bluuebunny/crossref_metadata_2025 huggingface dataset:
37 Supplemented with Yucca Schidigera Extract to Feedlot Cattle Consuming Diets with or Without Monensin
Authors: Mackey Shea , Cooke Reinaldo F , Pickett Autumn , Mendes Egleu , Batista Luis Fernando , Colombo Eduardo
Published: May 2023

This experiment compared performance and physiological responses of feedlot cattle receiving a saponin containing feed ingredient manufactured from purified extract of Yucca schidigera [Micro-Aid (MA); DPI Global, Porterville, CA] which replaced or was fed in conjunction with feed-grade antimicrobials. Yearling, Angus-influenced steers (n = 20) arrived at the experimental feedlot on d -19 and a shrunk body weight (BW; 309 ± 4 kg) was immediately recorded. Steers were ranked by BW and allocated to 4 groups of 30 steers each. Groups were housed in of 4 drylot pens equipped with GrowSafe automated feeding systems (4 bunks/pen) during the experiment (d -15 to 69). On d 0 groups were randomly assigned to receive a total mixed ration containing: monensin and tylosin (RT; 360 mg/steer daily from Rumensin and 90 mg/steer daily from Tylan; Elanco Animal Health, Greenfield, IN) and/or 4 g/steer daily of MA in a 2 × 2 factorial arrangement of treatments. During the experimental period non-supplemented (CON) steers received a total mixed ration containing no additives. Individual feed intake was recorded daily, and steer BW was recorded every 28 d and before slaughter. Steers were slaughtered according to BW and slaughter groups were balanced by treatments (36 steers on d 120, 36 steers on d 146, and 48 steers on d 174). Carcass traits were recorded upon slaughter. On d 55 eight rumen-cannulated heifers were housed with yearling steers (1 pair/pen). Pairs rotated among groups every 21 d, resulting in a 4 × 4 Latin Square design (n = 8 per treatment) with a 5-day washout between rotations. Rumen fluid was collected from pairs on d 55, 75, 90,110, 125, 145, 160, and 180 (beginning and end of each 21-day rotation) and pH was recorded immediately after collection. No RT × MA treatment interactions were detected (P > 0.10). Feed intake was decreased (P < 0.01) in steers receiving RT, whereas feed efficiency was greater (P = 0.02) in steers receiving RT. Carcass variables including hot carcass weight, backfat thickness, Longissimus muscle area, marbling, yield grade, and percent of carcasses grading choice or better did not differ among treatments (P ≥ 0.17). Rumen fluid pH was greater (P = 0.04) in steers receiving RT. Steers receiving MA had greater (P = 0.03) rumen fluid pH and decreased (P = 0.04) rumen fluid viscosity. Collectively, supplementing feedlot cattle with Yucca schidigera extract improved rumen pH and viscosity, but failed to impact performance or carcass measures in feedlot cattle.
35 Effects of Supplementing Pre- and Pro-Biotic Feed Ingredients on Performance, Health, and Physiological Responses in Feedlot Cattle
Authors: Pickett Autumn , Cooke Reinaldo F , Colombo Eduardo , Batista Luis Fernando , Brandão Alice P
Published: May 2023

This experiment examined the effects of a synbiotic supplement (yeast-derived prebiotic + Bacillus subtilis probiotic), which replaced or was fed with feed-grade antimicrobials (monensin and tylosin), on performance and health responses of feedlot cattle. Angus-influenced steers (n = 192) from 4 different sources were weaned and transported 800 km to an experimental feedlot. Steers arrived on d 0 and a shrunk body weight (BW) was recorded. Steers were then ranked by source and shrunk BW and allocated to 1 of 24 drylot pens (8 steers/pen). Steers a received free-choice diet of 3 treatments: 1) monensin and tylosin (RT; 360 mg/steer/day from Rumensin and 90 mg/steer/day from Tylan; Elanco Animal Health, Greenfield, IN), 2) yeast-derived ingredient and B. subtilis probiotic (CC;8 g∙steer-1∙day-1 of Celmanax and 28 g∙steer-1∙day-1 of Certillus; Church and Dwight Co., Inc., Princeton, NJ), or 3) a combination of RT and CC (RTCC). Animals were adapted to diets in a stepwise manner which consisted of a receiving diet (d 0 to 56), two step-up diets (step-up: d 57 to 63; step-up 2: d 64 to 70), and a final diet (d 71 to slaughter). The cattle were slaughtered in four groups according to BW and balanced by treatments. More specifically, 33 steers were slaughtered on d 200, 33 steers on d 230, 63 steers on d 257, and 63 steers on d 285. Upon slaughter, hot carcass weight, backfat thickness, Longissimus muscle area, USDA marbling score, USDA yield/quality grades, and liver abscess score were recorded. Overall, feed intake during the duration of the experimental period (d 0 to slaughter) was greater (P < 0.01) in CC compared with RT and RTCC. However, no differences were observed for ADG (P = 0.61), final BW (P = 0.67), or morbidity (P = 0.15). With increases in intake but no differences in ADG the CC group had lower feed efficiency (P = 0.02) when compared with RT and RTCC. Upon slaughter, CC had higher marbling scores compared with RT (P = 0.04). Both the CC and RTCC cattle had larger Longissimus muscle area (P = 0.07) and more carcasses grading choice or better (P < 0.01) when compared with RT. Whereas, hot carcass weight, backfat thickness, and yield grade did not differ among treatments (P ≥ 0.20). There was tendency observed for liver abscesses (P ≤ 0.09) to be greater in CC compared with RT and RTCC. Overall, supplementing feedlot steers with RT and CC improved feed intake and some carcass measures despite the decreased feed efficiency experienced by these cattle but combining CC and RT did not yield any additional performance or health benefits.
36 Productive and Physiological Responses of Feedlot Cattle Receiving Different Sources of Ca Salts of Fatty Acids in the Finishing Diet
Authors: Colombo Eduardo , Cooke Reinaldo F , Mackey Shea , Pickett Autumn , Batista Luis Fernando , Pohler Ky , Sousa Osvaldo , Cappellozza Bruno , Brandão Alice P
Published: May 2023

This experiment compared productive and physiological responses in feedlot cattle receiving a finishing diet that included Ca salts of palm oil (CSPALM), or a blend of Ca salts of palm, cottonseed, and soybean oils (CSMIX). Ninety yearling steers were housed in 15 pens equipped with Calan-gate feeders (6 steers/pen). Steers within each pen were ranked by shrunk body weight (BW; 410 ± 3.3 kg) on d 0 and assigned to receive a total-mixed ration (TMR) containing (as-fed basis) 2% of CSMIX (n = 30), 2% of CSPALM (n = 30), or no supplemental fat (CON; n = 30). Individual TMR intake was evaluated weekly. Blood samples were collected on d 0, 28, 56, 119, and 147. Samples of the Longissimus muscle (LM) were collected on d 84 via needle biopsy. Upon slaughter on d 148, hot carcass weight (HCW) was recorded and used to determine final BW (63% dressing), whereas one LM steak sample (2.54 cm) was removed from the right side of each carcass. Steer ADG was greater (P = 0.02) for CSMIX compared with CSPALM and tended to be greater (P = 0.09) for CSMIX compared with CON. Feed efficiency was greater (P ≤ 0.05) for CSMIX compared with CSPALM and CON, and carcass LM area was less (P = 0.01) for CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.21) for TMR intake, final BW, and other carcass merit traits including marbling. Mean plasma cholesterol concentrations were greater (P < 0.01) in CSMIX and CSPALM compared with CON, and expression of adipocyte fatty acid binding protein in the LM was greater (P ≤ 0.04) in CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.15) for plasma concentrations of glucose, insulin, insulin-like growth factor I, and leptin, nor for other LM genes associated with marbling and muscle growth. Concentrations of total fatty acids (FA) in plasma and in LM steaks were greater (P < 0.01) in CSMIX compared with CSPALM and CON, and greater (P < 0.01) in the LM steaks of CSPALM steers compared with CON. Moreover, steers receiving CSMIX had greater (P < 0.01) concentrations of polyunsaturated and ω-6 FA in plasma samples and LM steaks compared with CSPALM and CON. Collectively, supplementing CSMIX improved performance traits and FA profile in the LM of feedlot steers, but the same responses were not observed when CSPALM was offered. The advantages noted from CSMIX supplementation appear to be resultant from the nutraceutical benefits of increased polyunsaturated ω-6 FA supply to the finishing diet.
39 An in-Vitro Model of the Equine Fecal Microbiome to Assess How Horse Population Affects Fermentation Following a Starch Challenge
Authors: Gluck Cassandra R , Fellner Vivek , McLeod Sarah , Stuska Sue , Pratt-Phillips Shannon E
Published: May 2023

The use of an in-vitro model of the equine microbiome is beneficial to assess how fermentation patterns differ based on a horse populations’ habitual diet. The purpose of this study was to determine the in-vitro fermentation patterns of the microbial community within different horse populations before and following a starch challenge. Fecal samples were taken from three different populations of horses: horses from the Shackleford Banks, a North Carolina feral horse population living on native grasses; horses from the NCSU Equine Educational Unit that are predominantly kept on cool season mixed pastures, though may be supplemented with hay and concentrates when warranted; and privately owned horses that were fed mixed diets consisting of grass hay, concentrates and some pasture. Horses were monitored and fecal samples were collected immediately following a void and were stored on dry ice and frozen until analysis. Fecal samples from individual horses were pooled to form a representative sample for each population and mixed with an anaerobic medium to prepare an inoculum. The inoculum was placed into bottles containing either a treatment substrate of alfalfa (A) or of alfalfa and starch (AS). Bottles were capped, purged with CO2 and placed in a water bath at 39°C to incubate for 0, 2, 4 or 24 hours. Culture samples were processed to measure methane and short chain fatty acids (SCFAs; acetate, propionate, butyrate and other isoacids) using gas chromatography. Results were analyzed using the Proc Mixed procedure in SAS to compare the effects of horse population, time and treatment. Methane was significantly greater after 24 hours within all populations with AS, as the inoculum compared with A alone (P = 0.03). Propionate was greater for AS (molar percentage, mean ± standard deviation; 2.21 ± 4.97%) versus the A treatment (11.95 ± 4.97%, P = 0.02). Acetate concentrations were significantly (P < 0.001) greater within the A treatment in the Shackleford and NCSU horses (60.31 ± 10.3% and 62.18 ± 11.47%, respectively) compared with the AS treatment (59.09 ± 11.21% and 59.77 ± 8.85%, respectively). Privately owned horses showed similar values of acetate concentration when comparing the treatment of A (63.42 ± 10.13%) versus AS (63.55 ± 10.77%). Butyrate concentrations were greater in the Shackleford Banks and NCSU horses (13.16 ± 1.92% and 2.64 ± 4.22%, respectively) compared with the privately owned horses (10.96 ± 2%). Isoacids were greater in the Shackleford Banks horses (10.19 ± 4.15%) than the NCSU horses (9.87 ± 3.98%) and the privately owned horses (9.52 ± 3.53%; P< 0.0001). It appears that fermentation of starch differs between these horse populations, likely due to their habitual diet.
63 Fatty Acid Profile of Beef from Feedlot Young Bulls of Two Genetic Groups
Authors: Rodrigues Barbara , Sarturi Jhones , Samia Leandro , Alvarenga Ramon C , Lanna Dante , Souza Fernando
Published: May 2023

The fatty acid profile of the longissimus thoracis (LT) muscle and the activity of Δ9 desaturase6, Δ9 desaturase8, and elongase enzymes of beef from feedlot cattle of 2 genetic groups were evaluated. Fifty long-yearling young bulls were divided into two groups following their breed composition: Nellore (n = 25) and Angus × Nellore crossbred (n = 25), were randomly assigned into 4 pens (12 or 13 animals/pen) following a completely randomized design. Animals were sourced from the same breeding season and endured a grazing growing phase in Megathyrsus maximus cv. Mombaça pasture, with protein and energy supplement offered at 0.2% of body weight (BW). The feedlot phase comprehended 105 days of feed, and the diet (80% concentrate) was formulated to meet or safely exceed the beef cattle requirements to target an average daily gain (ADG) of 1.6 kg/day, in which major ingredients were represented by (% DM basis): sorghum silage (20%), ground corn (57.6%), ground soybean seed as the lipid source (20.4%), and a mineral/vitamin premix (2%). Samples of the LT muscle (between the 12th and 13th ribs) were taken right after slaughter to determine the profile of intramuscular fat. Lipids were extracted (2:1 chloroform/methanol), and 5 mL of the lipid extract was used for saponification followed by methylation and submitted for analysis using gas chromatography. The activities of Δ9 desaturase6, Δ9 desaturase8, and elongase enzymes were determined through mathematical indexes, in which their respective saturated and monounsaturated fatty acids were used. Data were analyzed using R (R CORE TEAM, 2021), and the effect of breed on the fatty acid profile was evaluated using the completely randomized design one-way, in which animal was used as the experimental unit. The sum of saturated fatty acids and unsaturated fatty acids was not affected (P ≥ 0.12) by genetic groups. Within FA profiles, crossbred bulls had greater (P = 0.05) concentration of monounsaturated fatty acids (49.7 vs. 52.4%), while beef of Nellore cattle showed greater (P ≤ 0.02) concentration of polyunsaturated fatty acids (6.71 vs. 7.67%) and n-3 (0.53 vs. 0.68%). A tendency (P = 0.07) was observed for the sum of n-6 and n-6/n-3 ratio, in which Nellore cattle had numerically greater values (6.63 vs. 4.89%, and 9.75 vs. 9.22, respectively). The activity of Δ9 desaturase6 and Δ9 desaturase8 was not affected (P ≥ 0.14) by genetic groups, while crossbred animals had greater (P = 0.03) activity of elongase (67.8 vs. 65.6%). Although the overall sum of mono and polyunsaturated fatty acids seems not to be affected, the FA profile and unsaturation/elongation enzymatic activity of beef was influenced by the genetic groups evaluated, in which both Nellore and their F-1 crossbreed counterparts had attractive responses.
61 Altering Fatty Acid Ratios to Regulate Adipocyte HypertrophyIn Vitro
Authors: Udoka Aliute-Nkoyo S , Duckett Susan K
Published: May 2023

Adipose tissue deposition in cattle can prove advantageous and detrimental when grading carcasses. Intramuscular fat (IMF) deposition, or marbling, can enhance sensory qualities such as tenderness and flavor, whereas subcutaneous fat deposition reduces carcass red meat yield. Little is known about how different mixtures of fatty acids influence adipocyte hypertrophy in vitro. Primary preadipocytes were isolated from subcutaneous fat harvested from Angus-cross yearling steers. Preadipocytes were propagated and differentiated into adipocytes. Then eight different mixtures with pairs of different fatty acids (C16:0, C18:0, C18:1cis-9, and C18:2) at varying ratios were added to the cultures. Each individual mix was applied at the same total molar concentration. At the end of the 4-day treatment period, cells were harvested for future RNA extraction and fatty acid analysis. The expression of critical adipogenic and lipogenic genes was evaluated. Mixes exhibited differences in total fatty acid content (ug) which would not only confirm that the adipocytes are differentiated but also translates to potential differences in hypertrophic growth between mixes (P < 0.05). The control exhibited significantly different fatty acid binding protein-4 (FABP4) and stearoyl co-A desaturase-1 (SCD-1) expressions in comparison with all other mixes (P < 0.05). The expression of FABP4 in mix 3 (75% C16:0-25% C18:1cis-9) was substantially different from all other treatments aside from a similarly structured mix (50% C16:0-50% C18:1cis-9; P < 0.05). The SCD-1 was upregulated, while peroxisome proliferating-activated receptor gamma (PPARy) was downregulated in the fully saturated fatty acid mix, mix 5 (50% C16:0- 50% C18:0), compared with all other treatments (P < 0.05). All three mixes containing C18:2cis-9 exhibited a greater relative expression of sterol-regulatory element-binding protein (SREB) than all other mixes (P < 0.05). The supplementation of fatty acids at different ratios can affect molecular mechanisms and hypertrophic growth in differentiated bovine adipocytes. Further investigation of this type of fatty acid supplementation could impact the future understanding of hypertrophic growth in the bovine adipocyte and provide further insight into the alteration of fat deposition in cattle.
62 Awardee Talk: Correlation Between Color Parameters and Internal and Surface Metmyoglobin Content of thePsoas Major Muscle
Authors: Denzer Morgan , Piao Daqing , Pfeiffer Morgan , Mafi Gretchen G , Ramanathan Ranjith
Published: May 2023

Meat discoloration starts from the interior and rises to the surface of steaks. Recently developed near-infrared single-fiber probe (SFP) in our laboratory allows characterizing interior color changes. The objective was to determine how changes in surface and interior metmyoglobin correlate with color changes in psoas major muscle during retail display. Seven USDA Select tenderloins were collected from a commercial processing facility. Steaks were cut from each muscle and placed in polyvinyl chloride overwrap trays for retail display. The SFP was a 400-µm fiber in a 5-gauge needle and inserted into the muscle at five positions with each position increasing in depth by mm. A mathematical model developed in MATLAB determined the percent metmyoglobin at each depth and day. Surface color was analyzed using a HunterLab MiniScan spectrophotometer each day and percent metmyoglobin was determined. Steaks were randomly assigned to analysis of oxygen consumption (OC) and metmyoglobin reducing activity (MRA) of the interior and retail surfaces on d 0, d 3, and d 5 of display. Pearson’s correlation coefficients were used to evaluate the relationship between calculated percentages, color stability parameters, and retail color with significance considered at a P < 0.05. Metmyoglobin determined by the SFP increased at all depths during display with greater metmyoglobin at shallower depths. Metmyoglobin calculated by the SFP at mm and by HunterLab spectrophotometer were strongly negatively (P < 0.05) correlated with a* values during retail display. The MRA determined using the retail surface was strongly negatively (P < 0.05) correlated with HunterLab surface metmyoglobin and SFP metmyoglobin at mm depth. The OC of the retail surface was moderately negatively correlated (P < 0.05) with HunterLab surface metmyoglobin and SFP metmyoglobin at all depths. The development of internal metmyoglobin demonstrated a strong relationship with retail color and negatively impacted color stability attributes.
112 Herbage Mass, Nutritive Value, and Grain Yield of four Wheat Varieties Managed as a Dual-Purpose Crop
Authors: West Micayla H , Smith William B , Rabinowitz Adam , Mullenix Kim K , Dillard Leanne L
Published: May 2023

Dual-purpose wheat (Triticum aestivum L.) systems increase farm sustainability by diversifying on-farm income. While these systems are common in the Southern Great Plains of the U.S., they are not often utilized in the Southeast. This study aimed to evaluate pre- and post-grazing herbage mass (HM) of four winter wheat varieties managed under a dual-purpose grazing and grain production system. The wheat varieties evaluated were generic feed-type wheat (unknown variety blend, Feed), seed-type wheat ‘GA Gore’ (Seed) and two forage-type varieties, ‘AGS 2024’ (AGS) and ‘Pioneer 26R41’ (Pioneer). The experiment was a randomized complete block design (n = 4) conducted during the winter of 2021 and 2022. Three grazing frequencies were utilized: an ungrazed control (NG), low frequency (LF) and high frequency (HF) grazing schedule. Low frequency plots received monthly grazing in January and February while HF treatments received a third grazing in March. Plots were grazed with 20 cow-calf pairs (Bos taurus) until an even defoliation height of 10 cm was achieved. Herbage mass was determined using three 0.1m2-quadrats per plot and clipped to a 10 cm stubble height before (PreG) and after (PostG) each grazing event. Forage samples were then dried at 45°C for 72 h. Data were analyzed using PROC GLIMMIX of SAS (SAS Inst., Cary, NC) with forage sample date as a repeated measure. Differences were declared at P < 0.05. Final biomass, including stems, chaff, and grain, was greatest for Pioneer but was not different from AGS or Feed (4,112 kg/ha and 4,003 kg/ha; P ≤ 0.94). Before grazing, AGS herbage mass (2,646 kg/ha) was greater (P ≤ 0.03) than all other varieties. There was an interaction (P ≤ 0.01) of variety and grazing frequency for Pre-G herbage mass. Compared with all other varieties, AGS had greater ADF (24.93%; P < 0.01) and least TDN (72.49%: P < 0.01). Forage nitrate-nitrogen was not different (P ≥ 0.49) among all varieties or grazing frequencies (157.73 ppm). Across grazing frequencies, Pioneer had greater final grain yield (3,619.43 kg/ha; P < 0.01) with Seed having the least (1,272.12 kg/ha; P < 0.01). These results indicate that common Southeastern wheat varieties can be successfully utilized in a dual-purpose management system; however, grazing frequency should be monitored to prevent grain yield losses.
111 Forage Mass and Nutritive Value of Cool-Season Grass-Legume Mixtures Overseeded into Bahiagrass Pastures
Authors: Zessin Peyton , Mullenix Kim K , Vasco Carol , Silva Liliane , Justice Maggie M , Elmore Josh , Dillard Leanne L , Parker Chris , West Micayla H
Published: May 2023

Warm-season perennial pastures are the base of livestock production systems in lower Alabama. To overcome the shortage in forage production during the late fall and winter months, during bahiagrass dormancy, overseeding pastures with cool-season annuals can be used as an option for providing forage during this period. Diverse forage mixtures of multiple species and functional groups have gained popularity in use among forage-livestock producers, but few evaluations have been conducted in overseeded sods. The objective of the study was to evaluate forage mass and nutritive value of cool-season forage mixtures overseeded into bahiagrass pastures. Six, 0.40-ha paddocks of ‘Pensacola’ bahiagrass were overseeded with one of three cool-season forage mixtures (n = 2 paddocks/treatment) on November2, 2021: 1) oat (Avena sativa), wheat (Triticum aestivum), and balansa (Trifolium michelianum), red (Trifolium pratense), and white clover (Trifolium repens; ‘clovers’); 2) oat, cereal rye (Secale cereale), and clovers; and 3) cereal rye, annual ryegrass (Lolium multiflorum), and clovers. When forage mixtures reached a target grazing height of 20 cm, paddocks were managed using flash mob stocking with beef cow-calf pairs to graze to a target height of0 cm. Herbage mass, nutritive value, botanical composition and height samples were collected pre- and post-grazing events. There was no treatment (P = 0.240) or treatment × harvest (P = 0.4239) effect on forage mass. Harvest date affected (P = 0.029) forage mass, with greater forage mass at late harvest (1,903.33 kg DM·ha-1) than at early (1,253.33 kg DM·ha-1) in the growing season. There were no treatment effects observed for species components (P > 0.05), although grasses dominated the forage mixtures with an average of 80% grass presence. Legume establishment was poor (less than%) and the remaining species composition consisted of weed species (19%). There was a treatment effect (P = 0.003) on CP, where oat-rye-clovers had the greatest CP and rye-ryegrass-clover had the least CP. Oat-wheat-clover mixtures had greater TDN (79.2%), less NDF (39.8%), and ADF (18.7%) than cereal rye-ryegrass-clover (75.4%, 46.1%, and 22.2% for TDN, NDF, and ADF, respectively), but did not differ from oat-cereal rye-clover mixtures (76.6%, 45.7%, 21.0% for TDN, NDF, and ADF, respectively). In year of this study, overseeding bahiagrass supported forage production over a 2-month period and can be a management tool used to reduce the need for supplementing in the dormancy periods of warm season perennial grasses.
118 Nutrient Cycling Potential from Manure from Heifers Fed Four Bermudagrass Cultivars
Authors: Hines Abbigail R , Siziba Cynthia , Mullenix Kim K , Dillard Leanne L , Smith William B
Published: May 2023

Maintenance of pastures for grazing accounts for $132.50/animal in the United States (23% of operating costs), and pasture nutrient input represents the single greatest influence in productivity per unit area. Cultivar differences in the forage offered to cattle have the potential to manifest differences in digestive efficiency, resulting in different nutrient excretion profiles. The objective of this study was to assess the growth potential and incorporation of N, P, and K into forage material from manure from cattle fed one of four bermudagrass (Cynodon dactylon [L.] Pers.) cultivars. Ruminally fistulated heifers (n = 4) were assigned randomly to one of four bermudagrass cultivars (Coastal, Russell, Tifton 44, or Tifton 85) for four 30-d in vivo periods (21-d adaptation and 9-d collection). On d 23, total fecal collections were subsampled from each heifer. As a hierarchical addition, a controlled greenhouse experiment was conducted for each period [15 pots per period; 5 manure treatments (four bermudagrass diets plus a negative control) × 3 replications]. Manure was added to 4.58 L pots based on stocking rate estimates for Central Alabama (1,110 kg/ha). The pots were seeded with bermudagrass (cv. Giant) as an indicator for forage nutrient uptake. At harvest (d 70), herbage, root, and soil samples were collected. Herbage and root samples were assayed for CP. Soil samples were assayed for pH, N, P, K, Mg, and Ca. Data were analyzed using SAS v. 9.4. There was no effect of manure treatment on herbage (P = 0.88) or root DM yield (P =.00;.54 and.73 g/pot, respectively). Similarly, there was no effect of manure treatment on soil pH (P = 0.18; 5.5), P (P = 0.78; 24.2 kg/ha), or K (P = 0.42;56.7 kg/ha). Results are interpreted to mean that, regardless of the cultivar effects on ruminal digestive dynamics, there is little to no effect of the resulting manure on subsequent forage production and nutrient uptake.
72 Seminal Plasma Uterine Priming Reduces Offspring Growth and Alters Uterine Artery Indices of Vascular Resistance in Embryo-Recipient Beef Cows
Authors: Swanson Rebecca M , Messman Riley D , Lemley Caleb O
Published: May 2023

Uterine priming with seminal plasma has been shown to alter endometrial gene expression as well as uterine cytokines and chemokines. However, the effects of seminal plasma uterine priming on uterine blood flow, fetal and postnatal offspring growth performance have yet to be elucidated. Therefore, we investigated the effects of pooled seminal plasma uterine priming at estrus on embryo crown-rump length, uterine blood flow, and birth weights. Commercial cows (n = 65) were synchronized, evaluated for standing estrus (day 0), and randomly assigned to treatment groups: seminal plasma or control. Seminal plasma treated cows (n = 27) received 0.5 mL of pooled seminal plasma from commercial bulls mismatched from embryo sire placed in their uterine body via artificial insemination rod2 hours after estrus detection (day 0). Control cows (n = 27) were passed through the chute without receiving treatment. On day 7, cows underwent non-surgical embryo transfer and were confirmed pregnant on day 35 via ultrasonography. Final treatment numbers were n = 9 seminal plasma and n = 7 control. On days 35, 40, and 45 embryo crown-rump length was measured via transrectal ultrasonography. On days 140, 180, 200 and 220, uterine artery hemodynamics were measured via Doppler ultrasonography. Birth weights were collected within 24 hours of birth. Data collected over time were analyzed using repeated measures of ANOVA with fixed effects of treatment, day, and their respective interaction. Birth weights and gestation length were analyzed using ANOVA. Embryo sire and dam, side of pregnancy, and fetal sex were included as covariates if P < 0.10. Covariance structure was selected based on lowest AIC and BIC. Embryo crown-rump length was decreased (P = 0.0483) among seminal plasma treated cows compared with controls. Embryo crown-rump length increased (P < 0.0001) by day. Total uterine blood flow increased (P < 0.0001) as gestation proceeded. Ipsilateral resistance index was increased (P = 0.0431) among seminal plasma treated cows compared with controls. Ipsilateral resistance index was increased (P = 0.0107) on day 180 of gestation compared with days 200 and 220 of gestation. Ipsilateral pulsatility index was decreased (P < 0.0001) on day 220 of gestation compared with days 140 and 180 of gestation. Contralateral blood flow was decreased (P = 0.0037) on day 140 of gestation compared with days 180, 200, and 220 of gestation. There were no differences in contralateral uterine artery blood flow, resistance index, or pulsatility index, or gestation length between treatment groups. Birth weights were decreased (P = 0.0102) among calves from seminal plasma treated cows compared with calves from control cows. In summary, seminal plasma uterine priming reduced offspring growth while increasing uterine artery resistance index, which indicates uterine vascular bed anomalies that persisted into the third trimester of pregnancy.
94 Changes in Vaginal Microbiome of Beef Cows Enrolled in an Estrous Synchronization Protocol
Authors: Dias Nicholas W , Schettini Gustavo , Goncherenko Guillermo , Pancini Stefania , Biase Fernando , Mercadante Vitor R G
Published: May 2023

Vaginal pH and microbiome have been reported to influence fertility in women. In cattle, estrous synchronization protocols are a great tool to overcome infertility; however, the effects of the hormones administered in the protocol on vaginal microbiome and pH are unknown. A total of 24 cows were enrolled in the 7-d Co-Synch + controlled internal drug release (CIDR) protocol and had individual vaginal flushes collected during the handling events of the protocol on days 0, 7 and on day 10 at timed-artificial insemination (TAI). Flushes were used for pH analysis and DNA extraction. Extracted DNA was submitted to analysis by whole genome shotgun sequencing. Pregnancy status was assessed by ultrasonography 35 days after TAI. Firmicutes was the most abundant phylum, followed by Proteobacteria, and Actinobacteria for all collection days. Bacteria from the Clostridia genus were the most abundant in all samples. Greater alpha Shannon diversity (within sample diversity) was observed for pregnant animals on day -10 compared with non-pregnant animals at the phylum, class, and order (P < 0.01), as well as family, and genus level (P < 0.001). Overall, Shannon diversity was decreased on day 7 compared with day 0 (P < 0.05 at class and order level; P< 0.01 at genus and family level) and was greater at TAI compared with day 7 (P < 0.01 at the phylum, class, and order level; P < 0.001 at family and genus level). No differences were observed for Shannon diversity between samples from D0 and TAI (P > 0.05). No correlations between Shannon diversity were observed in relation to vaginal pH (P > 0.1). Bray-Curtis analysis (between sample diversity) revealed clustering by day (P < 0.05 at the order, family, and genus level) and a tendency (0.1 < P < 0.05) at the phylum and class level. In conclusion, greater fertility was observed for animals with greater within sample diversity prior to protocol initiation. Furthermore, vaginal bacterial diversity changes throughout the protocol, with decreased diversity observed on day 7 of the protocol, but restored diversity on day0 at TAI.
91Ex Vivo Fermentation of Corn and hay by Rumen Bacteria from Sheep and Cattle
Authors: Weinert-Nelson Jennifer R , Ely Donald , Flythe Michael D , Hamilton Tracy , Ferrell Jessica , Hamilton Matthew , Jacks LeeAnn , Harlow Brittany
Published: May 2023

Data from cattle and sheep studies are often utilized interchangeably to make inferences regarding ruminant nutrition and physiology, but few studies have directly compared rumen microbiological responses. The objective of this study was to evaluate species differences in ex vivo fermentation of concentrates and forages. Rumen fluid was obtained via oral intubation from Holstein steers (n = 3; age: 212 ± 8 d) and Polypay ram lambs (n = 3; age; 34 ± d) fed a 100% tall fescue (TF) hay diet ad libitum. Mixed bacterial cell suspensions in buffered media contained the following feed substrate treatments (3% wt/vol): TF hay (HY), 2:1 TF hay-to-corn (HC), 2:1 corn-to-TF hay (CH), and corn (CN). Samples were collected after 2, 4, 8, and 24 h of incubation (39°C) for analysis of pH and lactate. Data were analyzed by PROC MIXED in SAS (v. 9.4, SAS Inst. Inc., Cary, NC). The pH differed by species (P = 0.004), treatment (P = 0.005), and time (P < 0.001), with a species by treatment by time interaction (P = 0.001). The pH at 2 h was 6.61 ± 0.02 regardless of species or treatment, and pH declined by 24 h for both steer and ram rumen cell suspensions in all treatments (P < 0.001). Final pH at 24 h did not differ between species for HY (6.15 ± 0.03), but for all treatments including corn, pH was lower in steer rumen cell suspensions (HC: steer – 5.86, ram – 6.06; CH: steer – 5.59, ram – 5.98; CN: steer – 5.26, ram – 5.91 ± 0.05; P ≤ 0.004). Lactate accumulation differed by species (P = 0.038), treatment (P = 0.048), and time (P < 0.0001), with a species by treatment by time interaction (P < 0.001). Lactate at 8 h did not differ between species for HY (steer:3.06, ram: 9.22 ±.84 mmolּ L-1), but was greater in steer than in ram cell suspensions fermenting HC (steer: 12.64; ram: 6.39 ±.84 mmolּ L-1), CH (steer: 13.44; ram: 3.21 ±.84 mmolּ L-1), and CN (steer:3.63; ram:.10 ±.84 mmolּ L-1; P ≤ 0.023). By 24 h, lactate accumulation was minimal for HY, HC, and CH (≤ 1.50 mmolּ L-1) and did not differ between species (P ≥ 0.657). However, lactate at 24 h was greater in steer rumen cell suspensions fermenting CN (steer: 25.78; ram: 182 ± 1.84 mmolּ L-1; P < 0.001). These results indicate that the rumen microbial community of sheep and cattle may differ both in composition and function resulting in different capacities to utilize common dietary feed ingredients.
166 Maternal Versus Environmental Contributions to the Piglet Pioneer Microbiome
Authors: Eldridge Landon , Hickman-Brown Kyle J , McAnally Brooke E , Smith Molly S , Poole Rebecca K , Wiegert Jeffrey G
Published: May 2023

The pioneer microbiome is the initial and foundational colonization of microbiological organisms within the neonatal animal and has lifelong implications for health and performance. The objective of this project was to quantify various maternal and environmental sources contributing to the pioneer microbiome of the piglet. Five pregnant gilts farrowed at the Texas A&M University Swine Center in April 2022. Litters were a Duroc x Landrace x Yorkshire composite and averaged 13.4 total number born and 11.4 number weaned. At birth, all piglets were individually identified and weighed and 5 piglets per litter weighing ≥1,200 grams were selected for microbiome analysis. Sterile swabs were used to collect, in duplicate, samples from the farrowing crate before gilt introduction (EMPTYCRATE) and after gilts were moved in (FULLCRATE), from the birth canal during farrowing (BIRTHCANAL), and from the rectum of the piglet on days 0 (prior to suckling), 3, and 10 post-farrowing and at weaning (21.6 ±.0 days post-farrowing). Colostrum was collected from each gilt during farrowing from a representative sample of teats into a single sterile collection cup (COLOSTRUM). Swabs and colostrum were stored in sterile microcentrifuge tubes at -80°C until sequencing. Bacterial DNA was extracted, and sequencing targeted the V4 hypervariable region of the6S rRNA gene. Statistical analyses were conducted using PROC GLM and PROC REG in SAS 9.4. The phyla Firmicutes and Proteobacteria were not different between maternal (BIRTHCANAL, COLOSTRUM) and environmental (EMPTYCRATE, FULLCRATE) sources (Table 1). The piglet microbiome shifted from birth to weaning. The relative abundance of phylum Firmicutes was less on day 3 compared with day 0 and at weaning but did not differ from day0 (Table 1). Within the phylum Firmicutes, Lactobacillus and Clostridium genera were greater on day 3 compared with day 0, 10, and at weaning (Table 1). The relative abundance of phylum Proteobacteria, and the relative abundance of genus Escherichia within phylum Proteobacteria, were greater on day 3 compared with day 0, 10, and at weaning (Table 1). Multiple regression analyses indicated that BIRTHCANAL explained 51.6% of the variation observed in piglet day 0 microbiome (P < 0.0001), and 6.5% of the variation in the piglet day 10 microbiome (P = 0.01). The piglet day 0 (pre-suckle) microbiome explained 10.0% of the variation observed in day 3 microbiome and 15.6% of the day 10 microbiome (P < 0.05). Finally, day 10 microbiome explained 58.6% of the variation observed in the piglet microbiome at weaning (P < 0.0001). The microbiome of COLOSTRUM and the farrowing crate did not impact piglet microbiome (P > 0.10). Results indicate that the piglet pioneer microbiome is largely influenced by the microbiome of the birth canal and that the microbiome of the animal at weaning may be largely established by 10 days of age.
98 Utilizing gas Flux from an Automated Head Chamber System to Estimate Dietary Energy Values in Cattle Fed a Finishing Diet
Authors: Proctor Jarret A , Smith Jason K , Gunter Stacey A , Beck Matthew R
Published: May 2023

Automated head chamber systems (AHCS; GreenFeed, C-Lock Inc., Rapid City, SD) provide estimates of daily flux of methane (CH4), carbon dioxide (CO2), and oxygen (O2) from free roaming cattle. This provides the opportunity to conduct energetic research from cattle in their production environment. One opportunity is to evaluate agreement between performance-estimated (P) net energy [Mcal×(kg DMI)-1] for maintenance (NEm) and gain (NEg; pNEm and pNEg, respectively) and gas-estimated (G) NEm and NEg (gNEm and gNEg, respectively). To assess this, yearling steers (n = 54; initial BW = 484.1 ± 26.0 kg) were assigned to one of two pens containing an AHCS and feed bunks designed to measure individual feed intake (Calan Gate; American Calan, Northwood, NH). Steers were transitioned to one of three finishing diets and were then fed for 80 days. Paired day initial and final unshrunk BW were measured on day 0 and 1, and on day 79 and 80, respectively. Following the feeding period, steers were transported to a commercial abattoir where carcass data were collected. Average daily gas flux was utilized to calculate heat production (HP), ignoring the energy losses from urinary nitrogen. Empty body weight (EBW) and empty body gain (EBG) were calculated and used to estimate retained energy (RE). The estimates of RE and HP were used to calculate ME intake and DMI was used to quantify dietary ME content. Through previously established cubic models, gNEm and gNEg were calculated. Ultimately, gNEm and gNEg were estimated from gas flux, DMI, ADG, and initial and final BW. A previously established quadratic model was used to estimate pNEm and pNEg using calculated energy requirements and available carcass parameters. Statistical analyses to compare the P and G energy values were conducted utilizing R (v.4.1.0) to assess precision (Pearson Correlation; r), method agreement (Lin’s Concordance Coefficient Correlation; CCC), Root Mean Square Error of Prediction (RMSEP), and Relative Prediction Error (RPE; RMSEP as a % of average performance estimated values). On average, P provided greater estimates of NEm [0.074 Mcal×(kg DMI)-1] and NEg [0.070 Mcal×(kg DMI)-1] relative to G. The G and P provided values which were highly correlated and had excellent agreement (r = 0.92, P < 0.01; CCC ≥ 0.87) for both NEm and NEg. Additionally, predictive capability was high for NEm (RMSEP = 0.12; RPE = 5.3%) and NEg (RMSEP = 0.11; RPE = 6.8%) between P and G values. The excellent agreement between P and G derived NEm and NEg values suggest that researchers can utilize AHCS to conduct energetic studies with cattle in their production environment. Moreover, the G methodology provides an alternative method for retrospective assessment of animal energetic efficiency.
102 A Comparison of Deworming Protocols Using Eprinomectin and Fenbendazole in Grazing Beef Steers
Authors: Wray Eva M , Tucker Chris , Reynolds Jana L , Shoulders Benjamin P , Midkiff Kirsten A , Powell Jeremy G
Published: May 2023

Many generic anthelmintics are commercially available; however, very little information exists regarding effectiveness of these products compared with pioneer brands. Therefore, the objective of this study was to conduct a fecal egg count reduction test comparing generic eprinomectin (Eprizero) to pioneer eprinomectin (Eprinex), as well as to fenbendazole in grazing beef steers. Naturally infected steers (n = 40; BW = 212±5 kg) were allocated into five treatment groups based on ranked fecal egg counts:. Eprinex (EX), 2. Eprizero (EZ), 3. Safeguard (SG), 4. Eprinex + Safeguard (XS), or 5. Control/No treatment (NT). Fecal samples were collected on days -7, 0, 14, and 29, and body weights were recorded on days -14 and 29. Data were analyzed using the MIXED procedure of SAS 9.4. At day 14 post-treatments, the EX treatment group demonstrated a 50% fecal egg count reduction (FECR), while EZ treatment group had a 79% FECR. Both the SG and XS treatment groups showed a 98% and 100% FECR, respectively. At day 29 post-treatment, EX and EZ treatment groups demonstrated a1% and 5% FECR, while the SG and XS treatment groups displayed a 94% and 89% FECR. The coproculture data indicated that Cooperia punctata, Cooperia oncophora and Ostertagia ostertagi all persisted and comprised at least 90% of the larvae recovered from both the EX and EZ coprocultures performed on days 14 and 29. Haemonchus spp. was recovered from EZ coprocultures on days 14 and 29 (10% and 1%, respectively, of recovered larvae), as well as from the EX coprocultures (4% and%, respectively). Interestingly, the proportions of C. punctata and C. oncophora essentially demonstrated a post-treatment reversal in the both the SG and XS treatment groups when comparing days 0 and 29, possibly indicating a greater efficacy of fenbendazole against than C. punctata. There were no significant differences (P < 0.05) in average daily gains between the treatment groups.
1 Challenges in the Pasture
Authors: Poore Matthew H
Published: May 2023

Cow-calf farms are abundant across the southeastern US and there is a wide diversity of farm sizes and types of farmers. Farms include small-scale part-time farms, and large commercial-scale farms, often integrated with other farm enterprises. Many farmers have full-time employment off the farm and little if any hired labor, such that there is little time to devote to farming activities. In contrast, large farms often have access to labor, equipment and other inputs that may not be available to small farms. The diversity of farms and farmer demographics makes extension programming challenging as motivational factors vary considerably. Many pasture management practices proven by research have very low levels of adoption including active grazing management, pasture renovation, hay testing, etc. We assume that all farmers are focused on profitability, but this is clearly not the case especially with small part-time farmers. Other motivations may be enjoyment of spending time with animals, time spent with family, improving animal welfare, interest in machinery and “gadgets”, and other non-farm interests including using a cow-calf enterprise to hold land in some kind of agriculture for future development. New management practices may make sense from a profitability perspective but might require the development of new skills that the farmer does not have. Additionally, there may be other barriers including access to necessary equipment, conflicting information provided by advisers, and expertise in simple practices such as planting and spraying. As an example, novel endophyte tall fescue (NETF) has potential to eliminate the negative aspects of endophyte infected tall fescue while maintaining the desirable agronomic characteristics. While NETF technology is research proven and has been available to producers for over two decades, adoption has been very slow. The Alliance for Grassland Renewal is a multi-state private/public collaborative formed to promote the appropriate adoption of NETF. The Alliance conducts workshops to teach farmers and their advisors about how to best implement the NETF technology. The collaborative effort provides a more uniform set of recommendations than was formerly available through each member state. Through workshop evaluations we found several important factors that limit adoption including 1) the balance of cost and benefit is unclear, 2) farmers have limited financial resources, 3) the land is rented or unsuitable for renovation, and 4) farmers lack of knowledge, and 5) farm forage reserves are limiting. Many of these pasture management practices are difficult to adopt because they require many sequential steps that must be completed in a timely way. This may leave the farmer hesitant to take the first step in the process. For practices that are very different than standard management, use of on-farm demonstrations and hands-on learning have proven valuable.
125 Residual Effects of Creep Feed Management on Reproductive Performance of Meat Goat does Across Multiple Years
Authors: Hayes Emily G , Stevens Lauren , Thomas Shaneqwa , Hillin Kaylee , Browning Richard
Published: May 2023

Creep feeding is a management practice used to improve the weaning weights of livestock including meat goats. The effects of creep feeding on replacement doe performance have received little attention. This study examined creep feeding effects on fitness traits of replacement does over their first five years in the breeding herd. Doelings that were either creep-fed (CF; n = 79) from 30 days of age until weaning (90 days of age) or not creep-fed (NC; n = 71) entered the breeding herd at 18 months of age and remained until death or failure to wean offspring in a second year. Doe body weights, packed cell volume (PCV), and fecal egg counts (FEC) were recorded each year at breeding. Cumulative totals for survivability to 6 years of age (SURV), kids weaned (TKW), weight weaned (TWW), and weaning rate (TWR) were analyzed for each doe. Doe body weights, PCV, FEC, TKW, TWW and TWR were analyzed using SAS MIXED models. Treatment group along with the sire breed, litter type, and dam age as traits of the doe were used as model terms. SURV was tested using SAS GLIMMIX models. Treatment, sire breed, litter type, and dam age of the doe were used as main effects. For sire breed, does were either Kiko-, Spanish-, Myotonic-, or Savanna-sired. There was no weight advantage (P > 0.05) observed in CF does (CF = 34.8 ± 0.9 kg vs. NC = 34.1 ± 0.9 kg) at breeding. A previous study on the same group of did show a weight advantage for CF at weaning and at 1 year of age, but that significance was lost by entry into the breeding herd. However, sire breed (P < 0.05) did impact body weights. Kiko-sired does were the heaviest (P < 0.05) and Myotonic-sired does were the lightest (P < 0.05) at breeding. Creep feed did not (P > 0.05) impact TKW (CF = 2.8 ± 0.3 kids vs. NC = 2.4 ± 0.3 kids) or TWW (CF = 35.7 ± 3.8 kg vs. NC = 32.7 ± 4.0 kg). Sire breed impacted (P < 0.05) TWW. Kiko-sired does weaned more (P = 0.02) weight than Savanna-sired does (43.4 ± 4.7 kg vs. 21.8 ± 4.8 kg, respectively). TWR, SURV, FEC, and PCV were not affected (P > 0.05) by treatment group. Preliminary assessment suggested that creep feeding doelings did not affect their reproductive performance as adults under the conditions of this study.