engleski

The influence of dairy cows age and calves gender on the stress level in early weaning

In the first 24 hours after calving, a strong bond between dam and calf is created. In natural conditions, this bond would last for a period of six to nine months before the naturalweaningoccure. Under intensive breeding conditions, calves are often forcedly separated from their mothers immediately or several hours after birth.This procedureis called early weaning anddoes not imply only the denial of suckling, but also includes the physical separation of the calf from the dam, and presents an extreme stress in terms of adaptation to many physical and social factors of the environment. The stress response in the early weaning is very complex and most often accompanied by anincrease of cortisol concentrations in serum, saliva, milk and other secretions, and in significant changes ofanimal behaviour. These behavioural changes can be identified through the assessment of the emotional state of the animal, ie the recognition of several specific behavioural patterns such as frequent movement (reciprocally search) and frequent vocalisation which sometimes is followed by highlighting the sclera. Above mentioned patterns of behaviour are often interrupted by the periods in which animal express a certain form of depression – periods of "protest" or "despair". Early weaning presents stress both for calves and mothers, and it is justifiably considered to be one of the leading problems of animal welfare in intensive dairy production. The study will investigate the influence of early weaning on the occurrence of specific behaviours in both categories of cattle (cows and calves), and cortisol concentrations in cow's milk and calves saliva. With further distribution of cows to age groups and calves according to gender, study will show whether there are differences in their response to early weaning. Outcomes of the study will be used for improving the breeding conditions of calves and dairy cows, respectively reducing the level of stress at early weaning.

dairy cattle, calves, welfare, early weaning

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