THE introduction of young dairy goats into an existing herd is stressful for all animals involved. Rank fights and aggressive behavior can further result in injury.
Researchers at the University of Veterinary Medicine (Vetmeduni Vienna) in Vienna, Austria, have examined conditions under which young goats can acclimatize into new herds in a relatively low-stress manner. It seems that introducing young goats into herds works best if goat kids are present. The results of the study were published in the current issue of the Journal of Dairy Science.
Dairy goats are usually separated from their dams a few days to a few weeks after being born, and young does are reintroduced into the herd months later — on most farms, either in the last months of hew first pregnancy or shortly after parturition/kidding.
The practice is supposed to ensure stable milk production in the herd, but it causes stress to the goats, Vetmeduni Vienna said. Problems arise because goat herds have a strictly hierarchical social structure, and changes in herd composition may lead to serious rivalries and increased aggressive behavior.
Susanne Waiblinger from the Vetmeduni Vienna Institute of Animal Husbandry & Animal Welfare has investigated the social behavior and levels of stress hormones in 32 young goats following their introduction into a new herd. Half of the animals were introduced during the dry phase, when all of the goats in the herd as well as young goats are pregnant and not giving milk. The other half were introduced shortly after parturition/kidding during the lactating period, when mothers were nursing their kids.
Waiblinger found that the newly introduced goats experienced markedly less social stress in flocks with lactating mothers and goat kids. In "dry" herds, the goats were frequently confronted with aggressive social behavior.
Waiblinger explained, "We think the oxytocin system is activated in the presence of kids. Oxytocin is released during (parturition), sucking and other positive tactile contact in mammals and acts not only as a bonding hormone but also (is) calming, pro-social and stress-reducing. Thus, it is less likely that there will be aggression between the goats."
Once the young goats have been introduced into the new herd, they appear to prefer staying close to other goats of the same age rather than to adult and unknown members of the herd.
"The social and exploratory behavior in a herd is a reliable indicator of the stress experienced by the animals. When less stressed, goats are more likely to try to become acquainted with unfamiliar adults. Stressed goats prefer to surround themselves with well-known peers," Waiblinger said, suggesting that it would be "interesting to see whether it is the presence of kids or the mother lactating that plays the crucial role in stress reduction."