Tvåstegsavvänjning av köttraskalvar med hjälp av nosbricka

Sammanfattning: When beef calves are weaned abruptly at 5 to 6 months of age this triggers a strong stress reaction, since the animals have not yet untied the bonds to their mothers or stopped suckling. This is displayed as extensive vocalization and restlessness. Attempts to diminish the negative effects of weaning on sucking calves have been showing varying results. The study presented here emanates from the observation that when calves are weaned without human interference they are only prevented from suckling, but are still allowed to have social contacts with their mothers. The hypothesis was that calves weaned in two steps would be calmer, gain more weight, and be healthier than animals that were abruptly weaned. To investigate this, 15 calves where weaned in two stages (Group 2), by fitting the calves with nose tags that prevented them from suckling during 5 days prior to the separation of the cows and calves. These calves were compared with 15 calves that were abruptly weaned (Group 1). The results showed that calves weaned in two stages vocalized significantly less (during the first two days after weaning 37.5 times less) compared to calves weaned abruptly. There was also a statistically significant difference with regard to their degree of activity, with the gradually weaned calves being calmer than the others. Especially during the first two days after weaning when the calves weaned abruptly spent 3,3 times more time on walking and took 3,5 times the number of steps as the calves weaned in two stages did. These findings indicate that the two step weaning procedure was less stressful for the calves than the method of abrupt weaning. There was a significant difference in growth where the abruptly weaned calves ceased to gain weight during days 5 to 9, while the gradually weaned calves did not. However, the difference in total weight gain during the entire experimental period was not statistically significant. There was no significant difference in body temperature. However, the number of times a body temperature equal to or above 39.5ºC was registered in Group 2 was only around 70% of Group 1. In conclusion, two step weaning with the aid of nose tags seems to be a good alternative to abrupt weaning since the calves weaned according to the alternative method kept calmer and didn't cease to gain weight compared to calves weaned abruptly. Moreover, the nose tags are cheap and can be used repeatedly after cleaning and disinfection. Further studies with a larger number of calves are needed to establish whether there is a significant difference in weight gain or body temperature when comparing between the two methods of weaning.