing, but also a significantly lower percentage of animals as classified in the lowest or below average group (see Table 2).

Like plants in the U.S., slaughterhouses in Europe pay more money for uniform pigs compared to groups with higher body weight variation.

In conclusion, the researchers stated that opportunity for increasing income should not be missed by failing to effectively prevent ileitis. These three trials in three different countries demonstrate that growth performance and uniformity is improved with ileitis vaccination. These results reinforce ongoing success with Enterisol Ileitis and proven return-on-investment of over $4.00²

References:
1. Hardge, T. et al. 2006. Serological prevalence of Lawsonia intracellularis across European pig herds. 19th Int Pig Vet Soc 1:77.
2. Kolb, J. et al. 2003. Summary of field trials implementing Enterisol Ileitis against ileitis. *Enterisol Ileitis is approved in the United States for administration via drinking water to pigs three weeks of age and older.