title: Cardiac responses to palpation per rectum in lactating and nonlactating dairy cows.
abstract: Interest in the monitoring of heart rate variability (HRV) has increased recently, as it gives more detailed and immediate information about the level of stress than traditional behavioral or hypothalamus-pituitary-adrenal measures. In this study, we evaluated heart rate (HR) and parasympathetic HRV parameters to monitor cardiac stress responses to palpation per rectum (PPR) in lactating (LACT; n = 11) and nonlactating (NLACT; n = 12) dairy cows. Heart rate and HRV were recorded from 40 min before PPR until 120 min after it was completed. Heart rate, the root mean square of successive differences (RMSSD), and the high-frequency component (HF) of HRV were analyzed by examining 5-min time windows. To compare cardiac responses to PPR between groups, changes in HR and HRV parameters were calculated as area under the curve (AUC) for LACT and NLACT cows. An immediate increase in HR was detected during PPR in both LACT (+21.4 ± 2.4 beats/min) and NLACT cows (+20.6 ± 2.3 beats/min); however, no differences were found between groups on the basis of parameters of AUC. The increase in HR in both groups along with a parallel decrease in RMSSD (LACT cows: -5.2 ± 0.4 ms; NLACT cows: -5.1 ± 0.4 ms) and HF [LACT cows: -10.1 ± 0.8 nu (where nu = normalized units); NLACT cows: -16.9 ± 1.2 nu] during PPR indicate an increase in the sympathetic, and a decrease in the parasympathetic tone of the autonomic nervous system. The increase in RMSSD (LACT cows: +7.3 ± 0.7 ms; NL cows: +17.8 ± 2.2 ms) and in HF (LACT cows: +24.3 ± 2.6 nu; NLACT cows: +32.7 ± 3.5 nu) immediately after PPR indicated a rapid increase in parasympathetic activity, which decreased under the baseline values 10 min following PPR. The amplitude and the maximum RMSSD and HF values were greater in NLACT cows than in LACT animals, suggesting a higher short-term cardiac responsiveness of NLACT cows. However, the magnitude and the duration of the stress response were greater in LACT cows, as indicated by the analysis of AUC parameters (area under the HRV response curve and time to return to baseline). Cow response to the PPR was more prominent in parasympathetic HRV measures than in HR. Based on our results, the effect of PPR on the cows' cardiac stress responses may have an impact on animal welfare on dairy farms, and investigating the effect of lactation on the cardiac stress reactions could prove useful in modeling bovine stress sensitivity. Further research is needed to find out whether the differences due to lactation are physiological or management related.
authors.affiliation: Institute of Animal Husbandry, Faculty of Agricultural and Environmental Science, Szent István University, Páter Károly utca 1, Gödöllő 2100, Hungary; Hungarian Academy of Sciences-Szent István University (HAS-SZIU) Large Animal Clinical Research Group, Üllő-Dóra major 2225, Hungary. Electronic address: Kovacs.Levente@mkk.szie.hu.
authors.forename: L
authors.initials: L
authors.lastname: Kovács
authors.affiliation: Institute of Animal Husbandry, Faculty of Agricultural and Environmental Science, Szent István University, Páter Károly utca 1, Gödöllő 2100, Hungary.
authors.forename: J
authors.initials: J
authors.lastname: Tőzsér
authors.affiliation: Hungarian Academy of Sciences-Szent István University (HAS-SZIU) Large Animal Clinical Research Group, Üllő-Dóra major 2225, Hungary.
authors.forename: O
authors.initials: O
authors.lastname: Szenci
authors.affiliation: Institute of Animal Husbandry, Faculty of Agricultural and Environmental Science, Szent István University, Páter Károly utca 1, Gödöllő 2100, Hungary.
authors.forename: P
authors.initials: P
authors.lastname: Póti
authors.affiliation: Institute of Animal Husbandry, Faculty of Agricultural and Environmental Science, Szent István University, Páter Károly utca 1, Gödöllő 2100, Hungary.
authors.forename: F L
authors.initials: FL
authors.lastname: Kézér
authors.affiliation: Institute of Economics, Law and Methodology, Faculty of Economics and Social Sciences, Szent István University, Páter Károly utca 1, Gödöllő 2100, Hungary.
authors.forename: F
authors.initials: F
authors.lastname: Ruff
authors.affiliation: Institute of Economics, Law and Methodology, Faculty of Economics and Social Sciences, Szent István University, Páter Károly utca 1, Gödöllő 2100, Hungary.
authors.forename: Gy
authors.initials: G
authors.lastname: Gábriel-Tőzsér
authors.affiliation: Bóly Co., Ady Endre utca 21, Bóly 7754, Hungary.
authors.forename: D
authors.initials: D
authors.lastname: Hoffmann
authors.affiliation: Rumino-Vet Bt, Csillés utca 2, Érd 2030, Hungary.
authors.forename: M
authors.initials: M
authors.lastname: Bakony
authors.affiliation: Department of Animal Hygiene, Herd Health and Veterinary Ethology, Faculty of Veterinary Science, Szent István University, István utca 2, Budapest 1078, Hungary.
authors.forename: V
authors.initials: V
authors.lastname: Jurkovich
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D007774:Lactation; D008991:Monitoring, Physiologic / Q000662:veterinary*; D010173:Palpation / Q000009:adverse effects / Q000662:veterinary*; D012007:Rectum / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*
keywords: dairy cow; heart rate; heart rate variability; palpation per rectum