Good overall condition and appetite are essential for the development of sheep and lambs. When vitality and feed intake decrease, this has a negative impact on the development of the animals and susceptibility to disease increases. Factors that can influence condition and resistance include transport, poor ventilation, poor hygiene, changes in weather and ration changes. When feed intake decreases, growth retardation occurs, which negatively affects production efficiency. The combination of increasing disease susceptibility, decreasing resistance and reduced feed intake can lead to significant economic consequences.