Autor: Fritz Beyer

Teaching artificial insemination in cattle: Assessment of the stress level and evaluation of a simulator-supplemented training According to the Animal Breeding Act Course Ordinance (TierZG1989LehrgV), practical training on animals is required by law to study artificial insemination in cattle. To date, the well-being of the cattle used in these exercises has not been assessed. The present work dealt for the first time with the exposure of stress in cows as test animals in practical AI exercises. It should also be investigated if the repeated use of the animals in an AI exercise leads to habituation in the situation. Finally, the added value of training supplemented by simulators for cattle and humans was assessed. For the assessment of the stress level, 31 exercise animals of the breeds Holstein-Friesian, German Schwarzbuntes Niederungsrind (DSN), Simmental cattle, Brown Swiss, Danish-Holstein, and a DSN x Belgian blue cross between the ages of 15 months and twelve years from the herd of the institute for reproduction of farm animals Schönow e.V. (IFN) were accompanied over 15 exercises within one year. For a differentiated analysis, the animals were randomly grouped into inexperienced (used in ≤ 8 exercises, UK), experienced (used in ≥9 exercises, EK), and resting animals (RK). RK animals were fixed in the feed fence without further use during the AI exercises. The determination of cortisol concentrations was carried out in serum (SCK) and saliva samples (SpCK) 60 and 30 min before the start of the exercise as a basal sample (B1 and B2), 30 and 60 min after the start of the exercise (Ü1 and Ü2) and finally 30 min after the end of the exercise (Be). The heart rate variability (HRV) was derived on the left side of the thorax using a sensor belt (equine belt® H7,) and evaluated using Kubios software (version 3.1.0). The HRV was determined 60 and 30 minutes before the start of the course, in the beginning, in the middle and at the end of an exercise and finally 30 minutes after the end of the course. Additionally, rumination time was recorded (Heatime® Pro v 15.2.10.0). Sampling of the SCK and Dihydroepiandrostendione (DHEA) concentration was carried out on separate dates after a four- or eight-week course or rest phase. On these dates, cell smears were taken additional from the uterus using the Cytobrush method. The assessment of a simulator-added training took place in separate IFN courses with 57 participants without previous experience in artificial insemination. These were randomly divided into three groups: A, B, and C. Before the first practical exercise with the cow, two basal samples were taken from each animal to determine SCK and SpCK. During the exercise, each participant had the opportunity to practice the correct insertion of the AI gun with a cow for 15 minutes. Questionnaires were collected before and after the practical AI exercise rated the improvement of training by contributing a simulator. Also, the performance and learning success of the course participants were assessed objectively by the course instructor. The analyses of the SCK, SpCK, and DHEA samples were carried out in the endocrinological laboratory of the cattle clinic of the University of Veterinary Medicine Hannover. The evaluation of the parameters for acute stress showed an increase in the SCK of all animal groups during the exercise times (n = 156, B1 to Ü1: P = 0.000, B2 to Ü1: P = 0.013, B1 to Ü2: P = 0.002, B2 to Ü2: P = 0.022) and a significant recovery to the basal level 30 min after the end of the insemination exercise (Ü1 to Be: P = 0.000, Ü2 to Be: P = 0.01). These results could also be reproduced in the evaluation of the SpCK (n = 156) and the netSCK (n = 155). The chewing time increased significantly during the fixation and exercise interval (n = 237, P = 0.000). The course of the HRV showed no significant difference between the measurement times B1, B2, Ü1, Ü2, and Be. In a comparison of the animal groups RK, UK, and EK, the values of the RK concerning “area under the curve” of the SCK were significantly (P = 0.007) below the results of the UK group. The long-term evaluation showed no difference in DHEA (n = 100 / 77) or cortisol concentrations (n = 102 / 77) after a course or rest phase. Also in the cell smear, there was no difference in the proportion of polymorphonuclear neutrophils between the animal groups. Cows manipulated by only theoretically taught participants (group A) showed a significant increase in SCK during the time of exercise (P = 0.01). Once participants had previously practiced on slaughter organs (Group B) or simulators (Group C), the cows showed no significant increase in SCK during the 15-minute exercise. In summary, the stress load on cattle, which arises during training exercises to learn artificial insemination, is to be regarded as low due to the rapid calming down after the insemination exercises. Furthermore, habituation of the animals can be determined in the exercise situation. Repeated exercises do not cause permanent activation of the hypothalamic-pituitary-adrenal axis or an immunological defense reaction of the uterus of the test animals. Furthermore, the results of this study show the positive potential of training supplemented by a simulator to reduce the stress level of the training cows.