Background: The abolition of in-feed antibiotics or chemotherapeutics as growth promoters have stimulated the swine industry to look for alternatives such as organic acids, botanicals, probiotics and tannin. The objective of the present study was to compare the effects of a combination of acids and tannin with diet with organic acids and diet without growth promoters on the growth performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs. Tannin is more natural and cheaper but possibly with the same effectiveness as organic acids with regard to growth performance.Methods: Thirty-six 7 week old grower pigs, divided into three equal groups, were used in a three week feeding trial. Group I was fed basal diet, group II basal diet with added organic acids and group III basal diet with added organic and inorganic acids and tannin. Pigs were weighed before and after feeding and observed daily. Blood was collected before and after the feeding trial for the determination of selected biochemical, haematological and antioxidant enzyme parameters. One-way ANOVA was used to assess any diet related changes of all the parameters. Paired t-test was used to evaluate changes of blood parameters individually in each group of growers before and after feeding.Results: No clinical health problems related to diet were noted during the three week feeding trial. The average daily gain (ADG) and selected blood parameters were not affected by the addition to basal diet of either acids and tannin or of organic acids alone. Selected blood parameters remained within the reference range before and after the feeding trial, with the exception of total serum proteins that were below the lower value of reference range at both times. The significant changes (paired t-test) observed in individual groups before and after the feeding trial are related to the growth of pigs.Conclusion: Diet with acids and tannin did not improve the growth performance of grower pigs but had no deleterious effects on selected blood parameters. The possibility of beneficial effects of adding acids and tannin in diets on growth performance over a longer period, however, could not be excluded.

Porcine reproductive and respiratory syndrome (PRRS) has become one of the most economically important diseases for the swine industry worldwide. The objective of the study was to determine selected blood antioxidant enzymes (glutathione peroxidase (GPX), superoxide dismutase (SOD)), biochemical and haematological parameters in PRRS positive and negative pigs of three different categories, mainly to test oxidative stress hypothesis in pigs naturally infected with PRRS virus. Ninety PRRS positive and 90 PRRS negative pigs were included in the study. The presence of PRRS was confirmed by serological detection of antibodies against PRRS virus (PRRSV) and detection of PRRS viral RNA by RT-PCR. Pigs were further divided into three groups of 30: piglets just before weaning (weaners), fatteners and finishers. Blood samples for determining selected blood parameters were collected from the vena cava cranialis. Significantly (P < 0.05) higher activities of SOD in weaners and fatteners and of GPX in weaners were determined in PRRS positive pigs than in corresponding groups of PRRS negative pigs. In contrast, significantly (P < 0.05) lower GPX activity was observed in finishers of PRRS positive pigs than in the corresponding group of PRRS negative pigs. Concentrations of serum total protein in PRRS positive weaners and fatteners were significantly (P < 0.05) higher than those found in PRRS negative pigs. Leukopenia was observed in all three groups of PRRS positive pigs. It has been demonstrated, for the first time, that oxidative stress might be increased in PRRSV naturally infected pigs, especially in weaners.

Implementing biosecurity measures in the pig production is crucial to optimize animal health and reduce antimicrobial usage. A legal framework may help to ensure all stakeholders understand the need of biosecurity measures and to implement them correctly. Limited knowledge is available about how implementation of biosecurity measures is regulated in European countries. Therefore, the aim of this study was to identify which biosecurity measures were mandatory by national legislation and/or by pig sector organizations of European countries for the intensive pig production under normal circumstances (i.e. no (threat of) disease outbreaks). A questionnaire including 51 biosecurity measures, 32 on external and 19 on internal, was developed and sent to national country representatives. Twenty-four European countries, of which 18 belonging to the European Union, indicated which biosecurity measures were mandatory by law. Four countries, France, Spain, Italy and Romania had a single national pig-specific biosecurity legislation, while in the other countries multiple legislations had to be consulted to complete the questionnaire. In general, there was a high heterogeneity in the number of measures that were mandatory by law per country. Most biosecurity measures addressed in the national legislation focused on external biosecurity and were measures that can be easily audited when conducting a farm visit such as the presence of a hygiene lock, fencing around the farm and the existence of documentation. A significant (p < 0.001) positive correlation was observed between the presence of external and internal biosecurity measures in the legislation. Yet, no significant association was observed between the number of biosecurity measures present in the national legislation and the size of the pig production. Fourteen countries indicated which biosecurity measures were required by pig sector organizations for intensive pig farms. The median number of biosecurity measures mandatory by pig sector organizations but not by law was 13 with a minimum of one measure in Germany and a maximum of 24 in Croatia. Different countries apply different strategies to increase the level of biosecurity. Further research is needed to investigate the impact of the different strategies on the implementation of biosecurity on intensive pig farms in the countries.

African Swine Fever (ASF) is persistently spreading and hindering pork production in Europe. Slovenia is one of the last countries in Central Europe without a confirmed ASF case in domestic pigs or in wild boar. The aim of this study was to assess the current biosecurity implementation on different types of pig farms. Internal and external biosecurity status was determined in 17 commercial (CF), 15 non-commercial (NC), and 15 outdoor (O) farms. Data were collected using the Biocheck.UGent questionnaire and assessed in combination with the latest information on the wild boar population in Slovenia. Biosecurity was compared between farm types based on the assessment of 12 subcategories. Statistically significant differences (p < 0.05) were found in six subcategories: (i) purchase of pigs and semen, (ii) visitors and farmworkers, (iii) vermin and bird control, (iv) finishing unit, (v) measures between compartments and use of equipment, and (vi) cleaning and disinfection. The highest total biosecurity score (0–100%) was determined on CF with 64.59 ± 16.47%, followed by NC with 55.73 ± 10.67%, and O with 48.47 ± 8.20%. The density of the wild boar population was estimated from the number of wild boars per km² per year, with 3 or more hunted wild boars per unit representing the highest density. Geolocation of farms on the wild boar population map showed that two O farms are at high risk and seven farms (1 O, 5 NC, and 1 CF) are at medium risk for disease transmission from wild to domestic pigs. Biosecurity measures must be tightened in some subcategories, especially in areas with a high density of wild boar.