In Switzerland, approximately 73% of dairy cows are hornless. Dehorning is practised in 61% of European cattle herds – in 75% of cases by disbudding young calves. The reasons for dehorning are both economic and safety-related: horned animals need more space, and horns pose an additional risk of injury.
In Switzerland, disbudding is regulated in the Animal Protection Ordinance and the Animal Protection Act (Art. 32 AniPO and Art. 16 AniPA). The latter stipulates that the calves to be disbudded may not be more than three weeks old, and that the disbudding must be performed with a cautery iron under anaesthesia and analgesia.
Focus on Long-Term Effects of Disbudding
Since 2015, Agroscope, together with the ETH Zurich and INRAE, the French National Research Institute for Agriculture, Food and the Environment, has for the first time been investigating potential long-term consequences of disbudding on stress reactivity, meat quality and the behaviour of fattening cattle in a Fondation Sur-la-Croix-sponsored project. The following results are available:
(1) Physiological Stress Test Shows Hard-to-Interpret Results
The experience of chronic stress can lead to a change in physical stress reactions and affect the release of stress hormones, e.g. cortisol. In order to determine whether horn status shapes physical stress reactions, the so-called ACTH test was performed repeatedly on horned, unhorned and mixed groups of fattening bulls. For this, the test animals were administered the stress hormone ACTH (adrenocorticotropic hormone), after which was measured the cortisol release from the adrenal glands. The results show an influence of horn status. Repeatability between the ACTH tests was only moderate, however, making interpretation difficult. The results could be associated with the observed behavioural differences between horned and dehorned animals (see (3)).
2. Meat Quality Affected Mainly by Stress, but also by Horn Status
Agroscope examined whether disbudded and horned bulls differ in their stress reactions in the abattoir, and whether this is detectable in the meat quality. On the one hand, the results confirm that stress in the abattoir negatively affects the juiciness of meat, regardless of whether or not the bulls have horns; on the other, horn status influenced the tenderness of meat.
3. Behavioural Differences between Horned and Unhorned Fattening Cattle
Using reliable test methods, the activity, social behaviour, reactions to new objects and competitive behavior in a situation of feed competition of 81 male and 64 female fattening cattle were studied. Groups of horned animals (12-month-old bulls and 4-to-9-month-old heifers) were physically more active in the field. Horned bulls exhibited less fear-associated behaviour towards an unknown object than bulls without horns; the opposite effect for horned and disbudded heifers was observed. In a feed competition situation, horned animals displaced other conspecifics more frequently than disbudded ones, owing to more displacement with physical contact (bulls) as well as without (heifers). The results show that horn status influenced behaviour, and that this influence depended on the experiment (bulls vs. heifers) and situation (behavioural test). The differences observed in fear-associated and conflict behaviour are connected with aspects of animal welfare, since the latter is adversely affected by negative emotions or experiences such as fear or pain. In this respect, having horns can exert both negative and positive effects on animal welfare.
Publications of other research institutions on this subject:
Folgen der Enthornung können über die Akutphase hinausreichen, University of Bern press release (in German only).
Casoni, Daniela; Mirra, Alessandro; Suter, M R; Gutzwiller, A; Spadavecchia, Claudia, 2019. Can disbudding of calves (one versus four weeks of age) induce chronic pain? Physiology & behavior, 199, S. 47-55. Elsevier 10.1016/j.physbeh.2018.11.010.
Mirra, Alessandro; Spadavecchia, Claudia; Bruckmaier, Rupert; Gutzwiller, Andreas; Casoni, Daniela, 2018. Acute pain and peripheral sensitization following cautery disbudding in 1- and 4-week-old calves. Physiology & behavior, 184, S. 248-260. Elsevier 10.1016/j.physbeh.2017.11.031.
Vidondo, B., Stettler S., Stojiljković A., Mogel H., Gaschen V., Spadavecchia C., Casoni D., and Stoffel M.. 2019. Assessment of potential neuropathic changes in cattle after cautery disbudding. Research in Veterinary Science, 126.
Lutz, Janika; Burla, Joan-Brice; Gygax, Lorenz; Wechsler, Beat; Würbel, Hanno; Friedli, Katharina, 2019. Horned and dehorned dairy cows differ in the pattern of agonistic interactions investigated under different space allowances, Applied Animal Behaviour Science, Volume 218, 104819.