bluuebunny/crossref_metadata_2025 huggingface dataset:
423 Effects of Prescribed Fire Timing on Stocker Cattle Performance and Native Plant Species Composition in the Kansas Flint Hills
Authors: Duncan Zachary M , Tajchman Alan J , Lemmon Jack , Hollenbeck William R , Blasi Dale A , Olson K C
Published: November 2023

Ranchers in the Kansas Flint Hills apply spring-season prescribed fire to improve growth performance of yearling stocker calves, increase native warm-season grass production, and reduce encroachment of woody and invasive plant species. Shifting prescribed fire application from spring (i.e., April) to late summer (i.e., August) or early fall (i.e., September) can reduce Sericea lespedeza infestation, increase native forb diversity, and improve air quality by distributing smoke produced from burning the Flint Hills throughout the year. Effects of late-summer or early-fall prescribed fire on yearling grazing cattle performance is unknown; therefore, our objective was to determine the impact of prescribed-fire timing on growth performance of yearling grazing cattle and plant community characteristics in the Kansas Flint Hills. Over a four-year period, 18 pastures were grouped by watershed and each watershed was assigned to one of three prescribed-fire treatments (24 pastures/treatment): spring (9 April ± 5.1 d), summer (23 August ± 4.9 d), or fall (29 September ± 8.7 d). Burn treatments were applied in years 1, 2, and 3 but were not applied in year 4 due to unfavorable burn conditions. Over 4 consecutive grazing seasons, 1,416 yearling calves (initial BW = 304 ± 49.6 kg) were grazed from May to August following prescribed fire application. Calves were grazed for 90 d at a targeted stocking density of 280 kg live-weight· ha-1. A permanent 100 m transect was established in each pasture and was used to determine plant species composition and soil cover using a modified step-point method. Plant species composition was determined annually in June. Data were analyzed as a completely random design using a mixed model. The final model contained treatment as a fixed effect and year and pasture within treatment as random effects. Average daily gain (ADG) tended to be greater (P = 0.06) for spring-burned pastures compared with fall-burned pastures, whereas ADG for summer-burned pastures were intermediate. Proportions of bare soil were greater (P < 0.01) in spring-burned pastures compared with summer- and fall-burned pastures. Conversely, proportions of litter on the soil surface were greatest (P < 0.05) in summer, intermediate (P < 0.05) in fall, and least (P < 0.01) in spring-burned pastures. Total grass, native grass, total forb, and native forb basal cover did not differ (P ≥ 0.13) among treatments. Conversely, basal cover of nectar-producing forbs was greater (P < 0.01) in fall-burned pastures compared with spring- and summer-burned pastures. Overall, fall prescribed-fire tended to reduce ADG; however, stocker cattle growth performance and native rangeland plant composition was similar between spring- and summer-burned pastures.
232 In Vitro Digestibility of Dry Matter and Nitrogen of Napier Grass Silage Is Affected By Fertilization with Cow-Dung Bio-Digester Slurry and Fermentable Carbohydrate Additives at Ensiling
Authors: Rambau Mashudu Daniel , Fushai Felix , Baloyi Joseph J
Published: November 2023

The use of silages during the dry season could ameliorate major nutritional constraints in ruminant livestock production in tropical regions. Napier grass (Pennisetum purpureum) is a tropical forage source that is used for silage in South Africa. The present objective was to determine the effects of fertilization with bio-digester slurry (BDS) and of carbohydrate additives [no additive (control), molasses, brown sugar, and maize meal] at ensiling on in vitro digestibility of Napier grass silage. Fresh Napier grass irrigated weekly with either BDS or water was cut after 12 weeks and ensiled for 90 days in 1 liter glass jars in a 2 (control and slurry irrigation) x 4 (no additive, molasses, maize meal and brown sugar) factorial arrangement replicated three times. The nutrient composition was determined using standard protocols. The in vitro digestibility of dry matter (DM) and crude protein (CP) were determined by the three-stage method after incubation in rumen of steers for 12, 24 and 48-hour incubation. The bags containing rumen undegradable residuals (RURs) were removed from the bags, composited by treatment, and ground through a 1 mm sieve. Approximately 1g samples of RURs of each silage sample were placed in a 0.1 N HCl solution adjusted to pH 1.9 with 1 g ℓ-1 of pepsin, and then in pancreatin solution and rinsed with deionized water and dried at 60°C for 48 h. At 24 h incubation, the no BDS, no additive (control) treatment had the least (P < 0.01) DM degradability. As incubation time progressed to 48 h, fertilization with BDS with molasses inclusion increased (P < 0.05) DM disappearance. However, the BDS fertilization and carbohydrate additive interaction had no effect (P > 0.05) on 12 incubation h, and in vitro digestibility after 12, 24 and 48 h of incubation. Fertilization with BDS reduced (P < 0.05) DM digestibility after 48 hours of rumen incubation. Carbohydrate additives increased (P < 0.01) DM disappearance at 12, 24 and 48 rumen incubation h but did not not influence in vitro DM digestibility after 12, 24, and 48 h of rumen incubation. Fertilization with BDS and carbohydrate additives at ensiling interaction had no effect (P > 0.05) on CP degradability at 12, 24, and 48 h of rumen incubation, and in vitro CP digestibility after 12, 24, and 48 h of incubation. Carbohydrate additives increased (P < 0.01) CP disappearance at 12, 24 and 48 rumen incubation h and reduced (P < 0.01) in vitro CP digestibility after 12 h of rumen incubation but did not have an effect (P > 0.05) on in vitro CP digestibility after 24 and 48 h of rumen incubation.
426 Forages Containing Plant Secondary Compounds Can Improve Digestibility, Rumen Ammonia and Rumen Metabolites of Pasture: an in Vitro Continuous Culture Case Study
Authors: Christensen Rachael G , Halvorson Jonathan , MacAdam Jennifer W , Kronberg Scott L , Hendrickson John R
Published: November 2023

Forages containing plant secondary metabolites (PSM) have been investigated for use in reducing nitrogen waste in feedlot and dairy cattle diets but use as supplements to grazing beef cattle to capture the positive effects of PSM is unclear. Here we investigate potential improvement in rumen digestibility and metabolome, rumen ammonia production and flow from feed protein due to PSM bioactivity in forages used to supplement pasture grass using in vitro methods. Can PSM-containing forages offer a practical way to improve range nutrition and provide delivery of phytochemical benefits? Phytochemical- containing forages birdsfoot trefoil (BFT), sainfoin (SAN), small burnet (SMB) and cicer milkvetch (CMV) supplemented grass pasture diets (200 g/kg of DM). In vitro true dry matter digestibility was determined using 2-stage in vitro methods. Randomly assigned diets of PAS supplemented with one of the PSM-containing forage diets (PAS+X) or not supplemented (PAS) were randomly applied to in vitro dual flow continuous culture (CC) vessels inoculated with grazing beef cow rumen fluid as a metabolic host. For 2-stage digestibility, SMB digestibility exceeded that of CMV, followed by BFT and SAN. The grass diet (PAS) was the least digestible (Table 1). Saponin was detected in CMV samples, which is a new finding. For CC, compared with PAS, minimum culture pH for PAS+CMV was highest (P < 0.02) but no differences were observed in pH between PAS, and PAS+BFT and PAS+SAN. Compared with PAS, the molar proportion of the fatty acid propionate increased with PAS+CMV(P = 0.03) in contrast to the acetate- to- propionate ratio found highest for PAS and decreased for all diets with supplementation of PSM forages. Concentration of rumen NH3–N flow to rumen fluid per gram of protein intake was lower (P < 0.01) with PAS+CMV and PAS+SMB, compared with grass only. Feeding CMV and SMB to grazing cattle may improve nutrient utilization, metabolome, and environmental sustainability of beef cattle production by improving diet digestibility and reducing ammonia waste.
234 Can We Use Moderate Quality Round Bale Bermudagrass Silage to Stretch Wheat pasture?
Authors: Beck Paul A , Beck Matthew R , Hubbell Don , Hess Tom , Foote Andrew P , Gadberry Shane , Kegley Beth B
Published: November 2023

Grazing wheat pasture with growing calves is an economically important enterprise in the Southern Great Plains and Southeastern U.S. Wheat forage is available when there are few other high quality forage options, and a offers a favorable seasonality of net returns for the stocker cattle enterprise. Our objective was to determine if a moderate quality wrapped round bale silage can be used to profitably increase stocking rates during the fall and winter. This research was conducted at the University of Arkansas System Division of Agriculture Livestock & Forestry Research Station near Batesville, AR (35°50′N, 91°48′W; elevation 150 m) over 3-yr from fall 2018 to spring 2021. Treatments were: HCON, where steers were stocked at 2.47 steers/ha in the fall without bermudagrass baleage or were stocked at 1× (H1.0), 1.5× (H1.5), or 2× (H2.0) the HCON stocking rate with ad libitum access to bermudagrass round bale wrapped silage during the fall. In the spring all pastures were stocked at 5.56 steers/ha without baleage (HCON) or with access to baleage (H1.0, H1.5, H2.0). Steer performance, forage mass and nutritive quality were analyzed as a randomized complete block design with SAS 9.4 (SAS Inst. Inc. Cary, NC). The bermudagrass baleage was analyzed to be 48.8% DM in yr 1, 40.2% DM in yr 2, and 46.8% DM in yr 3; and ranged from 13 to 14% CP and 55 to 56% TDN across the 3-yr (Table 1). Baleage intake based on estimated disappearance from feeders increased (P < 0.01) with increasing stocking rate in the fall and tended (P = 0.07) to increase during the spring with increased fall stocking rate. Steer ADG showed a positive associative effect of baleage feeding in the fall with greater (P = 0.01) ADG for H1.0 than HCON, while HCON and H1.5 did not differ (P = 0.71), but were greater (P ≤ 0.03) than H2.0. Gain per hectare in the fall tended (P = 0.06) to be greater for H1.0 than HCON, H1.5 and H2.0 were greater (P < 0.01) than H1.0 but did not differ from each other. Performance and BW did not differ (P ≥ 0.73) during the spring, but steer grazing days/ha and BW gain/ha were greater when baleage was offered in the spring compared with HCON. Supplemental efficiency of feeding silage did not differ (P ≥ 0.47) among treatments, on the average gains were increased by 0.22 kg/kg baleage DM fed in the fall and 0.11 kg/kg baleage DM in the spring. Offering moderate quality warm-season grass baleage to steers on wheat pasture enabled increased stocking rates in the fall while maintaining acceptable levels of performance and extending the length of the grazing season in the spring.
239 Impaired Myoblast Function and Poor Muscle Growth in Intrauterine Growth-Restricted Fetal Sheep Is Improved By the Anti-Inflammatory Nutraceutical, Eicosapentaenoic Acid
Authors: Gibbs Rachel L , Beer Haley N , Lacey Taylor A , White Melanie R , Hicks Zena M , Grijalva Pablo Cesar C , Peterson Jessica L L , Schmidt Ty B B , Yates Dustin T
Published: November 2023

Chronic heat stress during pregnancy causes low birthweight due to intrauterine growth restriction (IUGR) of the fetus. Recent findings indicate that IUGR fetal programming includes enhanced inflammatory sensitivity that disproportionally affects skeletal muscle. Thus, our objective was to determine if 5-d intravenous fetal infusion of the anti-inflammatory ω-3 polyunsaturated fatty acid, eicosapentaenoic acid (EPA) improved growth metrics and ex vivo myoblast (i.e., muscle stem cell) function in heat stress-induced IUGR fetal sheep. Maternal heat stress (40°C, 35% humidity, THI = 85) from d 40 to 95 of gestation was used to produce IUGR fetuses. Saline or EPA (25 mg/d) was infused via fetal femoral catheter from d 118 to 122 of gestation. At 122 d gestation, IUGR fetuses (n = 10; 2.31 ± 0.16 kg) were 26% lighter (P < 0.05) than control fetuses (n = 10; 3.10 ± 0.15 kg). Body mass of EPA-infused IUGR fetuses (n = 9; 2.70 ± 0.16 kg) were intermediate between controls and IUGR fetuses. Likewise, IUGR fetuses had lighter (P < 0.05) hindlimbs (28%), semitendinosus (30%), longissimus muscle (28%), flexor digitorum superficialis (30%), and soleus (31%) than controls. EPA infusion partially recovered (P < 0.05) hindlimb and longissimus muscle mass and fully recovered (P < 0.05) flexor digitorum superficialis and soleus mass but did not improve semitendinosus mass. Primary myoblasts were isolated at necropsy and incubated in proliferation media (DMEM + 20% fetal bovine serum) for 2 h or differentiation media (DMEM + 2% fetal bovine serum) for 96 h. Proliferation rates (determined by EdU incorporation over 2 h) were less (P < 0.05) for myoblasts from IUGR fetuses (38 ± 2% EdU+) and EPA-infused IUGR fetuses (39 ± 2% EdU+) than controls (44 ± 1% EdU+). Differentiation rates (determined by myogenin expression after 96 h) were less (P < 0.05) for myoblasts from IUGR fetuses (9 ± 1% myogenin+) but not EPA-infused IUGR fetuses (13±1% myogenin+) compared with controls (12 ± 1% myogenin+). IUGR fetuses had lighter (P < 0.05) heart (19%) and brain (11%) mass than controls, but heart/fetal mass and brain/fetal mass were greater (P < 0.05) than controls, which indicates tissue sparing for these organs. EPA infusion did not affect heart or brain mass but reduced (P < 0.05) heart/fetal mass and brain/fetal mass. Together, these findings demonstrate that skeletal muscle growth is disproportionately restricted compared with whole-body, brain, heart, or liver growth, and that this is facilitated by intrinsic impairment of myoblast function. Moreover, prolonged fetal infusion of the anti-inflammatory nutraceutical, EPA, partially recovered myoblast function and muscle growth in IUGR fetal sheep.
79 Functional Amino Acids in Dogs and Cats: Implications for Overall Health
Authors: Pezzali Julia Guazzelli
Published: November 2023

The majority of pets depend exclusively on commercial pet food supplied by their owners, who now more than ever are looking for diets supporting the health and well-being of their companion animals. Due to the diverse roles of amino acids beyond protein synthesis, their use as functional nutrients in canine and feline nutrition has gained attention. Dietary supplementation of tryptophan or tyrosine, as the precursors of serotonin and catecholamines, respectively, may reduce stress, anxiety-related and agonistic behavior in dogs. Surplus dietary arginine may also confer benefits by improving cognitive function in aging dogs likely through the enhancement of nitric oxide synthesis. In adult cats, phenylalanine has been studied for its potential effect on delaying gastric emptying and promoting satiety, which could aid in prevention of feline obesity. On the other hand, diets with greater dietary lysine:calorie may protect lean body mass of senior cats, and thus, may help combat sarcopenia. Studies investigating the functional role of amino acids in dogs and cats, however, are limited and the results are often conflicting. Additionally, data on empirical determination of amino acid requirements in adult dogs and cats are scarce, potentially preventing the dietary delivery of the ideal ratios of amino acids and subsequently the provision of specific amino acids in targeted doses above the requirement to evaluate their potential functional roles. Consequently, although the functional properties of some amino acids in dogs and cats are promising, more research focusing not only on their potential health benefits, but also on the empirical determination of amino acid requirements in dogs and cats is warranted to promote their use as functional nutrients in pet food.
432 Fluctuations in Equine Cutaneous Ph and Trans-Epidermal Water Loss Associated with Anatomical Location, Time, and Weather
Authors: Discepolo Dakota , Perry Erin B , Gaare Elizabeth
Published: November 2023

Although skin health is of critical importance for all horse owners, understanding of cutaneous pH and trans-epidermal water loss (TEWL) and the normal ranges of these variables is lacking. Cutaneous pH and TEWL measures provide insight into the barrier function of the epidermis and have the potential to determine the resident dermal microbiota. However, these measures have been recorded to fluctuate due to a variety of factors such as environment and anatomical locations in other species. Accordingly, the objectives of this study were to identify the impacts of anatomical location, weather, and time of day on cutaneous pH and TEWL in equines. This study utilized nine (n = 9) stock type mares, group-housed in a pasture setting at Southern Illinois University Equine Center. Researchers measured cutaneous pH and TEWL three times (6:00 AM, 12:00 PM, 6:00 PM) daily across five anatomical locations (nose, whither, heart-girth, mid-back, and base of tail) for five consecutive days. All statistical analysis was conducted using SAS On Demand for Academics (P < 0.05). Analysis of changes in variables associated with time, anatomical location, and day were conducted utilizing a PROC GLM three-way repeated measures ANOVA utilizing a Greenhouse-Geiser correction. Cutaneous pH results displayed significant main effects of day (P = 0.0052) and time (P = 0.0073) as well as a significant interaction of day and location (P = 0.0004). Mean cutaneous pH fluctuated daily, however, certain anatomical locations fluctuated more than others each day. Additionally, pH was highest in the morning (mean of 7.28) and lowest in the evening (mean 7.011). However, the mean overall pH for the study is 7.14 which is congruent with other work. TEWL measurements had significant main effects of day (P < 0.0001), time (P < 0.0001), and location (P = 0.0231), as well as a significant interaction of day, time, and location (P < 0.0001). TEWL measurements fluctuated with day, likely a result of weather changes. Mean TEWL measurements were less in the morning (mean 24.68) and greatest in the afternoons (mean 38.52). Overall mean TEWL measurement was 30.25. The results of this work indicate fluctuations in dermal barrier variables are associated with day, anatomical location, and time of day. These findings may have implications for applications of dermal treatments for horses as well as catalog the natural fluctuations which may affect future research.
252 Use of Agomir and Antagomir Technologies to Alter Mirna Expression and Muscle Hypertrophy in Intrauterine Growth Restricted Lambs
Authors: Greene Maslyn A , Powell Rhonda R , Bruce Terri , Klotz James L , Checura Celina M , Duckett Susan K
Published: November 2023

microRNAs (miRNA) are present in skeletal muscle and play important roles in regulating gene expression. Previous research identified miR-22-3p and miR-127 as differentially regulated during muscle hypertrophy and in vitro experiments found that antagomir-22-3p and mimic-127 enhanced satellite cell proliferation. The objective of this study was to test in vivo intramuscular injection of agomiR-127 or antagomir-22-3p in the longissimus muscle (LM) on miRNA and target mRNA expression in intrauterine growth restricted lambs. Pregnant ewes (n = 18) with twins were nutrient restricted (60%) from gestational d 85 to parturition. On d 2 of age, lambs were randomly selected and assigned to one of two miRNA treatments, 1) agomiR-127 (AGO127, 100 nM, n = 9) to assess gain of function or 2) antagomiR-22-3p (ANT22, 500 nM, n = 9) to assess loss of function. AgomiR and antagomiR technologies are chemically modified miRNA mimics or inhibitors that do not require transfection for in vivo use. AgomiR-127 or antagomir-22-3p were reconstituted in phosphate buffered saline (PBS) and injected into the center of the LM on the left side every 3-d starting at the 10th rib and moving posterior by 1.27 cm at each injection for a total of 7 injections. A sham control treatment (SHAM127 or SHAM22) of PBS was administered following the same protocol in the right LM to serve as the in-animal control. Lambs were harvested 4 d after the last injection and samples were collected from the injection region of each LM for miRNA and mRNA expression, histology, and proteomic analyses. Data were analyzed using paired t-tests to compare each miRNA treatment to its SHAM within animal. AGO127 up-regulated (P = 0.0071) miR-127 expression compared with SHAM127. mRNA expression of PAX7 and MSTN were up-regulated (P < 0.05) and IGFBP2 expression was down-regulated (P < 0.05) for AGO127 compared with SHAM127. Both protein and DNA content of AGO127 were increased (P < 0.05) but the ratio of protein to DNA did not change (P > 0.05). Proteomic analyses found 11 proteins that were differentially expressed for AGO127 compared with SHAM127. ANT22 down-regulated (P = 0.0024) miR-22-3p expression from SHAM22. Expression of predicted mRNA targets of miR-22-3p (ACVR2a, ACVR2b, SIRT1), myosin heavy chain isoforms (MyHCI, MyHCIIa, MyHCIIx), and other myogenic genes (MAPK6, IGF1, MyoG) were also altered (P < 0.05) in the LM compared with SHAM22. DNA content and the protein to DNA ratio was greater (P < 0.05) in ANT22 than SHAM22. Proteomic analyses identified nine proteins that were differentially expressed (P < 0.05) for ANT22. The direct injection of agomiR and antagomir technologies in the LM up- and down-regulated expression, respectively, for the miRNA of interest, which altered mRNA expression of predicted targets, protein abundance and muscle fiber type.
248 Divergent Satellite Cell Profiles of Bovine Trapezius, Longissimus, and Bicep Femoris Muscles in Utero
Authors: Hall Jerica R , Benitez Oscar J , Johnson Bradley J
Published: November 2023

As we look to better understand whole body growth and development, there are still many mechanisms of individual muscle growth that we have yet to comprehend. Therefore, the objective of this study was to compare proliferative capacity and satellite cell number within the trapezius (TP), longissimus (LM), and bicep femoris (BF) muscles of fetal bovine throughout mid and late gestation. We hypothesized a difference in satellite cell number across these three muscles may further explain the differential growth pattern of each of these muscles in utero. Muscle samples were harvested from bovine fetuses at a commercial abattoir and aged using crown rump length (~150-220d in utero). These samples were then dissected into single fibers and seeded in a 3D hydrogel culture with 20% FBS media. Cells were fixed using 4% paraformaldehyde and stained for DAPI, Pax-7, Myf-5 (Invitrogen, Bedford, MA) at 72, 96, and 120h. Wells were imaged and analyzed for proliferation rate using the Cytation 5 (Agilent; La Jolla, CA) Prime Gen 5 software. Data were analyzed as a two-way ANOVA with repeated measures using GraphPad Prism (Version 9.5). For Myf-5, Pax-7, and dual positive cells (P ≤ 0.05) there was a difference across muscle type with BF having an increased number of positive cells compared with the TP muscle and LM being intermediate (Myf-5 mean = 51, 23, and 40 respectively; Pax-7 mean = 45, 30, and 20 respectively; Dual mean = 39, 20, 16 respectively). This variation was further supported by a similar divergence in proliferation rate across muscle type (P = 0.04), with BF muscle having increased proliferative capacity over TP muscle and LM muscle being intermediary. These findings suggest contrasting growth patterns across muscle types in utero that may influence postnatal growth patterns. Further research is needed to understand how the variability in satellite cell number contributes to differences in individual muscle growth.
260 Identification of Candidate Gut Bacterial Species from Atlantic Salmon (Salmo salar) That Can Metabolize Ingredients Derived from Bioprocessed Soybean Meal
Authors: Fowler Emily , St-Pierre Benoit , Gibbons William , Kerr Phil , Brown Michael
Published: November 2023

In the aquaculture industry, plant-based protein sources have emerged as an economically and environmentally sustainable replacement for traditional animal protein sources. Yet, due to decreased digestibility, the presence of anti-nutritional factors, and an increased risk of inflammation of the digestive system, the inclusions of plant-based protein ingredients must be limited in the diets of carnivorous fishes. To gain further insight on the adaptation of the fish digestive tract to plant-based protein ingredients, slurry from cultured Atlantic Salmon (Salmo salar) was used as a proxy in an in vitro model system to identify candidate gut bacterial species from fish that can metabolize bioprocessed soybean meal. Triplicate slurry cultures were supplemented with one of each of the following ingredients: fishmeal (FM – control#1), soybean meal (SBM-control#2), MEPro (bioprocessed soybean meal product), as well as three ingredients derived from bioprocessed soybean meal (SPC1 - soy protein isolate #1; SPC2 - soy protein isolate #2; SPC3 - soy protein isolate #3). Data were generated by Illumina MiSeq 2X300 sequencing of PCR-generated amplicons targeting the V1-V3 regions of the 16S rRNA gene. A comparative analysis of the most highly represented Operational Taxonomic Units (OTU) using the non-parametric Kruskal-Wallis sum-rank test and Wilcoxon pairwise test identified candidate bacterial species that were enriched in cultures supplemented with specific bioprocessed soybean meal-derived ingredients compared with non-supplemented cultures (negative control). These results indicate that certain species may utilize these ingredients. Notably, OTUs Ss_1-37437 and Ss_1-13316 were found in the greatest abundance in cultures supplemented with SPC1 (31.4 - 49.7%) and SPC2 (7.2 - 17.4%), respectively. Interestingly, both OTUs were likely to represent novel bacterial species, based on their limited nucleotide sequence identity to their corresponding valid relative: Ss_1-37437: Prevotella paludivivens (96.58%); Ss_1-13316: Acetoanaerobium sticklandii (86.51%). In contrast, the most abundant OTUs enriched in SBM- and MePro-supplemented cultures were likely strains of known bacterial species. Indeed, OTU Ss_1-00386 was most abundant in SBM-supplemented cultures (16.4 - 32.5%), and it was found to be closely related to Leuconostoc mesenteroides (98.69%), a bacterial species with reported probiotic properties, while OTU SS_1-10030, a close relative of Bacteroides graminisolvens (99.24%), was most highly represented in MePro-supplemented cultures (21.9 - 32.7%). Together, these results suggest that ingredients derived from bioprocessed soybean meal have the potential to be developed as prebiotics to modulate the gut microbiome of aquaculture fish species.
258 Effects of Dietary Supplementation of Myristic Acid on Intestinal Health and Growth Performance of Nursery Pigs
Authors: Choi Hyunjun , Rocha Gabriel , Kim Sung Woo
Published: November 2023

The objective of this study was to investigate the effects of myristic acid on intestinal health and growth performance of nursery pigs. Thirty-six newly weaned pigs (6.6 ± 0.4 kg BW) were assigned to 3 treatments (n = 12) in a randomized complete block design with initial BW and sex as blocks. Pigs were fed for 35 d in 3 phases (10, 10, and 15 d respectively). Treatments were 1) NC: basal diet; 2) PC: NC + 0.25% bacitracin methylene disalicylate (antibiotic; bacitracin: 276 g/t feed) in all phases; and 3) MA: NC + myristic acid at 0.075% in phases 1 and 2 and 0.045% in phase 3. Diets contained nutrients meeting the requirement. Growth performance and fecal score were measured for each phase. Pigs were euthanized to collect jejunal mucosa, jejunal tissues, and ileal digesta. Data were analyzed using preplanned contrasts (NC vs. PC and NC vs. MA) in the Proc MIXED procedure of SAS. Compared with the NC, the PC improved (P < 0.05) ADG in phase 1 (43 to 101 g/d) and ADFI in phase 2 (458 to 578 g/d), whereas the MA improved (P < 0.05) ADG (541 to 668 g/d) and ADFI (801 to 996 g/d) in phase 3. Overall, the PC tended to improve ADG (353 to 419 g/d; P = 0.063), and ADFI (515 to 606 g/d; P = 0.051), whereas the MA improved (P < 0.05) ADG (353 to 431 g/d) and ADFI (515 to 623 g/d) compared with the NC group. The PC decreased (P < 0.05) fecal score (3.17 to 3.03) in phase 2 compared with the NC. The PC tended to decrease IL8 (P = 0.053; 0.53 to 0.37 ng/mg of protein) and protein carbonyl (P = 0.075; 2.65 to 1.66 nmol/mg of protein) in jejunal mucosa compared with the NC. The PC increased (P < 0.05) the villus height to crypt depth ratio (2.61 to 3.02) compared with that of NC. The MA tended to decrease IgG (P = 0.051; 2.44 to 1.67 µg/mg of protein) and IL8 (P = 0.090; 0.53 to 0.39 ng/mg of protein) in jejunal mucosa compared with that of the NC. The MA tended to increase relative abundance of Bacteroidetes (P = 0.075; 3.8 to 13.9) at phylum level, Prevotellaceae (P = 0.073; 3.7 to 13.8) at family level, and Prevotella (P = 0.085; 4.2 to 15.4) at genus level compared with the NC. In this study, it was shown that both bacitracin and myristic supplementation could improve the intestinal health and growth performance of nursery pigs. Effects of bacitracin on intestinal health and growth performance was rather immediate whereas the effects of myristic acid were obtained after a 3-week feeding.
430 Awardee Talk: Recent Breakthroughs in Mineral Nutrition Research That Are Influencing Commercial Swine Diet Formulation
Authors: Woodworth Jason C , DeRouchey Joel M , Tokach Mike D , Goodband Robert , Gebhardt Jordan T
Published: November 2023

Mineral nutrition research continues to be of great importance to swine nutritionists because of the direct impact on swine performance and health, and consequently producer profitability. The emphasis of recent mineral research has often been focused on trying to overcome areas of concern in commercial production as opposed to the foundational work that historically was designed to establish basal nutrient requirements. Increased prevalence of post-wean diarrhea has stimulated a renewed interest in adding pharmacological levels of Zn from ZnO in nursery diets. However, environmental and regulatory concerns are creating the need to find ZnO alternatives that will yield similar growth promotional benefits while also reducing diarrhea. Additionally, formulating nursery diets with an ABC-4 formulation concept considers the influence of dietary mineral concentrations and could allow for less dependence on high ZnO inclusion in nursery pig diets. Interest in identifying the correct Ca and P inclusion rate and relationship that supports optimum growth, feed efficiency, and bone mineralization continues to be of high importance, especially with the increased observation of lameness in commercial barns. Properly adjusting dietary P with the use of phytase is increasing in complexity as the number of new phytase sources enter the market. Research comparing different sources of minerals such as Zn, Cu, Mn, Se, and Fe continues to be conducted to identify the combination of source and inclusion rate that yields the greatest return for the producer. The trend for mineral research conducted in commercial barns with pigs exposed to a wide range of stressors will continue in the future. Additionally, an enhanced focus on research conducted with the goal of improving sustainability through life-cycle assessment analysis will drive future mineral research interests. While mineral-focused research has a long history in swine nutrition, the evolution of commercial production needs and consumer demands means that there will be heightened interest in studies that demonstrate optimum mineral feeding strategies in the future.
263 Dietary Supplementation of Tryptophan, Threonine, and Methionine Improves the Growth and Immune Status for Lighter Body Weight Pigs But Not for Heavier Pigs Under a Sanitary Challenge
Authors: da cunha valini Graziela Alves , Remus Aline , Hauschild Luciano
Published: November 2023

Great variability in growth performance and blood metabolites is observed between animals and within the same group. This variation may exist between individuals due to the initial body weight (BW) which may determine different abilities to cope with a sanitary challenge (SC). Besides, supplementing tryptophan (Trp), threonine (Thr), and methionine (Met) above NRC requirements supports the immune system and growth performance costs during a SC. Therefore, this study aimed to investigate the effect of initial BW on changes in body composition, and blood metabolites of growing pigs housed under poor SC and receiving Trp, Thr, and Met at 100 or 120% of NRC recommended levels. Twenty gilts were categorized into two groups according to initial BW: light (22.5 ± 0.8 kg) and heavy (28.5 ± 1.0 kg). Both BW groups were group-housed for a 28-d trial. Pigs were orally inoculated with 2 × 109 CFU of Salmonella typhimurium, and manure from a commercial pig farm was spread on the floor. Two dietary treatments were provided: control (CN) or supplemented (AA+) diet with Trp, Thr, and Met:Lysine 20% above the NRC (2012) requirements. Serum albumin and urea, along with BW were measured on days 0, 14, and 28. Body composition was estimated by dual-energy X-ray densitometry on days 0, and 28 to obtain protein (BP, % of BW) and lipid (BL, % of BW) masses. A linear mixed regression considering repeated measures in time was used to compare the slopes of the BW groups, day, and their interaction within dietary treatments. The BW and BP increased, whereas BL decreased with time (P < 0.10; Table 1). However, light pigs had greater BL than heavy pigs (P < 0.10). Dietary treatment influenced BW differently, and BL changes over time within BW groups (Figure 1). Light pigs fed the CN diet had a faster decrease in BL and a slower increase in BW over time than heavy pigs (P < 0.10), which was not observed in pigs fed AA+ diet. Light pigs fed CN diet had greater serum urea than heavy pigs (P < 0.10), with no differences for pigs fed AA+ diet. No changes in serum albumin were observed between BW within diets. Heavier pigs tend to adapt and cope better under a SC and may not need AA supplementation above the requirement. On the other hand, increasing AA improved ability of lighter pigs to cope with the SC allowing for a greater growth potential under a poor SC.
261 Variations in Protein Deposition Might Be Associated with Insulin Resistance and Differences in Amino Acids Metabolism in Growing Gilts
Authors: Remus Aline , Pomar Candido
Published: November 2023

Pigs with similar body weight (BW), same genetic background and sex vary in terms of protein deposition (PD) overgrowth. Insulin stimulates protein synthesis, and differences in PD could be associated with the variation among pigs in postprandial insulin secretion. Therefore, this study aimed to investigate if changes in preprandial and postprandial amino acids (AA) response and insulin resistance differ between pigs having Low or High PD. Seventy gilts (33 kg BW, ± 3.6; Alphagène) were assigned to a randomized complete block (BW) design and housed in the same pen equipped with automatic feeders. Pigs were fed ad libitum with a diet balanced to maximize PD. Dual X-Ray estimated body protein (BP) and lipid (BL) masses on d 1 and 21, and by difference, PD was calculated. On d 23, pigs were grouped in Low (157 g/d) and High (219 g/d) PD. Eight pigs per PD group were canulated in a jugular vein, and after 48h recovery receiving feed at 90% of the measured feed intake, they were fasted for eight hours to study preprandial metabolism (-5, -1 min before the meal). In sequence, all pigs received a 300 g meal and blood samples were collected at 10, 15, 20, 30, 40, 50, 60, 75, 90, 120, 150, 178, 178 min, relative to the meal, to measure AA, insulin and glucose concentrations. In addition, insulin resistance (HOMA-IR) was calculated based on fasting glucose and insulin concentrations. The AA response was modeled for each PD group based on the average group response using differential equations derived from the Erlang equation. Thus, the basal concentration, area under the curve (AUC) and AA flux could be compared among groups using the parameters obtained by the non-linear model. An F-test was used to compare the difference in the indexes between Low and High PD pigs. The basal concentration of methionine, valine and leucine were similar, whereas AUC was greater for Low PD pigs with no difference in flux, with the exception of methionine (P < 0.10; Table 1). Conversely, lysine (15%) and threonine (10%) basal concentrations were less in Low PD pigs. Lysine AUC was greater (8%), whereas others AA AUC were on average 27% less for High PD than for Low PD pigs. Lysine maximal concentration was 11% greater for High PD pigs and occurred later than for Low PD (1.15h vs 1.03h). Such differences in AA postprandial metabolism might be partially due to metabolic differences in response to anabolic hormones such as insulin. For instance, HOMA-IR differed (P < 0.05) among PD categories, with Low PD showing a 44% lower index for insulin resistance than high PD pigs. High PD pigs are less insulin-resistant and show differences in pre- and postprandial AA metabolism.
31 Importance of Good Sow Development: Focusing on Nutrition and Feeding from Gilt Development to Subsequent Parities
Authors: Orlando Uislei A , Lu Ning , Vier Carine M , Cast Wayne R , Navales Ron , Montoro Jordi Camp , Canavate Sergio , Piva Jose Henrique , Pinilla Juan Carlos , Dritz Steve
Published: November 2023

Continuous genetic progress leads to significant improvements in growth and efficiency of PIC Camborough gilts. As an example, gilt weight gain per day of age has increased dramatically in the past decade. This implies that gilts are heavier at a similar breeding age, which increases the likelihood of breeding overweight gilts. Additionally, sows have less backfat depth and are leaner compared with their predecessors. It has been reported that gilt retention rate until parity 3 declines when breeding gilts with over 160 kg of body weight. Hence, controlling growth rate of developing gilts could be helpful to achieve the target breeding weight (135 to 160kg). A recent study reported that reducing dietary nutrient density (ME and SID Lys) from 57 kg until breeding significantly reduced breeding weight by 4 kg (P < 0.05). The slower growing gilts had reduced stillborn (P < 0.01), had 0.79 more pigs born alive (P = 0.10), and weaned a total of 238 more pigs over three reproductive cycles. However, with the genetic trend for faster growth rate, it is inevitable to breed overweight gilts in production. Energy requirement for maintenance (MEm) of gestating sows is a function of body weight of the sow. Thus, heavier gilts at breeding need more energy for maintenance. An assessment using data from 2,475 gilts collected in commercial sow farms evaluated how different feeding levels satisfy the MEm of a gilt herd bred at 154 kg. The results showed that feeding 5.90 Mcal of ME/day or 4.40 Mcal of NE/day results in only a few gilts fed below maintenance from 90 to 112 days of gestation. However, if a decreased feeding level (5.17 Mcal of ME/day or 3.85 Mcal of NE/day) was adopted, which has been seen in production with a purpose of reducing body condition, almost all the gilts would be fed under maintenance from 90 to 112 days of gestation. Gilts are still growing and developing during their first gestation and inadequate feeding level may jeopardize their growth and development, which could lead to poor lifetime productivity. Heavier gilts become heavier sows in the subsequent parities; thus, the sows also require more energy for maintenance during subsequent gestations. Therefore, PIC recommends feeding gilts, ideal and fat sows with 5.90 Mcal of ME/day or 4.40 Mcal of NE/day throughout gestation. Feeding this level throughout gestation will result in an estimation of no overall caliper change. Whereas for thin sows that need to recovery condition, PIC recommends feeding 8.60 Mcal of ME/day or 6.50 Mcal of NE/day (Figure 1). Feeding this level throughout gestation will result in an estimated overall gain of 3 caliper units. In summary, the increased potential for growth and efficiency of PIC gilts warrants the adoption of multiple strategies to improve longevity and lifetime productivity.
434 Creating Market Opportunities with Climate-Smart Agricultural Practices
Authors: Cammack Kristi M
Published: November 2023

Supporting producer implementation of climate-smart animal and land-management practices to reduce greenhouse gas emissions, monitoring and verifying effects of these practices, and developing market opportunities for beef and bison products raised with these practices are essential to addressing climate change. Learn about partnerships among universities, underrepresented and tribal beef and buffalo producers, and other organizations working towards a common goal of sustainability of agriculture for future generations.
285 Duration of Ergovaline Exposure Influences Serotonin-Mediated Vasoconstriction and Vasorelaxation of Bovine Vasculature
Authors: Trotta Ronald J , Harmon David L , Klotz James L
Published: November 2023

Ergovaline (ERV), produced in toxic endophyte-infected tall fescue, causes potent vasoconstriction of bovine peripheral and visceral vasculature. Ergovaline acts as both an agonist and an antagonist in bovine gut blood vessels through serotonin (5-HT) receptors and it appears that the type of action could be influenced by the extent of ERV exposure. Because it was unclear how the duration of ERV exposure influences 5-HT-mediated vasoactivity, experiments were designed to evaluate how simultaneous or prior ERV exposure influenced 5-HT-mediated vasoactivity of mesenteric artery (MA) and vein (MV) segments from Holstein steers (n = 10). Isolated vessel segments were incubated in Krebs-Henseleit buffer containing 0, 0.01, or 0.1 mM ERV for 24-h befoe the 5-HT dose-response or exposed to fixed concentrations of 0, 0.01, or 0.1 mM ERV simultaneously during the 5-HT dose-response. Vessels were suspended in chambers of a multi-myograph containing 5 mL of continuously oxygenated Krebs-Henseleit buffer and equilibrated to 1 g tension for 90 min. Vessels were exposed to increasing concentrations of 5-HT (5 × 10-8 M to 1 × 10-4 M) every 15 min and contractile responses were normalized as a percentage of the maximum contractile response induced by 120 mM KCl reference addition. Two-way analysis of variance was used to separately analyze data for each vessel type and duration of exposure using the MIXED procedure of SAS for the main effects of 5-HT and ERV concentration and the 5-HT × ERV concentration interaction. When 5-HT concentration increased from 5 ′ 10-8 M to 1 ′ 10-6 M, simultaneous addition of 0.1 mM ERV increased (P < 0.01) the contractile response of MV compared with additions of 0 mM ERV and 0.01 mM ERV. At 1 ′ 10-4 M 5-HT, the simultaneous presence of 0.01 mM ERV and 0.1 mM ERV decreased (P < 0.01) the contractile response of both MA and MV compared with 0 mM ERV addition. As 5-HT concentrations increased, the contractile response increased (P < 0.01) in both MA and MV with no previous ERV exposure, but decreased in MA and MV with 24-h prior exposure to 0.01 mM ERV and 0.1 mM ERV. These data demonstrate that the duration of ERV exposure influences 5-HT-mediated vasoconstriction and likely vasorelaxation in bovine mesenteric vasculature. If ERV and 5-HT exposure occur simultaneously, ERV can act as a partial agonist of 5-HT-mediated vasoconstriction. If 5-HT exposure occurs after blood vessels have had prior ERV exposure, it appears that 5-HT may induce vasorelaxation of blood vessels. More research is needed to identify receptors and mechanisms involved with 5-HT-mediated vasoconstriction and vasorelaxation before and after exposure to ERV. This will aid in the development of strategies for alleviating symptoms of sustained vasoconstriction that occur during fescue toxicosis in ruminants.
284 Supranutritional Mineral Supplementation During Pregnancy Alters Placental Blood Flow and Calf Mineral Concentrations
Authors: Ogg Makayla A , Marques Rodrigo S , Stratton Sidney , Dafoe Julia , Boss Darrin L , Sanford Carla , McCoski Sarah
Published: November 2023

Fetal development is dependent on maternal nutrient status, and the maternal-fetal connection is mediated by the placenta. There are well-established nutrient requirements for gestating cattle aimed at promoting the health of dam and fetus; however, there is limited information on the impact of supranutritional nutrient availability on placental function and calf development. This study evaluated the effect of supranutritional mineral administration during gestation on uterine artery blood flow and calf mineral status. Angus and SimAngus cows (n = 52) were bred via artificial insemination. At d 60 of gestation, cows were assigned to treatment groups; an injectable group (INJ, n = 26) receiving a single subcutaneous mineral injection and access to free-choice trace minerals and a control group (CON; n = 26) having access to free-choice trace minerals. Liver mineral content was analyzed in a subset of cows (CON n = 10; INJ n = 6) at d 60 and 209 ± 1 of gestation. At d 139.5 ± 0.5 and 209 ±1 of gestation, uterine artery measurements were collected using Color Doppler ultrasonography. Placental cotyledons, liver tissue, and blood samples were collected from a subset of animals at calving (n = 11; CON, n = 5; INJ, n = 6). Analysis revealed a TRT*day interaction at d 139.5 ± 0.5 for circulating Co concentrations which were greater (P = 0.05) and Se tended to be greater in INJ cows (P = 0.09) compared with CON cows. Circulating Zn concentrations tended to be decreased at d 209 ± 1 (P = 0.06) in INJ cows compared with the CON cows. Circulating Cu tended to be increased (P = 0.09) and Mn was decreased (P = 0.04) in INJ cows throughout the study. Hepatic Fe concentrations were decreased in INJ cows (P = 0.01) at d 209 ± 1. At d 139.5 ± 0.5, non-gravid uterine artery area, diameter, and circumference were increased in the INJ cows (P < 0.006 ). Additionally, pulsatility index of the gravid uterine artery tended to be increased (P = 0.09) in the INJ cows. Blood and liver samples were collected from calves (CON n = 24; INJ n = 26) at 4 to 8 d post-calving to assess mineral concentrations. INJ calves had greater liver Se (P = 0.001), decreased Fe (P = 0.04), and tended to have increased Zn (P = 0.09) and Mn (P = 0.08) concentrations compared with CON calves. Finally, INJ calves tended to have greater serum Se concentrations (P = 0.09) compared with CON calves. Trace minerals have roles in immune function and impact overall calf health. These results indicate that supranutritional trace mineral administration during early gestation alters placental blood flow and improves calf mineral availability. This supplementation protocol may provide the opportunity to improve the health of future calf crops.