Preliminary Investigation to Address Pain and Haemorrhage Following the Spaying of Female Cattle

SIMPLE SUMMARY: The spaying of female cattle is a routine husbandry procedure conducted in some extensive beef systems, including in northern Australia. Female cattle may be spayed to control stocking rates, reduce mortalities associated with breeding, or to enable surplus females to be sold in compliance with live export requirements. The more widely practiced Willis dropped ovary technique involves severing the ovarian attachments via use of an ovariotome, which is inserted trans-vaginally to enter the abdominal cavity. While the procedure has been shown to cause pain, stress, morbidity, and mortality, it is mostly conducted without the use of veterinary pharmaceuticals. This study evaluates the efficacy of a topical anaesthetic, haemostatic wound dressing, and a non-steroidal anti-inflammatory drug for minimising pain and haemorrhage in the acute period post-spaying via the Willis dropped ovary technique. Adverse behavioural responses observed in spayed heifers were reduced in those cattle that received the non-steroidal anti-inflammatory drug, suggesting an improvement in animal welfare. ABSTRACT: Multiple physiological and neuroendocrine changes consistent with stress and pain have been demonstrated in cattle spayed via the Willis dropped ovary technique (WDOT). The procedure is routinely conducted without the use of anaesthetics or analgesics and has major implications for animal welfare. This study aimed to evaluate the effect of a topical anaesthetic (TA), haemostatic wound dressing, and meloxicam on pain behaviour and haemorrhage in the acute period following spaying. Yearling Brahman heifers (n = 75) were randomly allocated to the following treatment groups: (1) rectal palpation/control (CON); (2) WDOT spay (S); (3) WDOT spay with meloxicam (SM); (4) WDOT spay with TA (STA); and (5) WDOT spay with TA and meloxicam (STAM). Individual behavioural responses, body weight, packed cell volume (PCV), and total plasma protein (TPP) were monitored for up to 24 h following treatment. Head tucking behaviour and tail stiffness was increased in all spay groups compared to the CON group (p < 0.001), with the lowest proportional increase in the SM group. Rumination was initially reduced in S, SM, and STA heifers compared to CON heifers (p < 0.001), though SM heifers ruminated more than S heifers (p < 0.001). CON and SM heifers stood with an arched back the least, spent the most time eating, and spent less time lying down and more time standing compared to other treatment groups (p < 0.001). There was no significant effect of treatment on weight change (p = 0.519), PCV (p = 0.125) or TPP (p = 0.799). The administration of meloxicam is suggested as an effective, currently available method for improving the welfare of cattle undergoing WDOT spaying.