4. Husbandry interventions in suckling piglets, painful consequences and mitigation

Abstract

During their first days of postnatal life, piglets reared for meat production are often subjected to numerous husbandry practices that cause injury of sensitive tissues and hence are potential sources of pain. The intensity and duration of the pain engendered depend on the nature and magnitude of tissue damage. Each of these practices is carried out for specific reasons, such as preventing boar taint (castration), reducing the risk of tail biting (tail docking), limiting lesions on siblings and the sow's teats (tooth resection), improving health (injections) or identifying animals (ear tagging or notching). This chapter will discuss the rationale and methods used, the evidence of pain during and shortly after the procedure, the long-term pain consequences, the consequences for health and human-animal relationships, the current options for pain mitigation and the pros and cons of avoiding these practices completely. Solutions are emerging to minimise the industry's dependence on these practices and, when still considered necessary, to enable selection of the least painful option and best mitigate any residual pain. A better knowledge of the affective component of the pain involved in the practices as well as the establishment of standard and validated protocols of pain evaluation are needed in order to move forward and determine the best solutions from an animal welfare perspective and feasibility by farmers.

Impact of tearing spermatic cords during castration in live and dead piglets and consequences on welfare

“…From this year on, piglets in Germany have to be surgically castrated under general anesthesia induced by inhalation or injection [ 2 ]. Options for mitigating pain during castration have been discussed in detail [ 17 , 18 ]. Also in the present study, it was analyzed whether treatment with general or local anesthesia affected the physical reactions of piglets during castration.…”

“…In a recent trial, vocalizations have been assessed without software in a more practical approach, but only an acute onset of increased vocalizations was evaluated and no further categorization has been made [ 11 ]. Detailed reviews on the subject have recently been published [ 17 , 18 ], where it was emphasized that there is no standardized procedure yet to assess the impact of castration and the efficacy of analgesic treatments. However, general findings with regard to movements and vocalizations indicate that castration induces (i) higher screams with higher frequency, energy and longer call duration [ 10 , 13 , 16 ] as well as (ii) increased movements of front and hind limbs and back, trembling and escape attempts [ 7 , 19 , 20 ].…”

Early Life Painful Procedures: Long-Term Consequences and Implications for Farm Animal Welfare

“…Physical methods include surgically removing the testicles, applying a rubber ring at the base of the scrotum, or crushing the spermatic cords with a clamp. Regardless of the method used, castration causes acute pain in calves, piglets, lambs, and goat kids (Rault et al, 2011;Coetzee, 2013;Stafford, 2017;Graves et al, 2020;Prunier et al, 2020). Surgical incisions take between 4 and 11 weeks to heal in beef calves, and behavioral and physiological changes indicative of pain are present for several weeks, with the most persistent changes seen after the rubber-ring method [reviewed in Adcock and Tucker (2018b)].…”

Welfare Aspects of Raising Entire Male Pigs and Immunocastrates

“…Controlled systematic studies on lifetime health benefits of EM vs. castrates and females are not available. However, there are few studies that indicate benefits for EM pigs in health and performance pre-weaning compared to piglets that are surgically castrated [ 11 ]. The main benefit is to prevent stress and pain associated with surgical castration as reviewed in several papers.…”

“…This idea of reduced pain perception in the first weeks of life was also applied to young animals and explains why animal welfare legislation in most countries allowed the practice of surgical castration without pain relief in the first week of life in pigs until now. The pros and cons of the various methods used for analgesia and anaesthesia during surgical castration have been reviewed extensively (see, e.g., [ 2 , 7 , 8 , 9 , 10 , 11 ]) and are not the focus of this publication. In brief, surgical castration with pain relief has all the advantages of surgical castration in terms of easier management, lower expression of aggressive and mounting behaviours and quality of carcasses.…”