Automatic estrus detection techniques in dairy cows have been present by different traits. Pedometers and accelerators are the most common sensor equipment. Most of the detection methods are associated with the supervised classification technique, which the training set becomes a crucial reference. The training set obtained by visual observation is subjective and time consuming. Another limitat...

This study was conducted to assess whether varying the time of artificial insemination (AI) after detection of estrus influences the sex ratio of Japanese Black cows offspring. Data were collected from 1,829 inseminated cows, of which 753 gave birth to calves, over a period of two and a half years. The animals were divided in two groups: the early AI group (3 h after estrus detection) and late ...

Although studies have demonstrated reasonable pregnancy rates in single-ovulating heifers inseminated with sexed sperm, it is not yet clear if sexed sperm can be successfully used in superovulated females. Therefore, the objective of this trial was to determine fertilization rate and embryo quality in superovulated heifers inseminated with frozen-thawed Xchromosome bearing sperm at 2 different ...

The objectives of this study were to determine residual and absorbed levels of medroxyprogesterone acetate (MAP) after treatment with intravaginal sponges impregnated with different doses of MAP in an ewe herd and to determine the effects of such treatments upon estrus incidence, interval to estrus onset and pregnancy rate. Polyurethane sponges impregnated with 40, 50 and 60mg of MAP were prepa...

BACKGROUND Suppression of cyclic activity in cattle is often desired in alpine farming and for feedlot cattle, not intended for breeding. A cattle specific anti-GnRF vaccine (Bopriva™) is registered for use in heifers and bulls in different countries. In adult cows vaccinated with Bopriva™, the median period until recurrence of class III follicles was 78 days from the day of the 2nd vaccination...

A total of 191 crossbred sows were used to determine the effect of energy intake during one lactation on (1) sow and pig performance and (2) the percentage of sows in estrus by 7, 14, 21 and 70 d postweaning. Sows received 8 (Lo) or 16 (Hi) Mcal of metabolizable energy (ME)/d (Exp. 1 and 2) and 8 (Lo), 12 (Md) or 16 (Hi) Mcal of Me/d (Exp. 3) during a 28-d lactation period. All sows were fed an...

Human chorionic gonadotropin (hCG) may boost progesterone production and attenuate maternal-immune response against concepti in ewes, increasing prenatal survival. The present study examined effects of repeated hCG administration after mating on serum progesterone concentration and complete blood counts (CBC) during early gestation, as well as offspring numbers at parturition. Fifty-six ewes we...

Introduction: RFamide-related peptide (RFRP) is believed to act as an inhibitor of gonadotropin releasing hormone (GnRH) secretion. The aim of the present study was to compare the expression pattern of RFRP neurons in the dorsomedial nucleus of hypothalamus (DMH) at different phases of the rat estrous cycle. Methods: The phases of the estrous cycle were determined in 16 adult female Sprague-...

The objective of the study was to compare three systems for detection of estrus and combinations of these systems on a large commercial dairy (1000 lactating cows) during stress of summer heat. At 37 to 45 days in milk (DIM), 266 cows were fitted with a HeatWatch (HW) device (HeatWatch; DDx Inc., Boulder, CO), an activity (A) sensor (ALPRO; DeLaval Inc., Kansas City, MO), and observed visually ...

To investigate uterine and serum copper (Cu) and zinc (Zn) concentrations variation during the bovine estrus cycle , 232 blood and genital tract samples were collected from the abattoir in Urmia. The phase of the estrous cycle was determined by the examination of the ovaries and the uterine tonicity. Of the 46 samples selected for use in the study, 13 were pro-estrus, 10 estrus, 8 metestrus, an...