منابع مشابه
Factors Associated with Shortened Estrous Cycles after Abortion in Beef Heifers 1
Forty-six crossbred Hereford heifers were allotted into five experimental groups. Fenprostalene, a prostaglandin analogue, was administered to induce abortion and (or) to regress the corpus luteum (CL) in four groups of heifers about 75 d after conception. The four groups were 1) pregnant heifers, 2) pregnant heifers with the ovary contralateral to the gravid uterine horn removed 24 h after fen...
متن کاملEndocrine changes during restoration of estrous cycles following induction of anestrus by restricted nutrient intake in beef heifers.
The working hypotheses in this experiment were: that ovarian estradiol would inhibit luteinizing hormone (LH) secretion in heifers that were anestrus as a result of restricted dietary energy intake and the responsiveness of LH secretion to estradiol negative feedback would decrease during the period when restoration of estrous cycles occurred following feeding of diets adequate in energy. Fifte...
متن کاملEndocrine changes and ultrasonography of ovaries in suckled beef cows during resumption of postpartum estrous cycles.
Changes in follicular and luteal structures were assessed and concentrations of estradiol and progesterone were measured in 13 Hereford X Angus suckled beef cows during resumption of estrous cycles. Transrectal ultrasonography was used to monitor follicular size, ovulation, and formation and regression of the corpus luteum (CL). The interval from parturition to first postpartum ovulation (FO) w...
متن کاملComparison of protocols to synchronize estrus and ovulation in estrous-cycling and prepubertal beef heifers.
The objective of the experiment was to compare follicular dynamics, ovulatory response to GnRH, and synchrony of estrus and ovulation among estrous-cycling and prepubertal beef heifers synchronized with a controlled internal drug-release (CIDR)- based or GnRH-PGF(2alpha) (PG) protocol. Estrous-cycling beef heifers were randomly assigned to 1 of 4 treatments (C1, C2, C3, C4), and prepubertal bee...
متن کاملLuteinizing hormone-releasing hormone fusion protein vaccines block estrous cycle activity in beef heifers.
Two LHRH fusion proteins, thioredoxin and ovalbumin, each containing seven LHRH inserts were tested for their ability to inhibit estrous cycle activity. The objective was to evaluate immune and biological responses from alternating the two fusion proteins in an immunization schedule. One hundred ten heifers were divided equally into 11 groups. Two control groups consisted of either spayed or in...
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ژورنال
عنوان ژورنال: Kansas Agricultural Experiment Station Research Reports
سال: 1986
ISSN: 2378-5977
DOI: 10.4148/2378-5977.2389