Complex sentence: Outbreaks in herds are common, so this is of major importance for the dairy industry, and programs to reduce the impact of "S. agalactiae" disease have been enforced in many countries over the last 40 years.
Split into simpler sentences: Outbreaks in herds are common, and this is of major importance for the dairy industry. And programs to reduce the impact of "S. agalactiae" disease have been enforced in many countries over the last 40 years.