Short communication: Relationships among temperature-humidity index with rectal, udder surface, and vaginal temperatures in lactating dairy cows experiencing heat stress

Abstract

The objective of this study was to evaluate relationships between measurements of temperature-humidity index (THI) and rectal, vaginal, and udder surface temperatures in lactating cows exposed to heat stress (HS). In experiment 1, 12 multiparous and 8 primiparous Holstein cows experienced a THI ranging from 69 to 76 at 2000 to 1000 h and THI from 74 to 82 at 1000 to 2000 h (peaked at 82 from 1400 to 1800 h). Cows were exposed to HS 10 h daily for 21 d. Measurements of rectal temperature (RT) and udder surface temperature were collected at 1000 and 1500 h (±30 min). Vaginal temperature was monitored every 10 min using digital loggers, averaged over 1 h, and paired with corresponding rectal and udder surface temperature data. In experiment 2, 12 multiparous Holstein cows experienced a THI ranging from 60 to 76 at 2000 to 1000 h and THI from 69 to 83 at 1000 to 2000 h (peaked at 83 from 1600 and 1900 h), eliciting 10 h/d of HS for 7 d. Rectal and udder surface temperatures were analyzed at 0700 and 1500 h (±30 min). Vaginal temperature was recorded and analyzed as indicated in experiment 1. Afternoon THI showed weak correlations with surface temperature (r = 0.19, n = 420 in experiment 1; r = 0.23, n = 84 in experiment 2), weak to moderate correlations with RT (r = 0.34, n = 366 in experiment 1; r = 0.26, n = 84 in experiment 2), and moderate correlations with vaginal temperature (r = 0.34, n = 175 in experiment 1; r = 0.35, n = 40 in experiment 2). Moreover, vaginal temperature increased 0.10 and 0.22°C per unit of THI (R = 0.15 in experiment 1; R = 0.40 in experiment 2). Afternoon vaginal temperature strongly correlated with RT (r = 0.69, n = 131 in experiment 1; r = 0.63, n = 37 in experiment 2) and explained 57 (experiment 1) and 68% (experiment 2) of variation in RT. Surface temperature showed moderate to strong correlations with RT (r = 0.57, n = 84) and vaginal temperature (r = 0.74, n = 37) in experiment 2. In conclusion, THI showed a weak to moderate relationship with core body temperatures and explained the increase in rectal and vaginal temperatures experienced by HS cows. Compared with rectal temperature, vaginal temperature showed stronger relationships with THI and can be used to determine thermal load. Udder surface temperature showed a moderate to strong relationship with core body temperature, and this relationship may support the use of surface temperature data to manage thermal load in HS cows.

Establishment of long-term chronic recording technique of <i>in vivo</i> ovarian parenchymal temperature in Japanese Black cows

“…Similarly, temperature gradient variations in reproductive organs could affect the efficiency of ovulation and fertilization in female rabbits, swine, and humans [10]. Under heat stress conditions, development of the dominant follicle is suppressed [1], suggesting that suppression is due to a higher reproductive organ temperature [11]. Thus, reproductive organ temperature could be critical to ovulation and/or follicle development.…”

Relationship between Rectal Temperature and Vaginal Temperature in Grazing Bos taurus Heifers

“…Previous studies have suggested that a strong relationship exists between T REC and T VAG in Bos indicus heifers (r = 0.92, p < 0.0001; Burdick et al [ 21 ]), pregnant dairy cows (R 2 = 0.90, p < 0.05; Hillman et al [ 19 ]), and lactating dairy cows (r = 0.81, p < 0.001, Vickers et al [ 18 ]; r = 0.92 ≤ 0.94, p < 0.001, [ 26 ]), although the strength of the relationship between T REC and T VAG decreased (r = 0.46, p < 0.001) during peak lactation [ 18 ]. Additionally Kaufman et al [ 20 ] showed that the relationship between T REC and T VAG increased from morning (1000 h, r = 0.47, p < 0.01) to afternoon (1500 h, r = 0.69, p < 0.01) in lactating dairy cows. The relationships identified within the current study are greater than those described by Hillman et al [ 19 ], Vickers et al [ 18 ], and Kaufman et al [ 20 ].…”

“…Additionally Kaufman et al [ 20 ] showed that the relationship between T REC and T VAG increased from morning (1000 h, r = 0.47, p < 0.01) to afternoon (1500 h, r = 0.69, p < 0.01) in lactating dairy cows. The relationships identified within the current study are greater than those described by Hillman et al [ 19 ], Vickers et al [ 18 ], and Kaufman et al [ 20 ]. However, the relationships between T REC and T VAG within these studies were evaluated using intra-vaginal data loggers and hand-held thermometers to obtain time point measurements of T REC , with variable intervals.…”

“…Previous studies have established moderate to strong relationships between T REC and vaginal temperature (T VAG , °C) in dairy cows [ 17 , 18 , 19 , 20 ] and Brahman heifers [ 21 ]. However, previous evaluations of the relationship between different measures of body temperature have often utilized continuous recordings of one measure, i.e., vaginal, compared with time point sampling of another measure, i.e., rectal [ 2 , 15 , 17 , 18 , 19 , 20 ]. Therefore, these studies may be under or over estimating the relationship that exists between these measures of body temperature.…”

The status of Mycoplasma bovis infection in clinical mastitis cases in China

“…The specific calculation formula for THI is as follows (Sch€ uller et al 2013;Contreras-Jodar et al 2018;Kaufman et al 2018): THI = (1.8 9 T air + 32)À(0.55-0.55 9 RH) 9 (1.8 9 T air À26), where THI is the temperature humidity index, T air is the air temperature (°C), and RH is the relative humidity (%). We calculated the monthly variation in THI in the Inner Mongolia Autonomous Region by introducing the data from the Inner Mongolia Meteorological Service database.…”