Location: Livestock Issues ResearchTitle: Phenotypic and genetic parameters of circadian rhythms from core body temperature profiles and their relationships with beef steers’ production efficiency profiles during successive winter-feeding periods
|DURUNNA, OBIOHA - Lakeland College|
|Carroll, Jeffery - Jeff Carroll|
|DAMIRAN, DAALKHAIJAV - University Of Saskatchewan|
|LARSON, KATHY - University Of Saskatchewan|
|TIMSIT, EDOUARD - University Of Calgary|
|PARSONS, REX - Queensland University Of Technology|
|MANAFIAZAR, GHADER - Dalhousie University|
|LARDNER, BART - University Of Saskatchewan|
Submitted to: Frontiers in Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2023
Publication Date: 2/10/2023
Citation: Durunna, O., Carroll, J.A., Dailey, J.W., Damiran, D., Larson, K.A., Timsit, E., Parsons, R., Manafiazar, G., Lardner, B.A. 2023. Phenotypic and genetic parameters of circadian rhythms from core body temperature profiles and their relationships with beef steers’ production efficiency profiles during successive winter-feeding periods. Frontiers in Genetics. 14. https://doi.org/10.3389/fgene.2023.1154825.
Interpretive Summary: Recent advancements in telemetry or wireless data transfer systems have made it easier and cheaper to automate and acquire difficult-to-measure data from individual cattle. Compared to conventional manual body temperature measurements, these devices enhance the ability to collect individual temperature information from large groups of cattle under different environmental conditions. To evaluate the feasibility of using these devices in feedlot cattle, ARS, Canadian and Australian scientists conducted a two-year study in Canada. The study evaluated the potential of capturing, analyzing, and using sensor-generated data to improve the assessments and selection of replacement cattle during western Canadian winters. The results from this study support the existence and potential use of circadian rhythm-adjusted parameters in selecting cattle due to high heritability or the rumen or rectal temperature. This information will be of interest to beef cattle producers, veterinarians, feedlot managers, and scientists working in the field of beef cattle production as it relates to environmental temperature.
Technical Abstract: This 2-yr study evaluated differences in circadian parameters obtained from measures of core body temperatures using telemetric reticulo-rumen and rectal devices during two winter feeding periods in western Canada. The study also estimated phenotypic relationships and genetic parameters associated with circadian parameters and other production traits in each period. Each year, 80 weaned steer calves (initial age: 209 ± 11 d; BW: 264 ± 20 kg) from the same cohort were tested over two successive periods, Fall-Winter (FW) and Winter-Spring (WS) at Lanigan, Saskatchewan, Canada. The steers received forage-based rations in both periods where the individual feed intake was measured with automatic feeding units. During the trial, the reticulo-rumen (RTMP) and rectal (RCT) temperatures were simultaneously measured every 5 minutes using telemetric devices. These were used to calculate the circadian parameters (mesor, amplitude, and peak time) for both temperature measures. Growth and efficiency performance traits were also determined for all steers. Each steer was assigned into inefficient, neutral, and efficient classes based on the SD of the residual feed intake (RFI), residual gain (RG), and residual intake and gain (RIG) within each year and feeding period. Higher (P < 0.0003) RTMP and RCT mesors were observed in the FW compared to the WS period. While the two test periods were different (P < 0.05) for the majority of the RTMP or RCT temperature parameters, they did not differ (P > 0.10) with the production efficiency profiles. The heritability estimates were higher in FW (0.78 vs. 0.57) than WS (0.50 vs. 0.43) for the rumen and rectal mesors, respectively. There were positive genetic correlations between the two periods for the RTMP (0.69) and RCT (0.35). There was a strong negative correlation (P < 0.0001) between body temperature and ambient temperature. The high heritability estimates and genetic correlations for rumen and rectal temperature parameters demonstrate their potential as beef genetic improvement tools of economic traits associated with the parameters. However, there are limited practical implications of using only the core-body temperature as a proxy for production efficiency traits for beef steers during winter.