bluuebunny/crossref_metadata_2025 huggingface dataset:
116 Oklahoma State University Continuing Education Online Courses for Extension Educators in 2020
Authors: Moehlenpah Alexi , Lalman David L
Published: November 2020

The Smith–Lever Act of 1914 established a system of cooperative extension services to connect the land-grant universities to the people. Agricultural extension educators serve as the “front door” to the University, providing research-based information in a wide variety of agricultural topics such as livestock, crops, entomology, natural resources, etc. A bachelor’s degree in agriculture is a requirement for employment as an agricultural extension educator in most states. Generally, most new hires are knowledgeable in one or more areas and perhaps possess a degree focused in the same area. However, many educators are not fluent in all the agriculture sectors they are required to address on a daily basis. Our objective is to gradually develop an online in-service program specifically designed to strengthen educators’ knowledge and proficiency in basic beef cattle production. These courses will consist of five to ten modules each with an estimated five hours of course work per subject. The courses will include reading material, listening and visual material, interactive activities, and quizzes to aid in learning the basics. The Introduction to Beef Cattle Nutrition course is intended to enhance extension educators’ knowledge of the nutrient requirements of beef cattle, body condition scoring, ration calculation, etc. Extension educators will be expected to pass quizzes at the end of each module with an eighty percent or higher. Oklahoma extension educators will enroll in the Introduction to Beef Cattle Nutrition course during the 2020 calendar year and complete over a ten-week period. A survey at the end of each module will allow the authors to see how effective the course was, and if the representative feels more confident in discussing and helping producers with their herd nutrition upon completion.
172 The Mississippi Beef Quality Assurance Program: Certification Demographics from 2015 to 2019
Authors: Pittman Alexandra M , Karisch Brandi , Huston Carla
Published: November 2020

The Mississippi Beef Quality Assurance Program (BQA) has been in place since the early 1990s. In 2015, program materials and format were updated to reflect changing needs of clientele. The current program is a combination of in-person presentation with demonstration of tools such as castration equipment, needles, syringes, etc. to supplement the educational materials. Each registered participant receives a manual, tri-fold supplement, cooler, bumper sticker, and certificate upon completion of the certification. After viewing the presentation, participants complete a 14-question exam to test their knowledge of materials important to the BQA program. Upon passing the exam, participants receive certification, which is valid for 3 yr. Certification events are encouraged to include multiple counties, and reach a wide range of producers. In 2015 to 2017, events were specifically scheduled by state coordinators to ensure cattle producers in all areas of the state had the opportunity to attend a nearby program. Events were also held on an as requested basis. At the end of each certification, participants completed an anonymous survey reporting information on demographics and program effectiveness. From 2015 to 2019, there were 1,734 total certifications through 57 BQA programs provided. At these events, 26 states were represented. From Mississippi, 64 of 82 counties were represented. When describing total number of cattle, the majority of producers reported owning 1 to 50 head (46%) while only 3% reported owning over 1000 head. Producers also listed the total number of acres in pasture, where the majority reporting 1 to 100 acres (32%) and 6% reporting over 1000 acres. When asked to rank economic impacts, most (26%) reported an estimated more than $25 per head benefit due to increased production and marketing. In summary, producers had small number of cattle and acres of pasture but reported large economic benefits to the certification.
135 Public perceptions of equine processing and welfare
Authors: Melvin Kelly , Schneider Liesel G , Ivey Jennie L , Krawczel Peter D
Published: November 2020

Equine welfare and processing are a major topic of interest, often debated by industry professionals and the public alike. These debates often focus on the welfare of equines during the different aspects of processing and the impacts related to the processing legislation passed in 2007. Our objective was to determine if one’s definition of welfare, industry connection, or their classification of equines was associated with their perceptions of equine processing and related impacts. Over a 6-wk period, a survey was distributed via email and social media outlets to U.S. residents over the age of 18 (n = 1,334). Participants responded to questions including demographic information, connection to the industry, equine classification, and indicated the changes they expected occurred due to the 2007 processing legislation. Furthermore, participants selected sources from which they commonly obtain information regarding animal welfare issues. Statistical significance was set at α=0.05. Multinomial logistic regression in SAS (SAS Institute, Cary, NC; PROC LOGISTIC) was used to determine factors associated with participants’ likelihood to respond “increase,” “decrease,” or “no impact” to each area in which the 2007 legislation could have impacted the industry. When asked if there was an impact on the number of horses processed, connection to the industry (P = 0.03), welfare definition (P < 0.0001) and classification of horses (P = 0.009) were associated with responses. Respondents with light connection, when compared to moderate connection, were 10 times more likely (OR=10.9; 95% Cl: 1.03, 111.1) to say there was an increase in horse processing, versus no impact, in response to the 2007 legislation. Understanding interactions between industry connection, welfare definition, classification of equids relative to current industry issues may prove beneficial to bridge an educational gap and provide clarity to important welfare concerns.
131 Producer adoption of preconditioning strategies in the Oklahoma Quality Beef Network
Authors: Robe Jeff , Beck Paul A , Zook Dana , New Marty , Ward Earl , Freking Brian
Published: November 2020

The Oklahoma Quality Beef Network (OQBN) Vac-45 program was designed to provide health management certification and value-added marketing for cow-calf producers since 2001. The objective of this abstract is to examine trends in health management systems by OQBN participants. Participants chose from one of three options for administering vaccinations: Option 1) branding and weaning, Option 2) 2–6 weeks before weaning and weaning, Option 3) weaning and 14–28 d post weaning. From 2014–2018, 596 participants enrolled 30,452 calves. Preferred vaccine options were: Option 1) 210 participants (35%) and 12,015 calves (37%), Option 2) 96 participants (16%) and 3,016 calves (10%), Option 3) 290 participants (49%) and 15,421 calves (51%). Producer choice of a viral vaccine component included 251 (42%) participants using killed vaccine at least once. A five-yr average of cattle marketed with at least one modified-live vaccine (MLV) exposure was 73% of calves (22,138) and 27% (8,314) were treated with only killed vaccines. In Option 1, 57 (10% of the total) participants used killed vaccines at both times, 33 (6%) used a killed vaccine followed by a MLV at weaning, 120 (20%) used MLV at both times. Option 2, 55 (9%) participants used killed vaccines at both times, 4 (1%) participants used a killed vaccine follow by a MLV at weaning; 37 (6%) used a MLV at both times. Option 3, 114 (19%) participants used killed vaccines at both times, 2 (< 1%) participant used a killed vaccine followed by a MLV, 1 participant used MLV followed by killed vaccine, 173 (29%) participants used MLV at both times. Cattle marketed with killed vaccines have seen an increase in use; 2014 (27%), 2015 (17%), 2016 (27%), 2017 (31%), 2018 (39%). These data show the preferred method of MLV vaccination utilized is a weaning and post-weaning system with an increased use of killed vaccines, which may be due to producer concerns regarding exposure of brood cows to MLV.
174 The Southeast hay contest: 10 year summary
Authors: Dillard Sandra L , Baxter Lisa , Wallau Marcelo , Harmon Deidre D , Hancock Dennis W
Published: November 2020

The Southeast (SE) Hay Contest was started by a group of Extension agents from across the SE with the objective of increasing producer knowledge of the relative forage quality (RFQ) index. Since its inception, the program has grown to over 350 hay and baleage samples annually. Forage samples were categorized into warm-season perennial grass hay (WSPGH), alfalfa hay (AH), perennial peanut hay (PPH), cool-season perennial grass hay (CSPGH), mixed annual grass, or other hay (MAG), grass baleage (GB), and legume baleage (LB). Samples were analyzed for RFQ and crude protein (CP) using near infrared reflectance spectroscopy (NIRS) at the UGA Forage Testing Center (Athens, GA). The following summary includes data from 2009–2018 analyzed using Proc Glimmix of SAS 9.4 (SAS Inst., Cary, NC) with category and year as fixed effects and α = 0.05. Alfalfa hay had the greatest RFQ, followed by LB (P ≤ 0.004; 199 and 186, respectively). Perennial peanut and GB had median RFQ values (P ≤ 0.001; 169 and 150, respectively), and WSPGH had the least (P ≤ 0.008; 117). With the exception of 2017, the years 2013 to 2018 had the greatest RFQ (P < 0.001; 165). 2017 had a greater amount of rain than average, likely resulting in its lower average RFQ. Alfalfa hay had the greatest (P < 0.001) CP of all categories (23.9%; P < 0.001). Crude protein concentrations did not differ among WSPGH, CSPGJH, and MAG (P ≥ 0.192; 14.5%). While these forage samples were likely greater quality than samples not submitted, we conclude that outreach efforts, including the SE Hay Contest, have increased knowledge of the hay and baleage production process leading to increased hay quality from 2009 to 2018.
185 Utilizing craft brewing side streams of trub, hops, and yeast mix (THYM) as a novel feed additive and an alternative to monensin in beef cattle diets
Authors: Phipps Kendra P , Harmon Deidre D , Poore Matt H , Henderson Ethan , Bryant Robert , Ashburn Brock , Shaeffer April , Rogers Johnny R
Published: November 2020

The objective of this experiment was to evaluate craft brewing side streams of trub, hops and yeast mix (THYM) as a potential feedstuff and replacement for monensin in growing beef cattle rations. British-cross steers (n = 45, initial BW = 732 ± 58kg) were stratified by BW and randomly assigned to 1 of 15 pens (3 head/pen). Treatment diets were randomly assigned to pen and consisted of a corn silage based total mixed ration (TMR) with no supplementation (CON; 70.99% TDN, 12.25% CP), supplementation with monensin (MON; 22g/907kg ration, dry matter basis) or supplementation with the brewery side streams (THYM; 70.95% TDN, 12.49% CP, 2.65% THYM, dry matter basis). Steers were adjusted to a TMR for 14 d prior to a 63 d collection period. Body weight and serum urea nitrogen (SUN) were measured on d 0 and every 21 d thereafter. Rumen fluid was collected via esophageal/rumen tube at d 42 and 63 for short chain fatty acid analysis (SCFA). Data were analyzed using the MIXED procedure of SAS 9.4 (Cary, NC) with treatment as the main effect and using repeated measures. Average daily gain and dry matter intake did not differ among treatments (P = 0.96, respectively), but a tendency was noted for THYM to have greater average gain:feed than the CON treatment. SUN concentrations were least on d 0 (P < 0.01) but did not differ among treatments at any time (P =0.11). On d 42, THYM had a greater (P = 0.05) A:P than MON. Concentrations of propionic and valeric acid were greater (P < 0.05) for CON than THYM on d 63, while SCFA concentrations tended to be greater (P = 0.08) for CON than THYM. THYM also tended to have a greater A:P on d 63 than CON. Interpretation of the data indicates that inclusion of THYM in growing cattle rations has no negative impact on animal performance.
63 Effects of forage allowance and supplementation on performance of steers grazing wheat pasture
Authors: McNeill Kynzie , Reuter Ryan R , Beck Paul A
Published: November 2020

A 72-d trial was conducted to estimate the combined effect of forage allowance and a fiber-based energy supplement in stocker cattle grazing wheat. Eight pastures (2.7 to 5.1 ha) each contained seven test steers (initial BW = 210 ± 36 kg). Weekly, additional steers were stocked in each pasture in a put and take method to achieve forage allowance of either 2.5 or 5.5 kg forage DM / kg steer BW (4 pastures each). Two pastures in each forage allowance were fed daily with a supplement containing 50% wheat midds and 50% soybean hulls at the rate of 1.5 kg per steer. Forage mass was measured twice weekly using a calibrated rising plate meter. Cattle were weighed weekly on calibrated scales. Data were analyzed using linear regression with pasture as the experimental unit. Mean ADG was 1.36 kg/d. One pasture in the high forage allowance, non-supplemented treatment was removed because we were unable to maintain the designed forage allowance. The interaction of forage allowance and supplement was not significant (P = 0.37) for ADG, and supplementation did not affect ADG (P = 0.20), however increased forage allowance tended to improve ADG (P = 0.06, 0.21 kg ADG per kg forage allowance). To further investigate forage DMI, a 14-d trial began on day 36. Three of the seven test steers in each pasture were randomly chosen and administered 7 ± 0.1 g of TiO2 daily at 0700 as an external marker to estimate fecal output. Forage DMI (at an assumed 72% DM digestibility) averaged 2.1% of midpoint BW, below our expectation. Additional forage allowance tended to improve estimated forage DMI (P= 0.06), but supplement had minimal effect (P = 0.30).
134 Public perceptions of equine processing and welfare
Authors: Melvin Kelly , Schneider Liesel G , Ivey Jennie L , Krawczel Peter D
Published: November 2020

Equine welfare and processing are a major topic of interest, often debated by industry professionals and the public alike. These debates often focus on the welfare of equines during the different aspects of processing and the impacts related to the processing legislation passed in 2007. Our objective was to determine if one’s definition of welfare, industry connection, or their classification of equines was associated with their perceptions of equine processing and related impacts. Over a 6 week period, a survey was distributed via email and social media outlets to United States residents over the age of 18 (n=1,334). Participants responded to questions including demographic information, connection to the industry, equine classification, and indicated the changes they expected occurred due to the 2007 processing legislation. Furthermore, participants selected sources from which they commonly obtain information regarding animal welfare issues. Statistical significance was set at α=0.05. Multinomial logistic regression in SAS (SAS Institute, Cary, NC; PROC LOGISTIC) was used to determine factors associated with participants’ likelihood to respond “increase”, “decrease”, or “no impact” to each area in which the 2007 legislation could have impacted the industry. When asked if there was an impact on the number of horses processed, connection to the industry (P=0.03), welfare definition (P< 0.0001) and classification of horses (P=0.009) were associated with responses. Respondents with light connection, when compared to moderate connection, were 10 times more likely (OR=10.9; 95% Cl: 1.03, 111.1) to say there was an increase in horse processing, versus no impact, in response to the 2007 legislation. Understanding interactions between industry connection, welfare definition, classification of equids relative to current industry issues may prove beneficial to bridge an educational gap and provide clarity to important welfare concerns.
17 Comparing Natural Vegetation and Food Plot Preference against Supplemental Protein Pellets in Captive White-tailed Deer (Odocoileus virginianus) and Exotic Species
Authors: McQueen Robert W , Beverly Marcy M , Kelley Stanley F , Anderson Mark
Published: November 2020

Supplemental feed is the most expensive input in the captive wildlife industries. This is due to operations utilizing high-energy pellets as supplemental feed. Low fence operations often utilize food plots with high quality vegetation to minimize cost and increase forage availability for wildlife. The objective of this study was to determine forage preference of animals in captivity, and determine the most cost effective method of supplemental feeding. Seven food plots covering 25 acres contained one of three treatments. The treatments were: a commercial blend of soybeans; a commercial blend of soybeans, sunflowers, and milo; native/unplanted. Three utilization cages were set up to inhibit wildlife access to samples within each food plot to act as a control. Height of vegetative samples, inside and outside of the utilization cages, was collected on days 30, 60, and 90 after planting. The 30-d sample showed a preference of native/unplanted vegetation over the commercial treatments, P < 0.05. However, samples taken on days 60 and 90 showed the preference shifted toward the commercial blends, P < 0.05. This browsing preference indicates stage of maturity had an impact on plant selection. Regardless of sample date, the commercial blends showed a difference of P < 0.01, selecting the soybean blend more frequently. With an increased selection of the forages in the food plots, there was a decrease in cost of purchasing feed pellets with a total savings of approximately $5,500.00 from April 5-July 5, 2019. These results suggest that white-tailed deer and exotic species in captivity prefer forages compared to pelleted feed. Supplemental feeding programs that include food plots could allow for natural feeding tendencies, while being more cost effective for operations in the captive wildlife industries.
99 Impact of social mixing on feedlot steer eating and lying behavior
Authors: Hubbard Amanda J , Sawyer Jason , Cooke Reinaldo F , Jennings Jenny , Daigle Courtney L
Published: November 2020

This study evaluated the impact of mixing cattle from two sources of feedlot steers (n = 96) on feeding and lying behavior. Angus crossbred steers (n = 48 McG and n = 48 BCS), similar in genetic composition, were transported (833.64 ± 85.29 km) to a feedlot 39-d prior to mixing where the two sources were housed without visual or tactile contact. Steers, blocked by source and stratified by d -34 body weight, were randomly assigned to one of 12 pens (n = 8 steers/pen) for the 42-d study. Pens were assigned to one of two treatments (n = 6 pens/treatment): 1) NOMIX—100% of cattle from McG (n = 3 pens) or BCS (n = 3 pens) and, 2) MIX—50% of cattle from BCS and 50% from McG (n = 6 pens). Instantaneous scan sampling (n = 61 scans/d; 10 min intervals) recorded the number of steers per pen eating and lying on d1, 2, 3, 4, 5, 6, 7, 8, 9, 14, 15, 16, 21, 22, 23, 28, 29, 36, and 37 after mixing. Proportion of steers lying varied across time (P < 0.0001); however, a greater proportion of steers laid down on d1 compared to d7, 8, 9, 16, and 28 (P < 0.03). The proportion of steers observed eating increased over time (P < 0.0001). Fewer steers ate on d1 than d9, 14, 15, 28, 29, and 36 (all P < 0.01). More steers were observed eating on d8 and 16 than the first seven days (all P < 0.01) and on d37 than the first 6 days (all P < 0.02). While there was no impact of mixing, data indicate that handling and sorting cattle into new pens impacts eating and lying behavior and it takes approximately a week for behavior to stabilize.
77 Evaluating Nitrogen Management Strategies to Improve Southern Bermudagrass Grazing Systems
Authors: Burt Justin C , Tucker Jennifer J , Baxter Lisa
Published: November 2020

Bermudagrass (Cynodon dactylon) is one of the most common perennial warm-season forage crops grown in the South. While prominent in the region bermudagrass management requires large amounts of fertility and forage quality is moderate at best. Incorporating a legume into bermudagrass pastures could serve as an alternative to the necessary applications of synthetic N, while also improving the nutritive value of the forage base. A two-year grazing evaluation was conducted from May-Sept. 2018 (Y1) and May-Aug. 2019 (Y2) at the University of Georgia Tifton Campus in Tifton, Georgia, to compare concurring production of alfalfa/bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BGZ) the application of synthetic nitrogen. The experimental design was a randomized complete block with three treatments and two replications. All paddocks were evaluated pre and post grazing event for herbage availability, botanical composition, forage species competitiveness, and nutritive value. Paddocks (0.8-ha) were rotationally grazed using put and take management with stocker steers (Y1 BW=195.9±22.9 kg; Y2 BW=228.5±30.0 kg), two testers per treatment. Steers were weighed at initiation, conclusion, and on a 28–30 day interval for calculation of ADG and gain/ha. Statistical analysis was conducted using the PROC MIXED procedure of SAS. Despite significant drought in Y2, year did not affect total gain/ha; however, treatment did (P = 0.04), such that BGA was highest (383.6±35.1 kg/ha), and BGN and BGZ were not different (261.2±35.1 kg/ha and 239.0±35.1 kg/ha, respectively). This is likely due to the lower stocking density and inclusion of high-quality volunteer annual grasses in BGZ treatments which allowed for selective grazing. These data suggest that rotationally grazing alfalfa/bermudagrass mixtures can result in a higher gain/ha, than bermudagrass pastures that are supplemented with or without synthetic N in the South.
6 Animal performance in grass monoculture or silvopasture systems using tree legumes
Authors: da Silva Izabela Aline Gomes , Dubeux Jose Carlos Batista , de Mello Alexandre C Leão , da Cunha Márcio Vieira , dos Santos Mércia Ferreira , Apolinário Valéria Oliveira , da Silva Gleise Medeiros , de Freitas Erinaldo Viana , DiLorenzo Nicolas
Published: November 2020

Silvopasture systems (SPS) area management option to enhance delivery of ecosystem services and diversification of income. This study evaluated productive responses of signalgrass (UrochloadecumbensStapf.) in monoculture or in SPS in the sub-humid tropical region of Brazil during six months of the rainy season. The experimental design was randomized complete block with three replications. Treatments were signalgrass + Mimosa caesalpiniifolia Benth. (SPS-Mimosa); signalgrass + Gliricidia sepium (Jacq.) (SPS-Gliricidia); and signalgrass monoculture. Cattle were managed under continuous stocking with variable stocking rate. Response variables included herbage mass (HM), herbage accumulation (HA), stocking rate (SR), average daily gain (ADG), and gain per area (GPA). Herbage mass (HM) was greater (P < 0.0001) on signal grass monoculture (2045 kg DM/ha) than in SPS (1370 kg DM/ha, average for both SPS). Herbage accumulation rate was similar for signalgrass in monoculture and SPS-Gliricidia (avg. 61 kg DM ha-1 d-1), and both were greater than SPS-Mimosa (37 kg DM ha-1 d-1). Average daily gain was greater(P < 0.0001) for SPS-Gliricidia (1.1 kg head-1 d-1), followed by signalgrass in monoculture (0.9 kg head-1 d-1), and SPS-Mimosa (0.3 kg head-1 d-1). Stocking rate ranged from 0.6 animal units (1AU = 450-kg animal) per ha in April to 2.2 AUha-1 in June. Stocking rate and animal performance per area were similar for signalgrass in monoculture and SPS-Gliricidia, and both greater than SPS-Mimosa. Gliricidia enhanced animal performance and provided ecosystem services. Mimosa, however, reduced animal performance likely due to the competition with signalgrass. Mimosa trees, however, are an important source of income (timber used for fence posts) and that might overcome the losses in animal performance.
130 Presynchronization with Prostaglandin F2αand prolonged exposure to exogenous progesterone impacts estrus expression and alters fertility in beef heifers
Authors: Oosthuizen Nicola , Fontes Pedro , Lamb Cliff
Published: November 2020

To determine the effects of 2 presynchronization strategies in conjunction with delayed fixed-time artificial insemination (TAI) on pregnancy rates to TAI (PR/AI), 1,700 Angus beef heifers at 3 locations were enrolled in a completely randomized design with a 2×2 factorial arrangement of treatments. Within location, all heifers were randomly assigned to 1 of 4 treatments: 1) PG54 (n = 434), heifers received a 25-mg injection of prostaglandin F2α (PGF) 7 d prior (d -14) to the initiation of the 7-d CO-Synch + CIDR protocol wherein they received a 100-µg injection of gonadotropin-releasing hormone (GnRH) and a CIDR insert on d -7, a 25-mg injection of PGF at CIDR removal on d 0, and a second injection of GnRH concurrently with TAI 54±2 h later; 2) PG72 (n = 426), heifers were exposed to the same treatment as PG54; however, TAI was performed 72 ± 2 h after CIDR removal; 3) PG-CIDR54 (n = 422), same as PG54 but heifers received a CIDR insert on d -14 in addition to PGF; 4) PG-CIDR72 (n = 418), same as PG-CIDR54; however, TAI was performed 72±2 h after CIDR removal. Estrus detection patches were applied to all heifers on d 0 and were evaluated for activation at TAI. Pregnancy was diagnosed between 30 and 47 d after TAI. The percentage of heifers exhibiting estrus between d 0 and TAI was greater (P < 0.001) in the PG72, PG-CIDR54, and PG-CIDR72 treatments compared to the PG54 treatment (78.11, 86.59, and 91.09 vs. 31.05%, respectively). Furthermore, estrus response was greater (P < 0.001) in PG-CIDR72 heifers when compared to PG72. Pregnancy rates to TAI differed among treatments and were greater (P < 0.05) in the PG72 and PG-CIDR54 treatments when compared to PG-CIDR72 (48.8 and 50.4 vs. 38.4%, respectively), and were greater (P = 0.034) in PG-CIDR54 vs. PG54 (43.1%). Moreover, a tendency (P = 0.097) was determined on PR/AI between PG54 and PG72. In conclusion, presynchronization strategies and prolonged exposure to exogenous progesterone have the potential to alter estrus expression and improve fertility in replacement beef heifers.
64 Effects of grazing cool-season cover crops on forage and animal performance
Authors: Carrell Russell C , Dillard Sandra L , Mullenix Mary K , Gamble Audrey , Muntifering Russ B
Published: November 2020

Utilization of cool-season cover crops has been shown to increase soil health and cash crop performance in minimum tillage cash crop systems. Though evidence that grazing of cover crops can be viable is limited. Our objective was to determine animal and forage performance when grazing a cool-season annual cover-crop. Twelve 1.2 ha pastures were established in a forage mix consisting of black oats (Avena strigose), cereal rye (Secale cereal), crimson clover (Trifolium incarnatum), and T-raptor (Brassica napus × B. rapa) and randomly allocated to be grazed either 0, 30, 60, or 90 days. Three tester steers were randomly placed in each paddock with the exception of control paddocks and allowed ad libitum grazing. Animals were weighed every 30 d for determination ADG and total gain (TG). Forage was harvested bi-weekly and analyzed for NDF and ADF using an ANKOM fiber analyzer (ANKOM Tech, Macedon, NY). All data were analyzed using MIXED procedure of SAS version 9.4 (SAS Inst., Cary, NC). Differences were found in ADG between 90 and 60 days grazed (4.2 ± 0.12 vs. 2.8 ± 0.12 kg/d; P < 0.01) and 90 and 30 days grazed (4.2 ± 0.12 vs 2.7 ± 0.12 kg/d; P < 0.01). Differences in TG were detected between 90 and 60 days grazed (819 ± 13.35 vs. 386.67 ± 13.35 kg; P < 0.01), between 90 and 30 days grazed (819 ± 13.35 vs 261.33 ± 13.35 kg; P < 0.01), and between 60 and 30 days grazed (386.67 ± 13.35 vs 261.33 ± 13.35 kg, P < 0.01). No differences in NDF (44.86%, P = 0.99) or ADF (27.20%, P = 0.92) were detected between treatments. These results indicate that different grazing periods could influence cattle growth and performance without negatively impacting forage quality and production.
110 Metmyoglobin reducing activity and oxygen consumption properties of atypical dark-cutting beef
Authors: Ramanathan Ranjith , Cassens Andrew M , Yoder Laura , Mafi Gretchen G
Published: November 2020

Deviation from characteristic bright-red color during grading leads to discounted carcass price and value. Dark-cutting carcasses are examples of color deviation due to high-pH. However, atypical dark-cutters are not discounted at grading but have a dark color compared to normal-pH beef. Limited knowledge is currently available on the biochemical properties of atypical dark cutting beef compared with normal-pH beef. Therefore, the objective of the study was to determine metmyoglobin reducing activity and oxygen consumption of atypical dark-cutting beef. Strip loins from atypical dark-cutting (ADC; selected based on HunterLab L* values and pH less than 5.8 and not discounted by grader) and USDA Low Choice (C) carcasses were selected from a commercial beef processing plant and transported to the Food and Agricultural Products Center in Stillwater, Oklahoma. pH, color, oxygen consumption, and metmyoglobin reducing activity of atypical dark cutters and normal pH loins were determined on d3 postmortem. The surface color was determined using a HunterLab Miniscan spectrophotometer. Reflectance-based methods using K/S ratios were utilized to determine oxygen consumption and metmyoglobin reducing activity. The data were analyzed using the Mixed Procedure of SAS and the experiment was replicated 10 times (n = 10). There were no differences in initial pH (C = 5.46 and ADC = 5.6 atypical dark-cutter; P = 0.05) between normal-pH and atypical dark cutters. However, atypical dark cutters had lower lightness (L* values; C = 44.2 and ADC = 38.4), redness (a* values; C = 28.6 and ADC = 25.2), and red intensity (chroma; C = 40.2 and ADC = 36.4) compared with normal-pH. Further, atypical dark cutters had greater (P < 0.05) oxygen consumption and metmyoglobin reducing activity than normal-pH. The results suggest that atypical dark cutters and normal-pH beef have different biochemical properties.
147 Tenderness and Retail Display Evaluation of Non-Enhanced, Enhanced and High-Quality Pork Chops
Authors: Cassens Andrew M , Mafi Gretchen G , VanOverbeke Deb L , Ramanathan Ranjith
Published: November 2020

Quality variation within the pork industry is commonly associated with intramuscular fat and muscle color. The objective of this study was to determine the effects of packaging, pork quality types, and cooking temperature on color and shear force. Normal, non-enhanced (N, n = 10), Enhanced with salt and phosphate (E, n = 10) and Highly Marbled (H, n = 10) pork loins from a local food distributor. Loins were cut into 2.54-cm-thick chops and assigned to retail display or tenderness evaluation. Retail display chops were assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP) and high-oxygen modified atmospheric packaging (HiOx-MAP). Visual color measurement for muscle color (MC), fat color (FC), surface discoloration (SD), and surface color uniformity (SCU) was recorded on d 0, 2, and 4 of retail display. Pork tenderness was evaluated at 3 different degrees of doneness (63, 68, & 74°C) using Warner-Bratzler shear (WBS) force. There were significant treatment and packaging interactions for muscle color. For muscle color score, E pork loins had a significantly lower (P < 0.05) muscle color score compared with N and H loins indicative of a brighter, more pale pink color. In addition, CO- and HiOx-MAP packaged chops were significantly brighter (P < 0.05) compared to PVC chops. There were treatment and degree of doneness main effects (P < 0.05) for WBS force values. Enhanced pork loins were more tender (P < 0.05) than N pork loins. Furthermore, pork chops cooked to 63 °C were more tender than chops cooked to 68 and 73°C. In conclusion, enhanced chops packaged in CO- or HiOx-MAP result in a brighter color of lean compared non-enhanced and high-quality. Additionally, the results suggest that enhanced, non-enhanced, and high-quality pork products available in market have different quality parameters.
25 Cooking method and muscle type impact volatile compound development in beef steaks
Authors: Vierck Kelly R , Legako Jerrad F , Brooks J Chance
Published: November 2020

The objective of this study was to determine the influence of dry heat cookery on beef flavor development of multiple beef muscles. Beef strip loins, top sirloin butts, tenderloins, shoulder clods, and chuck rolls were collected from USDA Low Choice carcasses (Small00-Small100 marbling; n = 20). Subprimals were wet aged in the dark for 21 d at 0 - 4℃. Following aging, subprimals were fabricated into 2.54 cm thick steaks of the following muscles: Gluteus medius (GM), Infraspinatus (IF), Longissimus lumborum (LL\), Psoas major (PM), Serratus ventralis (SV), and Triceps brachii (TB). Steaks were cooked to a medium degree of doneness (71℃) on one of four randomly assigned cooking methods: charbroiler grill (CHAR), clamshell grill (CLAM), convection oven (OVEN), or salamander broiler (SALA). Volatile compound analysis was conducted using gas chromatography-mass spectrometry with solid phase microextraction. Data were analyzed as a split plot arrangement, with subprimal serving as the whole plot factor and cooking method serving as the subplot factor. The majority of compounds evaluated were impacted by the cooking method main effect (n = 21), followed by the cooking method × muscle interaction (n = 18), and muscle (n = 12). Charbroiler GM steaks produced the greatest amount of methional, 2,5-dimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine, and 2-ethyl-3,5-dimethylpyrazine compared to all other treatments (P < 0.05). Charbroiler and CLAM steaks produced the greatest concentration of methylpyrazine and trimethylpyrazine, as well as Strecker aldehydes (P < 0.05), indicating that more direct applications of heat increased Maillard product production. Steaks cooked using OVEN and SALA produced more lipid oxidation products, such as alkanes, aldehydes, and lipid derived ketones. Gluteus medius and SV steaks produced the greatest concentration of volatile compounds, with SV steaks producing an increased concentration of lipid derived compounds (P < 0.05) and GM steaks producing a greater concentration of Maillard products (P < 0.05). These data indicate that cooking method has a direct impact on the flavor profile produced by steaks.
176 The Suitability of Autoclave and Pressure Cooker Washing Methods in Comparison to ANKOM200 to Determine Neutral Detergent Fiber Using Different Feedstuffs and Washing Solutions
Authors: Adams Jordan , Norris Aaron B , Rivera Madeline E , Batista Luiz Fernando Dias , Tedeschi Luis O
Published: November 2020

The use of the in vitro gas production (IVGP) technique requires accurate determination of neutral detergent fiber (NDF) residue. However, the NDF determination using standard procedures are not always feasible for IVGP; thus requiring micro-NDF methods, which need autoclave (AC) and pressure cooker (PC) to boil the solution. A complete randomized design using a 3×3 factorial arrangement was implemented to investigate the effect of washing methods (WM: AC, PC, or ANKOM200) and solution ratios (WS: 100 mL neutral detergent solution (ND), 150 mL ND, or 100 mL H2O/g sample) to determine NDF residues, assuming ANKOM200 and 100 mL ND/g as the standard methodology. Each factor combination was performed in triplicate with a replicate being comprised of 12 bottles or bags (two blanks and five feedstuffs in duplicate). Feedstuffs were: alfalfa hay (AH), bermudagrass hay (BH), two high-forage rations (G1 and G2), and a high-concentrate ration (FR). Following each run, bottles were filtered to obtain the NDF. Data were analyzed by diet using a random coefficients model. An interaction of WM ′ WS was present for AH and G1 (P < 0.01), G2 and FR had tendencies (P = 0.08 and 0.06, respectively), whereas BH demonstrated no interaction (P = 0.37). The PC with 100 mL or 150 mL did not differ from the standard methodology for AH, G1, G2, and FR. The BH demonstrated differences between WM and WS (P < 0.01). The PC had lower NDF residue compared to the AC and ANKOM200, whereas H2O had substantially greater NDF residue relative to both ND ratios. We concluded that H2O is not a suitable substitute for ND solution regardless of the feedstuff. Both micro-NDF washing methods may be satisfactory depending on the type of feedstuff used, but further investigation is required.
11 Carcass Attributes and Performance of Poultry (Gallus gallus domesticus) fed Olive Pomace
Authors: Conn Benny J , Snokhous Payton , Carter Ethan , Urso Phil , Legako Jerrad F , Kelley Stanley F , Beverly Marcy M , Anderson Mark
Published: November 2020

In livestock production systems, feed is the most expensive production input. The goal of any producer is to find feed that provides a balance of nutrients to meet requirements for maintenance, growth, and performance while efficiently contributing favorable carcass attributes at a low cost. Olive pomace, a by-product of the olive industry, can serve as a source of fat (14%), protein (3.6%), and fiber (44.5%). The objective of this study was to determine adipose tissue content and sensory attributes of chicken breast (Phase I), as well as determine growth of growing chickens fed a mixture of commercial feed and olive pomace (Phase II). In Phase I, mature broilers were fed rations consisting of 25%, 50%, and 75% olive pomace blended with standard poultry feed for 27d. After harvest, a fat sample was taken for fatty acid analysis, and a breast was taken from each bird for sensory analysis. The only difference in fatty acid composition was in the 50% treatment, which had lower amounts of docosahexaenoic acid and higher amounts of decanoic acid. No significant differences were detected between treatment groups in the sensory analysis (P = 0.79). The young chickens (n = 40) were divided into three groups and fed a standard diet (control), or a standard diet with either 25% or 75% replaced with olive pomace. They were fed ad libitum for 35d; total feed consumed was measured daily and bodyweight (BW) was recorded weekly. No difference was detected between control and 25% in BW, but the 75% was lighter (P < 0.01) than the other groups. Additionally, 75% consumed more feed (0.91/lb/bird/d; P < 0.01) than any other group with no difference between control (0.64/lb/bird/d) and 25% (0.71/lb/bird/d). The results show that olive pomace can be utilized in chicken rations and will not affect growth or the quality of the end product.
115 Nitrogen fertilizer effects on above ground sward characteristics and beef heifer performance from native warm-season grass blends
Authors: Chappell Caroline , Marks Landon , Mason Katie , Mullenix Mary K , Dillard Sandra L , Muntifering Russ B
Published: November 2020

A 2-yr study was conducted at Black Belt Research and Extension Center in Marion Junction, AL, to evaluate the effect of nitrogen (N) fertilizer application rate on forage production characteristics, nutritive value, and animal performance of beef heifers grazing a mixture of native warm-season grasses (NWSG) including big bluestem, little bluestem, and indiangrass. Six, two-hectare plots were randomly assigned to one of two treatments (0 or 67 kg N ha-1 applied in early April; n = 3 replications per treatment). Paddocks were continuously stocked with four weaned Angus × Simmental beef heifers (initial BW 288 ± 7 kg) from late May/early June through mid-to-late August during 2018 (73 grazing d) and 2019 (70 grazing d), respectively. Put-and-take cattle were used to manage forage to a target of 38 cm. Forage mass and canopy heights were collected every two weeks during the trial. Visual ground cover ratings, canopy light interception, and botanical composition were measured at the beginning and end of the trial in each year. Hand-plucked samples were collected every two weeks during the grazing trial to determine forage nutritional value. Data were analyzed using the PROC MIXED procedure in SAS 9.4, and differences were declared significant when P ≤ 0.05. Nitrogen fertilized NWSG had greater crude protein (P < 0.0001), sward heights (P = 0.0003), and canopy light interception at the beginning of the season (P = 0.0049) compared to non-fertilized paddocks. However, there were no differences (P ≥ 0.05) among N-fertility treatments for mean forage mass, heifer ADG, or BCS across the 2-yr study. Botanical composition data indicated that indiangrass decreased from 64% to 61% (P = 0.0022) and weed pressure increased from 11% to 15% (P = 0.0064) across the summer grazing season. Canopy light interception decreased by 51% from early June to August in fertilized NWSG and 26% in unfertilized paddocks, respectively. These data illustrate that NWSG systems may provide a viable grazing system in the summer months under reduced N inputs.
87 Evaluation of two stocking rates for grazing heifers on mixed sward native warm-season grass pastures in the Black Belt Prairie region
Authors: Parish Jane A , Yankey Kalisha C , Durst Libby S
Published: November 2020

Optimal use of native warm-season grasses in pasture systems involves stocking grazing livestock at suitable rates. The study objective was to evaluate forage nutritive value and heifer ADG at two stocking rates on mixed-sward pastures of big bluestem (Andropogon gerardi Vitman), little bluestem (Andropogon scoparius), and indiangrass (Sorghastrum nutans L.). Pastures (3 replications) were stocked for 56 d during June and July in 2 yr with crossbred (Bos taurus) heifers (n = 24 heifers/year) stratified by initial BW (288.3 ± 1.7 kg) to one of two continuous stocking rates: 1.9 heifers/ha (HIGH) and 1.2 heifers/ha (LOW). Mean forage nutritive values on a DM basis were not different between HIGH and LOW stocking rates, respectively, for CP (7.0 ± 0.2% vs 6.7 ± 0.2%; P = 0.27), ADF (41.0 ± 0.6 vs. 41.4 ± 0.6; P = 0.64), NDF (69.9 ± 0.5 vs. 68.7 ± 0.5; P = 0.09), or relative feed value (RFV) (76.0 ± 1.0 vs. 76.9 ± 1.0; P = 0.53). There was a year effect (P < 0.01) and stocking rate x day effect (P < 0.01) for TDN. At LOW, TDN decreased from day 0 to day 28 (P = 0.02) and day 28 to day 56 (P = 0.02). At HIGH, TDN decreased (P < 0.01) from day 0 to day 28 but remained steady until day 56 (P = 0.21). There was a stocking rate x day interaction (P < 0.01) with ADG: LOW day 28 to 56 (1.20 ± 0.08 kg/day), HIGH day 0 to 28 (0.89 ± 0.08 kg/day), HIGH day 28 to 56 (0.44 ± 0.08 kg/day), and LOW day 0 to 28 (0.30 ± 0.08 kg/day). Further assessment of cattle ADG using more divergent stocking rates and plant persistence measures is warranted to inform ideal native grass stocking rate recommendations.
5 Animal performance in grass monoculture or silvopasture systems using tree legumes
Authors: da Silva Izabela Aline Gomes , Dubeux Jose Carlos Batista , de Mello Alexandre C Leão , da Cunha Márcio Vieira , dos Santos Mércia Ferreira , Apolinário Valéria Oliveira , da Silva Gleise Medeiros , de Freitas Erinaldo Viana , DiLorenzo Nicolas
Published: November 2020

Silvopasture systems (SPS) area management option to enhance delivery of ecosystem services and diversification of income. This study evaluated productive responses of signalgrass (Urochloadecumbens Stapf.) in monoculture or in SPS in the sub-humid tropical region of Brazil during six months of the rainy season. The experimental design was randomized complete block with three replications. Treatments were signalgrass + Mimosa caesalpiniifolia Benth. (SPS-Mimosa); signalgrass + Gliricidia sepium (Jacq.) (SPS-Gliricidia); and signalgrass monoculture. Cattle were managed under continuous stocking with variable stocking rate. Response variables included herbage mass (HM), herbage accumulation (HA), stocking rate (SR), average daily gain (ADG), and gain per area (GPA). Herbage mass (HM) was greater (P < 0.0001) on signal grass monoculture (2045 kg DM/ha) than in SPS (1370 kg DM/ha, average for both SPS). Herbage accumulation rate was similar for signalgrass in monoculture and SPS-Gliricidia (avg. 61 kg DM ha-1 d-1), and both were greater than SPS-Mimosa (37 kg DM ha-1 d-1). Average daily gain was greater(P < 0.0001) for SPS-Gliricidia (1.1 kg head-1 d-1), followed by signalgrass in monoculture (0.9 kg head-1 d-1), and SPS-Mimosa (0.3 kg head-1 d-1). Stocking rate ranged from 0.6 animal units (1AU = 450-kg animal) per ha in April to 2.2 AUha-1 in June. Stocking rate and animal performance per area were similar for signalgrass in monoculture and SPS-Gliricidia, and both greater than SPS-Mimosa. Gliricidia enhanced animal performance and provided ecosystem services. Mimosa, however, reduced animal performance likely due to the competition with signalgrass. Mimosa trees, however, are an important source of income (timber used for fence posts) and that might overcome the losses in animal performance.
58 Effects of Diploid and Tetraploid Annual Ryegrass Cultivars on Cattle Performance, Herbage Mass, and Nutritive Value
Authors: Montgomery Sarah M , Karisch Brandi , Parish Jane A , Morrison Jesse , Baldwin Brian
Published: November 2020

Annual ryegrass (Lolium multiflorum Lam.) can be divided into two cytotypes: diploid (2n = 2x) and tetraploid (2n = 4x). Polyploid versions of a given plant species result in increased seedling vigor, more robust growth and, potentially, greater yield. While most data suggest no difference in yield between diploid and tetraploid cultivars, there is still potential for weight gain advantages thanks to increased non-structural carbohydrates in tetraploid cells. The objectives of this study were to compare weight gain of cattle grazing either diploid or tetraploid cultivars of annual ryegrass. Two diploid annual ryegrass cultivars (Marshall and Tam 90) and two tetraploid cultivars (Jumbo and Nelson) were planted in 0.81-ha pastures, each replicated four times. Four steers (mean initial BW = 214 kg) were randomly assigned to each pasture for an 82-d grazing period. Body weights were recorded starting at day 0 then every 28 days throughout the season. Data were analyzed in the GLM procedure of SAS using a significance level of α = 0.05. There were significant differences between cytotypes with respect to seasonal yield with diploids (9547.90 kg/ha) yielding greater than tetraploids (7762.00 kg/ha). As expected, ADF and NDF fractions were significantly less for tetraploids (ADF; 31.39%, NDF; 31.39%) compared to diploids (ADF; 33.75%, NDF; 53.25%). Tetraploids also contained significantly greater crude protein (13.50%) than diploids (12.90%). Cytotype had no effect on final average daily gain (ADG) (P = 0.9427). However, final ADG was significantly impacted by cultivar (P = 0.0134). Final ADG for Tam 90 (1.10 kg/d) was greater than Marshall (0.92 kg/d). Cattle grazing Nelson (1.04 kg/d) and Jumbo (0.99 kg/d) did not differ. Results show that regardless of differences in seasonal yield and nutritive value between cytotypes, there were no advantages in ADG for cattle grazing either cytotype.