A welfare friendly way of keeping livestock is a goal in organic animal husbandry: farm animals should be enabled to satisfy behavioral and biological needs. Ruminants have developed a unique digestive system enabling them to produce meat and milk from grasslands. It is important however that the pasture system and its intensity is matching the environment and animal needs. Pasture animals with different production yields (milk, meat) have different needs concerning fodder base, climate and weather protection. Moreover animals are exposed to gastrointestinal parasites while grazing. Not treated parasite infections can lead to significant economic losses, especially in regard to youngstock rearing, and major obstruction of animal welfare. Through optimization of pasture management and an anticipatory animal health management these massive health problems of youngstock have to be avoided.