Associations between Heart Rate Variability Parameters and Housing- and Individual-Related Variables in Dairy Cows Using Canonical Correspondence Analysis

PLOS ONE, Dec 2019

We investigated the associations between heart rate variability (HRV) parameters and some housing- and individual-related variables using the canonical correspondence analysis (CCOA) method in lactating Holstein-Friesian dairy cows. We collected a total of 5200 5-min interbeat interval (IBI) samples from 260 animals on five commercial dairy farms [smaller-scale farms with 70 (Farm 1, n = 50) and 80 cows per farm (Farm 2, n = 40), and larger-scale farms with 850 (Farm 3, n = 66), 1900 (Farm 4, n = 60) and 1200 (Farm 5, n = 45) cows. Dependent variables included HRV parameters, which reflect the activity of the autonomic nervous system: heart rate (HR), the root mean square of successive differences (RMSSD) in IBIs, the standard deviation 1 (SD1), the high frequency (HF) component of HRV and the ratio between the low frequency (LF) and the HF parameter (LF/HF). Explanatory variables were group size, space allowance, milking frequency, parity, daily milk yield, body condition score, locomotion score, farm, season and physical activity (lying, lying and rumination, standing, standing and rumination and feeding). Physical activity involved in standing, feeding and in rumination was associated with HRV parameters, indicating a decreasing sympathetic and an increasing vagal tone in the following order: feeding, standing, standing and rumination, lying and rumination, lying. Objects representing summer positioned close to HR and LF and far from SD1, RMSSD and HF indicate a higher sympathetic and a lower vagal activity. Objects representing autumn, spring and winter associated with increasing vagal activity, in this order. Time-domain measures of HRV were associated with most of the housing- and individual-related explanatory variables. Higher HR and lower RMSSD and SD1 were associated with higher group size, milking frequency, parity and milk yield, and low space allowance. Higher parity and milk yield were associated with higher sympathetic activity as well (higher LF/HF), while individuals with lower locomotion scores (lower degree of lameness) were characterized with a higher sympathetic and a lower vagal tone (higher HR and LF/HF and lower RMSSD and SD1). Our findings indicate that the CCOA method is useful in demonstrating associations between HRV and selected explanatory variables. We consider physical activity, space allowance, group size, milking frequency, parity, daily milk yield, locomotion score and season to be the most important variables in further HRV studies on dairy cows.

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Associations between Heart Rate Variability Parameters and Housing- and Individual-Related Variables in Dairy Cows Using Canonical Correspondence Analysis

December Associations between Heart Rate Variability Parameters and Housing- and Individual- Related Variables in Dairy Cows Using Canonical Correspondence Analysis Levente Kovács 0 1 Fruzsina Luca Kézér 0 1 Mikolt Bakony 0 1 Levente Hufnágel 0 1 János Tőzsér 0 1 Viktor Jurkovich 0 1 0 1 MTA-SZIE Large Animal Clinical Research Group, Üllő-Dóra major, H-2225, Hungary, 2 Institute of Animal Husbandry, Faculty of Agricultural and Environmental Science, Szent István University , Páter Károly u. 1, Gödöllő, H-2100, Hungary, 3 Rumino-Vet Bt., Csillés utca 2., Érd, H-2030, Hungary , 4 Institute of Crop Production, Faculty of Agricultural and Environmental Science, Szent István University , Páter Károly u. 1, Gödöllő, H-2100, Hungary , 5 Department of Animal Hygiene, Herd Health and Veterinary Ethology, Faculty of Veterinary Science, Szent István University , István u. 2, Budapest, H-1078 , Hungary 1 Editor: Peter J. Hansen, University of Florida, UNITED STATES Data Availability Statement; All relevant data are within the paper - Funding: This study was supported by the Research Centre of Excellence, grant number: 9878/2015/ FEKUT, http://www.nemzetikivalosag.hu. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. We investigated the associations between heart rate variability (HRV) parameters and some housing- and individual-related variables using the canonical correspondence analysis (CCOA) method in lactating Holstein-Friesian dairy cows. We collected a total of 5200 5min interbeat interval (IBI) samples from 260 animals on five commercial dairy farms [smaller-scale farms with 70 (Farm 1, n = 50) and 80 cows per farm (Farm 2, n = 40), and larger-scale farms with 850 (Farm 3, n = 66), 1900 (Farm 4, n = 60) and 1200 (Farm 5, n = 45) cows. Dependent variables included HRV parameters, which reflect the activity of the autonomic nervous system: heart rate (HR), the root mean square of successive differences (RMSSD) in IBIs, the standard deviation 1 (SD1), the high frequency (HF) component of HRV and the ratio between the low frequency (LF) and the HF parameter (LF/HF). Explanatory variables were group size, space allowance, milking frequency, parity, daily milk yield, body condition score, locomotion score, farm, season and physical activity (lying, lying and rumination, standing, standing and rumination and feeding). Physical activity involved in standing, feeding and in rumination was associated with HRV parameters, indicating a decreasing sympathetic and an increasing vagal tone in the following order: feeding, standing, standing and rumination, lying and rumination, lying. Objects representing summer positioned close to HR and LF and far from SD1, RMSSD and HF indicate a higher sympathetic and a lower vagal activity. Objects representing autumn, spring and winter associated with increasing vagal activity, in this order. Time-domain measures of HRV were associated with most of the housing- and individual-related explanatory variables. Higher HR and lower RMSSD and SD1 were associated with higher group size, milking frequency, parity and milk yield, and low space allowance. Higher parity and milk yield were associated with higher sympathetic activity as well (higher LF/HF), while individuals with lower locomotion scores (lower degree of lameness) were characterized with a higher sympathetic and a lower vagal tone (higher HR and LF/HF and lower RMSSD and SD1). Our findings indicate that the CCOA method is useful in demonstrating associations between HRV and selected explanatory variables. We consider physical activity, space allowance, group size, milking frequency, parity, daily milk yield, locomotion score and season to be the most important variables in further HRV studies on dairy cows. Introduction Stress affects many physiological systems including the cardiovascular system, which is controlled by the autonomic nervous system [ 1 ]. Heart rate variability (HRV), i.e. the short-term fluctuations in the length of successive cardiac interbeat intervals (IBI) is essentially based on the antagonistic oscillatory influences of the sympathetic and parasympathetic nervous system on the nodus sinuatrialis of the heart [ 2 ]. It thus reflects the prevailing balance of the sympathetic and the parasympathetic (vagal) tone. As stress responses are accompanied by the rapid increase in sympathetic activity and a parallel decrease in vagal activity [ 3 ], HRV has been increasingly used in farm animals, such as cattle, swine, sheep and poultry as an indicator for the response of the autonomic nervous system (ANS) to stress [ 4 ]. According to our recent review on the welfare implications of HRV in dairy cattle [ 5 ] several HRV indices are useful in investigating stress caused by technological elements or diseases. So far, cattle HRV (...truncated)


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Levente Kovács, Fruzsina Luca Kézér, Mikolt Bakony, Levente Hufnágel, János Tőzsér, Viktor Jurkovich. Associations between Heart Rate Variability Parameters and Housing- and Individual-Related Variables in Dairy Cows Using Canonical Correspondence Analysis, PLOS ONE, 2015, Volume 10, Issue 12, DOI: 10.1371/journal.pone.0145313