bluuebunny/crossref_metadata_2025_split huggingface dataset:
39 Cow-calf Management Strategies and Their Influence on Environmental Sustainability
Authors: Lalman David , Briggs Emma A , Moore Mikayla F 
Published: March 2022

Abstract
Forage and supplemental feed costs remain the overriding factors driving profitability in U.S. cow/calf operations. The cow/calf sector uses 74% of the total feed energy required to produce one pound of carcass weight. Methane is the second most abundant anthropogenic greenhouse gas after carbon dioxide. The cow/calf sector of beef production accounts for 77 to 81% of enteric methane emissions per unit of carcass weight produced. Reducing feed energy required and methane emissions by the cow/calf segment of the beef production system will improve economic, environmental, and social sustainability. Most of the beef production cycle occurs on land not suitable for raising crops. Of the 2.3 billion acres available in the United States, about 655 million acres (29%) are classified as grassland pasture and rangeland, and 316 million acres (14%) are identified as parks and wildlife areas, some of which are grazed. Therefore, improving forage utilization efficiency would have a wide-reaching impact on U.S. food security and profitability of cow/calf enterprises. Beef production is a critical component in U.S. and global food security because cattle upcycle poorly digestible plant components and food waste products into high-quality human edible protein. In recent years, substantial progress has been made in understanding biological variation and genetic components of feed efficiency in growing animals consuming energy-dense mixed diets during the post-weaning phase. Much less is known about within-animal variation of forage utilization efficiency for beef cows consuming moderate to low-quality forage diets common to most cow/calf production systems. Considerable evidence indicates the existence of an environment by genetic interaction for feed efficiency. More rapid progress in forage utilization efficiency and reduction in greenhouse gas emissions could be made by studying forage utilization efficiency directly.
41 Genomic Approaches to Improving Forage-based Beef Cow Efficiency
Authors: Rowan Troy N 
Published: March 2022

Abstract
In recent decades, the U.S. beef herd has seen massive gains in efficiency, driven by innovations in genetics, nutrition, reproduction, and resource management. Despite these advances, the industry remains under pressure to further reduce its environmental footprint. Perhaps the greatest opportunity to drive increases in sustainability is through targeted genetic improvement of forage-based cow-calf systems. While the industry has long focused on selecting for pre- and post-weaning performance, improvements in mature cow efficiency are more challenging to attain. One major impediment to directly selecting for cow efficiency is a lack of easily measured indicator phenotypes, leading some segments of the industry to focus exclusively on moderating mature size. The optimal solution to this problem will likely require a more complex understanding of the underlying biology of cow efficiency. As we consider how genomics might increase the environmental sustainability of forage-based beef production, we will need to focus on developing and measuring novel phenotypes and accounting for the complex interplay between an animal’s genetics, environment, and management. Using stochastic genetic simulations, we demonstrate the potential environmental and economic impacts of genetic selection for more efficient and well-adapted cows. We also describe possible solutions for measuring a cow’s efficiency on grass (e.g., forage intake to weaned calf pounds) that could be used to develop novel EPDs and economic selection indexes. Finally, we discuss the concept of precision genomic predictions that account for how genotypes interact with environmental stressors and management differences. We propose two potential solutions to address this concern: 1) Selecting robust cattle that perform well across all environments and management levels or 2) Developing precision predictions for precisely matching animals to their ideal production scheme.
53 Oxygen Exposure Effects on the Biochemical Attributes oflongissimus Lumborum Muscle During Retail Display
Authors: Denzer Morgan , Mafi Gretchen G , Pfeiffer Morgan , Ramanathan Ranjith 
Published: March 2022

Abstract
Limited studies have compared the effects of oxygen within a steak on biochemical properties. The objective was to evaluate the effects of oxygen exposure on the biochemical attributes of longissimus lumborum muscle. Steaks were (1.91 cm) sliced from USDA Low Choice beef strip loins (n = 7), packaged in polyvinyl chloride overwrap trays, and randomly assigned to day 3 or day 6 in retail display. During display, instrumental color was evaluated daily using a HunterLab MiniScan spectrophotometer. The display surface was considered as oxygen exposed (OE), while the interior of the steak was denoted as not exposed to oxygen (NOE). NOE was obtained by slicing the steak in half parallel to the previously OE surface. The NOE pieces were evaluated for bloom, while NOE and OE surfaces were used oxygen consumption (OC) and metmyoglobin reducing ability (MRA). Nitrite-induced metmyoglobin reduction was used to measure MRA, while changes in deoxymyoglobin level with vacuum were used as an indicator of OC. The data were analyzed using the GLIMMIX Procedure of SAS (n = 7 replications) and considered significance at P &lt; 0.05. With increased display time, the a* values (redness) decreased (P &lt; 0.05) for instrumental color. NOE steak surface had greater (P &lt; 0.05) MRA compared with OE surfaces. Oxygen exposure affected the OC of the steaks, with the OE surfaces having lower (P &lt; 0.05) OC compared to NOE surfaces on day 6 of display. The exposure of oxygen to the muscle resulted in a decrease in activity, paralleling in decline in retail color and color stability. In conclusion, the presence of oxygen can result in negative impacts on the shelf life of steaks; however, the non-exposed interior of muscle remains more biochemically active.
50 Implications of a Thermoforming Vacuum Packaging or Overwrap Packaging Method on a Simulated Retail Display of Longissimus Lumborum Steaks
Authors: Reyes Tristan , Wagoner Madison , Zorn Virginia , Coursen Madison , Wilborn Barney , Bonner Tom , Sawyer Jason T 
Published: March 2022

Abstract
Fresh surface color of beef remains a focus for consumers at the time of purchasing in the retail sector. The objective of this study was to evaluate instrumental surface color, expert color evaluation, and lipid oxidation (TBARS) on beef longissimus lumborum steaks packaged using recycle-ready film (RRF) or polyvinyl chloride overwrap (PVC). Paired strip loins (IMPS # 180), fabricated from beef carcasses (n = 7) 10 d postmortem, cut into 2.54 cm-thick steaks, and assigned to one of two packaging treatments RRF (OTR = 0.8 cc/m2/24 h) or PVC (OTR = 14,000 cc/m2/24 h). Steaks were stored under simulated retail conditions (3 °C ± 1.5 °C) in a LED (2297 lux) lighted, three-tiered retail cabinet, rotated daily among shelves for 35 days. From d 0 to 35 objective surface color was captured every 5 days to record changes in lightness (L*), redness (a*), yellowness (b*), Chroma, Hue Angle, and calculated values of spectral wavelengths (Red to Brown, Oxymyoglobin, Deoxymyoglobin, & Metmyoglobin) using a HunterLab colorimeter. Steaks packaged in RRF became lighter (L*) as display period increased (P &lt; 0.05), whereas steaks packaged in PVC became darker (P &lt; 0.05). Redness (a*) values were greatest (P &lt; 0.05) for PVC steaks until day 5, whereas RRF steaks had greater (P &lt; 0.05) surface redness from day 10 to 35 of the display period. Calculated spectral values red to brown were greater (P &lt; 0.05) for steaks in RRF than PVC. Expert color evaluators rated RRF steaks having less browning and less discoloration (P &lt; 0.05) from day 5 to 35 of display. Lipid oxidation was greater (P &lt; 0.05) for PVC steaks from day 10 through day 35 of the display. These results suggest that the use of RRF vacuum packaging for beef steaks is plausible and can maintain surface color characteristics during extended display periods.
108 Forage Mass and Nutritive Value of Stockpiled Alfalfa-bermudagrass Systems
Authors: Silva Liliane , Burt Justin J , Mason Katie , Jacobs Luke L , Groce Kaylyn , Mullenix Kim , Tucker Jennifer J 
Published: March 2022

Abstract
The development of newer alfalfa cultivars with improved adaptation to local growing conditions and dual-purpose applications has increased alfalfa incorporation into grass systems in the southern United States. The complementary growth of both species helps to extend the forage production season length, decreasing producer reliance on supplementation. The objective was to determine forage mass (FM) and nutritive value, botanical composition, and structural responses of alfalfa-bermudagrass systems managed under five stockpiling strategies (6-, 8-, 10-, 12- and 14-weeks of accumulation) in Shorter, AL. A randomized complete block design with eight replications was used. Harvested forage samples were manually separated into individual components and placed into 60° C until constant weight, then weighed. Measurements of ground cover, and alfalfa density and persistence were taken prior to plot harvest. There was a treatment × year interaction (P= 0.009) and greater FM was observed for 10- and 12-wks of regrowth (4,279 and 4244 kg DM/ha, respectively) in Year 2. This response was associated with greater (P &lt; 0.001) bermudagrass percentage in the mixture in Year 2 than 1 (averaged 57 vs 23%, respectively). Weeds remained below 4% in both years. There was a direct relationship between increased regrowth period length with leaf shattering and lodging. Over 10-wks of regrowth, percentage of lodging was &gt;30% and rate of leaf shattering doubled. This response directly affected leaf area index observed for the alfalfa-bermudagrass mixtures at 14-wk with a reduction of 30% when compared to 6-wks regrowth (2.6 vs 3.9, respectively). Greater (P &lt; 0.001) digestibility was associated with shorter regrowth period (6-wk), although the values observed ranged from 62 to 87% which represents high nutritive value forage that can meet higher animal requirements. Based on results, stockpiling alfalfa-bermudagrass mixtures using varying accumulation period lengths may be a viable system to provide high quality feed and extend the grazing season length into the fall and winter. This can also be an important strategy aiming to increase diversity and sustainability in forage-based livestock systems.
80 Randel Lectureship: Practical Applications for Developmental Programming of the Bovine Ovary
Authors: Cushman Robert A 
Published: March 2022

Abstract
Mammalian females are born with a finite supply of follicles within their ovaries that may be related to fertility and reproductive longevity. The number of microscopic follicles in the ovarian cortex is positively correlated to the number of antral follicles. In cattle, the number of antral follicles can be determined by ultrasonographic examination of the ovaries, is repeatable within a female, and has a moderate heritability. Studies in rodents suggest that nutritional status early in life can alter structure and function of the ovarian reserve, resulting in changes in follicle numbers, estrous cycle parameters, and reproductive longevity. This raises questions about how early life events might influence the ovarian reserve and reproductive performance in bovine females. A central hypothesis of our research is that the number of follicles that a heifer has when entering her first breeding season is influenced by external factors such as maternal nutrition during pregnancy, maternal stress during pregnancy, peri-pubertal nutrition, and health events. Understanding how these factors influence the structure and function of the ovarian reserve in replacement heifers may allow us to translate this knowledge into management practices that developmentally program the bovine ovary prior to the first breeding season to improve reproductive performance in the cow herd. Accomplishing this is made difficult because our understanding of the mechanisms controlling pre-antral follicle development in cattle is limited and growth of pre-antral follicles is occurring at the microscopic level within the ovarian cortex where it is difficult to monitor changes in real time. There has been some success, but variation in response across studies indicates that further research to understand the causes of this variation is required before we will be able to apply developmental programming in beef production systems to improve ovarian function in replacement heifers. USDA is an equal opportunity provider and employer.
120 Trilostane Effectively Reduces CL Progesterone Synthesis Prior to Acquisition of Luteolytic Sensitivity in Cyclic Gilts
Authors: Alexander Molly K , Wang Xiaoqiu , Gadsby John E , Poole Daniel H 
Published: March 2022

Abstract
Understanding the mechanisms of luteolytic sensitivity (LS) is critical for identifying novel methods of controlling the reproductive cycle of livestock species. Uniquely, porcine corpora lutea (CL) remain unresponsive to the luteolytic effects of prostaglandinF2a (PGF) until days 12-13 of the estrous cycle. Previous data from our laboratory has demonstrated that luteal macrophages (MACs) play an active role in this process. It was hypothesized that suppressing progesterone (P4) production prior to LS would activate MACs and initiate LS. The objective of this study was to determine the optimal dose of Trilostane, (TRIL) a commercially available 3β-hydroxysteroid dehydrogenase inhibitor, to reduce luteal and serum P4 by a minimum of 80% and induce LS. Gilts received Matrix® for 14 days and then checked twice daily for estrus. At estrus (day 0), gilts were randomly assigned to receive the TRIL treatment (0,3,5,7.5,or 10mg/kg, n=2 per treatment) orally, every 12h for 36h starting on day 7 of the estrous cycle. Blood samples were taken every 12 hours on days 6 through 9 post estrus to measure P4 following treatment. Gilts were euthanized on day 9 of the estrous cycle, and CL tissue was frozen for P4 analysis. Progesterone concentrations were determined via RIA. Data were analyzed using a MIXED procedure of SAS and statistical significance was determined at P &lt; 0.05 and a tendency at 0.05&lt; P &lt; 0.10. Serum P4 was reduced by 50% by 12h post treatment in all TRIL groups compared to control (P &lt; 0.05). However, only the 10mg/Kg dose effectively reduced P4 by 80% compared to control (P &lt; 0.05) and suppressed P4 throughout the treatment period. Luteal P4 was reduced by 72.4,82.4,87.7, and 88.6% compared to controls (P &lt; 0.05) in treated with 3,5,7.5 and 10 mg/kg of TRIL, respectively. Collectively, oral administration of TRIL effectively reduced both serum and luteal P4, and the optimal dose of 10mg/Kg TRIL will be utilized in future studies addressing progesterone’s regulation of luteal macrophage, and their role in controlling LS.
133 Ranking Mature Beef Cows for Residual Intake Using an Unprocessed Grass Hay Diet and Its Relationship to Greenhouse Gas Exchange
Authors: Moore Mikayla F , Briggs Emma A , Lalman David , Holder Amanda 
Published: March 2022

Abstract
The objective of this study was to compare high and low residual feed intake (RFI) beef cows when consuming an unprocessed, grass hay diet (93% DM, 8.73% CP, 2.11 Mcal ME, and 59.25% TDN). Relationships of hay intake to carbon dioxide (CO2) and methane (CH4) production were also evaluated. Thirty-six mature Angus and Angus x Hereford cows were assigned randomly to five pens (n = 6 or 9) and individual feed intakes were collected for 52-d using SmartFeed intake units (C-Lock Inc., Rapid City, SD) at a stocking rate of 3 cows per feeder. An open-circuit, gas-quantification system (GreenFeed, C-Lock Inc., Rapid City, SD) was used to collect CO2 (7611.63±714.09 g) and CH4 (283.64±37.10 g) production for 9 days of collection per pen for a minimum of 20 visits per cow (n = 22 cows, 36.18±14.24 visits). Data collection on cows included (means ± SD) dry matter intake (DMI; 13.86±2.16 kg), metabolic body weight (MBW, 111.65±9.28 kg), average daily gain (ADG, 0.77±0.29 kg), and rib eye area by ultrasound (REA, 46.62±6.34 cm).To calculate RFI (0.03±1.71), a multiple regression model was used to predict DMI (PDMI = ADG + REA + MBW; R2=0.50, P = 0.001). Cows were categorized into three RFI classes: low (n = 7), moderate (n = 6), and high (n = 9). Differences between RFI and RFI class and DMI and RFI class were analyzed using PROC MIXED in SAS (SAS, Cary, NC). Low RFI cows (-1.81 kg) consumed 12.08 kg hay DM daily and high RFI cows (1.59 kg) consumed 15.27 kg hay DM daily (P &lt; 0.001). Correlations between DMI and daily gas exchange were estimated using PROC CORR in SAS (SAS, Cary, NC). Pearson Correlation Coefficients were significant between DMI and CO2 (r=0.58, P = 0.004), and CH4 (r=0.70, P &lt; 0.001) production. Differences in feed intake for high and low RFI rankings were similar to previously reported literature when growing cattle consumed energy-dense diets.
127 Effect of Inclusion of Dried Citrus Pulp in the Receiving Supplement for Newly Received Stocker Cattle
Authors: Cheek Robin A , Kegley E B , Cauble Reagan A , Reynolds Jana L , Shoulders Ben P , Midkiff Kirsten A , Powell J G 
Published: March 2022

Abstract
The objective of this experiment was to further investigate effects of feeding dried citrus pulp (DCP) to cattle. Crossbred beef heifers (n = 167, initial body weight = 266 ± 1.8 kg) arriving on 2 delivery dates were used in a 42-day receiving trial. Heifers were processed after arrival and placed randomly into 8 pens on each delivery date (10 or 11 heifers/pen; total of 16 pens). Each pen was assigned randomly to 1 of the 2 supplements. Dietary treatments were: 1) a corn and distillers’ grains based receiving supplement (control), or 2) an identical receiving supplement except it contained 20% dried citrus pulp (replacing a portion of the corn). Heifers had access to bermudagrass hay and water for ad libitum intake, but were only offered up to 1.8 kg/day of their appropriate receiving supplement. Cattle were observed daily for clinical bovine respiratory disease (BRD), if presenting symptoms of BRD and if rectal temperature was ≥ 40° C; cattle were treated according to a standard preplanned protocol with antibiotic and deemed morbid. Weights were recorded on day 0, 14, 28, 41, and 42. Statistical analyses were performed by using the Mixed and GenMod procedures of SAS 9.4 with treatment as the fixed effect and delivery date as a random effect. Dietary treatment had no effect on body weight on any day, or on the overall average daily gain (ADG; P &gt; 0.54). Heifers fed the control supplement had a greater ADG from day 28 to 42 (P = 0.07) compared to those fed DCP. Incidence of morbidity was not affected by DCP supplementation (P = 0.53). In conclusion, feeding dried citrus pulp in receiving supplements resulted in similar overall average daily gain and did not affect the incidence of bovine respiratory disease within the 42-day receiving period.
72 Keeping Animal Science Courses "Experiential" in an Online Classroom
Authors: Buttrey Emalee 
Published: March 2022

Abstract
Mid-March 2020 saw the world come to a screeching halt, so-to-speak. Faculty, staff, and students suddenly found themselves in a virtual educational environment, many for the very first time. For educators in animal science and many other lab-based disciplines, this virtual environment presented some exceptional challenges, primarily, how to provide the “hands-on” activities that make up the very core of our discipline. Therefore, the objectives of this presentation are to share the experiences of the author and colleagues at the University of Tennessee at Martin and to allow members of the audience to share their ideas. In an effort to semi-replicate the in-person classroom experience, the author created “virtual” field trips, lab activities, and assignments. Examples included: having students create reproductive and gastrointestinal tract models using items in their home, performing diet formulation and ration balancing using cereal, candy, and pretzels, and the author filming animal handling and management techniques on her own livestock operation, among other things. While most of the activities worked well, others did not. While nothing can take the place of actual hands-on experiences, many of the virtual activities can still be used to supplement animal science courses.
69 Animal Pharmacology: What Do Animal Science Students Know?
Authors: Garrison M E Betsy , Thomas Lauren R , Caldwell Isabelle , Williams Cathy , Kaller Mike , Crosswhite Mellissa 
Published: March 2022

Abstract
Careers in animal science are typically as much about animals as they are about people, which means that animal science undergraduate students should be not only knowledgeable about animals, but also people and their behavior, including substance use disorders, such as opioid abuse. The purpose of the study was to investigate the pharmacological knowledge of undergraduates who are majoring in Animal Science in colleges of Agriculture, including programs oriented to livestock, companion animals, wildlife ecology and those with a pre-veterinary medicine focus. Students at three different Southern Land Grant Universities completed an online survey, adapted from a previous study of veterinarians, in two waves. The response rates were comparable between the first wave of data collection in spring 2020 from University of Arkansas and Oklahoma State University, 32%, and 39%, respectively. The response rate from the second wave of data collection in fall 2020 at Louisiana State University, 51%, however, was greater. Not surprisingly, most of the respondents were white females. Based on a 10-point grading scale, students’ factual knowledge about opioids and the opioid crisis would have yielded an A grade at one of the universities and a C grade at the other two universities. The question all students scored the lowest on was “chemically, there’s a huge difference between prescription opioids people get from doctors or healthcare professionals and heroin.” Students seemed most knowledgeable about the prescribing or administration of Tramadol from a list of 10 medications. They agreed that DVMs have changed their prescribing practices because of human opioids misuse. Almost all of the students also agreed/strongly agreed that use in animals and the use or misuse of opioids in humans should be taught in veterinary medicine. In conclusion, the findings of the current study suggest that undergraduate curricula in animal science should not only include humans’ misuse of opioids, but also, other drugs meant for animals, such as ketamine or ivermectin.