bluuebunny/crossref_metadata_2025 huggingface dataset:
280 The Effect of Bromocriptine Mesylate and Heat Stress on Innate and Adaptive Immune Function in Beef Cattle
Authors: Zeltwanger Joshua M , Bailey Eric , Spiers Don , Petzel Emily , Nelson Benjamin , Brake Derek
Published: September 2022

Injection of bromocriptine mesylate has been used to mimic the symptoms of tall fescue toxicosis in beef cattle. Twelve steers (351 ± 11.82 kg) were used to investigate the effect of bromocriptine mesylate and heat stress on serum prolactin, rectal temperature, respiration rate, and innate/adaptive immune function. Steers were randomly assigned to receive an injection of saline (CON) or bromocriptine mesylate (BROMO; 0.1mg/kg BW) every three days. Animals were housed for 22 d in the Brody Climatology Laboratory at thermoneutrality (TN; 19.5±0.26°C; 10-d) before transitioning (2-d) to heat stress (HS; 27.2±0.26°C nighttime, 34.5±0.26°C daytime; 10-d). Cattle were fed 1.8% of BW (DM-basis) daily across two feedings. Rectal temperatures and respiration rates were measured daily at 0600, 0900, 1500, and 1800 h. Serum and plasma were harvested from blood collected on d 1, 9, and 21 (9th d of thermoneutrality and heat stress, respectively) and analyzed for prolactin and cytokines. Dry-matter intake was not affected by treatment (P=0.52) or temperature (P=0.78). Prolactin concentrations decreased (P=0.02) throughout the trial and decreased (P< 0.01) with BROMO. Rectal temperature and respiration rate were greater (P< 0.01) for BROMO during TN and HS. Rectal temperature and respiration rate were increased (P< 0.01) during HS. Pro-inflammatory cytokine (TNF-α, IFN-α, IFN-γ, IL-1α, IL-1β, IL-17, and IL-18) concentrations were greater (P< 0.01) for BROMO steers than CON. Heat stress increased (P< 0.01) pro-inflammatory cytokines with the exception of IL-18 (P=0.98) regardless of treatment. Anti-inflammatory cytokines (IL-13, IL-1-F5, IL-21, IFN-β, LIF) were decreased (P< 0.07) for BROMO steers with the exception of IL-10 (P=0.58). Regardless of treatment IL-13, IL-21, IL-10, and LIF concentrations were greater (P< 0.05) during HS. These results demonstrate that bromocriptine mesylate successfully mimicked the symptoms of fescue toxicosis. Innate and adaptive immune responses were influenced by treatment and temperature, potentially affecting beef cattle immune competency.
285 Effect of low Protein Diets on Oxidative Stress, Plasma Metabolomics and Cecal Microbiome of Broiler Chickens During Experimentally Induced Heat Stress
Authors: Sutton Julia , Habibi Mohammad , Shili Cedrick n , Pezeshki Adel
Published: September 2022

Low-protein diets mitigate the negative outcome of heat stress in birds; however, the underlying mechanisms are largely unknown. The objective of this study was to investigate the effects of low-protein diets on broilers oxidative stress, plasma metabolomics and cecal microbiota composition during experimentally induced heat stress. Two-hundred-day-old male broiler chicks were assigned into 36 pens with of 5-6 chicks/pen. All pens were weight-matched and randomly subjected into either thermoneutral (TN) or heat stress (HS) with 18 pens/treatment. Within each treatment, the birds were randomized to receive either normal protein (NP) or low protein (LP) diets with 9 pens/diet (50 birds/diet). The study lasted 6 weeks with 2 weeks of acclimation (starter phase) and 4 weeks of data collection (grower and finisher phases). On week 6, birds were euthanized and blood and cecal samples were collected. Oxidative stress biomarkers and peak height of metabolites in plasma were analyzed using GLM procedure (SPSS). Paired t-test was used for comparing diet treatments within TN and HS groups. Under TN condition, birds fed with LP had a decreased plasma superoxide dismutase activity and lipid peroxidation compared with NP (P< 0.05), but no differences on these measurements were detected during HS (P>0.05). Birds fed with LP diet had a greater lipid hydroperoxides than NP under HS (P< 0.05). Principal component analysis showed a clear separation for plasma metabolites found between NP and LP diets under TN and HS. Dietary protein content impacted plasma metabolites related with metabolism and biosynthesis of alanine, aspartate, glutamate and phenylalanine during both TN and HS. Compared with NP, cecal contents of chickens fed with LP diet had greater abundances of p_Tenericutes, c_Mollicutes, c_Mollicutes_RF9, and f_tachnospiraceae under HS. Thus, dietary protein content influenced the plasma metabolites with similar pattern during TN and HS, but that had differential effects on cecal microbiota composition under TN and H.
292 Evaluation of two Beef cow Fixed-Time AI Protocols That Utilize pre-Synchronization
Authors: Ketchum Jaclyn N , Quail Lacey K , Epperson Kaitlin M , Guy Chloey , Rich Jerica J J , Zoca Saulo Menegatti , Kline Adalaide , Andrews Taylor , Walker Julie , Fontes Pedro , Johnson Sandy , Owen Megan P , Harvey Kelsey M , Summers Adam F , Perry George A
Published: September 2022

Pre-synchronization has been evaluated as a method to improve synchrony of ovulatory follicles before fixed-time AI (FTAI). The objective was to compare FTAI results in beef cows from two protocols that utilize pre-synchronization. Blood samples were collected on d-14 (d0=CIDR removal) to determine progesterone concentration at the start of synchronization (P4start: ≥1ng/mL=high, < 1ng/mL=low). In a subset (n=1,032), an additional blood sample was taken between d-21 and -29 to determine cyclicity. Cows (n=1,119), from 21 herds, were grouped by days postpartum and age and randomly assigned to one of two protocols. Cows assigned to the PG 6-day CIDR protocol (PG6d) received prostaglandin F2α (PG) on d-9, CIDR insertion and GnRH on d-6, and CIDR removal and PG on d0. Cows assigned to the 7&7 Synch protocol (7&7) were administered PG and CIDR insertion on d-14, GnRH on d-7, CIDR removal and PG on d0. For both protocols, FTAI occurred coincident with GnRH 66 h after second PG. Pregnancy was determined by transrectal ultrasonography 30-40 d following FTAI. The GLIMMIX procedure of SAS (9.4) was used to detect differences in estrus response and pregnancy success with herd included as a random variable. Estrus response (0 to 66 h) was influenced by treatment (P< 0.01; PG6d=60±5% and 7&7=74±4%), Body Condition Score (P< 0.01), cycling status (P=0.03), P4start (P< 0.01), and a P4start by treatment interaction (P< 0.001; PG6d-highP4=62±6%, PG6d-lowP4=58±6%, 7&7-highP4=84±3%, 7&7-lowP4=60±6%). Pregnancy success was influenced by estrus expression (P< 0.01; estrus=38±4% and no estrus=62±6%), and a treatment by P4start interaction (P=0.04; PG6d-highP4=58±5%, PG6d-lowP4=39±7%, 7&7-highP4=49±5%, 7&7-lowP4=55±8%) but was not influenced by treatment (P=0.45; PG6d=49±4% and 7&7=52±4%). In conclusion, effectiveness of pre-synchronization method depends on a cows’ physiological status at the beginning of the protocol. The 7&7 protocol increased estrus response compared to PG6d, but there was no difference in pregnancy success.
293 Awardee Talk: Innovations in Bovine Reproductive Management: What the Future Holds
Authors: Pohler Ky G
Published: September 2022

At least 1 billion people globally still experience inadequate protein intake of which 16.5% represent children under the age of 5. To further complicate matters, resources for food and agriculture production will become more limited as the planet becomes more populated and urban areas expand. This demands a dramatic and timely increase in agricultural efficiency to meet the global food demand within a sustainable framework. As the human population grows and dietary preferences increasingly include animal protein, global meat consumption is expected to increase by 30%, requiring a 72% increase in current meat production to meet these goals. One major protein source cattle, represent a major opportunity to increase overall efficiency of our herds globally. In the past 50 years, we have seen drastic increases in innovative technology, specifically in the area of reproductive biology and management. This talk will focus on what has been accomplished to date and what the future may hold for cattle producers around the world. More specifically, focus and discussion on embryonic mortality which is the number one driver of reproductive inefficiency. This project was supported by Agriculture and Food Research Initiative Competitive Grant no. 2017-67015-26457, 2019-67015-28998 and 2022-67015-33675 from the USDA National Institute of Food and Agriculture.
302 Implications of the Paternal Environment for Future Generations
Authors: Bailey Janice L
Published: September 2022

The use of genetically superior males for artificial insemination has arguably been the most important tool to maximize the dissemination of desirable genes and improve the performance traits of agriculturally important species. The sire’s reproductive fitness traditionally focuses on breeding soundness, with the narrow assumption that role of the male is restricted to providing sperm to the oocyte, such that once fertilization occurs, the gestational outcome depends entirely on the dam. The sire’s role, however, extends beyond fertilization as the sperm epigenome mediates early embryo gene expression, thereby influencing subsequent embryo quality and developmental competence. Since the epigenome is sensitive to the environment, including nutrition, we used a rodent model of paternal exposures to test the hypothesis that multigenerational effects are transmitted through the paternal lineage. We also demonstrate that a possible mechanism for paternal transmission of environmental information is via the sperm epigenome. These findings should inspire animal industry to increase their consideration of the sire’s environment in the context of optimizing productivity. (This research was funded by CIHR, FRQNT and NSERC.)
306 Cattle Performance and Forage Nutrients While Grazing an Integrated Crop-Livestock System Compared with Grass Pasture in the Northern Great Plains
Authors: Christensen Rachael G , Kronberg Scott L , Hendrickson John R , Archer David W , Liebig Mark A
Published: September 2022

Many integrated crop-livestock system (ICL) studies have been conducted, but few report cattle performance and forage nutrients. Here, we report one year of cattle weight gains for Angus yearling heifers and steers grazing ICL plots (ICL) or tame grass pastures (PAS) in four replicates. Five yearlings (avg. BW 390 ± 26 kg) were randomly assigned to graze each plot while provided ad libitum water and trace mineral salt. Cattle assigned to ICL grazed three crop rotations: 1) corn interseeded with soybean (C/S), 2) spring wheat interseeded with cover crop and 3) cover crop planted into spring wheat from the previous year. Yearlings in ICL were stocked first on green C/S, grazing an average of 60 days. Beginning C/S biomass was 1,827 ± 638 g m−2, yearling end BW was 465 ± 34 kg and ADG 1.28 ± 0.27 kg. Yearlings then grazed residual cover crop growth, averaging additional 42 d grazing while supplemented with a ration of baled cover crop forage, wheat straw, and corn. Ration intake averaged 15.35 ±0.6 kg animal-1 d-1. Final BW of ICL yearlings on cover crops averaged 499 ± 34 kg, ADG of 0.79 ± 0.29 kg. Yearlings assigned PAS were provided 1,911 ± 162 g m−2 at the beginning of grazing for 69 days, had final BW 443 ± 35 kg, ADG of 1.01 ± 0.22. Forage nutrient analyses are reported in Table 1, showing that individual crops are similar in ADF and TDN, but vary in crude protein content. Performance of ICL cattle exceeded that of PAS while on corn and soybean but decreased ICL performance while grazing cover crop was likely due to extreme cold weather at the time of grazing. Nutrient values reported here can be used to plan and predict cattle growth while grazing crop residues instead of pastures.
312 Characterizing Riding Tendencies of Owners, Managers, or Riders of Indoor Arena Through an Anonymous Survey
Authors: McGill Staci , Hayes Morgan , Coleman Bob
Published: September 2022

Indoor riding and training facilities allow for horses to be worked no matter the weather conditions which prevents downtime that could result in lost profits. Research on these facilities has been limited so during the summer of 2018, an anonymous online survey was conducted to begin to characterize indoor arenas. Respondents, grouped by designations of owners, managers, and riders, were asked common questions regarding the region they were from, their main discipline and riding interest, their preference of riding indoors or outdoors, how often they rode, and the average duration of their rides. These questions were analyzed for associations or trends based on whether the respondents were owners, managers, or riders. While many of the respondents were riders at facilities and did not own or manage an indoor arena, trends were visible in the data. All respondents favored riding outdoors rather than in an indoor arena and tended to ride for 30 minutes to one hour on average. In regards to disciplines, most of the managers and owners tended to prefer riding disciplines with a flat emphasis, while riders were evenly split amongst eventing, a flat emphasis, and a flat and over fence emphasis. Examining how often the respondents rode yielded unsurprising results as most respondents who identified as owners and/or managers rode multiple times per day while those who identified as riders typically rode multiple times a week. Understanding how the respondents use and interact with an indoor arena facilitates better opportunities to develop future research as well as allows for programming and publications that can help build and manage facilities that work best for those in the industry using them.
336 Anavrin®, Monensin or Both on the Diet of Finishing Steers fed TMR? Effect on Performance and Rumen Fermentation
Authors: Ciancio Bruni Falero Eliana Y , Santana Álvaro , Diez Hugo , Longueira Emanuel , Hernández Dermidio M , Repetto José Luis , Cajarville Cecilia
Published: September 2022

The objective of this was to evaluate the effects on dry matter consumption (DMI), daily gain (DG), feed efficiency (FE) and rumen fermentation of including monensin or an additive composed of essential oils, flavonoids and tannins. (Anavrin) in the diet of fattening steers, studying possible associative effects between them. Thirty steers (12 with 8 mm rumen probes), feeders with TMR diet (ground corn, soybean meal, grass hay, mineral-vitamin concentrate; 65% MS, 12.8% PB, 23% FDN), offer 2.8% of your PC (MS base), were blocked by PC and distributed in 3 treatments (n=10/treatment), adding to the basal diet: 1) 0.033 g of monesin/kg TMR offered: MON', 2) 0.35 g of Anavrin/100 kg BW: 'Anavrin' or 3) both included each at the same dose of 1 and 2 treatments: 'Anavrin® +MON'. The experiment lasted 60 d, and the steers were weighed every 12 d, for 2 consecutive days each time. The DMI was measured individually 3 times over 5 consecutive days, starting on days 20, 34 and 48, by difference offered-rejected for each food. Rumen pH, N-NH 3 and volatile fatty acids (VFA) were measured on days 19, 33 and 47, at 9:30; 13:00; 15:00; 17:00; 19:00; 21;00; 3:00 and 9:30h. Productive behavior (GR and FE) was similar for all treatments, and rumen fermentation was similar for Anavrin and MON. Adding a combination of both additives (Anavrin+MON) leads to a lower DI with respect to Anavrin alone, a lower butyrate concentration than monensin alone, showing associative effects. The percentage of propionic tended to be higher when the combination was added, which should lead to lower methane emissions. Overall, the use of Anavrin led to results similar to those of monensin.
348 Including Alfalfa in the Diet of Steers fed TMR: Effect on Rumen Fermentation and Performance
Authors: Falero Eliana Y Ciancio Bruni , Santana Álvaro , Dayuto Juan E , Ricci María J , Capucho Juan P , González Ana L , Cajarville Cecilia , Repetto José Luis
Published: September 2022

The aim of this study was to evaluate the effects on dry matter intake (DMI), daily gain (DG), feed efficiency (FE) and rumen fermentation of including fresh alfalfa (FA) on a restricted TMR diet of finishing steers. Twenty steers (8 with 8-mm ruminal catheters), fed a TMR diet (ground corn grain, soybean meal, pasture hay, mineral-vitamin concentrate and Anavrin; 65% DM, 12.8% CP, 23% NDF) were blocked by BW and distributed in 2 feeding treatments (n=10/treatment): 1) TMR offered at a level of 2.8% of BW (DM basis): ‘TMR’ or 2) TMR offered at a level of 1.7% of BW (DM basis) plus FA (22.1% DM, 14.5% CP, 50.3% NDF) offered in an unlimited quantity: ‘PMR+FF’. The experiment lasted 60 d, and steers were weighed every 12 d, for 2 consecutive days each time. DMI was individually measured 3 times for 5 consecutive days, beginning days 20, 34 and 48 days, by difference offered-refused for each feedstuff. Ruminal pH, N-NH3 and volatile fatty acids (VFA) were measured on days 19, 33 and 47, at 0930, 1300, 1500, 1700, 1900, 2100, 0300 and 0930 h. The inclusion of fresh forage resulted in 40% of the total DMI, with no differences on intake (Table 1). However, in the PMR+FF treatment DG and FE tended to be reduced, possibly due to a reduced energy ingestion, considering the fiber content of FA and TMR. As expected, the inclusion of FA in the diet increased pH and acetate, and reduced propionate ruminal percentage, resulting in triplicated acetic/propionate rate. Overall, the inclusion of fresh alfalfa in the diet increased ruminal pH and acetic/propionate rate without affecting DMI. Including fresh alfalfa in finishing steers’ diet could have positive implications on feed costs and meat composition without negatively affecting productivity, but more studies are needed.
347 Using Whole Cottonseed to Replace Dried Distillers Grains Plus Solubles and Prairie hay in Finishing Rations Balanced for Physically Effective Neutral Detergent Fiber
Authors: Schneid Kasi N , Foote Andrew P , Beck Paul A , Wilson Blake K
Published: September 2022

The objective of this experiment was to determine the effects of replacing hay and dried distillers grains plus solubles (DDGS) with whole cottonseed (WCS) in diets balanced for physically effective neutral detergent fiber (peNDF) on performance, carcass characteristics, and plasma metabolites of finishing cattle. Heifers (n = 103) and steers (n = 104) were blocked by sex and bodyweight (BW) and randomly allocated to pens within block (6 pens per treatment). Pens were randomly allocated to 1 of 2 experimental treatments: a control diet (CON; prairie hay, DDGS, dry-rolled corn, and liquid supplement), and a WCS diet (CTN; WCS, dry-rolled corn, and molasses). A vitamin and mineral supplement and urea were included in both diets at same rate. Data were collected on 14 d intervals through d 56, then every 28 d until harvest. Animals were harvested in 3 different groups based on BW block. Average daily gain (ADG) and gain to feed ratio (G:F) were greater for the CTN treatment overall (P ≤ 0.05), and the CTN treatment tended to have a greater final BW (P = 0.10). Fecal consistency score was greater for CON treatment on d 42, at beginning of the beta-agonist feeding period, and at the final collection (P ˂ 0.03). The CTN treatment had a more neutral fecal pH on d 140 and at the final collection (P ˂ 0.01). No treatment × day interaction (P ≥ 0.70) was detected for plasma glucose, lactate, or urea nitrogen (PUN) concentrations. The CON treatment had greater plasma lactate and PUN concentrations (P ˂ 0.01). A day effect was observed for all analyzed plasma metabolites (P ˂ 0.01). This experiment suggests that WCS improves growth performance and feed efficiency when replacing the roughage and byproduct protein and fat source within a finishing diet.
359 Using an Extruded 100% Dried Distillers' Grains Cube to Intensify Production in a Stocker Grazing Enterprise on Native Range in Northwestern Oklahoma
Authors: Grigsby Zane N , Gunter Stacey A , Beck Paul A
Published: September 2022

A 2-year experiment was conducted at the USDA-ARS Southern Plains Experimental Range (SPER) near Fort Supply, OK to define the effects of supplementing steers grazing native range with extruded 100% dried distillers' grains (DDGS) cubes. Each year 126 steers (259 ± 43 kg) grazed from late May to late September allocated to 3 treatments: 1) negative control (NC) stocked at 2.4 ha/steer with ad libitum mineral only, 2) positive control (PC), supplemented with 1.8 kg/steer on alternate days during the late summer stocked at 2.4 ha/steer, and 3) high supplement (HS) fed 0.75% BW supplemental DDGS cubes all season stocked at 1.6 ha/steer. Data were analyzed across years using PROC MIXED in SAS as a complete block design using year as the random block and pasture within treatment by year as the error term. Early season ADG and BW gains for HS were 0.30 ± 0.031 kg and 20 ± 2.1 kg greater (P < 0.01) than NC and PC, respectively. However, late season ADG for HS and PC steers were 0.34 ± 0.08 and 0.36 ± 0.08 kg greater (P < 0.01) than NC. Late season BW gains for HS and PC did not differ (P ≥ 0.76) but were 22.3 ± 5.3 and 23.9 ± 5.4 kg greater than NC, respectively. Hence, overall ADG, total BW gain, and BW gain/ha for HS were 0.32 ± 0.04, 0.14 ± 0.04; 42 ± 5.4, 18 ± 5.4; and 53 ± 2.2, 42 ± 2.2 kg greater (P < 0.01) than NC and PC, respectively. Supplementing 100% DDGS cubes during summer grazing is an effective management option to increase stocking rates without negatively impacting individual animal performance, and increasing gain/hectare.
364 Comparison of Semi-Confined and Pasture-Based Fall Calving Beef cow Systems
Authors: Speer Hannah , Drewnoski Mary E
Published: September 2022

Conversion of perennial grasslands to crop land in U.S. Northern Plains has resulted in a need to evaluate alternative management strategies for cow-calf production. A 3-yr study was conducted to compare beef cow/calf performance in two different August-calving cow systems. Multiparous beef cows (n = 318) were allocated to 8 replicates, and replicate was randomly assigned to drylot (DL) or pasture (PAST) treatments. From mid-gestation (March/April) until breeding (October), DL cows were limit-fed to meet requirements and PAST cow grazed perennial pasture. Feed resource during the 47-d breeding period (November/December) varied by year and treatment. However, pregnancy rates did not differ (P=0.72) between treatments within year. Both treatments went to corn residue at the time of weaning (late January) and grazed for 37 d. A treatment × year × time interaction (P<0.01) was observed for cow BW, BCS, and calf BW. In Year 1, cow BCS at pre-calving, breeding, and weaning was less (P<0.01) for DL (5.3) than PAST (6.2; 1 to 9 scale). Weaning weights in Year 1 were less (P<0.05) for DL (178 kg) than PAST (183 kg) calves. In Year 2, cow BCS was less (P<0.01) in DL (6.1) than PAST (6.7) at pre-calving and breeding, but did not differ (P=0.12) at weaning. At weaning in Year 2, calf BW of DL (212 kg) was greater (P<0.01) than PAST (201 kg). Like Year 2, DL cows in Year 3 had decreased (P<0.01) BCS at pre-calving compared with PAST (7.3 vs. 7.7). However, breeding BCS (6.8) did not differ (P=0.98). In Year 3, cow BCS at weaning was greater (P<0.01) for DL (7.1) than PAST (5.9) but calf BW at weaning did not differ (P=0.17). Cow and calf performance are not sacrificed in semi-confined cow-calf systems and are a reasonable alternative to traditional pasture systems.
372 Selecting Goats for Juniper Consumption Increases Pentobarbital-Induced Sleep Time
Authors: Walker John , Shoemake Brian , Quadros Danilo G , Thorne Jacob W , Cahill Noah
Published: September 2022

A sodium pentobarbital-induced sleep time (ST) study was conducted on intact males, Boer x Spanish goats (n = 30), selected for high (J+) or low juniper (J-) consumption with the objective to compare the Phase I detoxification system of the genetic divergent lines (EBV of 13.1 ± 0.2 and -14.2 ± 0.3, respectively). The ST study was conducted following a minimum period of 21 days on three different diets: grazing juniper infested rangeland (JIR), forage diet with no monoterpenes (M0), and forage diet with 8 g/kg added camphor, sabinene, and α-pinene monoterpenes in a ratio of 5:4:1 (M+). Fecal samples from goats on the JIR and M+ diets were analyzed for camphor and sabinene, and, when on the JIR diet, analyzed for percentage juniper in the diet using previously developed NIRS calibrations. Data were submitted to ANOVA analysis with repeated measures, assuming as significant when alpha was less than 10% (P < 0.10) by the F test. Percentage of juniper in the diet of J+ goats on JIP (38.6 ± 3.4%) was greater (P < 0.001) than J- goats (28.0 ± 3.8%). The J+ goats slept 15.1 (P = 0.02), 14.3 (P = 0.06), and 15.8 (P = 0.06) minutes longer than J- goats on JIR, M0, and M+ diets, respectively. There was no difference in ST between diets, and there was no interaction line × diet. Goats from the J+ line had higher concentrations of camphor in their feces on the JIR (P = 0.07) and M+ (P = 0.09) diets, while sabinene concentration was similar. Goats selected for juniper consumption had longer ST than J- goats which indicates a less efficient Phase I detoxification system, probably because there were less monoterpenes in the blood to be metabolized in the liver by the cytochromes P450 enzymes.
374 The Effects of Zinc Sulfate on the in Vitro Feed Digestibility in White-Tailed Deer
Authors: Thibodeaux Reese J , Urso Phil M , Kelley Stanley F , Beverly Marcy M , Stewart Chris R
Published: September 2022

The captive white-tailed deer industry has an estimated economic impact of $1.6 billion, annually. However, nutritional requirements for cervids are determined through research based on sheep and goats. The objective of this study was to determine the effects zinc on in vitro dry matter digestibility for white-tailed does (Odocoileus virginianus). Does (n=2) were euthanized ethically, rumens were collected, and placed into a cooler containing warm water. Rumen contents were agitated and filtered using cheesecloth while applying CO2. The fluid was placed into four separate incubator jars with filter bags containing a 1:1 alfalfa to coastal hay blend. Zinc doses of 0.073 mg/kg/d were added to two of the jars (treatments), and the additional two jars received 0.00 mg/kg/d (control). Following 48 hours of incubation, in vitro true digestibility (IVTD) showed no significant differences (P >.05) between the control and treatment groups. Average dry matter digested in vitro was 91.87% and 95.13%; respectfully. Neutral detergent fiber (NDF) was no different (P >.05) between the two groups. The average digested NDF components for the control were 56.03% and the zinc group had a mean of 57.11%. Additionally, acid detergent fiber (ADF) did not statistically differ. The control group had an average of 74.56% for digested ADF components, and the treatment had a mean of 76.90%. No significant differences were observed in digested organic matter. The control group averaged 79.51% of digested organic matter (OM), and the treatment group averaged 79.38%. This methodology did prove to be viable and functional to evaluate microbial digestion in vitro. This study can be replicated with multiple experimental units to confirm the patterns of increased digestibility. Formal nutritional guidelines can be created to allow for more efficient feeding of deer. In turn, determining nutrient requirements for deer, reducing feed costs for operations, and continue educating the captive deer industry.
378 Characterizing Functional Genetic Regulatory Elements in Sheep Reference Genome
Authors: Murdoch Brenda M , Davenport Kimberly M , Xie Shangqian , Salavati Mazdak , Clark Emily , Archibald Alan , White Stephen N , Mousel Michelle R , Worley Kim , Bhattarai Suraj , McKay Stephanie D , Caulton Alex , Clarke Shannon , Brauning Rudiger , Hadfield Tracy , Rosen Benjamin D , Smith Timothy P L , Cockett Noelle
Published: September 2022

Characterizing the locations of genetic regulatory elements is critical for understanding the regulatory mechanisms of complex phenotypic traits related to production traits and health in livestock species. The Ovine Functional Annotation of Animal Genomes (FAANG) Project aims to characterize transcriptional regulatory elements across the sheep genome to facilitate a better understanding of the biological mechanisms influencing phenotypic traits in sheep. Assays including sequencing of messenger RNA (mRNA-seq), cap analysis of gene expression (CAGE), chromatin immunoprecipitation of histones (ChIP-seq), assay for transposase-accessible chromatin (ATAC-seq), whole genome bisulfite sequencing (WGBS) and reduced representation bisulfite sequencing (RRBS) were performed on tissues collected from the Rambouillet ewe used to assemble the reference genome ARS-UI_Ramb_v2.0. Histone modifications were used to define nine chromatin states for tissues across the genome depicting promoters and enhancers (active, poised, and repressed) using ChromHMM. Chromatin states were overlayed with RNA-seq, ATAC-seq and DNA methylation. These data suggest that active promoter and enhancer states reside in open chromatin regions with a greater transcriptional activity and hypomethylated regions than other states. Further, poised and repressed enhancers did not primarily reside in open chromatin and had less transcriptional activity and more hypermethylated sites compared with active states. Collectively these data define transcriptional regulatory regions throughout the ovine genome which provides a valuable resource to better understand regulatory regions in the genome and how these influence economically important traits in sheep and other livestock species.
383 Scientific Training Programs for Undergraduate and Graduate Students: Applied Animal and Food Science
Authors: Starkey Charles W , Starkey Jessica D
Published: September 2022

Training in animal sciences can be difficult to cover in a comprehensive manner. So many different areas are necessary to prepare students for the multiple employment opportunities afforded them upon graduation. This is an approach where students are trained in both experiential animal husbandry techniques as well as some areas of fundamental sciences. A farm to fork approach is being taken to demonstrate the varied areas of the industry and assist students in finding their preferred discipline. Initially, students are taught the basics of nutrition and animal food manufacturing to expose them to this aspect of the allied industry. Practical interactive methodology for raising both poultry and swine are developed through the daily welfare checks conducted by students twice daily at our research facilities. Through these activities students are taught to properly observe and conduct practices of feeding, welfare needs of animals, and health observations. Husbandry techniques are taught and demonstrated and then students are allowed to develop their competency through both participatory and observational methodologies during animal management observations with experienced students and advisor input including questions and answers. Exposure of animal performance objectives and management are delivered to better prepare students for the live animal aspect of the production industry. Additionally, students are involved in actual protein conversion and production of food for human nutritional needs. Students may not fully comprehend opportunities and applications of the protein conversion side of industry. Practical experiential learning is achieved through first-hand experience in the aspects of the protein production industry. Using food science technologies and interactive examples, students also learn about production of pet foods derived from low value co-products from both mammalian and poultry protein conversion. Exposure to both initial meat production and further processing unlocks opportunities for students and their employment success indicates the success of this approach.
384 Scientific Training Programs for Undergraduate and Graduate Students: Exposure to Fundamental Science
Authors: Starkey Jessica D , Starkey Charles W
Published: September 2022

Training students in animal science can be difficult to achieve in a comprehensive manner. It is a multidisciplinary field where many different areas are necessary to successfully prepare students at multiple levels for the multiple employment opportunities they can choose from as they near graduation and enter the workforce. The approach we have taken with our teaching program is one where students are trained in both experiential animal husbandry techniques as well as areas of fundamental sciences such as cellular and molecular biology. A farm to fork systems approach is being taken to demonstrate the varied areas of study available and aid students in finding their niche. Students first spend time acquiring practical and hands-on experience in animal husbandry, animal food manufacturing, and meat processing and food science research. Most of the projects that students participate in while acquiring animal husbandry skills involve several collections of various types of samples over the animal rearing period for cell isolation and in vitro culture, proteomics, cell-labeling technologies, cryohistology, immunofluorescence staining, and digital microscopy. Our research program focuses primarily on the influence of management and nutrition on the development of the local intestinal immune system, development and growth of the intestine and skeletal muscle and how those interact to impact the overall growth and health of livestock. Exposing students to some of the different types of analyses conducted in research involving fundamental science allows them to gain skills required to determine the mechanisms behind the more applied research results they obtain. Integrating applied and fundamental science in a research setting helps prepare students for several different avenues of employment upon completion of the program. The overall success of this training program has been demonstrated over the last 5 years based on student and employer feedback.
398 Young Scholar Award Talk: Influence of a Lifetime Regimen of a Modified-Live Viral or Killed Viral Vaccination Against Bovine Viral Diarrhea Virus on Beef Cattle Performance
Authors: Melchior Emily A
Published: September 2022

Bovine viral diarrhea virus (BVDV) is a major viral pathogen affecting the cattle industry. Control of BVDV occurs through preventative vaccination or elimination of persistently infected animals. However, evaluation of the longevity of cows vaccinated during pregnancy has not been conducted. In experiment 1, heifers born in 2014 (n = 32) were randomly assigned to receive a modified-live viral vaccination (MLV; Bovishield Gold 5 FP) at 3 months of age, and subsequently receive a MLV or killed viral vaccination (KV; Cattlemaster Gold 5 FP) against BVDV beginning at weaning for the duration of their lifespan in the herd. Heifers born in 2015 (n = 29) were randomly assigned to receive a MLV or KV beginning at 3 months of age for the duration of their lifespan in the herd. Heifers were bled for analysis of antibody titers throughout their first year of life, and twice-yearly beginning at 2 years of age. Titers for infectious bovine rhinotracheitis (IBR) and BVDV, herd longevity, and reproductive performance were collected. Vaccination type did not influence IBR titer (P ≥ 0.18), herd longevity (P ≥ 0.86), or reproductive development (P ≥ 0.19). Cows born in 2015 and their calves were used in experiment 2 (n = 24) to evaluate responses in the preweaning period. Cow and calf samples of blood and ruminal contents, and colostrum and milk were collected at d 1, 7, 35, 63, and 205 of age. Cows receiving KV vaccinations have ~60% more colostral IgG than cows receiving MLV vaccination (P = 0.02). Experiment 3 observed postweaning feed efficiency and ruminal fermentation of calves from experiment 2. Cow vaccine treatment did not affect average daily gain, gain:feed, ruminal fermentation, or metabolites (P > 0.05). An immune challenge was conducted in experiment 4. Calves (n = 8) were early-weaned and inoculated with BVDV Type 2a strain 1373. Samples were collected over 28 days to evaluate blood counts, virus isolation, and metabolites. A tendency for increased clinical scores, including mucosal discharge, and temperatures were observed for calves born to MLV cows (P = 0.08). Calves born to KV cows had increased leukocyte and lymphocyte concentrations compared to MLV calves (P ≤ 0.03). Overall, blood metabolites (glucose, non-esterified fatty acids, and blood urea nitrogen) were unaffected by treatment (P ≥ 0.8), however, metabolites did differ by day post-challenge (P ≤ 0.01). Metabolites were altered by the viral challenge and indicate the nutritional status of the animal shifted to support immune responses. Vaccination treatment had little influence on the calf’s ability to mount an immune response. These four studies indicate that both KV and MLV vaccination programs can be used to protect against BVDV without negatively impacting cow longevity, calf growth performance, and calf immunocompetence.
395 Young Scholar Award Talk: Melatonin: A Promising Therapeutic for Compromised Pregnancies
Authors: Contreras-Correa Zully E , Messman Riley D , Sanchez-Rodriguez Hector , Burnett Derris D , Lemley Caleb O
Published: September 2022

Poorly functioning placenta restricts oxygen and nutrient supply to the fetus resulting in fetal nutrient deficiency and intrauterine growth restriction. Intrauterine growth restriction dramatically increases neonatal mortality and those who survive are more prone to experience metabolic diseases such as cardiovascular diseases, hypertension, and type 2 diabetes in later life. Therefore, the placenta plays a critical role in the developmental origins of health and diseases. Currently, there is a vast effort evaluating the effects of compromised pregnancies such as maternal undernutrition, overnutrition, and heat stress on fetal development; however fewer studies have evaluated potential therapeutics to enhance placental efficiency and offspring performance. Melatonin, a hormone that modulates circadian rhythms, has shown to increase umbilical and uterine blood flow in pregnant dams. Moreover, a recent study observed that melatonin therapeutic effects during compromised pregnancies are seasonally dependent. Dietary melatonin supplementation to pregnant beef cattle increased uterine blood flow, rescued fetal weights, increased angiogenic factors in the placenta, and reduced vaginal temperatures in the summer, but not in the fall. The same study found that maternal nutrient restriction was more detrimental during the fall reducing uterine blood flow. Additionally, it was observed that dams that are nutrient restricted during the summer exerted a compensatory mechanism at the placentome level where they exhibited greater placentome vascularity and increased placental capillary size and angiogenic factors. Lastly, bovine placental circadian rhythms have been identified and interestingly, temporal increases in placental vascularity occur concomitantly with greater melatonin receptor 1A transcript abundance. In conclusion, these findings provide a better understanding of placental insufficiency and impaired fetal growth during maternal nutrient restriction, while temporal alterations in the placenta could lead to the development of proper guidelines for administration of placental blood flow therapeutics such as melatonin. Future studies should evaluate melatonin impacts on offspring organ development and potential for mitigating heat stress in livestock.
PSXIII-8 Grazing Behavior of Cows Grazing Natural Grassland Under Silvopastoral Systems or Full sun
Authors: Goncherenko Guillermo , Claramunt Martin , Cruz Rodrigo Santa , Fedrigo Jean , Báez Francisco , Pancini Stefania , Mercadante Vitor R G , Viñoles Carolina
Published: September 2022

The objective of this study was to evaluate the grazing behavior of mature beef cows grazing natural grassland in silvopastoral systems (SPS) in comparison with pasture systems in full sun (FS) during the austral summer in South America. A total of fifty-five Braford crossbred multiparous suckled cows (352 ± 43 kg) were randomly assigned to two treatments, with two replicates, in a complete randomized design: SPS (n=28) and FS (n=27). Global positioning system (GPS) devices were placed in six randomly selected cows per treatment (three per replicate) to track geolocation every five minutes during five consecutive days. Data were analyzed using the Java program GRAZEACT to determine total distance traveled (km), area explored (ha), and animal activities (h/d). Type of animal activity was defined by GRAZEACT based on movement velocity, being categorized as: resting (velocities< 3 m/min), grazing (3< velocities< 25 m/min), and traveling (velocities >25 m/min). Each of these variables were automatically calculated for four time periods: Night Pre-Dawn hours (00:00-06:00 h), Daytime hours (06:00-20:00 h), Night Post-Sunset hours (20:00-24:00 h), and 24 h. There was a treatment effect for distance traveled, explored area, grazing and resting in the 24 h period (P ≤ 0.0154). Specifically, cows grazing SPS had a greater distance traveled (P = 0.044) and area explored (P < 0.0001) during the daytime hours compared to cows grazing FS. In accordance to this, for the same period, SPS cows had lesser resting time (P < 0.0001) and spent an extra 1.5 h grazing (P < 0.0001) compared with their FS counterparts. In conclusion, SPS changed spatial and temporal grazing behavior. The provision of shade by SPS allowed a greater grazing activity through the daytime hours, period associated with greater temperatures during summer, most-likely by improving thermal comfort of animals.
PSXIII-6 Effects of Melatonin on Physiologic Responses and Behavior in Dairy Steers Following LPS-Induced Inflammation
Authors: Owen Megan P , Lemley Caleb O , Yankey Kalisha , Bily Codi , Eborn Douglas , Mumm Jared , Hart Caitlin , McCarty Keelee J , Epperson William
Published: September 2022

Mitigation of stress is critical in the livestock industry, especially in feedlot cattle where stress yields lesser productivity due to behavioral and physiological changes. In this experiment, dairy steers were allocated to one of two treatment groups that either received a single intravenous bolus of saline, control (CON; n = 4) or saline with melatonin (MEL; n = 4) at a rate of 100 µg/kg of body weight, 30 min (-0.5 h) prior to each lipopolysaccharide (LPS) challenge. For each LPS challenge, all steers were administered LPS from E. coli O111:B4 at 0.5 µg/kg of body weight intravenously 30 min following treatment, labeled as 0 h. Blood samples were collected at -0.5, 0, 0.5, 1, 2, 4, 6, and 24 h relative to each LPS challenge for serum cortisol analysis. Steers underwent a two-week washout period following the first LPS challenge, switched treatments, and underwent a second LPS challenge with their new treatment. Data were analyzed using a mixed model ANOVA in SAS 9.4. Main effects included treatment and hour on sickness score (SS; numerical scoring system based on outward signs of illness), rectal temperature (RT), respiration rate (RR), and cortisol concentrations (CORT), with period as a random effect. Statistical significance was set at P ≤ 0.05 and tendencies at 0.06 ≤ P ≤ 0.10. Cattle that received MEL tended to exhibit a lesser SS (P = 0.06) compared with CON cattle (1.94 vs. 2.13 ± 0.087, respectively). Treatment did not influence RT, RR, or CORT. The time effect followed the trend that -0.5 h, 0 h, and 24 h post-LPS challenge were similar, while elevated levels were observed for hours 0.5, 1, 2, 4 and 6. No interactions were encountered, indicating further research is needed to determine the best dosage of melatonin in calves to decrease response to stress.
PSXIII-1 Does Providing Bedding Change the Latency and Duration of Cattle Lying Behavior During Long-Distance Transport Rest Stops?
Authors: Guzman Paula Olivares , Marti Sonia , Pearl David L , Schwartzkopf-Genswein Karen S , Melendez Daniela , Haley Derek B
Published: September 2022

We explored whether straw bedding at rest stations might affect latency and duration of lying down beyond the 8h rest required at rest stops during long distance transport. Animals arriving to commercially operated rest stops (n=75, 6/load, opportunistically selected) were rested in pens (15.5 × 9.5 m) that were either bedded (n=38, straw, 14 cm deep) or non-bedded (n=37). The lying activity of each animal was recorded every 10 min for 8 h. The independent variables recorded included: bedding treatment, mean animal weight/load (kg), and space allowance [k-value = (m2/animal) / (BW2/3)] in the trailer. Ordinary linear and mixed linear regression models were fitted to assess lying latency and duration, respectively. Bedding affected latency to lie down, but its effect depended on space allowance in the truck: among cattle transported with low space allowance (2.08 - 3.29 m2/ 300 kg animal), bedded cattle laid down sooner than non-bedded cattle (P< 0.001). Comparing only cattle in bedded pens, cattle laid down sooner when transported with low space allowance (2.08 - 3.29 m2/ 300 kg animal) compared with medium space allowance (>3.29 – 3.69 m2/ 300 kg animal; P=0.003). Bedding also affected lying duration, but the effect depended on mean animal weight; as mean animal weight of the load increased so did duration but the effect was greater among bedded animals (P=0.027). In summary, cattle transported at high stocking densities are most likely to benefit from bedding as are heavier animals.
PSXII-7 Evaluation of Winter Hair Coat Shedding on cow and Calf Performance in Crossbred Angus Cattle in Arkansas
Authors: Midkiff Kirsten A , Kegley Beth B , Krumpelman B W , Kutz Bryan R , Powell J G
Published: September 2022

The objective of this study was to assess the effect of winter hair coat shedding for crossbred Angus dams (n = 544) on calf birth weights, calf weaning weights (WW), calf adjusted 205-day weaning weights (d205wt), artificial insemination (AI) pregnancy rates, overall pregnancy rates, cow pre-breeding body weights (PBW), cow pre-breeding body condition scores (PBCS) over a two-year collection period. Hair shedding data were collected on fall-calving crossbred cows from March to July using a visual hair shedding score of 1 to 5 was assigned to each cow, with 1 exhibiting 100% shedding of winter coat to 5 exhibiting 0% shedding of winter coat. Month of first shedding (MFS) was determined once a female reached a hair shedding score of ≤ 3 for any given month. Artificial insemination pregnancy and overall pregnancy was determined by rectal ultrasound. Data were analyzed using the MIXED procedure of SAS for calf performance, cow BW, and cow BCS, and the GLIMMIX procedure of SAS for AI pregnancy and overall pregnancy analyses. Statistical significance was declared at P ≤ 0.05 and tendencies declared at 0.05 < P ≤ 0.1. There was no effect of MFS on calf birth weights (P = 0.79), WW (P = 0.12), d205wt (P = 0.28), AI pregnancy (P = 0.76), overall pregnancy (P = 0.80), PBW (P = 0.11), and BCS (P = 0.69). The findings reported in this study indicate that MFS had no effect on cowherd performance during this two-year study in Arkansas; however, there is a need for continuing research to be performed to evaluate the effects of winter hair coat shedding in other environments.