We compared synchronization and pregnancy rates, and the increase in blood progesterone concentrations during luteal development, between (1) Ovsynch plus an intravaginal controlled internal drug release (CIDR) device protocol followed by timed embryo transfer (timed ET), and (2) a conventional estrus synchronization method using PGF(2 alpha) and ET in suckled postpartum Japanese Black beef cow...

Application of AI in extensive beef cattle production would be facilitated by protocols that effectively synchronize ovarian follicular development and ovulation to enable fixed-time AI (TAI). The objectives were to determine whether use of a controlled internal drug release (CIDR) device to administer progesterone in a GnRH-based estrous synchronization protocol would optimize blood progestero...

Although the discovery that follicles in bovine ovaries grow in a wave-like fashion has presented challenges for estrus synchronization and superovulation, recent protocols, designed to control follicular function have permitted fixed-time AI or fixed-time embryo transfer with high pregnancy rates, and the initiation of superstimulatory treatments at a self-appointed time, all without the neces...

For an embryo transfer program to be effective, numerous factors need to be put in place to ensure success. Nutrition, estrous cycle control, donor and recipient management are all factors responsible for the success or failure in fertility for a given herd. Utilization of body condition score is a practical method to determine nutritional status of both recipients and donors. Prepartum nutriti...

The CIDR is an intravaginal progesterone insert, used in conjunction with other hormones to synchronize estrus in beef and dairy cows and heifers. The CIDR was developed in New Zealand and has been used for several years to advance the first pubertal estrus in heifers and the first postpartum estrus in cows. The CIDR is a “T” shaped device with flexible wings that collapse to form a rod that ca...

Reproductive performance in cows following synchronization of estrus with intravaginal progesterone releasing devices (IVD) has varied with the length of treatment, cyclic status and prolonged return to estrus intervals in some cows following first AI. The objective of this study was to compare two methods of synchronizing and resynchronizing estrus on the reproductive performance of lactating ...

Background: Acute-phase proteins (APPs) may be increased due to different stresses during estrus phase in farm animals. Aims: Determining changes of APPs at different phases of non-synchronized estrous cycle group (NSEG), and Ovsynch-synchronized estrous cycle group (SEG) in Holstein cows. Methods: Twelve non-pregnant clinically and paraclinicaly healthy Holstein cows with a body condition scor...

Recently, weak estrous behavior was assumed to be the cause of a decline in breeding efficiency in cattle. The present study investigated the effect of measuring the vaginal temperature on the detection of estrus in Japanese Black cows. First, the effect of hormone administration to cows with a functional corpus luteum on the vaginal temperature was evaluated by continuous measurement using a t...

The purpose of this study was to determine whether administration of altrenogest (Regumate; Roussel-Uclaf, París, France) to primiparous sows would improve estrus synchronization rate and reproductive efficiency of the herd, measured in terms of the weaning-to-estrus interval (WEI), the weaning-to-first-fertile-estrus-interval (WFEI), rate of sows repeating estrus, and conception rate at first ...