Tomislav Balenović

Experimental model of enterotoxigenic Escherichia coli infection in pigs: potential for an early recognition of colibacillosis by monitoring of behavior

The hypothesis that altered behavior is a sign for an early recognition of disease was tested. The experiment was conducted to evaluate the behavioral patterns of pigs in a model of postweaning colibacillosis. Twenty-five weaned pigs (from a herd that was previously found to be highly susceptible to F4+ Escherichia coli strains) were randomly assigned into 5 groups, kept in isolated pens under the controlled ambiental conditions. One day after weaning, the pigs from three groups were intragastrically inoculated (via orogastric tube) with either F4ac+ (1466 or 2407) or F4- (1467) nonenterotoxigenic E. coli (non-ETEC) strains, respectively. The pigs from the fourth group were inoculated with F4ac+ ETEC strain M1823 and the remaining 5 pigs that received broth containing 1.2% sodium bicarbonate were kept as noninoculated controls. The pigs were examined daily and the frequency and duration of their behavioral patterns, such as eating, drinking, lying, standing, urinating, defecating, rooting and playing were monitored for 300 h during a period of 10 days. In this model, three conditions were also observed in F4-susceptible pigs: (1) acute fatal diarrheal disease; (2) moderate diarrhea and weight loss and (3) no diarrhea and weight loss. The incidence (both frequency and duration) of defecating was significantly higher (P < 0.05) in pigs inoculated with F4ac+ ETEC strain M1823 as compared to that of noninoculated (control) pigs. Pigs inoculated with F4ac+ non-ETEC strain 1466 had a significantly lower frequency of eating (P < 0.05) and frequency/duration of drinking (P < 0.05) than did the controls. The 1466-inoculated pigs, had an increased diarrhea score, but frequency/duration of defecating was not significantly different. Pigs inoculated with F4ac+ non-ETEC strain 2407 spent more time in lying (P < 0.05) than did noninoculated pigs. Conversely, the pigs that received F4- non-ETEC strain 1467 laid shorter (P < 0.05) and ate/drank less frequently (P < 0.05) than the controls. It was concluded that the changed occurrence of defecating and eating in pigs that were inoculated with either F4ac+ ETEC (M1823) or non-ETEC (1466) strain. respectively, was consistent with the pending clinical disease, i.e. postweaning colibacillosis.

Teat sanitation in lactating sows.

Preweaning piglet mortality is a serious source of economic losses in pig production, with enteric diseases as the most common infectious cause of mortality. The aim of this study was to determine the efficacy of teat sanitation in lactating sows in order to reduce the piglet bacterial invasion through contaminated teats leading to outbreaks of enteric diseases. The study was carried out in a farrowing pen with 60 sows divided into three groups of 20 animals. Group 1 animals served as control group and were left untreated. In group 2, sow teats were treated with water and in group 3 with a commercial antiseptic with potent bactericidal action. Microbiological purity of the teats was determined during 24 days of the piglet suckling period. Study results showed the bacterial count per teat to be significantly lower in both experimental groups as compared with control group (P<0.01). Also, bacterial count was significantly lower in group 3 treated with the antiseptic than in group 2 treated with water alone (P<0.01). Accordingly, sow teat sanitation as a potential prophylactic measure during the piglet suckling period significantly decreased bacterial count on sow teats, thus reducing the risk of bacterial invasion of the piglet alimentary system.

Preweaning losses of piglets on a state farm in Bosnia and Herzegovina

Abstract The objective of a 3 year pilot survey of preweaning mortality on a large swine farm in Bosnia and Herzegovina was to provide producers and/or veterinarians with information about causes of piglet losses, their occurrence and frequency at the herd (regional) level. This may also serve as a model for an assessment at the national level. The SNOVET system, a part of the National Animal Health Monitoring System (launched in the USA in 1985), was applied for the classification of causes of deaths among suckling piglets based on postmortem findings. To assess the incidences of causes of preweaning losses, 354094 piglets born in 34 648 litters were monitored daily from June 1985 to May 1988. Respective information from 20 682 (or 5.8%) stillborns and those piglets that died from birth to weaning (49 058 or 14.7%) was given. Among piglets born alive, overlaying was the most frequent cause of death (6%), followed by mortality due to gastrointestinal syndrome (3.9%), cachexia/inanitio neonatorum (2.2%), and losses of small or deformed piglets (1.6%). The incidence of pneumonia was very low (0.02%). A relatively high proportion of causes of mortality remained unknown (0.9%) partly owing to savaging or losing piglet corpses in the sewers. The use of recorded information on type, extent, and incidence of piglet mortality (gathered on the sample of appropriate size) on a long-term basis may help in the development of effective strategies to reduce/control losses until weaning.

Airborne dust distribution in a farrowing pen in dependence of other microclimatic parameters during spring-summer period

Abstract The study was carried out in a farrowing pen during 6 production cycles of 24 days in the spring-summer period. The effect of season and other microclimate parameters on airborne dust concentration was investigated. Study results showed a decrease in airborne dust concentration in summer period that yielded negative correlation with air temperature (P<0.05). Relative humidity was expected to decrease due to higher ventilation rates, however, a significant increase was recorded in summer (P<0.05) because of higher evaporation caused by floor wash. The decrease in airborne dust concentration was ascribed to temperature elevation due to intensified ventilation rate and relative humidity resulting in higher rate of dust settling.