Behavior and handling of physically and immunologically castrated market pigs on farm and going to market

Postweaning mortality in commercial swine production. I: review of non-infectious contributing factors

Postweaning mortality is a complex causal matrix involving animal, environment, and infectious etiologic factors. Despite advances in swine productivity such as total pigs born, growth rate, feed intake, and efficiency, there have been modest to no improvements in postweaning mortality rates over the last several years. Industry averages for postweaning mortality range from four to eight percent for each the nursery, grow-finish, or wean-finish stages. Retrospective mortality causal analyses of individual databases have been performed. However, little information derived from meta-analysis, systematic review, or comprehensive literature reviews are available. In order to develop and evaluate strategies to comprehensively manage and reduce postweaning mortality, addressing the complexity and range of impact that factors have on mortality is necessary to identify and prioritize such contributing factors. Our objective is to describe the current state of knowledge regarding non-infectious causes of postweaning mortality, focusing on estimates of frequency and magnitude of effect where available. Postweaning mortality can be generalized into non-infectious and infectious causes, with non-infectious factors further classified into anatomic abnormalities, toxicity, animal factors, facility factors, nutritional inadequacies, season, and management factors. Important non-infectious factors that have been identified through review of literature include birth weight, pre-weaning management, weaning age and weight, and season. Additionally, reasons for mortality with a low incidence but a high magnitude include abdominal organ torsion/volvulus, sodium ion or ionophore toxicosis, or dietary imbalance due to feed formulation or manufacture error. Many interactive effects are present between and among infectious and non-infectious factors, but an important trend is the impact that non-infectious factors have on the incidence, severity, and resolution of infectious disease. Strategies to reduce postweaning mortality must consider the dynamic, complex state that forms the causal web. Control of postweaning mortality through understanding of the complexity, evaluation of mortality reduction strategies through rigorous scientific evaluation, and implementation remains an area of opportunity for continued growth and development in the global swine industry.

Sustainability of Pork Production with Immunocastration in Europe

Immunocastration, a technique to replace surgical castration of piglets, consists of two consecutive vaccinations to induce antibodies which transiently suppress testicular functions and avoid boar taint. It is a method to ensure both a high product quality and a high level of animal welfare. The impact of immunocastration on the three pillars of sustainability has been studied extensively. While all aspects of sustainability have been studied separately, however, a contemporary global overview of different aspects is missing. In immunocastrates, performance results are better than in barrows, but worse than in boars. The environmental impact of pork production with immunocastrates is lower than with barrows, but higher than with boars. The level of aggression is considerably lower in immunocastrates compared to boars. Societal concerns are mainly related to food safety, and are not supported by scientific evidence. After second vaccination, immunocastrates switch from a boar- to a barrow-like status. Therefore, the timing of second vaccination is a fine-tuning tool to balance advantages of boars with environmental and economic benefits against increased risk of welfare problems and boar taint. Nevertheless, both synergic and conflicting relationships between the pillars of sustainability must be communicated along the value chain to produce tailored pork products.

Comparison of Intramuscular or Subcutaneous Injections vs. Castration in Pigs-Impacts on Behavior and Welfare

Simple Summary

Physical castration (PC) of piglets is a painful and stressful procedure and alternatives are being sought to improve animal well-being, such as immunological castration (IC). However, IC requires injections which may also cause pain and stress during handling. In this study, piglets and finishing pigs were placed in the following treatment groups: no handling or treatment (NO), sham-handling (SHAM), intramuscular injection (IM), subcutaneous injection (SQ), or PC on piglets only. Behavior was monitored for 1 h prior and 1 h post treatment in each age group. Social behavior and feeding behavior, and signs of pain were recorded. Physical castration caused measurable pain-like behaviors and general behavioral dysregulation at a much higher level than changes associated with handling associated with IM or SQ injections. Overall, injections did not cause a change in weaning pig behaviors. Finishing pigs given SQ injections showed a lower number of feeding behaviors post treatment but other changes were not observed in the other treatment groups.

Abstract

Physical castration (PC) is painful and stressful for nursing piglets. One alternative to PC is immunological castration (IC), but the pain and stress of handling associated with injections have not been assessed. The objectives of this study were to measure the pain and distress of subcutaneous (SQ) and intramuscular (IM) injections compared to PC in piglets, and to compare SQ or IM injections in finishing pigs. After farrowing, 3 to 5 d old male piglets were randomly assigned to (control) no handling treatment (NO), sham-handling (SHAM), IM, SQ, or PC. Finishing pigs were assigned to NO, SHAM, IM, or SQ. Behavior was monitored for 1 h prior and 1 h post treatment in each age group. Social, feeding behaviors, and signs of pain were recorded. Finishing pigs treated with SQ injections had higher feeding behaviors pre-treatment than they did post-treatment. Overall, physical castrations caused measurable pain-like behaviors and general behavioral dysregulation at a much higher level than the other treatment groups. SQ and IM injections did not cause either significant behavioral or physiological alterations in piglets. SQ injections caused a decrease in finishing pig feed behaviors post treatment (p = 0.02) and SHAM treated finishing pigs spent significantly more time lying than the other treatment groups. In general IM and SQ injections did not cause any other significant changes in behavior or physiology.