Interpretative Summary: Effect of castration method and analgesia on inflammation, behavior, growth performance, and carcass traits in feedlot cattle
By: Megan LaFollette
In January 2018, Journal of Animal Science published an article that investigated the effect of castration timing, method, and analgesia use on feedlot cattle behavior, physiology, and performance. Feedlot cattle are castrated to prevent breeding, reduce aggression, and improve meat quality. Castration is stressful and causes undesirable behavioral, physiological, and performance changes. Current practices vary with castration performed either at birth or feedlot entry via surgery or band methods, typically without analgesia. However, previously the administration an oral analgesia, meloxicam, at castration was shown to improve average daily gain, but its long-term effects are unknown. This study’s objective was to determine if castration method, timing, or meloxicam administration affects feedlot cattle performance, carcass traits, inflammation, and behavior.
In this study, across 3 years, cattle were split into five treatment groups: early band castration, feedlot surgical castration, feedlot surgical castration with meloxicam, feedlot band castration, and feedlot band castration with meloxicam. Each treatment group was evaluated with 6 pens of 4 to 9 animals for a total of 30 pens (150 to 270 animals) evaluated. Cattle were separated into light and heavy groups. Early band castration occurred within 48 hours of birth without meloxicam administration. Feedlot castrations were performed after a 10-day acclimation period in the feedlot. Meloxicam was administered orally. Behavior was evaluated via accelerometers.
Castration timing (early vs feedlot), method (surgical vs band), and meloxicam administration (none vs 15 mg/kg) impacted performance. Contrary to industry dogma, at weaning there was no difference in bodyweight between steers who had undergone early band castration and intact bulls. Final bodyweights were also similar between early band castrated cattle and feedlot castrated cattle. However, cattle castrated in the feedlot – regardless of method – had higher average daily gain if they received meloxicam. There was no effect of feedlot castration method on carcass traits. However, early band castration improved marbling and meloxicam administration increased backfat thickness and rib eye area.
Castration timing, method, and meloxicam administration also impacted inflammation and behavior. In terms of inflammation, surgical castration increased serum haptoglobin, an indicator of stress and inflammation, compared to band castrated animals. Meloxicam administration to surgically castrated animals reduced their serum haptoglobin concentration. In terms of behavior, surgically castrated cattle spent more time standing regardless of meloxicam administration. Band castrated cattle spent more time lying down and an increase in steps. Regardless of castration method, meloxicam administration decreased motion index and step count.
Overall, this study suggests that early band castration at the cow-calf origin (even without meloxicam) is beneficial to long-term animal welfare and production compared to feedlot castration. Both surgical and band castration of bulls at the feedlot reduced animal performance, changed physiology, and altered behavior indicating acute pain. Fortunately, administering the non-steroidal anti-inflammatory drug meloxicam reduced the serum haptoglobin increase from surgical castration and improved average daily gain regardless of castration method.
To read the full article "Effect of castration method and analgesia on inflammation, behavior, growth performance, and carcass traits in feedlot cattle," visit the Journal of Animal Science.