Risk factor analysis for beef calves requiring assisted vaginal delivery in Great Britain

Abstract

Background: Dystocia has serious consequences for both mother and offspring. This study therefore aimed to identify risk factors for dystocia in vaginally delivered spring born beef calves in Great Britain (GB). Methods: Information on calving assistance, calf sex, birthweight, breed, twinning, dam parity and body condition score (BCS) was collected from 1131 calves across 84 GB farms. Variables were modelled against calving assistance as a binary response variable. Results: Twins (Odds Ratio [OR] = 5.45), Charolais calves (OR = 3.24), calves from primiparous dams (OR = 5.75) and male calves (OR = 1.75) were at significantly increased risk of requiring calving assistance across all models. Calves born to cows classed as thin (BCS < 2.5/5) were identified in the univariate analysis and in one of the multivariate models (OR = 1.92) as having an increased likelihood of dystocia. Conclusions: Most beef herds have limited scope to manage cows on the basis of fetal gender and number. However, calf breed, dam body condition and management of primiparous dams can be manipulated to reduce the risk of dystocia and improve supervision. Poor body condition is a novel risk factor for dystocia in beef cows and worthy of further investigation.

Managing bovine dystocia – an age‐old problem

“…Almost one in five calvings were recorded as being assisted, which, as the authors point out, is likely to be an underestimate since calves born dead or via caesarean section were excluded from the analysis. 8 This is considerably higher than previous estimates in both the beef and dairy industries, 9 and it raises certain questions. First, is there a major problem in that one-fifth of the British beef cow population are unable to deliver their calves naturally?…”

“…However, the study did identify an increased dystocia risk for thin cows, which is a finding that warrants further investigation. 8 In recent years, a standard metric in assessing beef suckler productivity at herd level has been weaned calf weight as a percentage of adult cow weight, with a target of 50 per cent or more considered to indicate successful economic performance. However, as Bragg and colleagues state, adherence to this metric may emphasise the production of relatively large calves from small cows, thereby increasing dystocia risk.…”

“…A similar metric of birthweight as a percentage of average herd dam weight has demonstrated some utility as a predictor of dystocia, with a target value of less than 8 per cent being suggested. 8 However, herd average cow weight is a relatively crude measure. Bragg and colleagues suggest that further studies aimed at refining this metric should be undertaken with the intention of assisting farmers in breeding decisions.…”

“…Understanding the risk factors associated with dystocia, and implementing appropriate management strategies to reduce these risks, is critical for the production of healthy, viable beef calves RESEARCH COMMENT associated with dystocia in beef cattle in Great Britain. 8 The study included calves born in 84 British suckler herds, and, as with most studies of dystocia, ease of calving was recorded on a four-point scale. Individual calf data were collected within two to five days of birth, thereby minimising recall bias regarding calf delivery.…”

Assisting calving rates outdoor or indoor

“…I WOULD like to thank Dai Grove‐White for his insightful commentary ( VR , 23/30 January 2021, vol 188, pp 67–69) on our recent paper 1 …”