Epsilon Archive for Student Projects

Abstract

The welfare of laboratory animals is an important issue that has gained more and more attention in society. Laying hens (Gallus Gallus Domesticus) is one of the species that is used in animal testing. At the Swedish National Veterinary Institute (SVA) there are two flocks (15 hens in each) of the hybrid Bovans Robust hens; flock A around 18 months old and flock B around 20 weeks old at the start of the study. The staff at SVA had two concerns they wanted to address: the animals’ stress levels in flock A during blood sampling procedures and the insecurity of flock B during the presence of the animal technicians. Stress can have an undesired influence on the outcome of the studies that the animals are a part of at SVA, but also has negative consequences on animal welfare. Training with positive reinforcement has been used successfully for other species of laboratory animals, such as small rodents. Based on the positive results seen in other species, it could be used with the laying hens at SVA. The aim of this study was to reduce the stress the animals experience around blood sampling procedures, decrease the stress of the younger hens, as well as develop a training program the animal technicians can use for further training of the animals.
In the first part of the study, the food preferences of each flock was decided by scattering a small amount of the enforcers (oats, meal worms, dried apple, fresh apple, smashed and dried peas, black pudding, and sweet corn) and observing the flock. For both flocks, oats, meal worms, fresh apple and corn were the most popular, the majority of the animals chose to eat these treats. From these results, oats and meal worms were chosen as the treats used in the following parts of the study.
The next two parts of the study were conducted in parallel, and sessions were repeated over 9 days. One individual from flock A was trained to stand still and lie still using positive reinforcement (clicker and food treat) at the location used for the blood sampling procedures. The individual trained with positive reinforcement progressed positively throughout the study, increasing the time she could stand and lie still, from 0 seconds at session 1 to 2,4 seconds for standing still and 2,8 seconds for lying still at session 16.
In an attempt to reduce the fear of humans in flock B, a person was placed in their corral with a bowl of a mix of oats and meal worms between their feet. Flock B’s courage increased steadily over the nine days of the study, by increasing their time spent near the human and treat bowl. At the end of the study, the vast majority
Abstract
of individuals were brave enough to approach the observer and take the enforcer from the bowl.
The results indicated that progress can be seen after just a few days of repeated minute-long training sessions and that this type of positive reinforcement is a useful method for training laying hens.