Improvement of productivity and welfare of dairy cows by indentification and exclusion of stress factors

Stress can be external (heat, poor nutrition, care and keeping zoohygiene conditions) and internal (periparturient stress, metabolic stress, stress due to high milk production, stress due to the painful process of locomotion). The tests will be carried out on the influence of 5 basic categories of stress on health and productive traits of dairy cows as follows: heat stress, lameness as painful chronic stress, the food stress, illness as stress and high productivity as stress (over 25 liters of milk). Over cows under the stress AI till conception will be carried out. During their periparturient period metabolic profile, hematology profile, endocrine profile, immune reactivity and cellular response will be examined. The data will be compared with the health and production of cows in early lactation (milk production, ketosis, metritis, mastitis, the development of lameness, placenta retention, displaced abomasum). In the lactation that follows we will eliminate all stressogenic factors (ventilation, trimming hoof, correction of foot, zoohygienes factors and quality of food). Over the cows under the stress reduction AI till conception will be carried out. During the postparturient period metabolism and productivity of these cows will be compared with metabolism and productivity of cows prior to the reduction of stress.