Animal Sciences Commons^™

Estradiol’S Role In Timely Puberty Onset In The Ewe, Eliana Gerardine Aerts

Graduate Theses, Dissertations, and Problem Reports

In female sheep, the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus triggers luteinizing hormone (LH) to be released from the pituitary. Luteinizing hormone, in turn, acts on the ovaries to elicit estradiol (E₂) release. E₂ acts in a negative feedback manner to control the amount of LH released. The increase in LH release that drives puberty onset results from a decrease in sensitivity to E₂ as the animal ages. However, the neural mechanisms mediating this change in sensitivity are not known, as is where in the hypothalamus E₂-negative feedback occurs. In the arcuate …

Using Condensed Tannin To Mitigate Tall Fescue Toxicosis, Ally Jo Grote

Graduate Theses and Dissertations

Endophyte-infected (Neotyphodium coenophialum) tall fescue, [Schedonorus arundinaceus (Shreb.)] produces ergot alkaloids. Condensed tannins could bind to ergot alkaloids and render them ineffective. The first objective was to improve the health of sheep offered endophyte-infected tall fescue by binding toxins in the rumen with condensed tannins. Non-toxic novel-endophyte infected tall fescue (NE) or toxic endophyte-infected tall fescue forage was harvested, baled at targeted moisture of 55%, wrapped within 8 hours of baling with 2 layers of net wrap and 20 layers of plastic, and ensiled for at least 60 days. Prior to feeding, forages were chopped and packed into plastic trash …

Effect Of Fecal Egg Count Estimated Breeding Value On Antibody Production In Katahdin Lambs, Kelsey L. Bentley

Graduate Theses, Dissertations, and Problem Reports

With current pressures to seek out genetic solutions to combat antimicrobial resistance, genetic resistance to the gastrointestinal nematode Haemonchus contortus may reduce need for prophylactic antibiotic use. The Katahdin breed has effectively utilized post-weaning fecal egg count estimated breeding value (PFEC EBV) to reduce parasitism within their flocks, but there still remains significant opportunity for selection within breed. In a previous study, Katahdin sheep sired by low PFEC sires had greater survivability to weaning than lambs sired by high PFEC rams and preweaning was caused by other diseases than parasitism. Those data lead to the hypothesis that selection for PFEC …

Use Of Diatomaceous Earth And Copper Oxide Wire Particles To Control Gastrointestinal Nematodes In Lambs, Olivia Jones

Animal Science Undergraduate Honors Theses

Abstract

Anthelmintic resistance (AR) urges alternatives to control gastrointestinal nematodes (GIN). Copper oxide wire particles (COWP) are more efficacious when used with other dewormers and little is known on efficacy of diatomaceous earth (DE) to control gastrointestinal parasites. The objective was to examine the effects of DE and COWP on GIN control. Katahdin lambs (n = 32; ~150 d of age; 25.0 ± 1.8 kg) were randomly assigned to receive: 1) DE fed at an estimated 2% dry matter intake (with the assumption of moderate consumption of bermudagrass forage and provided supplement), 2) 1g COWP, 3) both 2% DE and …

Quantifying Greenhouse Gas Emissions And Ammonia Volatilization From Soil Amended With Excreta From Ruminants Fed Alternative Forage-Based Diets, Samuel Park

Graduate Theses and Dissertations

Forage-based ruminant diets supplemented with condensed tannins or polyphenolic-containing legumes may alter nitrogen (N) metabolism in the animal and reduce gas emissions from soil receiving excreta. The objective of the study was to determine if soil receiving urine or manure from sheep fed forage diets supplemented with condensed tannin or polyphenolic-containing legumes would decrease N gas emissions. Two field trials were conducted: in the first trial, sheep were fed alfalfa (Medicago sativa L.) silage diets supplemented with 0, 9, 18, or 27% sericea lespedeza (Lespedeza cuneate [Dumont de Courset] G. Don) (n = 4). In the second trial sheep were …

Impact Of Sire Selection And Breed On Parasite Resistance In Sheep, Andrew Ryan Weaver

Graduate Theses, Dissertations, and Problem Reports

Selection within and among breeds are strategies to mitigate the impact of parasitism given failing chemotherapeutics. While Texels have improved marketability compared to other parasite-resistant breeds, the mechanism by which Texels reduce fecal egg count (FEC) is unclear. The immune response to Haemonchus contortus (Hc) was compared in Texel, parasite-resistant St. Croix, and parasite-susceptible Suffolk sheep. Adult worms exposed to St. Croix- and Texel-derived peripheral blood mononuclear cells and serum in vitro had greater binding around the reproductive structures than Suffolk and worm egg release tended to be affected by breed (P = 0.09). Resistance in Texels …

Effect Of Sire Breed On Grass-Based Lamb Production, Camren L. Maierle

Graduate Theses, Dissertations, and Problem Reports

Improvement of lamb performance in low-input operations may prove vital for the sustainability of eastern US sheep production. Maintaining growth while improving carcass conformation using terminal sire crossbreeding systems may increase value in a pasture-based system. Therefore, the aim of this study was to compare effects of terminal sire breed on parasitism, growth, marketability of grazing lambs. Suffolk (SU; n = 2) and Texel (TX; n = 2) sires were mated to commercial ewes at the WVU Organic Farm. April-born lambs were managed on pasture as one group until weaning (mid-June), then were separated into 3 replicates per sire breed. …

Strategies To Improve Forage Utilization By Sheep Offered Forage Mixtures, Valens Niyigena

Graduate Theses and Dissertations

In the first experiment, alfalfa and novel endophyte-infected tall fescue (NE+) forages were harvested after a killing frost, then mixed to formulate 4 different treatments; alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. After 3 months of storage as silage, Dorper ewe lambs (n = 20; mean BW = 34.7 ± 6.65 kg) were fed silage for ad libitum consumption, using 5 animals per treatment. Increasing the proportion of NE+ tall fescue improved (P < 0.05) silage total acids and lactic acid concentrations and decreased silage ammonia concentration. Digestible dry matter and organic matter intake and nitrogen utilization parameters decreased with increasing inclusion of NE+ in diet. In the second experiment, 16 Dorper ewe lambs (41.8 ± 4.61 kg BW) were assigned to 4 different treatments; alfalfa silage alone (0 g/kg; CONT) or alfalfa silage mixed with chopped sericea lespedeza (SL) hay to provide 90 (LOW), 180 (MED), or 270 g/kg SL (HIGH) on a dry matter basis in a randomized complete block design experiment with 2 period to provide 4 observations per treatment for each experimental period. Increasing the proportion of sericea lespedeza in the diet decreased dry matter and organic matter digestibility but did not affect feed intake. Fecal nitrogen (g/kg N intake) increased linearly (P < 0.01) while urinary N (g/ day and g/ kg of N intake) tended to decreased linearly and quadratically (P ≤ 0.1) with increasing the proportion of SL in diet. In the third experiments, 16 gestating Dorper ewe lambs (49.1 ± 4.61 kg BW) were allocated to 4 treatments; alfalfa silage alone (0% g/kg; CONT) or alfalfa silage mixed with lablab purpureus(LP) hay to provide 90 (LOW), 180 (MED), or 270 g/kg LP (HIGH) on a dry matter (DM) basis, in a randomized complete block design experiment with a total 8 replication per treatment. Supplementation of LP in diet increased quadratically (P ≤ 0.04) forage dry matter, organic matter intake, digestible dry matter and digestible organic matter intake (P < 0.05). Nitrogen apparently absorbed and urinary N both decreased linearly (P < 0.01) with adding more LP hay in diet. Harvesting and mixing alfalfa and fescue after a killing frost improved silage fermentation characteristics and supplementation of tannins from SL and polyphenol from LP altered N excretion.

Key words: lablab, sericea lespedeza, alfalfa silage, nitrogen, sheep.

Cal Poly's Western Bonanza Junior Livestock Show Hosts First Annual Livestock Auction: The Best In The West Livestock Auction, Karl W. Montague, Tatum E. Holdener

Agricultural Education and Communication

Through this senior project, the authors researched whether or not Cal Poly's Western Bonanza Junior Livestock Show's first ever livestock auction was viable. Through their research, they found the addition of a livestock show to be successful and something that should continue.

Investigations Into The Cross-Infectivity Of Nematode Parasites Of Cattle And Sheep, Eva Marie Wray

Graduate Theses and Dissertations

The existence of anthelmintic resistance is not singular in parasite species, host species or geographic region. It has become a problem of worldly stature, especially when considering sheep nematodes. Recommendations have been modified from chemical-based control to multipart, managerial intervention. Compared with nematodes of cattle, the worldwide resistance of sheep nematodes to anthelmintic remedies is much more pronounced and urgent. As the resistance to essentially all anthelmintic classes approaches a cautionary level, the implementation of non-chemical controls has grown increasingly essential. Six-6 to 8 month old Holstein steer calves, six-5 month old Katahdin ram lambs and eight-5 month old Suffolk …

Identification Of A Genetic Marker For Litter Size In Sheep, Olivia Price

Undergraduate Honors Capstone Projects

The purpose of this experiment was to determine if the estrogen receptor gene (ESR) could be used as a genetic marker for litter size in sheep. The estrogen receptor gene was chosen because it has been successfully used as a genetic marker for litter size in swine. In this study, DNA dilutions from two experimental flocks, totaling approximately 200 animals, were used. Amplification of exon 1/intron 1 of the ESR gene was performed using PCR. Initial results indicated a polymorphism in the gene when cut with the restriction enzyme Ava ll. It appeared that the gene contained a deletion with …

Forage Selection And Nutrition Of Sheep And Goats Grazing In The Tunisian Pre-Sahara, Rudolfo Ricardo Griego

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nomadic pastoralism has been the traditional method of utilizing grazing resources in arid and semi-arid regions of Africa. However, increased sedentarization accompanied by growing human and animal populations during the past two decades is thought to be accelerating the desertification process, or desert expansion. The specific interactions of the grazing animal with this process has been speculated upon but not studied in detail. A comparative study was initiated during the spring grazing season of 1974 to determine sheep and goat nutritional and production responses, as well as patterns of vegetative selection and utilization under the pastoral system currently employed in …