Effect of castration timing and oral meloxicam administration on growth performance, inflammation, behavior, and carcass quality of beef calves12

Abstract

Beef bull calves (n = 62) were assigned randomly, within sire breed, to 1 of 4 treatments at birth. Treatments were 1) surgical castration near birth, 2) surgical castration near birth with oral administration of meloxicam (1 mg/kg BW), 3) surgical castration at weaning (WNG), or 4) surgical castration at weaning with oral administration of meloxicam (1 mg/kg BW; WMX). A subset of calves (n = 7/treatment group) were selected randomly near birth for blood collection, behavioral analyses, and rectal temperature (RT) records for a 7-d postcastration period on d 0 (birth), 1, 3, and 7, and on d 214 (weaning), 214 + 6 h, 215, 217, 221, and 228. Calf standing and lying activity were monitored from the same subsets by recording x- and y-axis positions of an accelerometer attached to the right metatarsus for 7 d postcastration. Calf BW was recorded throughout the entire production cycle, and carcass data were collected at slaughter. For statistical analyses, bulls left intact at birth were considered a positive control (BUL) for observations that occurred before their treatment application at weaning; likewise, bulls castrated at birth were considered a negative control (STR) during postweaning observations. No difference (P > 0.88) occurred in ADG between treatments throughout the preweaning period (d 0 to 214); however, 56-d postweaning ADG was greatest ( P= 0.02) in STR, intermediate in WMX, and least in WNG. At weaning, haptoglobin (Hp) was greater (P ≤ 0.005) for WNG and WMX compared to STR on d 214+6 h, 215, and 217, and Hp was greater (P = 0.05) in WNG compared to WMX on d 217. Neutrophils increased (P < 0.001) and red blood cells decreased (P ≤ 0.03) for WNG and WMX on d 214+6 h and 217, respectively. Postweaning behavior observations indicated that STR calves spent the least proportion of time standing (P = 0.002) when compared to WNG and WMX. Furthermore, WMX calves exhibited a greater proportion of time spent standing (P = 0.03) compared to WNG. Grazing and finishing phase ADG and carcass measurements did not differ (P ≥ 0.24) across treatments. In this study, surgical castration at weaning, but not near birth, altered the acute phase response, behavior, and growth performance. Oral meloxicam reduced serum Hp and improved ADG briefly when administered to calves castrated at weaning. Oral administration of meloxicam may be efficacious for mitigating some of the stress and inflammation associated with castration of weaning-age bull calves.

Effect of a single dose of subcutaneous meloxicam prior to band or knife castration in 1-wk-old beef calves: II. Inflammatory response and healing1

“…The lack of medication effect on APP concentrations in this study was similar to the findings of Brown et al (2015), who reported no differences in Hp concentrations when new born calves were castrated with or without the administration of oral meloxicam. In contrast, in the same study conducted by Brown et al (2015), as well as a study by Roberts et al (2015), it was found that oral meloxicam reduced peak Hp concentrations in calves castrated at weaning. Roberts et al (2018) observed that the reduction of Hp concentrations after oral meloxicam administration was only visible after surgical castration vs. band castration in weaned beef calves.…”

Effect of a single dose of subcutaneous meloxicam before knife castration alone or combined with hot-iron branding on scrotal healing, inflammatory response, and behaviour in 2-mo-old beef calves over 42 d post procedure

“…For example, Meléndez et al (2018b) observed that SAA concentrations were elevated during the first 3 d after castration and branding were conducted. Brown et al (2015) found differences in Hp up to 72 h post castration and Warnock et al (2012) up to day 6 post castration in weaned calves.…”

“…Meloxicam is a nonsteroidal anti-inflammatory drug (NSAID) that has been recently tested to mitigate the pain of castration in weaned calves (Brown et al 2015;Roberts et al 2015;Meléndez et al 2017b). Furthermore, the anti-inflammatory properties of oral meloxicam have been shown to reduce morbidity in weaned castrated beef calves suggesting that its effect may last several days after a single treatment (Coetzee et al 2012).…”

An investigation of hair cortisol as a measure of long-term stress in beef cattle: results from a castration study

“…Castration is known to be a painful and acute stressor (Stafford et al 2002;Brown et al 2015), and has been used as an applicable model of stress to better understand the cortisol response to acute stress (Earley and Crowe 2002). Following surgical castration of bull calves behavioural pain measures remain elevated for up to 3 d (Olson et al 2016); however, the full duration of time pain persists following castration is unknown.…”

“…The number of steps taken by calves as well as their stride length decreases following castration in calves castrated without pain medication (Currah et al 2009). In addition, abnormal postures, including statue standing, increase following castration to decrease the stimulation of the injured site (Molony et al 1995) and standing time can be measured using accelerometers (White et al 2008;Brown et al 2015). Thus, accelerometers were used in this study to determine lying and standing time as a behavioural measure of postcastration pain (Brown et al 2015).…”