Hossein Hamali - Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
Mohammadreza Nikan - Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran,Iran
Hossein Navaee - Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran,Iran

Deficiency of single or multiple minerals or their imbalances may cause various reproductive failures, such as infertility, poor conception, and anestrus. Copper deficiency is related to reproductive disorders. This study investigated the effects of slow-release copper bolus administration in postpartum anestrus cows. So, a hundred postpartum multiparous Holstein cows with a body condition score of ۵.۲-۳ and an average milk yield of ۳۳ kg, which did not show signs of estrus until at least the ۵۲th day after arturition were selected, and two ultrasound examinations of uterus and ovaries were performed ten days apart. Cows with normal uterus in both examinations, but inactive ovaries and without active structure(s), such as corpus luteum or cyst, were selected and randomly divided into two groups ۲۳. A ۵.۲-gram slow-release copper capsule (manufactured by Zofa Parnian Pars Company) was administered in the treatment group. In the control group, nothing was administered. Heat detection was done in both groups for ۰۳ days after the copper bolus administration; on the ۳۳th day, the pregnancy was checked by ultrasound. The average onset interval of estrus in the treatment group was ۳۵ days, and in the control group was ۵۳ days (p<۳.۳۲ ). The first service conception rate was ۰۵۶ in the treatment group and ۵۵۶ in the control group (p=۳.۳۵۰). The results showed that using a ۵.۲-gram slow-release copper capsule can effectively improve the estrus and increment of the first service conception rate in anestrus postpartum dairy cows.

copper, anestrus, slow-release capsule, dairy cow