Large or Food Animal and Equine Medicine Commons^™

Stereotypic Behaviors And Physiological Indicators Of Stress Occur In Horses With Restricted Durations Of Turnout, Elizabeth E. Rodgers

Department of Animal Science: Dissertations, Theses, and Student Research

The confinement of horses to stalls with limited or no turnout time restricts their natural roaming behaviors, which potentially increases stress and behavioral stereotypies. This study investigated the impact of turnout duration on behavioral and physiological stress indicators in healthy horses. Adult horses (n = 11) were enrolled in a 3 treatment (0-, 15-, and 60-minute turnout/day) Latin square design, including 3 12 d experimental periods over 6 weeks. Horses were acclimated to turnout (24.38 x 64.01m indoor arena) and stalls (2.74 x 4.87m - 3.66 x 3.66m) stalls prior to data collection on day 1. Experienced handlers managed …

Methane Mitigation And Its Effects On Energy Utilization In Lactating Dairy Cattle, Shan C. Sherwood

Department of Animal Science: Dissertations, Theses, and Student Research

Improved methane (CH₄) mitigation strategies are needed to achieve the greenhouse gas emission goals of the dairy industry. The first experiment was conducted to evaluate the effects of feeding black cumin (Nigella sativa) seed oil and acetate (BCA) on CH₄ production and whole-animal energy utilization. Twelve dry Jersey cows were used in a 2-period crossover design study with 28d periods. The BCA treatment was compared to a control diet with corn oil. Both BCA and corn oil were added to the base diet as a top dress. Results from this study did not show any …

Artificial Insemination And Fetal Programming In Beef Production Systems, Dempster M. Christenson

Department of Animal Science: Dissertations, Theses, and Student Research

Pregnancy to artificial insemination and late gestation fetal programming of the next calf crop are central to genetic development, reproductive longevity, calf crop productivity, and efficiency of cow/calf ranching. The purposes of this research are to find methods to improve pregnancy rate to artificial insemination, the growth and reproductive health of pregnant heifers, and the productivity of their offspring. In the first of four studies we found that extending the period of progesterone administration in an estrus synchronization protocol did not significantly hasten estrus response or increase pregnancy rate to artificial insemination, but timing of estrus within the melengestrol acetate …

Comparison Of Comprehensive Health Score In North American Housed Giraffe And Free-Ranging Giraffe From South Africa, Haley Beer

Department of Animal Science: Dissertations, Theses, and Student Research

Stress is evident in many animal species and has been correlated to disease prevalence. During stressful events, allostasis is initiated by physiologic systems to maintain or reestablish homeostasis to protect an organism’s viability. Over time, the acclimation to frequent stress causes systematic dysregulation, leading to the phenomena of increased allostatic load. Allostatic load has been assessed in animal species via serum through selection of representative, multi-system biomarker indices. Perception and number of stress events may impact dysregulation severity, yielding allostatic load as a predictive tool. However, the allostatic load methodology poses application limitations to individuals without historical data and those …

Efficiency Of Energy Utilization And Fecal Mineral Excretion In Holstein And Jersey Dairy Cows, Gabriel Garcia Gomez

Department of Animal Science: Dissertations, Theses, and Student Research

Eight multiparous Holstein and 8 Jersey dairy cows were used to complete energy balance trials designed to determine the effect of breed on the production and energy efficiency of milk, and energy partitioning. A repeated switchback design was used to compare the effect of cow breed. Diets consisted of 24.5% corn silage, 18.4% alfalfa hay, 6.9% grass hay, with either 22.9% rolled corn and 14.8% soybean meal (CON) or 8.95% rolled corn and 28.8% reduced fat distillers grains (RFDDGS) DM-basis. Diets were offered ad libitum for a 28 d adaptation period and 95% ad libitum for a 4 d collection …

Beef Cattle Management Systems For Estrus Synchronization And Heifer Development, Hazy Rae Nielson

Department of Animal Science: Dissertations, Theses, and Student Research

Four experiments were conducted to evaluate estrus synchronization and heifer development systems. In the first experiment delaying AI 19 h following GnRH administration in a hybrid estrus detection and time AI protocol was evaluated. Final pregnancy rate was not different among heifers detected in estrus, AI at the time GnRH administration, or delayed AI. The second study compared the effect of melengestrol acetate (MGA) -PG and 14-d controlled internal drug release (CIDR) -PG estrus synchronization protocols on estrus response and pregnancy rates of 311 d old heifers. Final pregnancy rate was similar between CIDR and MGA treatment groups. The objective …

Genetic Parameter Estimates And Breed Effects For Calving Difficulty And Birth Weight In A Multi-Breed Population, Cashley Ahlberg

Department of Animal Science: Dissertations, Theses, and Student Research

There are multiple breeds of beef cattle available to utilize in breeding systems to maximize production and economics. Calving difficulty (dystocia) is a significant cost to beef production and is more prevalent in first-calf heifers. The objectives of this study were to estimate genetic parameters and breed differences for calving difficulty and birth weight as a first step towards the development of across-breed adjustment factors for calving difficulty.

Two models were employed to analyze birth weight (BWT) and calving difficulty (CD) recorded on 4,579 first parity females from the Germplasm Evaluation program at the United States Meat Animal Research Center …