Surgical castration with pain relief affects the health and productive performance of pigs in the suckling period

Abstract

BackgroundSurgical castration is still practiced in many EU countries to avoid undesirable aggressive behavior and boar taint in male pigs. However, evidence shows that castration is painful and has a detrimental influence on pig health. This study investigated the clinical and productive effects of surgical castration in the suckling period.A total of 3696 male pigs, 3 to 6 days old, comprising of 721 litters from two different farms were included in the study. Within each litter, half of the males were kept as intact males (IM) and half were surgically castrated (CM). Surgical castration was conducted by a trained farmer. Average daily gain (ADG), body weight at weaning (BWW), percentage of pre-weaning mortality (PWM) and antibiotic usage were measured. Pig major acute phase protein (PigMAP) serum concentrations were analyzed prior to castration, and on days 1 and 10 after castration. Productive performance data were analyzed using a linear mixed model. Mortality and percentage of pigs treated with antibiotics were analyzed using the Fisher’s exact test.ResultsNo overall differences in BWW and ADG were observed between the two groups. However, differences were observed when the same effects were analyzed in the 25% lightest, 50% medium and 25% heaviest pigs at birth. PWM was higher in CM than in IM groups (6.3% vs 3.6%; p < 0.001), especially in the light (12.2% vs 6.2%; p = 0.02) and in the medium (5.5% vs 2.7%; p = 0.04) weight groups. In the heaviest pigs group PWM was not affected by castration, but IM tended to show higher ADG (p = 0.06) and showed higher BWW (8.0 kg vs 7.8 kg; p = 0.05) than CM. There were no differences in percentage of pigs treated with antibiotics between the two groups (5.8% vs 5.8%; p = 0.98) in this study. Furthermore, PigMAP was increased in CM the day after castration (0.944 mg/ml vs 0.847 mg/ml; p = 0.025), but there was no difference between CM and IM groups at day 10.ConclusionsSurgical castration has a negative impact on production in the suckling period because it causes an increase in PWM, especially in pigs in the three lower quartiles for body weight, and negatively affects the BWW in pigs born in the highest quartile for body weight.

Sustainability of Pork Production with Immunocastration in Europe

“…A major benefit of immunocastration is an increase in animal welfare by preventing painful surgical castration and the risk of wound infection in piglets. The study by Morales and co-authors [55] shows that the piglet mortality during the first week post-partum is higher in surgically castrated piglets than in intact piglets (6.3% vs. 3.6%). Especially piglets with a low or medium live weight at birth have a significantly higher mortality rate than uncastrated piglets (low:12.2% vs. 6.2%; p < 0.05, medium 5.5% vs. 2.7%; p < 0.05).…”

Pros and Cons of Alternatives to Piglet Castration: Welfare, Boar Taint, and Other Meat Quality Traits

“…The animals also show more pain-related behavior. There is some evidence of health impairment in castrated compared to entire male pigs, leading to higher mortality in surgically castrated piglets than in intact males [21].…”

Pain in Pig Production: Text Mining Analysis of the Scientific Literature

“…This could partly justify the fact that the analyzed publications consider the painful practices as a tool still needed to achieve specific production standards required by the industry and/or market. A relevant example at this regard is the practice of castration that is performed to avoid the occurrence of "boar taint" as well as to reduce mounting and aggressions following the onset of puberty (Morales et al 2017). Castration of piglets without pain relief is a common practice in swine production (Heid and Hamm 2012) despite research demonstrated that surgical practice without analgesia induces endocrine and behavioural responses linked with pain (Prunier et al 2006;Lonardi et al 2015).…”