Assessment of the temperature cut-off point by a commercial intravaginal device to predict parturition in Piedmontese beef cows

Authors: RICCI, ALESSANDRO - UNIVERSITY OF TURIN; IOTTI, B. - UNIVERSITY OF TURIN; BERTERO, A. - UNIVERSITY OF TURIN; REED, KRISTAN; PASCOTTINI, OSVALDO - UNIVERSITY OF GUELPH

Submitted to: Theriogenology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2018
Publication Date: 2/10/2018
Citation: Ricci, A., Iotti, B., Bertero, A., Reed, K., Pascottini, O. 2018. Assessment of the temperature cut-off point by a commercial intravaginal device to predict parturition in Piedmontese beef cows. Theriogenology. 10.1016/j.theriogenology.2018.02.009.

Interpretive Summary: Difficulty with calving causes health problems for both the dam and calf. If unattended, problems during parturition can even lead to death of the dam, calf, or both. Double-muscled breeds, like the Piedmontese breed from northwestern Italy, are especially at risk and require assistance at calving even more often than other breeds. To ensure timely arrival of veterinary assistance, parturition; must be predicted in advance of the event. Intravaginal temperature has been used as a physiologic property that changes prior to parturition however, a cut-off temperature or magnitude of temperature decrease, has not been established to standardize the use of this technique. An automatic intravaginal temperature sensor was used to continuously, remotely track temperature from one week before expected parturition in 248 Piedmontese cows from 4 commercial herds. A cut-off temperature of 32.8 degrees Celsius was found to be a more accurate metric for predicting parturition than a drop in temperature of 0.2 degrees Celsius. Use of this cutoff temperature in automatic intravaginal temperature devices has the potential to reduce health risks and costs associated with difficult calvings.

Technical Abstract: Dystocic parturitions have an adverse impact on animal productivity, and therefore the profitability of the farm. In this regard, an accurate calving prediction is essential since it allows for efficient and prompt assistance for the dam and the calf. Numerous approaches to predict parturition have been studied; among these, the measurement of intravaginal temperature (IVT) is the most effective method at field level. Thus, objectives of this experiment were, 1) to find an IVT cut-off to predict calving within 24 h, and 2) to clarify the use of IVT as an automated method of calving detection in stabbed beef cows. A commercial intravaginal electronic device (Medria Vel’Phone®) with a sensor that measures the IVT every 12 h was used. Piedmontese cows (n = 211; 27 primiparous and 184 multiparous) were included in this study. One-way analysis of variance was used to assess the temperature differences at 0, 12, 24, 36, 48 and 60 h before parturition. Receiving operator characteristic curves were built to determine the temperature cut-off which predicts calving within 24 h with the highest summation of sensitivity (Se) and specificity (Sp). Binomial logistic regression models were computed to identify factors that may affect the IVT before calving. Mean gestation length was 291.5 ± 13.7 d (primiparous, 292 ± 14.1 d; multiparous, 289±9.2 d). A decrease was found (P < 0.001) in the average IVT from 60 h before calving until the expulsion of the IVT device. Specifically, a significant (P < 0.05) reduction in IVT occurred in the final 24 hours before parturition.. The IVT drop to predict parturition 24 h before calving was 0.21°C (area under the curve [AUC] = 0.72; Se = 66%, Sp = 76%). Furthermore, the IVT cut-off value to predict parturition within 24 h was 38.2°C (AUC = 0.89; Se = 86%, Sp = 91%). None of the evaluated fixed effects (parity, dystocia, season or length of gestation) affected (P < 0.05) the IVT variation from 60 h before until calving. To conclude, the IVT average seems to be a better parameter than the drop of temperature to predict parturition within 24 h. In this regard, a cut-off of 38.2°C showed a high Se and Sp. This study demonstrates the usefulness of a commercially available device to predict calving to improve management in stabbed beef farms.