The castration of male piglets is carried out virtually throughout the EU within the first week of life without pain relief. The Austrian Animal Welfare Act (2005) also legalizes this type of castration. Possible alternatives to this solution, which is controversial from an animal welfare, ethical, and emotional perspective, are currently not relevant or competitive in practice due to their additional technical or financial costs (halothane anesthesia (complexity), injection of an anesthetic or local anesthetic (only possible by a veterinarian); use of painkillers (high costs), raising boars for meat (little experience, risk of boar odor and potentially uneconomical, consumer concerns?), immunocastration (costs, approval issues, ethical concerns, (male) consumers?).
The requirements for a suitable, practical solution are:
- Easy and quick to do, even for farmers
- As stress- and pain-free as possible for the animal
- Animal-friendly
- Ethically and morally justifiable
- Low cost
- Compliance with existing legislation (e.g., the Veterinary Medicinal Products Control Act)
In a trial at the HBLFA Raumberg-Gumpenstein, a variant for the castration of male piglets will be tested for its practicality and its effects on the cortisol level in the blood of the test subjects.
The method to be tested, which can also be carried out by a farmer, involves applying a local anesthetic in an unintended application method after local freezing of the testicular area with a spray and subsequent castration according to artis.
The local anesthetic (injectable LA, preferably with a retarder) is to be administered as a spray into the castration wound. From a pharmaceutical law perspective, this constitutes an off-label use, resulting in a 28-day withdrawal period for edible tissues, which is already being observed in this experiment. This withdrawal period also poses no problem in practice.
Experimental design: Castration group assignment
Group A: Control group: male piglets: local freezing and blood sampling, none
Group B: Conventional castration: Castration performed according to best practices, blood sample collection
Group C: Castration trial: Castration under freezing and spray local anesthesia, blood sampling
Group D: Group of female piglets: behavioral observations only, based on a checklist
Number of piglets per group: 12 (12x3=36)
Time sequence (h) Blood sample collections: -0.5, +0.5, 4, 12 (4x36=144)
In addition to determining the course of cortisol, the behavior of the piglets is assessed using a checklist at 10-minute intervals over a period of 12 hours post-op.
The experiment is an animal experiment (taking blood samples from piglets to determine cortisol levels) and is being conducted on animals from the HBLFA Raumberg-Gumpenstein animal breeding facility. The HBLFA Raumberg-Gumpenstein is a legally authorized animal testing facility according to a valid permit issued by the responsible authority (Office of the Styrian Provincial Government).
A corresponding application for approval of the present animal experiment (§9 TVG) is submitted by Dr. J. Gasteiner, head of the animal experimentation facilities of the HBLFA Raumberg-Gumpenstein.
The animal experiment was approved on January 23, 2007 by the responsible office of the Styrian state government.
Summary - Results
Under current Austrian animal welfare law, surgical castration of piglets may be performed without pain relief during the first 7 days of life. In a trial, a method for pain relief during surgical castration was tested on 5-day-old piglets (experimental group) in comparison to castration without pain relief (positive control group) and to a negative control group without castration (n=84). In the control group, the skin in the scrotal region was anesthetized using a cryo-method before the incisions were made. After the testicles were removed, a local anesthetic with a barrier device was applied in spray form to the wound cavity and the stump of the spermatic cord.
The results of the behavioral studies showed that, with regard to the parameter "suckling", the piglets castrated using the described method suckled significantly more frequently and for longer periods in the first 6 hours post-castration (p
The course of cortisol concentration in the blood differed significantly between the piglets in the experimental group (p < 0.00)
The method proved to be simple and quick to implement in practice, meaning it can also be carried out by a knowledgeable person (animal owner). The material costs for this method amount to 25 cents per piglet.
One disadvantage of this method is that the spermatic cord is not anesthetized, and its removal remains painful. A follow-up project aims to address this issue. Under current legislation, the local anesthetic used in this study may not be dispensed to farmers. The presented approach to pain reduction during surgical castration through cryotherapy, combined with postoperative pain management using a local anesthetic spray containing a barrier device, represents a significant improvement in the pain experienced by piglets during the procedure. The method is cost-effective, practical, and has potential for further improvement; it can be performed by a trained individual.
