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Reproduction

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Defining Amino Acid Requirements Of Pregnant Sows: Challenges And Opportunities, Christian D. Ramirez-Camba Jan 2022

Defining Amino Acid Requirements Of Pregnant Sows: Challenges And Opportunities, Christian D. Ramirez-Camba

Electronic Theses and Dissertations

The efficient use of protein in animal production is dependent on the protein supply and its constituent amino acids (AA) in relation to the animal's needs. Excess AA are deaminated, and the resulting nitrogen (N) is excreted, whereas suboptimal AA intake reduces animal performance. Both increased nutrient excretion and decreased animal performance reduce the overall efficiency of the production unit. In sows, AA requirements should be adequate for optimizing reproductive performance, as measured, for example, by the number of pigs produced per sow per year while limiting N excretion. There is a desire to feed pregnant sows AA levels that …


The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang Aug 2021

The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang

Electronic Theses and Dissertations

The Gulf of Maine northern shrimp (Pandalus borealis) once supported a significant winter fishery for the Gulf of Maine (GOM). Although the shrimp fishery is not comparable to the lobster business, it provided fishermen and many coastal communities jobs and incomes in winters after lobster seasons. However, a moratorium has been put on the shrimp fishery since 2014 due to record low population abundance and perceived recruitment failures. The recruitment failures have been correlated with warming water temperatures over the past decade. The GOM has been recognized as experiencing rapid warming as a result of global climate change. …


Optimization Of Reproductive Success In Beef Cattle By Implementation Of Estrus Resynchronization, Nutritional Management, And Evaluation Of Disease Prevalance, Kaitlin M. Epperson Jan 2019

Optimization Of Reproductive Success In Beef Cattle By Implementation Of Estrus Resynchronization, Nutritional Management, And Evaluation Of Disease Prevalance, Kaitlin M. Epperson

Electronic Theses and Dissertations

The beef industry is a unique community of operations that employ different management techniques to accomplish a similar goal. Like other facets of animal agriculture, profitability of the beef industry is heavily reliant upon the implemented management practices. Reproductive efficiency is an area of management that has great potential to positively influence the success of beef production. Through the use of reproductive technologies such as estrus synchronization and AI, a greater percentage of females can become bred to superior sires, breeding and calving seasons can be shortened, calf uniformity increased, and economic return maximized (Odde, 1990; Rodgers et al., 2012; …


Temperature And Polyunsaturated Fatty Acid’S Effect On Daphnia Magna Reproduction, Mark Albright Dec 2018

Temperature And Polyunsaturated Fatty Acid’S Effect On Daphnia Magna Reproduction, Mark Albright

Electronic Theses and Dissertations

Organisms adapt to their environments by adjusting their biochemistry and physiology; such adaptation is limited by resource availability and physiological constraints. The freshwater crustacean Daphnia magna inhabits a wide range of environments and must survive and reproduce within a range of temperatures. One limit to low-temperature adaptation is thought to be the availability of unsaturated fatty acids necessary to maintain proper fluidity of cellular membranes. D. magna maintained at 10 ºC on a diet poor in unsaturated fatty acids have been observed to produce clutches that fail to develop. However, this has not been observed on a diet rich in …


Improving Techniques To Study Equine Cervical Mucociliary Clearance, Melissa A. Hawkes May 2018

Improving Techniques To Study Equine Cervical Mucociliary Clearance, Melissa A. Hawkes

Electronic Theses and Dissertations

Bacterial uterine infections inflict major losses on the equine breeding industry. These infections usually arise from bacteria introduced at breeding. Micro-currents propelled by ciliated cells between the folds of the uterus and cervix have been proposed as a means by which contaminants are expelled. Previous data have shown possible ciliary micro-currents propelling carbon particles, occasionally rotating, through cervical folds. However, adherence to the epithelium may have interfered with movement of carbon in these studies. Therefore, we tested potentially non-adherent substances to reveal ciliary micro-currents on the equine cervix under high magnification video-endoscopy. We hypothesized that polyethylene green microspheres 1 - …


Local And Systemic Actions Of Gnrh Relating To Estradiol And Associated Reproductive Parameters In Beef Cattle, Jerica J.J. Rich Jan 2017

Local And Systemic Actions Of Gnrh Relating To Estradiol And Associated Reproductive Parameters In Beef Cattle, Jerica J.J. Rich

Electronic Theses and Dissertations

In cattle, estradiol is responsible for modulating many mechanisms involved in successful reproduction. Specifically estradiol is the primary signal for the initiation of standing estrus (Allrich, 1994), and cattle expressing estrus prior to fixed time AI (FTAI) have been reported to have increased preovulatory estradiol concentrations (Perry and Perry, 2008) and increased pregnancy success compared to animals that did not exhibit estrus (Richardson et al., 2016). Gonadotropin releasing hormone, classically, stimulates estradiol production via the two-cell two-gonadotropin hypothesis (Fortune and Quirk, 1988), and GnRH administered systemically in small doses (5 μg) has been reported to elicit an LH pulse similar …