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Effects Of An Injectable Zinc Solution At Weaning As An Alternative Castration Method In Beef Cattle, Reagan Nicole Cauble Aug 2022

Effects Of An Injectable Zinc Solution At Weaning As An Alternative Castration Method In Beef Cattle, Reagan Nicole Cauble

Graduate Theses and Dissertations

Two experiments were conducted to investigate a 1 mL intratesticular zinc (100 mg Zn) injection administered into each testicle at weaning (Z) and its effects on growth, health, behavior and testosterone. In the first experiment, beef bulls were assigned randomly to treatment at birth: 1) surgically castrated at birth (S; n = 37) or 2) Z (n = 37). Testicular thickness differed by day (P < 0.01) for Z. Testosterone concentrations were greater in Z by d 77 and remained so through d 280 (P = 0.02) compared to S. Zinc injected calves were heavier at the trail’s conclusion (P ≤ 0.04), had greater ADG overall (P < 0.01), heavier hot carcass weight (P = 0.01), and greater lean muscle area (P = 0.01) compared to S; but a lower marbling score (P < 0.01). Yield Grade, dressed carcass yield and fat thickness were similar (P ≥ 0.14). Zinc injected calves had greater haptoglobin (Hp) concentrations (P < 0.01). Zinc injected calves had greater concentrations of white blood cells on d 1 and 2 and greater concentrations and proportions of neutrophils on d 1, 2 and 3 (P < 0.01). Conversely, S had a greater percentage of lymphocytes on d 1, 2 and 3 and a lower ratio of neutrophils to lymphocytes during that same time (P < 0.01). Zinc injected calves spent more time on their side or sternum on d 1 and more time on their side on d 2 while S spend more time standing during that time (P < 0.01). During d 3, 4, 5, and 6, Z stood more while S laid on their sternum (P < 0.01). In trail 2, beef bulls were allocated randomly to treatment one week post weaning: 1) banded (B; n = 42) or 2) Z (n = 39). Body weights were similar (P ≥ 0.39) but ADG improved for Z compared to B (P = 0.05). Testosterone concentrations were greater in Z compared to B (P ≤ 0.02). Testicular width in Z differed by d (P < 0.01). Zinc castrated calves spent more time on their side compared to B one day post castration (P = 0.03) until d 3 and 4 where B spent more time on their side (P ≤ 0.02). Banded calves stood more the first two days (P ≤ 0.01). On days 3, 4, 5, and 6, Z stood more (P ≤ 0.01) while B were on their sternum (P ≤ 0.03). Banded calves had lower Hp concentrations compared to Z (P ≤ 0.01). Total white blood cell concentrations, proportions and concentrations of neutrophils, and proportion of lymphocytes were greater in Z compared to B on d 1, 2, and 3 (P ≤ 0.01). There was no interaction between treatments over time for IL1β, IL6, and TNFα expression (P ≥ 0.83). The findings in both studies indicate that intratesticular Zn injections at weaning can improve growth performance and some carcass attributes but produce a heightened inflammatory and immune response and cause discomfort. Injecting zinc, as formulated and administered in these trails, does not result in complete castration of beef calves at this age and therefore cannot be considered a true castration alternative.


Relationship Of Underline Scores And Production Traits In Beefmaster Cattle, Bryan R. Kutz May 2021

Relationship Of Underline Scores And Production Traits In Beefmaster Cattle, Bryan R. Kutz

Graduate Theses and Dissertations

The objective of this study was to establish the relationship of underline scores (UDLS), production traits, and conformation scores in Beefmaster cattle born between 1976 through 2008. Records provided by Beefmaster Breeders United (BBU) were analyzed. Certified classifiers approved by the BBU recorded scores. Sizes and shapes of the underlines differentiated the scores (1-4). A score of one was used to designate the least amount of navel flap or sheath and a score of four represents the maximum amount of naval flap or sheath accepted for registration in the BBU. In this study the relationship of the traits was determined …


Methods To Reducing Weaning Stress In Early Weaned Spring Beef Calves, Matthew Daniel Hahn May 2021

Methods To Reducing Weaning Stress In Early Weaned Spring Beef Calves, Matthew Daniel Hahn

Graduate Theses and Dissertations

Reducing weaning stress in beef calves can have dramatic benefits to the health, growth, and performance to beef calves post-weaning. Studies have shown that providing creep feed to calves during the pre-weaning period can improve their nutritional status, which can better prepare them for the stresses they will be exposed to during the weaning process. Studies have also shown that two-stage weaning can reduce the stresses associated with weaning. Previous research has suggested that this method resulted in dramatic changes in behavioral signs associated with stress. The objective of this study was to evaluate the effects of two-stage weaning with …


Biogeography Of The Bovine Respiratory Microbiome And Its Relationship With Bovine Respiratory Disease, Jianmin Chai Dec 2020

Biogeography Of The Bovine Respiratory Microbiome And Its Relationship With Bovine Respiratory Disease, Jianmin Chai

Graduate Theses and Dissertations

Bovine respiratory disease (BRD) is the most common and costly disease in the beef cattle industry, leading to high morbidity, mortality and huge economic loss. Despite the recent advances in vaccination and antimicrobial techniques, no significant health-improved outcomes have developed. Due to a deep investigation of the microbiome, respiratory microbiotas are known to have important roles for host health and disease. However, BRD specific pathogens have not yet been identified since they are found in both healthy and diseased animals. A systemic and comprehensive study of the biogeography of the bovine respiratory microbiome and its relationship with BRD is lacking …


The Effects Of Excess Dietary Sulfur Using Supplemental Sodium Sulfate On Beef Steer, Heifer, And Progeny Productive And Physiological Responses, Jamie Hawley Jul 2020

The Effects Of Excess Dietary Sulfur Using Supplemental Sodium Sulfate On Beef Steer, Heifer, And Progeny Productive And Physiological Responses, Jamie Hawley

Graduate Theses and Dissertations

For studies 1 through 3, 20 steers of predominantly Angus breeding, were stratified by body weight (279 ± 13.2 kg), assigned randomly to 6 paddocks, and fed a low S ground corn and soybean meal supplement that did not contain any byproduct feeds (0.31% total dietary S; LS) or LS supplement with an additional 0.25% S provided from sodium sulfate (Na2SO4; 0.58% total dietary S; HS) for a 114-d growing phase. Steers were moved to feedlot (373 ± 0.2 kg), remained on prior dietary S treatments, and fed corn and soybean meal diets (0.19 and 0.42% total dietary S; LS …


Effects Of Lasalocid And Energy Supplementation On Forage Intake, Energy Metabolism, And Performance Of Cattle Grazing Wheat Pasture, Autumn Tayler Pickett May 2020

Effects Of Lasalocid And Energy Supplementation On Forage Intake, Energy Metabolism, And Performance Of Cattle Grazing Wheat Pasture, Autumn Tayler Pickett

Graduate Theses and Dissertations

Cattle grazing wheat pasture have the potential to gain BW exceptionally well, but excessive nitrogen intake results in increased excretion and increased greenhouse gas (GHG) emissions. Supplemental concentrates with the addition of an ionophore given to ruminants grazing wheat is a potential practice for producers to increase nitrogen efficiency while decreasing GHG emissions. Therefore, the objective of this experiment was to quantify the effects of energy (2.95 kg/d) and lasalocid (200 mg/hd/d) supplementation on nutrient intake, energy metabolism, respiratory gas fluxes, and performance of grazing cattle. Methane emissions were not affected (P = 0.58) by treatment, hence methane intensity (P …


Associations Among Beef Cattle Genotypes, Neospora Caninum Infection, And Reproductive Performance, Ryan James Page May 2020

Associations Among Beef Cattle Genotypes, Neospora Caninum Infection, And Reproductive Performance, Ryan James Page

Graduate Theses and Dissertations

Reproductive performance is crucial for sustained financial success in the beef cattle industry. This dissertation includes a population study that quantified the incidence of Neospora caninum infections in the central region of the United States and tested its relationship with reproductive performance in beef cattle. Trial one of that study concluded that 6.9% of open, replacement heifers (n = 1306) tested seropositive. The second trial in that project found that 9.6% of the breeding age females (n = 500) tested were seropositive for Neospora caninum; and that state in which the cattle lived and age impacted (P < 0.05) infection rate. Breed composition, number of farm dogs on the ranch, and use of total mixed rations were not associated (P > 0.1) with seropositive …


Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford Dec 2019

Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford

Graduate Theses and Dissertations

The economic impact of infectious bovine keratoconjunctivitis (IBK) has been documented in many parts of the world. Many researchers have observed that prevention of this disease is very difficult given current methodologies. This is primarily due to the multifactorial nature of this disease. The objective of this dissertation was to determine the impact of IBK on calf performance and estimate genetic parameters, heritability and estimated breeding values for IBK susceptibility. Data were analyzed using PROC GLIMMIX of SAS; while genetic parameters were estimated using a linear animal model for both single- and two-traits through MTDFREML. Additional evaluations calculated heritability using …