Pregnancy Rate in Dairy Cows Inseminated on the Basis of Electronic Probe Measurements

Abstract

A new vaginal probe with two pairs of parallel electrodes 90 degrees apart was designed with a switching arrangement so that electrical resistance (ohms) of the dorsal and the ventral areas of the anterior vagina could be monitored separately during the estrous cycle. Three inseminators probed cows during February--April, 1977, in nine herds in stanchion barn housing. Cows not seen in estrus by 40 to 60 dyas after calving were probed every 3rd day. At each dairyman's option normal cows with a low porbe reading were inseminated. Controls consisted of cows seen in estrus by the dairyman and reported for insemination in the routine manner. The diagnosed pregnancy rate for 86 first service controls was 49% versus 52% for 58 cows not seen in estrus, but identified by low probe readings. Cows varied in electrical resistance at breeding, but the fact that pregnancy rates were equivalent in the two groups is interpreted to mean that the probe was as effective in identifying cows suitable for insemination as was visual observation of estrus by dairymen.

Relationships Between the Appearances and Changes of Estrous Signs and the Estradiol-17β Peak, Luteinizing Hormone Surge and Ovulation During the Periovulatory Period in Lactating Dairy Cows Kept in Tie-stalls

“…Many studies have indicated that the pH and electrical resistance of the cervical mucus decrease with estrus and are lowest at the time of the LH surge [7, 23,24,25,26,27,28,29,30]. In these previous studies, the measurement probe was maintained or surgically implanted in the mucosa or submucosa of the vagina, and continuous monitoring was carried out in most of the studies.…”

“…Many studies have been carried out on measuring the increase in the activity of cows around estrus by using a pedometer, and this is being used and developed in practice [13,14,15,16,17,18,19,20]. In addition some methods to predict estrus by monitoring internal changes such as body temperature [20,21,22], vaginal mucus pH [23], electrical resistance or conductivity of reproductive tissue and their secretions [7, 21, 24,25,26,27,28,29,30] have been reported. However, neither method has become generally applied.…”

Use of Vaginal Electrical Resistance to Diagnose Oestrus, Dioestrus and Early Pregnancy in Synchronized Tropically Adapted Beef Heifers

“…Some studies have reported that lower VER values at the time of insemination are associated with increased probability of conception (Foote et al. 1979; Canfield and Butler 1989; Meena et al.…”

Crystallisation pattern of vestibular mucus and its relation to vestibular electrical resistance in cycling sow

“…In cattle, changes in vaginal resistance have a closer relationship with the timing of ovulation (Smith and others 1989). The pregnancy rate was higher (52 per cent) in animals inseminated with low vaginal resistance, and not oestrus behaviour than animals with oestrus signs (49 per cent) (Foote and others 1979).…”