Twenty-four crossbred steer calves (235 + 6 kg initial BW) were weaned, adapted to a growing diet, trained to use Calan feeders and assigned to one of four treatments in a 2 x 2 factorial arrangement as follows: (1) no transit stress and saline injection, (2) no transit stress and trace mineral and vitamin E (TM/VitE) injections, (3) transit stress and saline injection and (4) transit stress and TM/VitE injection. TM/VitE injections consisted of MultiminTM to provide 0.3, 0.6, 0.15 and 0.6 mg of Cu, Mn, Se, and Zn/kg BW, respectively, and Vita ETM to provide 9 IU of VitE/kg BW on d 0 and 21 of the study. On d 24, transit-stressed steers were subjected to a three-d, 2000-km, transportation period. During the 56-d experiment, liver and serum samples were assayed to assess trace mineral status, antibody titers to keyhole limpet hemocyanin (KLH) measured to assess humoral immunity and phytohemagglutinin(PHA)- and ovalbumin(OVA)-induced skin swelling and lymphocyte proliferation measured to assess cellular immunity. TM/VitE-injected steers grew slower (P < 0.05) over the first 24 d of the experiment and tended (P = 0.10) to grow slower after transit. TM/VitE injections increased (P < 0.05) liver Cu and Zn concentrations 135 and 21 % by d 30, respectively. TM/VitE-injected steers had increased (P < 0.05) serum Cu on d 24 and 26, but decreased (P < 0.05) serum Zn and whole blood Se compared to saline-injected steers on d 24 and 56. TM/VitE injections increased serum α-tocopherol concentrations. TM/VitE injections did not affect humoral immunity, but decreased (P < 0.05) skin-swelling responses to PHA on d 21, and decreased (P < 0.05) lymphocyte proliferation to OVA and KLH. Transit-stressed steers had higher (P < 0.05) serum Cu on d 26, and higher (P < 0.05) liver Cu concentrations on d 56 than non-transit-stressed steers. Transit stress did not affect serum Zn or whole blood Se concentrations. Injections of TM/VitE increased Cu, Zn and vitamin E, but not Se status. The TM/VitE treatment suppressed growth and cellular immune function suggesting that levels of trace minerals used in this study were too high.

Twenty-four crossbred steer calves (235 + 6 kg initial BW) were weaned, adapted to a growing diet, trained to use Calan feeders and assigned to one of four treatments in a 2 x 2 factorial arrangement as follows: (1) no transit stress and saline injection, (2) no transit stress and trace mineral and vitamin E (TM/VitE) injections, (3) transit stress and saline injection and (4) transit stress and TM/VitE injection. TM/VitE injections consisted of MultiminTM to provide 0.3, 0.6, 0.15 and 0.6 mg of Cu, Mn, Se, and Zn/kg BW, respectively, and Vita ETM to provide 9 IU of VitE/kg BW on d 0 and 21 of the study. On d 24, transit-stressed steers were subjected to a three-d, 2000-km, transportation period. During the 56-d experiment, liver and serum samples were assayed to assess trace mineral status, antibody titers to keyhole limpet hemocyanin (KLH) measured to assess humoral immunity and phytohemagglutinin(PHA)- and ovalbumin(OVA)-induced skin swelling and lymphocyte proliferation measured to assess cellular immunity. TM/VitE-injected steers grew slower (P < 0.05) over the first 24 d of the experiment and tended (P = 0.10) to grow slower after transit. TM/VitE injections increased (P < 0.05) liver Cu and Zn concentrations 135 and 21 % by d 30, respectively. TM/VitE-injected steers had increased (P < 0.05) serum Cu on d 24 and 26, but decreased (P < 0.05) serum Zn and whole blood Se compared to saline-injected steers on d 24 and 56. TM/VitE injections increased serum &#945;-tocopherol concentrations. TM/VitE injections did not affect humoral immunity, but decreased (P < 0.05) skin-swelling responses to PHA on d 21, and decreased (P < 0.05) lymphocyte proliferation to OVA and KLH. Transit-stressed steers had higher (P < 0.05) serum Cu on d 26, and higher (P < 0.05) liver Cu concentrations on d 56 than non-transit-stressed steers. Transit stress did not affect serum Zn or whole blood Se concentrations. Injections of TM/VitE increased Cu, Zn and vitamin E, but not Se status. The TM/VitE treatment suppressed growth and cellular immune function suggesting that levels of trace minerals used in this study were too high.

No description available.

Master of Science / Department of Animal Sciences and Industry / Christopher Reinhardt / Crossbred bull calves at high risk for morbidity (n = 190; BW = 159 ± 68 kg) were received at a commercial stocker operation to evaluate the effects of meloxicam administered at the time of castration on performance and health through d 30 post-arrival. Calves were assigned randomly to receive either a whey-powder placebo (CON), 0.5 mg/kg BW meloxicam (LOW), or 1.0 mg/kg BW meloxicam (HIGH) administered orally. Calves were vaccinated, knife-castrated, and received experimental treatments on d 0. Meloxicam had no effect on ADG (P ≥ 0.63), morbidity (P = 0.66), or mortality (P = 0.62). A second study was conducted using crossbred calves from the southeastern US and Mexico (n = 472; BW = 227 ± 45 kg) to evaluate effects of an injectable trace-mineral solution administered at time of arrival at a commercial stocker operation on animal performance, health, and serum concentrations of Cu, Mn, Se, and Zn on d 0 and d 45. Calves were assigned randomly to receive saline (CON; 1.0 mL/45 kg BW) or injectable trace mineral (ITM; 1.0 mL/45 kg BW) on d 0. Average daily gain from d 0 to d 42, overall ADG from d 0 to d 139, mortality, and morbidity were not different (P ≥ 0.31) between treatments. Calves originating from the Southeastern US had greater (P < 0.01) overall ADG from d 0 to 139. There were no source effects (P ≥ 0.21) on initial serum mineral concentrations for Mn or Zn; however, cattle originating in Mexico had lesser serum Cu (P < 0.01) and cattle originating in the Southeastern US tended to have lesser serum Se (P = 0.06). On d 45, there were no treatment differences (P ≥ 0.20) in serum concentrations of Cu, Mn, or Zn but cattle that received ITM tended (P = 0.09) to have elevated serum Se concentrations compared to those that received CON.

Chromium has been reported to increase glucose clearance in insulin resistant and diabetic populations. Skeletal muscle is the tissue primarily responsible for glucose clearance. We therefore tested the effect of chromium chloride (CrCl3) on skeletal muscle glucose uptake both in the absence and presence of a submaximal level of insulin via the rat hindlimb perfusion technique. 0.096 μM CrCl3 was used with and without 200 μU/ml insulin. Our testing showed that insulin significantly increased [H3]-2 deoxyglucose (2-DG) uptake in both the gastrocnemius and quadriceps muscles. Additionally, the combination of CrCl3 and insulin (Cr-sIns) led to greater amounts of 2-DG uptake than insulin alone (sIns) in both the gastrocnemius (Cr-sIns 6.49±0.75 μmol/g/h, sIns 4.83±0.42 μmol/g/h) and quadriceps (Cr-sIns 6.74±0.62 μmol/g/h, sIns 4.54±0.43 μmol/g/h). However, CrCl3 without insulin (Cr) had no affect on 2-DG uptake above basal (Bas) in both the gastrocnemius (Cr 1.45±0.14 μmol/g/h, Bas 1.61±30 μmol/g/h) and the quadriceps (Cr 1.35±0.15 μmol/g/h, Bas 1.27±0.13 μmol/g/h). It has been speculated that chromium works to increase glucose uptake by increasing insulin signaling. To examine this, we used western blotting analysis to test both Akt and AS160 phosphorylation in the mixed gastrocnemius. We found that insulin increased Akt and AS160 phosphorylation, but chromium had no affect on Akt (Cr-sIns 25%±2%, sIns 22%±4%) or AS160 (Cr-sIns 35%±5%, sIns 36%±4%) phosphorylation in the absence or presence of insulin. Our results suggest that supplementation with CrCl3 can lead to an increase in glucose uptake in skeletal muscle, but only in the presence of insulin. However, this effect of CrCl3 does not appear to be a result of enhanced insulin signaling. / text

This thesis described the results of two studies that measured the concentrations of serum micronutrients in western Canadian beef cows at key production points, and examined associations between reproductive outcomes and micronutrient concentrations. The first study reported the serum copper and molybdenum concentrations at pregnancy testing time in cows from 66 cow-calf herds that were enrolled in a study of factors affecting productivity in 205 herds from western Canada. A relatively small proportion of cows had serum copper and molybdenum concentrations outside of adequate levels (16.2% of cows had below adequate serum copper, < 0.60 ppm; 12% of cows had high serum molybdenum, > 0.10 ppm). There were no associations between copper and molybdenum concentrations measured at the end of the grazing season and reproductive outcomes measured in these cows, with the exception that cows with the lowest serum copper concentrations at pregnancy testing were more likely to be pregnant than cows with higher copper concentrations. The practice of comparing serum copper and molybdenum concentrations between pregnant and non-pregnant animals in the fall as a tool in investigating poor pregnancy rates was not supported by this study. In the second study, serum micronutrient concentrations of beef cows (n = 791) in southern Saskatchewan were measured before placement onto summer grazing and breeding pastures and again at the end of the grazing season. Pre-breeding serum copper concentrations were less than adequate (< 0.60 ppm) in 75% of cows. High concentrations of serum molybdenum (d 0.10 ppm) were present in 19% of cows at pre-breeding. Cows < 10 years of age with lower pre-breeding serum copper concentrations were at increased odds of nonpregnancy. The greatest effect on pregnancy rates was observed for pre-breeding serum copper concentrations < 0.4 ppm. Season of measurement influenced the concentrations of serum micronutrients in these cows. Copper and vitamins A and E were higher in the fall, and molybdenum and selenium concentrations were lower in the fall. These studies described serum micronutrient concentrations from healthy cows in western Canada at two production points, pre-breeding placement onto grazing pastures and pregnancy testing when cows are removed from grazing pasture. Identifying increased odds of nonpregnancy in cows with below adequate serum copper at pre-breeding emphasizes the importance of ensuring adequate copper concentrations in breeding females during this critical production phase.

The initial study herein assessed mineral digestibility in situations when reducedamounts of inorganic and organic (proteinates) trace minerals (TM) were fed in finishingpigs, and their long-term effects on body mineral status. The second study was aslaughter-investigation that tested the impact of lean growth potential on phosphorusbody accretion from 30 to 110 kg.Organic TM exhibited neither improvement in digestibility nor in total retention;fecal excretion responded quantitatively to mineral intake independently of the source.Contents of copper in kidney and zinc in liver were higher for pigs fed the organic form.Phosphorus content was linearly related to live weight, empty body weight, andnitrogen content. Phosphorus accretion was very similar for both genetic backgrounds,with gilts retaining more mineral (Pandlt;0.05) than barrows. A N/P deposition ratio of 5.14was determined for pigs of both genders and genetic backgrounds to further predictphosphorus requirements based on protein accretion.Reduction of TM waste from growing-finishing pigs may be best addressed bylimiting their dietary inclusion rather than by using organic forms. Data from the secondstudy may be useful for an accurate estimation of phosphorus requirements, whichaccounts for variations in lean accretion rate.

Master of Science / Department of Animal Sciences and Industry / Karol E. Fike / Trace mineral supplementation is necessary for proper reproductive success. Little research has evaluated the effect of an injectable trace mineral product, in conjunction with a dietary mineral supplementation program, on reproduction. This thesis includes two separate studies evaluating the use of an injectable trace mineral product, in addition to a dietary mineral program, on the reproductive success of yearling bulls and heifers. In the first study, we hypothesized that when dietary trace mineral needs are met, administration of an injectable trace mineral product to developing beef bulls would cause a short-term increase in circulating trace mineral concentrations, but not alter semen quality nor ability to pass a breeding soundness examination. Trace mineral treatment did not affect scrotal circumferences and BW of bulls throughout the trial (P [equal to or greater than] 0.20). Trace Mineral bulls had greater (P [equal to or less than] 0.0001) trace mineral concentrations at 8 h post-treatment than Control bulls. Semen trace mineral concentrations on d 42 and 91 were similar (P [equal to or greater than] 0.52) between treatments. Sperm parameters improved (P [equal to or less than] 0.003) from d 42 to 91, but did not differ (P [equal to or greater than] 0.06) between treatments. A similar (P = 0.94) percentage of Trace Mineral (67%) and Control (68%) bulls passed a BSE 91 d post-treatment. In the present study, supplemental trace mineral injection was successful at raising circulating trace mineral levels, but did not alter semen trace mineral levels nor improve semen quality. In the second study we hypothesized that when dietary trace mineral needs are met, the use of an injectable trace mineral product in developing heifers would not affect pregnancy rates at single service fixed-time artificial insemination (FTAI). Trace Mineral heifers had greater (P = 0.02) pregnancy rates (51.28%) than Control heifers (25.58%). The percentage of Trace Mineral (30.77%) and Control heifers (47.50%) that displayed estrous behavior prior to FTAI as indicated by a red estrous detection patch was not different (P = 0.13) between treatments. In the present study, despite dietary trace mineral requirements being met, use of an injectable trace mineral injection improved pregnancy rates following FTAI, but did not affect estrous behavior.

Master of Agribusiness / Department of Agricultural Economics / Daniel M. O'Brien / In the manufacturing process one decision that is common to all industries is the sourcing of intermediate goods used in production. The decision to make internally verses to outsource can affect a firm's comparative advantage and increased company profits. This project deals with sourcing trace minerals used in the production of feed for the commercial production of food animals in the United States. From looking at the sources of minerals to the industry to the current market structure of the trace mineral production industry in the U.S. the question is asked whether trace minerals can be sourced differently for the client to gain this advantage. The specific objective of this research project is to determine whether it is more profitable either to purchase or manufacture trace mineral blends for use in feed ration formulations for a number of plants owned by a representative livestock feed company in western Kansas. The company has several feed plants in operation in the central Great Plains region. Does the company have enough volume of trace mineral usage to enable it to profitably produce its own mineral blends at one of its feed plants? If trace minerals can be profitably produced by the company, it will lead to a decrease in feed production cost for all of its plants. It is possible that this study will show that there is a large enough degree of consolidation in the U.S. mineral blending industry that there is little or no "room" or opportunity available in the competitive raw ingredient market to increase margin by self-producing trace minerals verses outsourcing. The rationale behind this perspective is that the supply of trace mineral blends is controlled tightly by a few existing suppliers / manufacturers who have enough market power and the subsequent ability to limit the entry of new firms. The raw ingredients required to produce these blends could not be purchased economically enough to realize any cost savings in the trace mineral production process.

Concerns about beef production are growing among consumers, questioning the use of antibiotics, hormones, and metaphylactic treatments, as well as its environmental footprint. Therefore, beef production systems need to be more efficient to increase productivity while using less resources to become sustainable and reduce environmental impact. There is a need to develop and apply non-pharmaceutical alternatives to improve health, feed efficiency and performance of beef cattle. We investigated four different targeted strategies to enhance performance of beef cattle: 1) The effect of an injectable multi-mineral complex supplementation for grazing beef cows on overall mineral status, fertility, and subsequent offspring performance. Two doses of the trace mineral injection increased in pregnancy rate after artificial insemination, with a greater impact on cows with poor body condition score; 2) Inclusion of a yeast-derived product combining live yeast (probiotics) and cell wall components (prebiotics), on performance and physiological responses of beef steers during backgrounding and finishing phases. Including a yeast-derived product into a finishing diet containing monensin did not improve performance, physiological responses, and carcass quality of feedlot cattle. Nonetheless, inclusion of the yeast derived product as a substitute of monensin during the backgrounding and finishing phases decreased feed intake without affecting growth, with an overall improvement in feed efficiency; 3) Use of phytotherapy (condensed tannins) to reduce protozoa parasites load and prevent coccidiosis in peripartum beef heifers and their newborn calves. Daily supplementation of condensed tannins reduced coccidia load in heifers and newborn calves, although this reduction was transient; and 4) following the smart farming approach, validate the use of an automated scale system for grazing or feedlot beef cattle, which was able to accurately measures body weight in grazing and feedlot systems for growing and mature beef cattle while reducing cattle handling, without disrupting feeding behavior, decreasing the probability of animal lesions, accidents and optimizing labor. / Doctor of Philosophy / Diet diversification is a response of a growing economy, growing population, and urbanization, which increases the demand of meat products, especially beef, in substitution of staple foods. However, concerns around beef production and its impact on the environment are becoming more relevant for consumers. The need to produce more with less resources requires a sustainable intensification process. Specifically, beef cattle production systems are less efficient when compared to poultry or swine in terms of time and amount of feed required. Beef production systems need to focus on environmental and socially conscious strategies to satisfy the demand, increase animal health, productivity, and profitability. One approach is based on nutritional strategies and applied technologies to enhance productivity, efficiency, welfare, and health. In this dissertation we present three different strategies to improve efficiency of beef production systems: 1) using injectable trace minerals supplementation to ensure adequate mineral nutrition in grazing cows, improving their pregnancy rate to artificial insemination, particularly when cows are in poor body condition; 2) use of yeast as natural additives to successfully substitute antibiotics as growth promotants in feedlot diets with an improvement in feed efficiency; 3) use of secondary plant compounds, such as tannins, to substitute prophylactic antibiotic utilization for coccidiosis in cows and newborn calves. We demonstrate three successful strategies that can improve health, feed efficiency and reproductive performance of beef cattle, all of which are important to achieve greater productivity and profitability in beef production systems.