10 PREDICTION OF CALVING TIME USING BODY-SURFACE TEMPERATURE SENSORS AND PEDOMETERS IN BEEF CATTLE

Abstract

Predicting the onset of calving is important for the prevention of stillbirths. This study aimed to investigate whether using body-surface temperature and number of steps at the time of calving could be used to predict calving time. Three heifers and 4 cows of the beef cattle variety were used in this study. All animals were housed in calving pens measuring 4.2 × 3.6 m each. Body-surface temperature was recorded using a sensor that was fixed ventrally to the body of the tail head (NIAH, NARO, Tsukuba, Japan). The number of steps the beef cattle took was measured using pedometers (Gyuho, Comtec, Miyazaki, Japan), where each 10 steps resulted in 1 count. The temperature sensors and pedometers were placed on the animals for at least 10 days before the estimated date of delivery. Body-surface temperature and pedometer readings were automatically collected every 2 min and every hour. The data used to predict calving were the means of the body-surface temperature and steps taken, which were recorded from the day the sensors were mounted until 1 day after calving. All data were statistically analysed using t-tests. The mean body-surface temperature before calving was 35.4°C (10 h), which was significantly lower than that recorded 3 days before calving (36.2°C; P < 0.05). The mean body-surface temperature of beef cattle 10 to 6 h before calving (36.0°C) was not significantly different from the mean temperature 3 days before calving. However, from 5 to 1 h before calving, the mean body-surface temperature (34.8°C) was significantly lower than that 3 days before calving (P < 0.05). The mean step number of 101.4 counts, taken 10 h before calving, was significantly increased compared with the mean step number of 44.7 counts 3 days before calving (P < 0.05). The mean step number of 59.7 counts from 10 to 6 h before calving was not significantly different from readings taken 3 days before calving. The mean step number count from 5 to 1 h before calving was 143.1 counts, which increased significantly from readings taken 3 days before calving (P < 0.05). In conclusion, ventral tailhead body-temperature sensors and pedometers can be used to predict the onset of calving in beef cattle. Their body-surface temperature, along with the number of steps taken before calving, decreased and increased, respectively, in the 5 h leading up to calving.

This study was supported by the Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), and the Technologies for creating next-generation agriculture, forestry and fisheries (funding agency: Bio-oriented Technology Research Advancement Institution, NARO).