Effectiveness of a Real-time Radiotelemetric Pedometer for Estrus Detection and Insemination in Japanese Black Cows

Abstract

Abstract. The objective of this study was to investigate the efficiency of estrus detection and determination of the time of ovulation in Japanese Black cows by a real-time radiotelemetric pedometer. A herd of Japanese Black cows was housed in a loose-housing barn. This pedometer system and a pressure-sensing radiotelemetric device, which detects standing events, were concurrently compared in regard to their availability for detection of estrus events. Pedometer estrus and standing events were observed for all cows (n=20), and the duration of increased walking activity was 15.8 ± 0.9 h, which was longer (P<0.0001) than the duration of standing events (9.0 ± 1.3 h). Ovulation was observed 30.2 ± 0.6 h after the onset of pedometer estrus and 29.0 ± 0.6 h after the first standing event. There was a high correlation (r=0.89, P<0.0001) between the intervals from the onset of pedometer estrus and onset of standing event to ovulation. The animals of the pedometric group (n=20) were inseminated 10 to 18 h after the onset of pedometer estrus and had a higher conception rate (90.0%, P<0.05) than those inseminated according to the a.m. /p.m. method (58.4%, n=24). In conclusion, the pedometer system is an excellent tool for precise estrus detection and insemination at the appropriate time, which ensure a high pregnancy rate in Japanese Black cows.

Efficiency of a pedometer device for detecting estrus in standing heat and silent heat in Japanese Black cattle

“…These results showed that the pedometer was an effective device for detecting estrus in Japanese Black cattle in ST heat. This finding agreed with previous reports which measured steps in Japanese Black cattle (Yoshioka et al., ). Furthermore, the number of steps clearly increased during estrus in silent heat as well as in ST heat, suggesting that the radiotelemetric pedometer is useful for detecting estrus in Japanese Black cattle (Figures and ), even in silent heat.…”

“…To calculate the estrus duration, the beginning of estrus (0 hr) was determined when the numbers of steps (/hr) became 1.5‐fold higher than the 14‐day average before estrus (steps/hr) and remained at this higher level for more than 3 hr (Sakatani, Balboula, Yamanaka, & Takahashi, ; Sakatani et al., ; Yoshioka et al., ). The end of estrus was defined as the time when the steps/hr returned to less than 1.5 times the 14‐day average level.…”

“…It has been shown that changes in the number of steps measured by a radiotelemetric pedometer functions as an index for the detection of estrus (Chanvallon et al., ; Roelofs, van Eerdenburg, Soede, & Kemp, ; Yoshioka, Ito, & Tanimoto, ). Moreover, it is reported that when AI is performed at the optimal time as calculated based on the onset of the increase in steps (pedometer estrus), it yields an appropriate conception rate in dairy cows (Maatje, Loeffler, & Engel, ).…”

“…Moreover, it is reported that when AI is performed at the optimal time as calculated based on the onset of the increase in steps (pedometer estrus), it yields an appropriate conception rate in dairy cows (Maatje, Loeffler, & Engel, ). To attach pedometers to cattle, it is necessary to restrain them, but pedometers make it possible to clearly detect the onset and duration of estrus (Yoshioka et al., ). Thus, the detection of estrus by the measurement of steps is suitable from the standpoint of labor reduction and animal welfare.…”

“…As described above, although pedometers have been suggested to be useful for detecting estrus in cattle, few reports have investigated the changes in the number of steps or in ST events during estrus (Yoshioka et al., ), and the usefulness of pedometer use in Japanese Black cattle is not completely understood. In the present study, to clarify the efficiency of radiotelemetric pedometers for detecting estrus and estimating the optimal time for AI in Japanese Black cows, the onset and duration of estrus as detected by pedometer were compared to the onset and duration of ST.…”