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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 159 for “"Estrus"”.
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Increasing estrus expression in lactating dairy cows
… would increase occurrence and intensity of estrus. In experiment 1, cows (n = 154) were fitted with an AMS collar and a pressure-sensitive, rump-mounted device (HW) and assigned to 3 treatments: 1) CL only; 2) no CL + progesterone insert (CIDR); or 3) CL + 2 CIDR to achieve different …
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Towards an electronic system for estrus detection in swine
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo terms
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Methods to Synchronize Estrus, Enhance Pregnancy, and Rescue Embryos in Cattle
… a timed Al improved PR in cows not observed in estrus. There were no differences in days to emergence and ovulation of a new follicular wave, ovulation rate and ovulated follicle size when EB (0 vs 4 mg; P > 0.05) was administered. More follicles classified as ""maintained"" were observed in the …
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Detecting estrus in sows using a robotic imaging system and neural networks
… as low breeding efficiency and high labor cost. Estrus detection is crucial to reproductive management of sows. Due to the longevity of the sperm and eggs, achieving timely and accurate estrus detection can lead to higher conception rates, larger litter size, and lower non-productive days. …
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Electrical Conductivity of Reproductive Tissue for Detection of Estrus in Dairy Cows
Inefficient detection of estrus is the principal cause of delayed conception and concomitant lengthened calving intervals. Consequently, interest is generated in devising new methods of detecting estrus. Electrical conductivity of reproductive tissue can be a potential method of doing so.
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Optimal time of insemination in dairy cattle identified in estrus by HeatWatch
Estrus detection programs practiced on most U.S. dairy farms are not intense enough to provide the information needed to accurately time insemination, thus preventing AI from obtaining its full conception rate potential. Herds (n = 17) participated in a trial designed to evaluate percent pregnant …
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Induction of fertile estrus during seasonal anestrus in ewes and fall born ewe lambs
… during the luteal phase. Percentage of ewes in estrus was greater in P4 treated than in control ewes. Estrous response was greater after treatment with P4 for 5 than for 12 d. Progesterone increased the percentage of ewes lambing to both service periods by 20 percentage points. Prolificacy to …
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Sow body temperature and behavioral changes associated with the onset of estrus and ovulation
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-03-28 without embargo terms
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Melengestrol acetate and norgestomet for the induction of synchronized estrus in seasonally anovular ewes
… for their ability to induce synchronized estrus in anovulatory ewes. Seasonally anestrous ewes (n=232; determined by blood serum progesterone concentration) of mixed breeding were randomly assigned within broad age groups to one of seven treatments: 1) control (C); 2) MGA only (OMGA); 3) …
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Possible role of the ventromedial hypothalamus in estrus termination following vaginocervical stimulation of the rat
… of the receptivity period called behavioral estrus. Central mechanisms by which VCS accelerates the onset of estrus termination in rats are not completely understood yet. Hence, the present study investigated the role of the ventromedial hypothalamus (VMH) in estrus termination using sexually …
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Effect of the timing of OvuGel administration on reproductive performance in gilts sycnhronized for estrus
… time of OvuGel® administration on the timing of estrus and ovulation and fertility results in gilts synchronized for estrus by administering Matrix® for 14 d. Insemination must occur near the time of ovulation to achieve high fertility results, however, there is no practical method available to …
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Efficacy of Synthetic Gonadotropin Releasing Hormone Analogs for Control of Ovulation During Estrus Synchronization Protocols
Two experiments were conducted to determine efficacy of GnRH analogs, Cystorelin (CYS, gonadorelin diacetate tytrahydrate) and Factrel (FAC, gonadorelin hydrochloride), for use in beef timed AI synchronization. In Experiment one 342 beef cows from 7 herds were assigned CYS or FAC treatment as part …
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Evaluation of long-term CIDR-based estrus synchronization protocols in primiparous two-year-old beef cows
… and ultimately enhance production efficiency. Estrus synchronization and artificial insemination (AI) are important management tools available to producers that facilitate genetic improvement and enhance reproductive efficiency. A list of recommended protocols may be used to facilitate …
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Comparison of three estrus detection systems during summer heat stress in a large commercial dairy herd
… 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 …
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Synchronizing Estrus and Improving Subsequent Production and Performance with Prostaglandin F2 Alpha and Pregnant Mare Serum Gonadotropin
… and pregnant mare serum on reducing weaning to estrus interval, increasing the degree of estrus synchrony and improving fertility at estrus resulting in improved pregnancy rates and subsequent litter performance. Sows were randomly allotted to treatments. In trial 1, sows were assigned to one of …
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The effects of resynchronization of estrus using the 5 d CO-Synch + CIDR system in beef heifers
… using a 5d CO-Synch + CIDR system. Estrus was synchronized in crossbred heifers (n=176) using 5 d CO-Synch + CIDR with FTAI at 72 h. After the initial AI, open heifers received either resynchronization (RS) or natural service (NS) return service treatments. The RS treatment was …
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Investigation of skin temperature differentials in relation to estrus and ovulation in sows using a thermal infrared scanning technique
Accurate estrus detection is an essential component of a successful artificial insemination program in modern swine operations. It is necessary to establish efficacious means of estrus detection and to optimize reproductive performance in the herd. Measurement of physical and physiological traits …
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Effect of Timing of Insemination and Synchronization of Estrus Method on Artificial Insemination (AI) Pregnancy Rates in Beef Heifers
… to evaluate time of insemination relative to estrus and synchronization with melengestrol acetate (MGA) plus prostaglandin (PG) or progesterone insert (CIDR) plus PG on AI pregnancy rate in beef heifers (n = 662) during Fall or Spring. Fall heifers (n = 349) received MGA-PG (MGA for 14 d …
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The Effects of Preovulatory Estradiol on the Uterine Environment and Conceptus Survival From Fertilization to Maternal Recognition of Pregnancy
… protocol and AIed (d 0). Cows were classified by estrus expression (estrus and no estrus), and uteri were flushed to collect d16 conceptuses nonsurgically (Rep 1; n = 29), or following slaughter (Rep 2; n = 37). Uterine luminal fluid (ULF) was analyzed for protein, glucose, and interferon tau …
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