Materials and Methods
Case 1: High health nucleus farrow-to-finish farm of 800 sows with a 3 weeks rhythm. The animals were positive only to Lawsonia intracellularis and Streptococcus suis, and were negative to the other frequent pathogens in swine. They were Lawsonia positive since they arrived and enteric disorders related to ileitis were always present at fattening facilities confirmed by autopsy, faecal PCR and ELISA. However there was an increase in mortality since October 2005, and a substantial decrease in animal growth. Piglets were vaccinated (Enterisol® Ileitis) by drench since October 2005. The monitored parameters were average daily weight gain (ADWG), mortality rate, runts percentage and medication cost.
Case 2: Farrow-to-finish farm of 120 sows. On this farm the feed had never been medicated before ileitis appeared in the fattening place. However, the disease circulated continuously in dry sows, accounting for 2% of sow deaths. Vaccination started in January 2006. The monitored parameters were monthly enteric medication cost (including feed, water and injectable drugs) and mortality rate.
Case 3: Farrow-to-finish farm with 400 sows. Ileitis was present and of swine dysentery (Brachyspira hyodisenteriae) had been diagnosed on this farm for some years. Initially our practice thought that vaccination might entail an added cost to medication expenses. Historically, the percentage of mortality between weaning and the slaughterhouse was very high, surpassing 25% in some months (October 2005 and January 2006). Vaccination on this farm began in February 2006. The monitored parameters were monthly enteric medication cost (including feed, water and injectable drugs) and mortality rate.
return of ileitis oral vaccination was very positive.
Table 1. Relevant parameters in Case 1
Case 2: Results were very satisfactory (Graph 1). After vaccination feed medication withdrawal was possible. Only some medications in water for sporadic E. coli diarrhoea outbreaks in fattening pigs and piglets were kept. By June there was a decrease in mortality and a return to regular consumption of medication (mainly due to the vaccine cost).
Graph 1. Medication cost (columns) and mortality (line) in Case 2.
Case 3: The results (Graph 2) indicated that medication cost decreased, even with the presence of chronic dysentery in the farm. Consumption of medication was higher before vaccination started, and fell as more animals were vaccinated. Mortality dropped very substantially, reaching 7% in August.
Graph 2. Medication cost (columns) and mortality (line) in Case 3.