Browsing by Author "Engle, Terry, advisor"

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Open Access
Effect of zinc concentration and source on performance and carcass characteristics of feedlot steers
(Colorado State University. Libraries, 2012) Caldera, Emmanuel, author; Engle, Terry, advisor; Wagner, John J., advisor; Pritchett, James G., committee member
Three-hundred and sixty cross-bred steers (348.1 kg ± 28.9) were utilized to investigate the effects of zinc (Zn) concentration on performance and carcass characteristics of feedlot steers. Steers were blocked by weight and randomly assigned to one of the 5 supplemental Zn treatments (8 pens per treatment; 9 hd per pen). Treatments consisted of: 1) Control-50 (CON-50; 50 mg of supplemental Zn/kg DM from ZnSO4); 2) Methionine control [MetCON-50; 50 mg of supplemental Zn/kg DM from ZnSO4 plus MHA to equalize HMTBa concentrations across treatments; 3) Organic-50 (ORG-50; Control diet supplemented with 50 mg of Zn/kg DM from Mintrex Zn plus MHA to equalize HMTBa intake across treatments); 4) Organic-100 (ORG-100; Control diet supplemented with 100 mg of Zn/kg DM from MINTREX Zn plus MHA to equalize HMTBa intake across treatments 2-5); and 5) Organic-150 (ORG-150; Control diet supplemented with 150 mg of Zn/kg DM from Mintrex Zn). All steers were fed a typical high concentrate steam-flaked corn based finishing diet twice daily. Steers were individually weighed on d −1, 0, 144, and 145 and pen weighed on d 28, 56, 84, and 111. Ractopamine HCl was fed for the final 29 d of the finishing period to all treatments. On d 145, steers were transported to a commercial abattoir for slaughter. Initial and final body weight, ADG, DMI, and feed efficiency (g/f), were similar across treatments. However, there was a diff (P < 0.04) for ADG to be increased when MetCON-50 was compared to Con-50 on d-56 pen weigh and d-84 pen weigh (3.91, 4.42 ± 0.17 and 4.96, 4.29 ± 0.21 respectively). ADG was also increased (P <0.03) when the CON-50 treatment was compared to the ORG-50 treatment for the d-84 pen weigh period (4.96, 4.29 ± 0.21). There was a trend (P< 0.07) for gain:feed to be increased for the CON-50 when compared to MetCON-50 and ORG-50 for the d57-84 period (0.228, 0.198, 0.199 ± 0.01). Fat thickness, internal fat, hot carcass weight, KPH, marbling score, and dressing percentage were similar across treatments. Steers receiving ORG-150 had a greater (P < 0.03) yield grade compared to steers receiving ORG-50 (2.99 vs. 2.76 ± 0.08; respectively). Steers receiving 1080 Zn also had a greater (P < 0.01) yield grade compared to steers receiving ORG-100 (2.99 vs. 2.68 ± 0.08; respectively). There was a trend (P < 0.07) for steers receiving MetCON to have a greater yield grade compared to CON-50 (2.82 vs. 2.67 ± 0.08; respectively). In addition, liver biopsies and blood samples were analyzed for Zn, Cu, and Fe concentrations as well as alkaline phosphatase in the blood. Initial liver biopsies were similar in Cu and Fe among treatments. Whereas, the Zn concentrations were greater (P < 0.01) in the CON-50 group compared to the Methionine treatment group (218.7 vs. 170.2 ± 12.9). Day 111 liver Zn concentrations tended ( P < 0.05) to be lower for CON-50 and MetCON-50 treatments compared to ORG-50 treatment, while no other differences were noted among treatments (117.8, 123.7 vs. 158.0 ± 16.1). Day-0 plasma results indicate levels of Zn, Cu, and Fe to be similar among treatments with a trend (P < 0.07) in Fe concentrations to be less in the MetCON-50 when compared to the CON-50 treatment (4.71 vs. 1.70 ± 0.85). As for the d-111 plasma analysis indicated no differences among treatments in regards to Zn, Cu, and Fe concentrations. The d-144 plasma analysis indicated no differences (P > .05) in Zn, Cu, and Fe concentrations among treatments. The alkaline phosphatase values for d-0, d-111, and d-144 were similar across treatments, yet the alkaline phosphatase means for each treatment increased over time. These data indicate that under conditions of this trial, increasing Zn concentration in the diet above NRC recommendations has little impact on performance, however, may impact lipid partitioning in steers.
Open Access
Effects of trace mineral source and concentration on production parameters throughout one cow-calf production cycle
(Colorado State University. Libraries, 2023) Hallmark, Harrison, author; Engle, Terry, advisor; Ahola, Jason, advisor; Garry, Franklyn, committee member
An experiment was conducted to evaluate the effects of Cu, Zn, and Mn supplementation on mineral status, production parameters, and cattle performance in a rangeland environment throughout a one -year period in eastern Colorado. One hundred and eighty multiparous crossbred (Angus and Angus x Hereford) beef cows were blocked by body weight, age, and gestational status and randomly assigned to 1 of 3 free-choice mineral treatments (n = 60 cows per treatment). Treatments were then assigned to 1 of 9 replicates (n=20 cows per replicate), resulting in 3 replicates per treatment. Treatments consisted of, 1) 1X NASEM (2016) sulfate base source, 2) 1X NASEM (2016) Intellibond source, or 3) 0.5X NASEM (2016) Intellibond source. Treatments 1 (1X Sulfate) and 2 (1X Intellibond) contained 1,000, 2,000, and 3,000 mg/kg DM of Cu, Mn, and Zn, respectively. While treatment 3 (0.5X Intellibond) contained 500, 1,000, and 1,500 mg/kg DM of Cu, Mn, and Zn. All free-choice mineral supplements were formulated to provide 0.15% supplemental S, 15 mg/kg Co from Co carbonate, and 55 mg/kg I from Ca iodate (Hubbard Feeds; Mankato, MN). Supplement consumption was formulated for 113 g·animal-1 ·d-1. Supplement intakes were determined every 28 d. Liver biopsies and blood samples were obtained before the experiment was initiated (d -45), after calving (d 158 and 159), and after weaning (d 294) at the end of the first production year. Each replicate was rotated to a different pasture every 2 to 4 weeks to minimize pasture effects. Cows were weighed during each liver biopsy event and at each scheduled handling events. A two-day calf weaning weight was collected during weaning (d 260 and 261). Over the first year of the experiment, cow BW, BCS, mineral status, mineral intake, and calf weaning weight were collected. There was no impact of treatment on any of the response variables measured during the first year of the experiment.
Open Access
Extracting copper from dairy footbaths to prevent heavy metal bioaccumulation in agricultural land
(Colorado State University. Libraries, 2018) Jalali, Sam, author; Engle, Terry, advisor; Archibeque, Shawn, committee member; Holt, Timothy, committee member; Roman-Muniz, Noa, committee member
To view the abstract, please see the full text of the document.
Open Access
Investigating hepatic copper trafficking in beef cattle
(Colorado State University. Libraries, 2020) Tillquist, Nicole, author; Engle, Terry, advisor; Coleman, Stephen, committee member; Nair, Mahesh Narayanan, committee member; Torres-Henderson, Camille, committee member
To view the abstract, please see the full text of the document.
Open Access
Management strategies to improve beef feedlot performance and assessment of nutrient composition of beef retail cuts
(Colorado State University. Libraries, 2011) Schutz, Jennifer Sue, author; Engle, Terry, advisor; Belk, Keith, committee member; Archibeque, Shawn, committee member; Van Campen, Hana, committee member
To view the abstract, please see the full text of the document.
Open Access
Molybdenum exposure in drinking water vs feed affects copper apparent absorption differently in beef cattle consuming a high forage diet
(Colorado State University. Libraries, 2020) Thorndyke, Meghan, author; Engle, Terry, advisor; Ahola, Jason K., committee member; Ippolito, Jim, committee member
Twelve Angus steers were utilized to investigate the influence of molybdenum (Mo) in drinking water or feed on apparent absorption and retention of copper (Cu) and Mo. Steers were fed a low-quality grass hay diet for 14 days. Steers were then housed in individual metabolism stalls for 5 days to determine dry matter intake (DMI). Steers were then blocked by body weight and DMI and randomly assigned within block to one of three treatments. Treatments consisted of: 1) control (no supplemental Mo); 2) 5.0 mg Mo/kg DM from sodium molybdate dihydrate (Mo-diet), and 3) 1.5 mg Mo/L from sodium molybdate dihydrate delivered in the drinking water (Mo-water). After the 5 day DMI determination period, total fecal and urine output was collected for 5 days. Dry matter intake, Cu and water intake, and DM digestibility were similar across treatments. As expected, Mo intake was greater (P < 0.05) in Mo-water and Mo-diet steers when compared to controls but similar between Mo-water and Mo-diet steers. Apparent absorption and retention of Cu (% of Cu intake) was greater (P < 0.05) in controls when compared to Mo-diet supplemented steers. Apparent absorption and retention of Cu (% of Cu intake) in steers in the Mo-water treatment did not differ from controls or those receiving the Mo-diet. Molybdenum-diet and Mo-water supplemented steers had similar apparent absorption and retention of Cu. Apparent absorption and retention of Mo (% of Mo intake) was greater in controls when compared to Mo supplemented steers. These data indicate that Mo consumed in water may impact Cu absorption and retention to a lesser extent than Mo supplemented in the diet.
Open Access
Sulfur metabolism in beef cattle and management strategies to improve performance and health in newly weaned beef cattle
(Colorado State University. Libraries, 2012) Neuhold, Kelley L., author; Wagner, John, advisor; Engle, Terry, advisor; Peel, R. Kraig, committee member; Rollin, Bernard, committee member
To view the abstract, please see the full text of the document.
Open Access
The effect of trace mineral source on solubility, rumen fermentation characteristics, and trace mineral concentration in protozoa and bacteria of steers consuming a lactation dairy type diet
(Colorado State University. Libraries, 2024) Loh, Huey Yi, author; Engle, Terry, advisor; Narayanan Nair, Mahesh, committee member; Coleman, Stephen, committee member; Torres-Henderson, Camille, committee member
A series of experiments were conducted to investigate the influence of trace mineral (TM) source on TM solubility, rumen fermentation characteristics, and trace mineral concentration in protozoa and bacteria of steer consuming a lactation dairy-type diet. Experiments 3 and 4 were classified as experiments 1 and 2 in chapter 3 for publication purposes in academic journal. In the first experiment, hydroxychloride TM (HTM) and sulfate TM (STM) sources of Cu, Mn, and Zn (n = 4/element/source; N = 24) were incubated separately in water for 24 h. Initial pH was measured after adding the TM to the solution, then the tubes were incubated at 39°C with agitation. After a 24-h incubation, samples were filtered to obtain the filtrate for TM analysis, and final pH readings were taken. Initial pH of each solution was greater (P < 0.03) for HTM compared to STM for all elements. Final pH tended to be greater for Cu (P = 0.09) and Zn (P = 0.07) from HTM compared to STM. Water solubility of Cu, Mn, and Zn from STM was greater (P < 0.01) than HTM sources. These data indicate that TM source influences pH and solubility of Cu, Mn, and Zn in water. In Experiment 2, eight steers fitted with rumen cannula were blocked by body weight and randomly assigned to treatments consisting of 10 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either STM or HTM sources (n = 4/treatment). Steers were individually fed a cracked corn-corn silage-based diet. Treatments were top-dressed daily. Rumen contents were collected at 0, 2, and 4 h post-feeding on d 1 and 14. On d 15, strained ruminal fluid (SRF) and particle-associated microorganisms (PAO) were obtained. Digesta from HTM-supplemented steers has a lesser (P < 0.01) Mn concentration than STM-supplemented steers on d 14 of the trial. Steers supplemented with STM had a greater (P = 0.0016) soluble Cu concentration in the rumen on d 14 than those fed HTM. Zinc was more tightly bound (P = 0.01) to the digesta in HTM-supplemented steers compared to STM on d 14. The data suggest that dietary TM source can affect rumen soluble Cu concentrations and binding strength of Zn to solid digesta. In Experiment 3, three cannulated steers were adapted to a diet formulated to meet the nutrient requirements for lactating dairy cows. Strained RF was obtained by straining rumen content through 2 layers of cheesecloth. Half of the remaining digesta was washed with McDougall's buffer and filtered through 2 layers of cheesecloth to obtain PAO. Both SRF and PAO were filtered again through 8 layers of cheesecloth. Strained RF was mixed with either McDougall's buffer (SRF) or PAO (SRF+PAO) at a ratio of 1:2 or 1:4 and incubated at 39°C for 12 h using the ground basal diet as the substrate. Digestibility of DM was greater (P < 0.05) in digestion tubes containing SRF and SRF+PAO at a 1:2 ratio. In Experiment 4, eight steers fitted with ruminal cannula were blocked by body weight and assigned to one of two treatment groups. Treatments consisted of 10 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either 1) sulfate (STM) or 2) hydroxychloride (HTM) sources. Steers were housed in individual pens and fed the same diet as described in experiment 1. Dietary TM treatments were mixed with dried distillers grains and mixed in the diet by hand, immediately after basal diet delivery. Dietary treatments were fed for 14 d. On day 15, SRF+PAO was collected from each steer (STM-RF and HTM-RF) and used in a series of in vitro crossover experiments. In vitro substrates (S) used were the ground diets consumed by the animals on each treatment (STM-S and HTM-S). Incubations containing HTM-S had greater (P < 0.01) total VFA concentration and propionic acid molar proportions, but lesser (P < 0.01) acetic acid molar proportions than STM-S. Rumen fluid from steers supplemented with HTM had a greater (P < 0.03) total VFA than STM-RF at 24h post incubation. After 12 h post incubation, the molar proportion of propionic acid in HTM-RF was lesser (P = 0.04) than STM-RF. After simulated abomasal digestion, soluble Mn concentration in HTM-S was greater (P < 0.01) than STM-S. These data indicate that the source of trace minerals can influence in vitro rumen fermentation characteristics and Mn solubility under simulated abomasal conditions.
Open Access
The effects of long-term molybdenum exposure in drinking water on molybdenum metabolism and production performance of beef cattle consuming a high forage diet
(Colorado State University. Libraries, 2024) Thorndyke, Meghan, author; Engle, Terry, advisor; Ahola, Jason, committee member; Edwards-Callaway, Lily, committee member; Holt, Timothy, committee member
In the current series of experiments the influence of long term molybdenum (Mo) exposure in the feed or water on copper (Cu) status, metabolic, reproductive, and carcass characteristics was investigated. The objective of experiment 1 was to conduct a life-cycle production and health assessment of lactating and gestating beef cattle, and their calves, exposed to varying doses of Mo. In this experiment Commercial, multiparous beef cows (n=54 in year 1; n= 51 in year 2) with calves (approximately 2 months of age) were used to evaluate the effects of Mo source (feed or water) on reproduction, mineral status, and performance in cows and calves receiving a grass hay diet [dry matter (DM) basis: 6.6% crude protein; 0.15% S, 6.7 mg Cu/kg, 2.4 mg Mo/kg] for 553 d. Cows were stratified by age, body weight (BW), and liver Cu and Mo status, and were then randomly assigned to one of six treatment groups. Treatments were: 1) Negative control (NC; basal diet with no supplemental Mo or Cu); 2) Positive control (PC: NC + Cu; 3 mg of supplemental Cu/kg diet DM from CuSO4·5H2O); 3) NC + 500 µg Mo/L from Na2MoO4·2H2O supplied in drinking water (Mo 500-water); 4) NC + 1000 µg Mo/L of Na2MoO4·2H2O supplied in drinking water (Mo 1000-water); 5) NC + Mo 1000-water + 3 mg of supplemental Cu/kg diet DM from CuSO4·5H2O (Mo 1000-water+Cu); and 6) NC + 3.0 mg of supplemental Mo/kg diet DM from Na2MoO4·2H2O (3.0 Mo-diet). During the winter months, animals were housed in three replicate pens per treatment and during the summer months animals were housed in separate pastures by treatment. Animals were allowed ad libitum access to both feed and water throughout the experiment. Cows were bred via artificial insemination during the summer months of both years of the experiment and calves were weaned at approximately 6 months of age in the fall of both years. All cows and calves were weighed, bled, and feed and water intake were determined every 28d. Cattle receiving diets containing less than 10 mg Cu/kg DM total diet became Cu deficient over the course of the experiment as determined by liver and plasma Cu concentrations. However, no Mo toxicity or Cu deficiency signs (e.g., reduction in growth rates, reproductive performance, or immune function) were observed throughout the course of the experiment for any treatment. Results suggest that Mo supplemented in water or feed at concentrations used in this experiment had minimal impact on Cu status and overall animal performance. However, dietary Cu concentration below 10.0 mg Cu/kg DM total diet reduced liver and plasma Cu concentrations to values indicative of a marginal Cu deficiency in beef cows. The objective of the chapter 3 review was to examine the impact of Mo in drinking water on cattle performance and Mo and Cu metabolism. The majority of Mo research has focused on the antagonist effect of Mo, alone or in combination with elevated dietary S, on Cu absorption and metabolism in ruminants. Diets containing both >5.0 mg of Mo/kg DM and >0.33% S have been reported to reduce the Cu status in cattle and sheep. Therefore, due to the potential for inducing Cu deficiency, Mo and S concentrations in the diet should be monitored and kept within appropriate values. Elevated sulfate concentrations in drinking water can also be detrimental to livestock production, especially in ruminants. High concentrations of sulfate in water have been extensively studied in cattle because high-sulfate water induces polioencephalomalacia in ruminants. However, little research has been conducted investigating the impact of Mo in water on Cu metabolism in ruminants. Based on the limited number of published experiments, it appears that Mo in drinking water may have a lower antagonistic impact on the cu status in cattle when compared to Mo consumed in the diet. This response may be due to a certain percentage of water bypassing the rumen when consumed by ruminants. The chapter 4 experiment objective was to of this experiment was to investigate the influence of prolonged exposure to elevated Mo water concentrations on apparent absorption and retention of both Cu and Mo in pregnant multiparous beef cows. In this experiment twelve multiparous beef cows of similar BW, age, and gestational length, from a larger cow-calf study, were utilized to evaluate the effects of molybdenum (Mo) consumption method (feed or water) on apparent absorption and retention of copper (Cu) and Mo. Cows (n=54) with calves had been assigned to one of six dietary and/or water treatments (n=9 cow-calf pairs per treatment) 301 d prior to selecting a sub-group of 12 cows. Treatments consisted of: 1) negative control (control; basal diet with no supplemental Mo or Cu), 2) positive control (control + 3 mg of supplemental Cu/kg DM), 3) control + 500 µg Mo/L from Na2MoO4·2H2O supplied in drinking water, (4) control + 1000 µg Mo/L of Na2MoO4·2H2O supplied in drinking water, (5) positive control + 1000 µg Mo/L of Na2MoO4·2H2O supplied in drinking water, and (6) control + 3.0 mg of supplemental Mo/kg diet DM from Na2MoO4·2H2O. The sub-group of cows were individually fed a low quality grass hay diet with their respective treatments, n=2 cows/treatment) for 14 d. On day 15, dry matter intake (DMI) was held at 90% of the group's average intake. Total fecal and urine output were then collected for 3 d. Dry matter digestibility and water intake were similar across treatments. Copper intake and apparent absorption and retention of Cu were greater (p < 0.05) in cows receiving supplemental Cu when compared to non-Cu supplemented cows. Apparent absorption of Mo was similar across all treatments. Apparent retention of Mo was greater while apparent absorption of Cu was lesser (p < 0.05) in cows receiving 3 mg of Mo/kg dm and cows receiving 1000 µg Mo/L when compared to all other treatments. These data indicate that Mo source (feed vs water) may impact apparent absorption of Cu in cows receiving a low quality forage diet. The chapter 5 survey of central Rocky Mountain livestock producers objective was to understand the mineral consumption within the forage and water as well as Cu and Mo status of the grazing cattle. Commercial, multiparous, crossbred beef cows from 3 independent cow-calf production operations were selected to assess the molybdenum (Mo) and copper (Cu) status of cattle raised in the Rocky Mountains. Fifteen cows from each operation were selected at random, during early summer and late fall processing. At the time of cattle processing, both jugular venipuncture blood samples and liver biopsies were obtained from each cow. Furthermore, all diet components, forage, water, and supplement samples were obtained from each location. Plasma, liver, water, and feed samples were analyzed for Mo and Cu concentrations via inductively coupled plasma mass spectrometry. Feed samples were also analyzed for moisture, crude protein (CP), ash, ADF and NDF. Water samples were sent to an established laboratory for general water quality analysis. On average, in the current survey forages samples contained 55.61% DM, 8.37% CP, 34.91% ADF, and 54.98 NDF with a Cu:Mo ratio of 2.8:1. Additionally, the water quality of the samples obtained were well within the "safe and should pose no health problems" category for beef cattle. Plasma Mo concentrations of 0.22 (±0.10) mg/kg DM were considered to be elevated in 64% of all samples obtained, likely a result of the elevated Mo forage concentrations in the grazed plant material. Plasma Cu of 0.83 (±0.11) concentrations were within normal ranges for all samples obtained. Molybdenum and Cu liver concentrations of 3.74 (±1.29) and 82.54 (±22.76) respectively, were within ranges considered to be normal for beef cattle for all samples collected. Based on the results of this survey, Mo and Cu plasma and liver concentrations in Colorado cow-calf operations in the central Rocky Mountains were similar to Mo and Cu plasma and liver concentrations in Cu supplemented cows in the previously described 2-year Mo supplementation cow-calf experiment. Furthermore, these data suggest that Cu supplementation at NASEM (2016) recommended concentrations of 10 mg Cu/kg DM total diet (or greater) meets the animals dietary Cu requirement for cattle consuming forages sampled.
Open Access
The effects of molybdenum water concentration on feedlot performance, tissue mineral concentration, and carcass quality of feedlot steers
(Colorado State University. Libraries, 2017) Kistner, Madison, author; Engle, Terry, advisor; Wagner, John J., advisor; Holt, Timothy N., committee member
Thirty cross-bred steers (initial BW 375 ±37.2, replicate 1; and 535.0 ± 39.4 kg, replicate 2) were utilized to investigate the effects of Mo water concentration on performance, carcass characteristics, and mineral status of feedlot steers fed a growing and finishing diet for 151 and 112 d for replicate 1 and replicate 2, respectively. The experimental design was a randomized complete block design. Steers were blocked by weight and then divided into 2 weight block replicates each consisting of 15 steers. Steers were randomly assigned within block to one of 5 treatments (3 pens/treatment; 1 steer/ pen; 2 replicates/treatment). Water treatments consisted of: 1) 0.0 µg, 2) 160 µg, 3) 320 µg 4) 480 µg Mo/L, and 5) 960 µg of supplemental Mo/L added as Na2MoO4 to the drinking water. Steers were housed in individual pens that contained individual 265 L water tanks for monitoring water intake. Daily water intake was recorded for each steer. Steers were individually weighed on 2 consecutive days at the beginning and end of the experiment and interim weights and jugular blood samples were obtained every 28 d. Liver biopsies were obtained on d0 and 84 from each steers. Steers were transported to a commercial abattoir, slaughtered, and individual carcass data and liver samples were collected. Initial BW was used as a covariate for statistical analysis of the data and significance was determined at P ≤ 0.05. No differences were observed for final BW (P ≤ 0.98). Overall ADG, DMI, feed efficiency and water intake were similar across treatments. Hot carcass weight, dressing percentage, yield grade, LMA, adjusted fat thickness, KPH, and marbling scores were similar across treatments. Liver and plasma Cu, Mo, and Zn concentrations were similar across treatments. These data indicate that water Mo concentration had no impact on performance, mineral status, water intake, and carcass characteristics in feedlot steers fed a high concentrate diet.
Open Access
The influence of trace mineral source on reproductive performance in recipient multiparous beef cows
(Colorado State University. Libraries, 2022) Thomas, Tyler, author; Engle, Terry, advisor; Hess, Ann, committee member; Coleman, Stephen, committee member
An experiment was conducted to determine the effects of copper (Cu), cobalt (Co), manganese (Mn), selenium (Se), and zinc (Zn) source on the reproductive parameters of multiparous beef cows. Fifty cow-calf pairs were divided into ten groups (n=5 cow-calf pairs per group) and balanced across groups for animal source, cow weight, calf age, calf sex, and breed type. Each group was randomly assigned to one of the following treatments: 1) Organic trace minerals: 75 mg of Cu/d from Cu proteinate, 8 mg of Co/d from Co proteinate, 105 mg of Mn/d from Mn proteinate, 3 mg of Se/d from Sel-Plex, and 220 mg of Zn/d from Zn proteinate; and 2) Inorganic trace minerals (at two times the NASEM (2016) requirements): 255 mg of Cu/d from CuSO4∙5H20, 2.6 mg of Co/d from CoCO3, 1018 mg of Mn/d from MnSO4, 3 mg Se/d from Na2SeO4, and 763 mg of Zn from ZnSO4∙5H2O. Animals were fed a corn silage – corn stalk-based diet that met or exceeded the NASEM (2016) requirements for gestating beef cows with the exception of Cu, Co, Mn, Se, and Zn. Cows were individually supplemented with their appropriate treatments daily for 89 days, five days after the initiation of estrus synchronization (day 0). Estrus synchronization was achieved through implantation of a progesterone controlled internal drug release (CIDR; Zoetis; impregnated with 1.38 g progesterone) device and 2ml of gonadotropin-releasing hormone (GnRH; Factrel from Zoetis) administered intramuscularly. After seven days, the CIDR was removed, 2 ml lutalyse (HighCon from Zoetis) was administered intramuscularly, and an Estrotect patch was applied for estrus detection. After two additional days, recipient cows were given a second dose (2ml) of GnRH. Eight additional days later, all recipient cows that were synchronized were palpated, and those with a viable corpus luteum (CL) received an embryo as well as a CIDR. The CIDR was removed 15 days later and an Estrotect patch was applied. Expression of estrus was evaluated for the following four days of the experiment. Cows that did not express estrus, and cows that did not maintain a pregnancy from the first embryo, underwent the same estrus synchronization protocol a subsequent time. A licensed veterinarian made pregnancy diagnoses on August 18th, September 12th, and October 8th using an ultrasound, recording each cow as either pregnant or open. Blood samples were collected via jugular venipuncture from each animal on days 0, 16, 43, 68, and 94 of the experiment and analyzed for progesterone, luteinizing hormone, anti-mullerian hormone, follicle-stimulating hormone, and estradiol. However, as animals in this study varied by pregnancy status and days pregnant, mineral status and hormone status were evaluated by time points (TP) defined as TP0: prior to embryo transfer; TP1: day of embryo transfer; TP2: 28-33 days post embryo transfer; TP3: 58-60 days post embryo transfer; and TP4: 84 days post to embryo transfer. There was a treatment by time effect for plasma Cu concentrations (P < .03), with Cu concentrations of the inorganic treatment decreasing (0.89 to 0.76 mg Cu/L) and those of the organic treatment increasing (1.01 to 1.19 mg Cu/L) as the experiment progressed. There were no other significant time or treatment by time effects for plasma trace mineral concentrations. Cows receiving organic trace minerals had greater plasma Se and Cu (P < .0001) concentrations when compared to cows receiving the inorganic trace mineral. Plasma cobalt, manganese, and zinc concentrations were similar between the two treatments (P > 0.1). Pregnancy rates of the inorganic and organic treatments were similar at the conclusion of the trial (66.6% and 62.5%, respectively). Treatment outcomes were also similar (P > 0.10) for embryo transfer attempts, calf birth weights, and days pregnant. There were no treatment or treatment by time interactions for serum progesterone, luteinizing hormone, anti-mullerian hormone, follicle-stimulating hormone, or estradiol concentrations (P > 0.10). The differences in circulating trace elements between treatments did not appear to impact the hormone concentrations or reproductive outcomes in this trial. Further research is needed to further understand the impact of mineral source on reproductive outcomes.
Open Access
Trace mineral source impacts rumen trace mineral distribution and fiber digestion in steers fed a low-quality forage-based diet
(Colorado State University. Libraries, 2020) Guimaraes, Octavio, author; Engle, Terry, advisor; Geornaras, Ifigenia, committee member; Holt, Timothy, committee member
Twelve Angus steers (BW 452.8 ± 21.8 kg) fitted with ruminal cannulae were used to determine the impact of trace mineral (TM) source on neutral detergent fiber (NDF) digestibility, short chain fatty acid (SCFA) production, ruminal solubility of Cu, Zn, and Mn, and relative binding strength of trace minerals located in the rumen insoluble digesta fraction. Steers were fed a low-quality grass hay diet (DM basis: 10.8% CP, 63.1% NDF, 6.9 mg Cu/kg, 65.5 mg Mn/kg, and 39.4 mg Zn/kg) supplemented with protein for 21 d. Treatments consisted of 20, 40, and 60 mg supplemental Cu, Mn, and Zn/kg DM, respectively, from either sulfate (STM) or hydroxy (HTM) sources (n=6 steers/treatment). Following a 21-d adaptation period, total fecal output was collected for 5 d. Dry matter digestibility tended (P < 0.07) to be reduced (51.9 vs. 53.4 ± 0.52%) and NDF digestibility was reduced (P < 0.04; 40.4 vs. 42.7 ± 0.67%) in STM vs. HTM supplemented steers. On d-6, rumen fluid was collected at 0, 2, and 4 h post feeding and analyzed for SCFA. There were no treatment x time interactions for any response variables measured. However, treatment was a significant (P < 0.05) source of variation for butyric acid and total SCFA production. Steers receiving HTM had less (P < 0.02) butyric acid and greater (P < 0.05) total SCFA than STM supplemented steers. Steers were then fed the same low-quality grass hay diet without supplemental Cu, Zn, or Mn for 14 d. On d-15, steers received a pulse dose of 20 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either STM or HTM sources (n=6 steers/treatment). Ruminal samples were obtained at 2-h intervals starting at -4 h and ending at 24 h relative to dosing. There was a treatment x time interaction for ruminal soluble Cu, Mn and Zn concentrations. Ruminal soluble mineral concentrations were greater (P < 0.05) for Cu at 4, 6, 8, 10, 12, and 14 h; for Mn at 4 and 6 h; and for Zn at 4, 6, and 8 h post dosing in STM compared to HTM supplemented steers. Concentrations of Cu and Zn in ruminal solid digesta were also affected by treatment, time, and treatment x time. At 12 h post dosing, Cu and Zn concentrations were greater (P < 0.05) in HTM supplemented steers when compared to STM supplemented steers. Upon dialysis against Tris-EDTA the % Zn released was greater at 12 h (P < 0.03) and 24 h (P < 0.05) and the % Cu released was greater (P < 0.02) at 24 h post dosing when compared to STM supplemented steers. Results indicate that Cu and Zn from HTM have low solubility in the rumen, may improve fiber digestibility and appear to be less tightly bound to ruminal solid digesta than Cu and Zn from STM.