bluuebunny/crossref_metadata_2025_split huggingface dataset:
175 GPS Tracking Collars and Accelerometers Provide Detailed Tracking of Foraging Behavior and Space Use in Grazing Steers in Bermudagrass and Tall Fescue Pasture
Authors: Parsons Ira L , Karisch Brandi B , Webb Stephen L , Stone Amanda E , Catrett Cassidy C , Dentinger Jane E , Norman Durham A , Street Garrett 
Published: October 2021

Abstract
Previous research in feedlot studies has demonstrated that cattle feeding behavior is driven by internal metabolic processes and external environmental stimuli and serves as an indicator of animal health, nutritional status, and growth and feed quality and availability. However, technology has only recently allowed measurement of foraging behavior in grazing cattle. Objectives of this study were to measure frequency and duration of foraging bouts, meals, and total distance traveled during meals in grazing steers. The study was conducted as part of a larger grazing study on a 10-hectare Bermudagrass and Tall Fescue pasture, overseeded with Annual Ryegrass, located at the HH Leveck Animal Research Center, Mississippi State, MS. Using tri-axial accelerometers and GPS information from 10 crossbred steers, we examined foraging and meal bout frequency and duration and distance and speed traveled per meal for the period of March 2019. Observed animal behavior was used to train a randomforest model to predict foraging behavior, with model accuracy and sensitivity of 0.95 and 0.93, respectively. We found individual foraging bouts occurred on average 2,849 bouts per day and took on average 5.0 ± 1.8 min (range: 3–9 min), and that steers fed on average 205 ± 52.8 min/day (range: 120–270 min/day). Steers had an average of 9.5 ± 2.9 meals/day, that took on average, 89.3 ± 93.9 min/meal (range: 0.5–938.5 min/meal). Steers traveled an average of 412.4 ± 93.9 meters per meal, with an average foraging speed between 0 and 0.63 m/s. Traveling distance while foraging was positively correlated with meal length (0.83, P &lt; 0.01) and foraging speed (0.70, P &lt; 0.01). These results show that cattle grazing behavior can be accurately quantified in grazing cattle and warrants further research to examine associations between animal efficiency and performance, forage quality, and pasture management.
179 The Effect of Sward Type on the Performance of Co-grazed Cattle and Sheep
Authors: Beaucarne Gaspard , Grace Cornelia , Shackleton Jane , Kennedy Jean , Sheridan Helen , Boland Tommy 
Published: October 2021

Abstract
A farmlet study was established to evaluate the effect of four sward types on the performance of heifers and lambs co-grazing: a perennial ryegrass only sward (PRG) receiving 170 kg N/ha each year; a permanent pasture (PP) receiving 135 kg N/ha each year; a six species mix (2 grasses, 2 legumes, 2 herbs) at 70 kg N/ha each year (6SP); and a 12 species mix (3 grasses, 4 legumes and 5 herbs) at 70 kg N/ha each year (12SP). Each farmlet (9 ha) was rotationally grazed with 20 dairy cross heifers (13 months old) and 22 ewes plus lambs from April to November 2020. Heifers and lambs were finished for slaughter from herbage only diets. Heifers were weighed monthly and drafted for slaughter on three occasions when their estimated fat class on the EUROP grid scale reached 3-. Lambs were weighed fortnightly and drafted for slaughter at 42 kg [lambing to weaning (July 7th)], 44 kg (weaning to September) and 46 kg (after September 1st) to obtain a target carcass weight of 21 kg. Average daily gain (ADG) was higher for heifers grazing the 6SP sward (1.13 kg/day) than the PRG (0.99 kg/day) or PP swards (1.03 kg/day; P &lt; 0.05). Kill out percentage (KO%) was higher for heifers grazing the 12SP sward (48.9%) compared to the PP sward (47.2%; P &lt; 0.01). Lamb ADG was higher for lambs grazing the 6SP sward (0.38kg/day) compared to lambs grazing either the PP (0.32kg/day) or the PRG sward (0.29kg/day) (P &lt; 0.01). Lamb KO% was higher for lambs grazing the 12SP sward (49.4%) compared to those grazing the PRG (45.7%) and the PP swards (44.5%; P &lt; 0.01). Lambs grazing the 6SP sward had reduced days to slaughter (109) compared to lambs grazing the PP (137) and PRG (149) swards (P &lt; 0.01). In conclusion, co-grazing multispecies swards improved overall heifer and lamb performance.
183 Designing Research for Beef Cattle Production in Extensive Environments
Authors: DelCurto Timothy , Wyffels Sam 
Published: October 2021

Abstract
Designing research for beef cattle production in rangeland environments is an ongoing challenge for researchers worldwide. Specifically, creating study designs that mirror actual production environments yet have enough observations for statistical inference is a challenge that often hinders researchers in efforts to publish their observations. Numerous journals will accept “case study” or observational results that lack valid statistical inference. However, these journals are limited in number and often lack impact. Approaches are available to gain statistical inference by creating multiple observations within a common group of animals. Approaches to increasing statistical observations will be discussed in this presentation. Modeling animal behavior and performance on extensive rangeland landscapes is commonly practiced in wildlife ecology and, more recently, has been published in Animal Science journals. Additionally, new technology has made it possible to apply treatments (e.g., supplementation studies) to individual animals on extensive environments where large, diverse herds/flocks of cattle/sheep are managed as a single group. Use of individual animal identification (EID) and feed intake technology has opened a wide range of research possibilities for beef cattle production systems research in rangeland environments. Likewise, global positioning system (GPS) collars and activity monitors have created the opportunity to evaluate animal grazing behavior in remote and extensive landscapes. The use of multiple regression models to evaluate resource use in extensive environments will, in turn, help managers optimize beef cattle production and the sustainable use of forage/rangeland resources. Embracing new technologies such as GPS, activity monitors, EID tags, and feed intake monitors combined with multiple regression modeling tools will aid in designing and publishing beef cattle production research in extensive rangeland environments.
184 Statistical Analysis of Grazing Research
Authors: Smith William B 
Published: October 2021

Abstract
Research in the area of pastures, forages, and grazing livestock has a storied history within the realm of statistical analysis. Unlike traditional experiments in ruminant nutrition, in which an animal is fed individually and data are collected to assess the applied treatment, research on the grazing animal presents its own unique set of challenges. The collection of data on multiple scales (e.g., animal, pasture, landscape, time) brings into question the appropriate assignment of the experimental unit, and variance and covariance estimates must account for both the spatial and temporal effects of the environment. Oftentimes, the designs, assumptions, and rules-of-thumb taught to us in graduate school do not meet muster to adequately address the intricacies of this situation. This presentation will seek to address these complications and present statistically-sound solutions to obtain the maximum information from experimental data. First, a historical examination will be offered of how grazing experiments were originally handled. Next, conjecture will be offered as to why these methods may not remain valid and how advances in computing power and statistical theory allow us to obtain more information from the experiment. Finally, solutions to common scenarios will be offered whereby a more adequate or complete description of the experiment may be obtained.
185 Opportunities and Challenges of Conducting Grazing Experiments in Pasturelands
Authors: Vendramini Joao , Sollenberger Lynn , Silveira Maria Lucia L 
Published: October 2021

Abstract
Grasslands cover approximately 30% of the world area and research conducted in pasturelands has been crucial to realize the benefits of grassland contributions to livestock production and ecosystem services. The Forage and Grazing Terminology Task Force has developed a list of recommended nomenclature for grazing lands research and this effort has been a landmark to avoid misleading terms in research reports. Other challenges remain. The intrinsic variability of pastureland research data limits the capacity of researchers to detect differences among treatments. In addition, the quantity of resources and labor required by pastureland experiments may lead researchers to decrease the size of experimental units and/or number of replicates, exacerbating the limitations in detecting differences among treatments. In general, experimental units in grazing studies encompass relatively large areas, which may pose a challenge to identifying representative sampling units that reflect the experimental area. The use of indirect measurements to estimate forage mass is a feasible approach to increase the representativeness of forage quantity evaluations. The nutritive value determination of forage samples from grazing studies also has many limitations. The collection of samples representing the animal diet and the methods of nutritive value determination, primarily digestibility, are major areas of concern. For animal performance evaluations, determination of the correct experimental unit has been a frequent issue. Among animal measures, forage intake is one of the most influential factors affecting animal performance and the existent methodology to estimate forage intake by grazing animals has limitations, reducing the accuracy of the results. Development and validation of mathematical models to estimate the benefits of grasslands on livestock performance and ecosystem services are important steps in the evolution of grassland science, but in some cases additional data are needed to support this effort.
188 Extension Programming in Forages: Opportunities and Challenges
Authors: Dillard Sandra L 
Published: October 2021

Abstract
Even though forage and grazing lands represent the largest land use in the United States, the number of forage faculty positions nationwide has decreased by 47% in the last 15 years, with only an estimated 2.3 forage research and Extension full-time equivalents (FTE) per state. This challenge has made partnerships with county/regional agents and Extension faculty from other states an increasingly important component of a successful Extension program. Whereas virtual/online programs existed prior to 2020, people of all ages are currently more comfortable and adept with virtual technology because of the COVID-19 pandemic. Moving forward, virtual meetings and hybrid meetings will likely become more routine, making it possible to disseminate knowledge to producers locally and across the state, region, and country concurrently. This approach will enable Extension educators to be more efficient in their knowledge transfer as illustrated by programs such as the Bermudagrass Hay Summit which has seen an almost six-fold increase in attendance from 2020 to 2021 because travel is not required. Lastly, there is a largely untapped opportunity in on-farm demonstrations and research. An example of how this can positively affect adoption of new technology is the regional program Alfalfa in the South. This program combines both on-farm and experiment station research. As a result of on-farm demonstrations, producer interest in adoption of alfalfa across Alabama and Georgia has increased in the last 3 years. There are many challenges to Extension programming in forages, but there are also ample opportunities to partner with other state Extension programs, as well as with producers to disseminate forage and pasture management effectively and efficiently to the forage and livestock sectors across the United States.
194 Avian Breast Muscle Development and Growth: Influence of Temperature on Growth Mediated by Breast Muscle Adult Myoblasts (Satellite Cells)
Authors: Velleman Sandra G 
Published: October 2021

Abstract
Newly hatched poults and chicks have immature thermoregulatory systems and are not able to maintain a constant body temperature when exposed to hot or cold ambient temperatures. During the immediate posthatch period during handling and transport, poults and chicks are commonly exposed to acute thermal conditions. This immediate posthatch period is when satellite cells, adult myoblasts, have their highest period of mitotic activity and are sensitive to extrinsic stimuli including ambient temperature. Variable temperatures can have long-lasting positive or negative effects on skeletal muscle growth. Satellite cells are a self-renewing multipotential stem cell population located between the basement membrane and sarcolemma of muscle fibers. They are responsible for all posthatch growth of muscle through muscle fiber hypertrophy. Results have shown that satellite cells are more sensitive to thermal stress during the period of satellite cell proliferation than during differentiation into multinucleated myotubes, and that pectoralis major muscle satellite cells from growth-selected lines of chickens and turkeys are more sensitive to temperature. Recent findings have shown that the rapamycin, mTOR, signaling pathway which is involved in muscle growth through hypertrophy is differentially affected by thermal stress in a growth-dependent manner. Since satellite cells are a stem cell population, they can also transdifferentiate into other cellular lineages. Anaerobic muscles like the pectoralis major muscle are more prone to converting to an adipogenic lineage compared to aerobic muscles like the biceps femoris. Thus, variable temperatures can impact the intramuscular fat content of the breast muscle. Taken together, changes in ambient temperature alter satellite cell function causing long-term effects on growth, morphological organization, and composition of the pectoralis major, breast, muscle.
199 Do the Microbiomes of Horses Process Nutrients Differently Based on Keeper Status?
Authors: Johnson Alexa C , Biddle Amy S 
Published: October 2021

Abstract
This study reports the differential response of the equine gut microbiome to protein and/or carbohydrate based on keeper status (easy keeper (EK), medium keeper (MK), hard keeper (HK)). Anaerobic equine fecal samples (n = 12 total, n = 3 / EK, MK, HK of four breeds) inoculated microcosms with three dietary conditions (C = Carb (cornmeal), P = Protein (soybean meal), and M = mix (50% C, 50% P)). Over 48 hours, fermentation products were measured using colorimetric assays and high-performance liquid chromatography. Microbial populations were surveyed using 16S rRNA gene sequencing analyzed by QIIME2. Linear mixed models were fit with fixed effects of Treatment and Keeper status and their interactions, with random effects of HorseID. Differences in fermentation products by keeper status included: MK had higher pH and greater gas production, EK produced higher hydrogen sulfide, and HK had greater total protein. Total SCFA was not different between keeper status (P = 0.89) but the acetate: propionate ratio was highest for HK (2.45mM) and lowest for EK (1.85mM) (P = 0.05). Isobutyrate production was highest in HK (2.34mM) compared to MK (0.85mM) and EK (0.17mM). Treatment had significant effects across all measurements; M and C treatment values were similar reflecting microbial preferences for carbohydrates before protein. P treated trials had increased fermentation outputs due to lower acidity effects. Keeper status had no effect on α-diversity (P &gt; 0.05) however HK horses were least affected by treatments. P treated samples were more diverse than C and M (P &lt; 0.001). Spearman correlation of Keeper x Treatment identified Oligosphaeria spp. in EK (r = 0.49) and Fusobacteria spp. in HK whole fecal samples (r = 0.37). These data suggest that while the compositions of the gut microbiomes of keeper groups were similar, they were functionally different in processing key nutrients.
202 Nature versus the NRC: Utilizing an Understanding of the “natural” Diet of the Horse in Contrast to Defined Guidelines
Authors: Gordon Mary Beth 
Published: October 2021

Abstract
A comprehensive look at nutrients available in nature compared to equine nutrient requirements and the modern diets we feed them. Horses can survive on a variety of feedstuffs that they ingest if they are relatively equine-specific and the horses’ forage requirements are met for basic gastrointestinal health. It is safe to say that some horses in the United States continue to be fed as “nature-intended” with 24/7 access to fresh pasture or adequate plant material and enough room to continually move and graze. Many other horses, however, have only limited or no access to pasture and their movement is greatly restricted via stall confinement or small areas to move. In addition, there is a wide variety in what we ask horses to do, from horses that are simply pasture pets, to horses performing as elite-level athletes in racing and competitions. And when we look at all these factors from a nutrition perspective, how do the nutrients provided by nature match up with the requirements as set by the National Research Council’s Nutrient Requirements for Horses? And how do these nutrients provided by nature compare to how we are feeding many modern horses today? This presentation will examine these factors and shed light on differences between the NRC nutrient requirements and what is provided by both nature and/or modern feeding practices in several scenarios, to identify areas of mismatch that could be potentially addressed or researched further in an effort to improve the health and well-being of horses.
206 Beyond NRC Requirements: The Role of Non-nutritives in Equine Health and Performance
Authors: Warren Lori K 
Published: October 2021

Abstract
Billions of dollars are spent annually on dietary supplements, with similarities between products consumed by humans and those offered to horses and other animals. Dietary supplements encompass a variety of substances, some non-nutritive and others recognized as essential nutrients, but all are fed with the intent of providing a health or performance benefit beyond that supported by the normal diet. Though many of these products are sold without sufficient evidence of efficacy, their increasing popularity has driven horse owner curiosity and researcher interest. Over the past two decades, funding for research on dietary supplements in horses has exceeded that spent addressing knowledge gaps in the nutrient requirements of horses. Many of these substances are difficult to study (e.g., herbs, botanical extracts), due to their complex composition, unidentifiable active compounds, or broad biological effects that are difficult to characterize. Others have shown promise for reducing inflammation and improving immunocompetence, including various fatty acids, probiotics, prebiotic fibers, and antioxidants. Among these are well-known nutrients that are either being fed above current requirements (e.g., vitamins, minerals), or are presumed to be essential but requirements have not been established for the horse (e.g., essential fatty acids, amino acids, vitamins). In most cases, the benefits are not realized in an already healthy horse but are instead demonstrable in animals under high stress conditions (e.g., intense exercise, transport) or states of immunocompromise (e.g., inflammatory disease, senior horses, foals). Should dietary supplements be included in discussions of nutrient requirements and a future revision of the horse NRC publication? When does a compound become a nutrient – or a drug? Could there be a situational requirement for a dietary supplement if it returns the animal to homeostasis when the regular diet does not? This presentation will provide fodder for a group discussion on future directions of equine nutrition.
219 Effects of Feeding Low Protein Diets with Additional Supplementation of First Five Limiting AA on Performance and Diarrhea Incidence in Weaned Pigs
Authors: Van Niekerk Natasha , Htoo John K , Vega Caroline Gonzalez 
Published: October 2021

Abstract
An experiment was conducted to evaluate the effect of feeding low crude protein (CP) diets and supplying 110% of the first 5 limiting AA on performance and diarrhea incidence in weaned pigs. One of 3 treatments were randomly assigned to 81 piglets (BW: 8.2 ± 1.2 kg; 9 pens/treatment; 3 pigs/pen) during 2 phases (3 wk each): a high CP (HP; 21 and 18%), a low CP (LP; 18 and 15%), or a low CP at 110% Lys, Met, Trp, Thr, Val requirements (LPAA; 18 and 15%) diet for phase 1 and 2, respectively. Pigs had ad libitum access to feed and water. Data were analyzed using PROC MIXED of SAS. During phase 1, pigs fed HP had the greatest ADG (P &lt; 0.05), but ADFI and G:F were not different among treatments. In phase 2, no effect of treatments was observed on growth performance. Overall, pigs fed LPAA had the lowest (P &lt; 0.05) ADG and G:F, and feeding LP decreased (P &lt; 0.05) G:F. The ADFI was not affected by the treatments. Only during wk 3, pigs fed LPAA increased (P &lt; 0.05) and LP tended to increase (P &lt; 0.10) frequency of diarrhea compared to HP. On d 21, no treatment effect was observed for ileal villi height, but LPAA reduced (P &lt; 0.05) and LP tended to reduce (P &lt; 0.10) crypt depth compared to HP. Diet analysis revealed that LP was deficient in Ile and non-essential AA (NEAA), and LPAA contained inadequate levels of Ile, Leu, His and NEAA, which explains why reduced pig performance was achieved with these 2 diets. In conclusion, low CP diets, even with additional supplementation of the first 5 limiting AA, if deficient in the next limiting AA, results in negative effects on performance and diarrhea incidence.
220 Effects of Actisaf HR+ SC47 Live Yeast Probiotic Fed at Two Levels to Sows on Offspring Performance Before and After Weaning
Authors: Loughmiller Joe , Corley Jimmie , Gourley Gene , Hotze Brian , Bruder Emily , Catunda Fabio 
Published: October 2021

Abstract
750 sows (PIC line 42) were used to evaluate the effects of ActiSaf HR+ SC47 live yeast probiotic (AS) on sow and litter performance when fed to sows and their weaned piglets (PIC line 42 x 359). 250 multiparous sows per treatment (average parity 3.6) were fed the control diet without a live yeast probiotic (NC) or a diet with 250 mg/kg AS from breeding through lactation (LY1) or 250 mg/kg AS during gestation and 500 mg/kg AS during lactation. Weaned pigs from these sows were subsequently fed 4-phase nursery diets containing 0 (wNC) or 1 g/kg AS from d 0–10 after weaning followed by 500 mg/kg AS (wLY) from d 10–42 after weaning. This provided a 3x2 nursery trial design. During lactation, number of pigs born; born live varied by treatment (P &lt; 0.05). After weaning, wLY fed pigs had lower BW on d 12, 23; d 0–12 ADG, ADFI, lower d 0–42 ADFI and $/kg gained (P &lt; 0.05). Pigs fed wLY after weaning also tended towards lower d 42 BW and d 0–42 ADG (P &lt; 0.06; Table 1). Conversely, weaned pigs from sows fed LY1 or LY2 had higher ADG and ADFI from d 0–12 and d 0–42 after weaning (P &lt; 0.05) versus pigs from sows fed NC. Pigs from sows fed LY1 or LY2 also had higher BW at d 12, 23, and 42 after weaning than pigs from sows fed NC. Pigs from sows fed LY1 and LY2 tended to have lower nursery $/kg gain (P &lt; 0.06) than pigs from sows fed NC. No significant interactions were observed. Feeding ActiSaf HR+ SC47 live yeast probiotic to gestating and lactating sows improved their weaned pigs’ growth performance and tended to improve piglet cost of production after weaning.