One of the main issues in swine husbandry is efficient and sustainable animal production. Several factors such as raw material prices and increasing worldwide competition force farmers to optimize their production cycles. Moreover, farmers have to deal with animal welfare regulation, restriction of antibiotic usage and prevalence of infectious diseases.
When pigs are subject to stress factors such as pig density, weaning, change of feed and change of social groups, they are highly susceptible to infectious diseases and (metabolic) disorders. These diseases can be caused by gram-positive pathogenic bacteria like Streptococci and Staphylococci, and viral infections. Antibiotics and vaccination programs are commonly used, however, not all bacteria and viruses can be targeted due to economic and/or practical disadvantages. Infection by Streptococci, Staphylococci and viral infections may lead to decreased reproduction and growth performance, high mortality rates and lower profitability.