bluuebunny/crossref_metadata_2025 huggingface dataset:
84 Evaluation of hair coat shedding ability as an adaptive trait in Angus cattle in the southern U.S
Authors: Burnett Randy H , Duvic Morgan A , Kutz Bryan R , Brown Avert H , Powell Jermey G , Smith Trent , Riley David G , Cauble R N
Published: November 2020

The objective of this study was to evaluate winter hair coat shedding ability and the association to cow production performance. This work was a collaborative effort from the S-1064 multi-state research project. Data were collected on spring and fall-calving purebred and commercial Angus females with calves (n = 1192) from March until July from 2008 to 2018 in Mississippi, Arkansas and Texas. Dams were observed once monthly by two trained technicians for winter hair coat shedding and give a visual hair shedding score of 1 to 5 with 1 indicating 100% shed, 2 = 75% shed, 3 = 50% shed, 4 = 25% shed, and 5 indicating 0% shedding of the winter hair coat. Month of first shedding (MFS) was determined once a female reached an average hair shedding score of ≤ 3.5 for any given month. Calf birth and weaning weights were considered as performance of the dam. For cow performance, the response variables included AdjBW and d205wt of the calf. Data were analyzed using the MIXED procedure of SAS with significance declared at P ≤ 0.05. The model included MFS as a fixed effect with calf sex as a covariate and calf sire as a random effect. Females that obtained a shedding score of ≤ 3.5 by May had heavier calves at birth (P ≤ 0.01) when compared with those that shed in June and July, with July weights being the lightest. Females that scored ≤ 3.5 by May has significantly heavier d205wt (P ≤ 0.01) when compared to those that shed by June and July. When comparing locations, females in Arkansas shed later (P ≤ 0.01) when compared with both Mississippi and Texas, which were similar. Shedding ability could be an important economic trait to be considered in cow-calf operations.
184 Utilizing Breeding Indictors for an Effective AI Program in Brahman Cows
Authors: DeShazo Emily K , Reese Sydney T , Franco Gessica A , Neuendorff Don A , Randel Ron , Pohler Ky
Published: November 2020

Estrus detection is crucial to an effective AI program. The objective of this study was to assess whether Estrotect Breeding Indicators were comparable to vasectomized gomer bulls wearing chin ball markers to accurately and efficiently identify estrus. It was hypothesized that Estrotect Breeding Indicators will accurately and more efficiently detect estrus than gomer bulls. On day 0, an Estrotect Breeding Indicator was placed on Brahman cows (n = 204) that were kept with four vasectomized bulls for the following 45-day study period. Once estrus was detected via activated heat patch, cows were artificially inseminated 14 hr later and the bull score was recorded on a scale from 1–3 (1- no bull marks; 3- solid bull marks). Cows were continually monitored for return to estrus and a pregnancy diagnosis was conducted on day 110. All cows displaying estrus (n = 137) had fully activated patches, while 67 cows were anestrous for the trial duration. A ROC curve analysis indicated that the sensitivity of the bulls detecting estrus was 77.4% compared with the Estrotect Breeding Indicators. Out of the cows with a fully activated patch, 62.77% (86/137) became pregnant to AI. Of these, 17.4% (15/86) of pregnant cows received a bull score of 1 or 2, meaning there were little to no marks left from the bulls. Failure of bulls to identify estrus can be attributed to bulls’ loss of energy, cows displaying homosexual behavior, bulls staying with a chosen cow, or even calves preventing the bull access to the cows in estrus. In conclusion, the patches detected estrus in a greater number of cows than the action of vasectomized bulls wearing chin ball markers leading to an increased pregnancy rate.
46 Effect of the addition of α-tocopherol to in vitro maturation media of bovine oocytes
Authors: Pérez Theisy P Acosta
Published: November 2020

α-tocopherol is known to be a powerful antioxidant, in this regard, it was added to bovine oocyte in vitro maturation media to evaluate its effect on oocyte maturation. Oocytes (n = 624) aspirated from ovaries of slaughtered cows were classified by quality and divided in four categories according to cytoplasm appearance and cumulus cells layers. Oocytes were washed in TCM-199 supplemented with fetal bovine serum (FBS) and FSH, then distributed in maturation media (TCM-199 supplemented with FBS, FSH and gentamicin). Three experimental groups of α-tocopherol (50, 100 and 200 mM) and a control group without α-tocopherol were used. Maturation was carried 22 h at 38.5°C in a 5% CO2 atmosphere. Oocytes were examined to determine cumulus expansion as categorical data (expansion or no expansion), as well as cumulus expansion Index (CEI). For CEI determination oocytes were graded 0 to 4, being 0 those with null expansion and 4 those with a noticeable cell expansion, then the number of oocytes were multiplied by the grade given and a sum of the totals was obtained, the new total was divided by the total of oocytes in the group and the result obtained corresponded to the CEI of the group. Results were analyzed with Chi Square test (for maturation rates) and an ANOVA (for the CEI) using the SAS system, data are presented as mean ± standard error. There was no statistical difference between control and α-tocopherol groups (P >0.05). Numerically, the control group showed a higher maturation rate (100%) and obtained a higher CEI (2.44±0.20), followed by the 50 mM group (98.16%; 2.39±0.13), the groups 200 mM (97.40%; 2.00±0.14) and 100 mM (96.25%; 2.06±0.24) were the lowest. The addition of the minimum concentration (50 mM) of α-tocopherol to the maturation media could improve maturation rates without exposing oocytes to toxic effects.
70 Effects of the addition of Moringa oleifera seed extract to in vitro maturation of bovine oocyte media and its antimicrobial activity
Authors: Pérez Theisy P Acosta
Published: November 2020

Moringa oleifera seed extract was added to the in vitro maturation media of bovine oocytes as an alternative antibiotic to evaluate its effect on the oocyte maturation and its antimicrobial activity. Oocytes (n = 405) were recovered from ovaries from slaughtered cows, classified by quality and divided in four categories according to the cytoplasm appearance and cumulus cells layers. Oocytes were washed four times in TCM-199 supplemented with fetal bovine serum (FBS) and FSH, then placed in maturation media, which contained TCM-199 supplemented with FBS, FSH and the corresponding treatments: TCM-199+gentamicin (Control), TCM-199 without antibiotic (Test), moringa (M) 1.0, 5.0 and 10.0 mg/mL. After 22 h at 38.5°C in a 5% CO2 humidified atmosphere, oocytes were examined to determine cumulus expansion (as categorical results yes or no) and cumulus expansion Index (CEI). Additionally, 400 µL of used maturation media was retrieved and stored for the antimicrobial activity tests in agar cultures. Evaluation of the cultures for colony-forming units (CFU) was done at 24 and 48 h post culture. Results were analyzed with Chi Square test (for expansion rates) and an ANOVA (for the CEI and CFU) using the SAS system, data are presented as mean ± standard error. Statistically, there was no difference between treatments (P >0.05). Numerically M 1.0 and Test obtained the highest maturation rate (96.43%; 96.20%). M 1.0 and Control showed the highest CEI (2.26±0.21; 2.25±0.26). For the CFU count, Control showed the lowest result at 24 and 48 h post culture (0.00 ± 0.00; 0.11 ± 0.33), as M 10.0 showed the highest result at both 24 and 48 h (2.00 ± 3.60; 2.55 ± 4.58). The addition M 1.0 mg/mL to the maturation media is an alternative for the use of conventional antibiotics without decreasing maturation rates.
187 Utilizing Working Groups to Provide Hands-On Learning Opportunities for Experienced Beef Cattle Producers
Authors: Vining Timothy P , Jacobs Joshua L , Marks Marty L , Thompson Gerald L , Mullenix Mary K
Published: November 2020

The Systems 360° Working Group program was created for experienced beef cattle producers who desired to learn more about timely topics related to beef cattle production than could be covered in a single night meeting. To aid in developing these working groups, the Alabama Extension Animal Science and Forages Team developed curriculum regarding grazing management, watering systems, marketing, handling facilities, and animal management. Regional animal science and forages agents then coordinated planned visits to producer farms and Auburn University research centers that highlighted specific management practices surrounding these topics, and facilitated group discussion at those sites to encourage peer-to-peer learning experiences. A working group consisted of beef cattle producers (n = 10–25 participants per group) sharing a common interest in learning more in-depth about strategies to improve their respective operations. Four working groups were organized in different regions of Alabama and met five times throughout 2018–2019. The closing survey (n = 50 responses) for the working groups indicated that 100% of participants felt this program met expectations, and given the opportunity they would join another working group. Overall, 94% of respondents indicated that they planned to adopt one of more of the management practices discussed in the group in the next 12 months. Top practices that producers planned to implement included improved winter grazing strategies, rotational stocking, water resource management and testing, and facilities design/animal handling. Producers indicated that they learned the most from farm-visits and speakers/discussion leaders as part of the program. Participants reported that knowledge gained from this program could potentially lead to a total farm economic impact averaging $6,095 per operation. These data indicate that Systems Working Groups are an effective means to disseminate knowledge, engage producers in peer-based learning opportunities and improve herd profitability among experienced beef cattle producers.
3 Addressing Food Animal Veterinary Services Shortages Through Veterinary Continuing Education Courses: A New Role for Extension as a Bridge Between Veterinary and Agriculture Communities
Authors: Ward Heidi M
Published: November 2020

Food animal veterinary services are in demand due to regulatory changes that require more veterinary oversight in animal agriculture. The USDA identifies 13 counties in Arkansas as having food animal veterinary shortages. In response, the University of Arkansas Cooperative Extension Service developed the Food Animal Medicine Workshop Series to train veterinarians in food animal medicine with the goal of encouraging veterinarians and their staff to provide more food animal services. The workshops are funded by the USDA NIFA Veterinary Services Grant Program, which allows for monthly continuing education (CE) courses for a two year period. Topics covered to date include: how to integrate backyard poultry into your practice, pharmaceutical use in food animal medicine, the Veterinary Feed Directive and the future of antimicrobial use in food animal medicine, infectious diseases in food animals, current issues and advances in food animal wellbeing, small ruminant medicine, cattle medicine, honey bee medicine, field services, and field necropsy. 171 veterinarians have attended the workshops, with an average class size of 18. All participants were awarded CE credits by the Arkansas Veterinary Medical Examining Board. Surveys were given to participants at the end of each course. A Likert scale was used to measure responses to statements about the workshop with 1 being “strongly disagree”, 2 being “disagree”, 3 being “agree” and 4 being “strongly agree”. Participants gave an average score of 3.9 when asked if their knowledge increased from the workshop, an average score of 3.8 when asked if they would attend future workshops in the series, and an average score of 3.2 when asked if they would incorporate what they learned into their practices. Information from the surveys indicates that the workshops are achieving the goal of increasing food animal services. A future survey of attendees will measure the actual increase in such services.
166 The effects of feeding lasalocid in combination with zeranol implants on performance and carcass traits in hair sheep
Authors: Lippy Brittany A , Wilson Blake K , Fitch Jerry , Mafi Gretchen G , Crosswhite Justin
Published: November 2020

The objective of this experiment was to determine the effects of dietary inclusion of lasalocid in combination with zeranol implants on the performance and carcass characteristics of hair sheep. Thirty wether hair lambs (BW = 25.8 + 4.6 kg) were stratified by BW and BCS and randomly assigned to 1 of 2 experimental treatments in a randomized complete block design. The treatments included no implant or ionophore (CON); and the experimental treatment, receiving the ionophore lasalocid (Bovatec® 91; Zoetis, Kalamazoo, MI) and anabolic zeranol implants (Ralgro®; MSD Animal Health, Spartan, RSA; LZ). Lambs on the LZ treatment received 12 mg of zeranol on d 0, 56, and 112, unless lambs were harvested prior to day 112, and consumed an average of 35 mg per day of lasalocid. Lambs had ad libitum access to feed and water throughout the experiment and were housed in individual, slatted floor pens. Performance data were collected on d 0, 14, 28, 56, 84, and at harvest. After d 84, harvest dates were selected and lambs were harvested by block based on proximity to ideal harvest weight and fat thickness. Lasalocid in the diet combined with zeranol implants increased final BW by 14.2% in comparison to CON (P < 0.01). Overall ADG was increased by 36.2% (P < 0.01), and overall G:F was improved by 24.4% for LZ when compared to CON (P = 0.01). There was no difference in overall DMI between treatments (P = 0.13). Hot carcass weight (HCW; P < 0.01), and loin eye area (LEA; P < 0.01) were also greater for the LZ treatment. Dietary inclusion of lasalocid in combination with zeranol implants improved overall BW, ADG, and feed efficiency as well as HCW and LEA in hair sheep.
83 Evaluation of feeding immunoglobulin-Y to Holstein feeder cattle for the control of liver abscesses & reduction of macrolide-resistant bacteria dissemination
Authors: Stotz Miranda K , Murillo Diego Casas , Henry Darren D , Crossland Whitney L
Published: November 2020

Despite the regular use of macrolide-antibiotics in the diets of feedlot cattle, liver abscesses persist representing a financial burden to both pre- and post-mortem sectors of the beef industry. Alternative strategies, which simultaneously address liver infections and reduce the dissemination of antibiotic-resistant bacteria, are needed. An immunoglobulin-Y (IGY) product, developed to target Fusobacterium necrophorum and Trueperella pyogenes, was evaluated for the control of liver abscesses and its effect on macrolide-resistant Enterococcus growth from feces. Sixty-four Holstein steers (Initial BW= 384± 13.5kg) consuming a finishing diet (90% concentrate) for 188 days (Final BW= 660± 42 kg) were used in a completely randomized design where steer was experimental unit and treatments included: TYL (Tylosin phosphate fed at 90mg/hd/day; n = 32) or IGY (fed at 2.5g/hd/day; n= 32). Feed intake was recorded daily and BW was recorded every 28 days until slaughter. After 150 d on treatment fecal samples were randomly obtained from each treatment group four times (n = 40) and cultured on bile-esculine agar enriched with 8 μg/mL of erythromycin. Continuous variables of feedlot growth performance, carcass data and bacterial growth were analyzed using the MIXED procedure of SAS with the fixed effect of treatment and random effects of steer or sampling day, respectively. Ordinal carcass data were analyzed using the FREQ procedure of SAS observing the Cochran-Mantel-Haenszel value. Treatment did not affect DMI (P= 0.21), ADG (P = 0.50) or G:F (P = 0.36). Treatment neither affected hot carcass weight (P = 0.37) nor longissimus muscle area (P = 0.25). However, TYL resulted in greater back fat thickness than IGY (0.32 vs. 0.23 in.; P < 0.02) and consequently greater numerical yield grade (P < 0.02). Quality grade was not affected by treatment (P = 0.65). No treatment difference was observed for liver abscesses prevalence (TYL=63% vs. IGY=52%; P = 0.40) or severity (P = 0.23). There was a greater proportion of erythromycin-resistant Enterococcus growth for TYL than IGY (42.6 vs. 21.9%; P < 0.04). Specifically formulated IGY feed additives may be viable alternatives to antibiotics in feedlot cattle diets.
154 The effect of number of cattle per pen on stocker cattle health and performance
Authors: Midkiff Kirsten A , Karisch Brandi , Woolums Amelia
Published: November 2020

The objectives of this study were to: 1) to examine the effect of number of stocker cattle in a receiving pen on BRD morbidity and mortality; and 2) to examine the effect of number of stocker cattle in a receiving pen on cattle performance. Crossbred steers of unknown origin and history (n = 200) were purchased from auction barns in the southern portion of the United States. Cattle were stratified by weight and assigned to either a small (10 head/pen) or large (50 head/pen) treatment on arrival. Calves were assigned to 1 of 3 large pens or 1 of 5 small pens. Cattle were observed daily for clinical signs of BRD and treated if rectal temperature ≥40°C. Body weight was collected on d 0, 14, 28, 42, and 56. Rectal temperature was collected at arrival. Days-at-risk for BRD was the number of days from arrival until a calf: (1) was first diagnosed with BRD; (2) died; or (3) finished the trial. Treatment effects on BRD incidence and performance were tested using Poisson distribution and logistic regression using GLIMMIX or linear regression using MIXED procedure of SAS, respectively, accounting for clustering by pen. Mortality was analyzed using the LOGISTIC function with Firth’s penalized likelihood. There were 8,698 total days at risk and overall incidence density was 7.82 BRD cases per 1,000 calf days. Overall morbidity totaled 32.5% with 5.5% mortality. No difference among treatment was observed for morbidity, mortality, or performance. Cattle with fever on arrival were 1.125 times more likely to contract BRD (P ˂ .0001). The number of BRD treatments received had an effect on ADG at d 0–14 (P ˂ .0001), 0–28 (P ˂ .0001), and 0–60 (P ˂ .0001), with ADG decreasing as number of treatments increased. In summary, fever on arrival affected BRD incidence, and number of treatments cattle received affected growth throughout the trial.
163 The effects of energy and lasalocid supplementation on forage intake and energetics of cattle grazing wheat pasture
Authors: Pickett Autumn T , Kegley Elizabeth , Beck Paul A , Gunter Stacey A
Published: November 2020

Cattle grazing wheat have the potential to gain BW exceptionally well, but excessive nitrogen intake results in increased excretion and increased greenhouse gas (GHG) emissions. Supplemental grain with the addition of an ionophore given to ruminants grazing wheat is a potential practice for producers to increase nitrogen efficiency while decreasing GHG emissions. Therefore, the objective of this experiment was to quantify the effects of energy and lasalocid supplementation on nutrient intake, respiratory gas fluxes, and performance of grazing cattle. Heifers (n = 18) were used in a 49-d experiment that consisted of two 21-d blocks with 7 d between them (initial BW=311±17.3 kg and 339±16.7 kg, Block 1 and 2, respectively). Heifers were assigned randomly to 1 of 3 treatments; no supplement (Control, n = 6), 2.95 kg control feed/d (Energy, n = 6), or 2.95 kg feed with lasalocid/d (Lasalocid, n = 6). Cattle grazed an 8.1-ha paddock of winter wheat and had access to a GreenFeed system used to quantify the respiratory gas fluxes (CH4, CO2, and O2). Cattle were weighed on d 0 and 21 of each block, on d 15 to 21 cattle were gathered every 12 h and fecal samples were collected. Data were analyzed using the PROC MIXED in SAS. Methane emissions were not affected (P = 0.58) by treatment, but supplemented cattle had greater (P = 0.04) CO2 emissions and O2 consumption (P = 0.03). Hence, ADG tended to be greater for supplemented cattle (P = 0.09) compared with Control (1.22 and 1.00 kg, respectively), but no effect (P = 0.88) was observed for the Lasalocid. Fecal output was greater for supplemented cattle (P < 0.01), but forage intake was lower (P < 0.01) and nutrient intake was higher (P < 0.01) for supplemented cattle compared to Control. Supplemented cattle had lower forage intake with greater CO2 emissions and O2 consumption, but the Lasalocid did not affect any parameter.
119 Palatability of Olive Pomace in Mozambique Tilapia (Oreochromis mossambicus)
Authors: Krasue Ethan , Conn Benny J , Kelley Stanley F , Beverly Marcy M , Anderson Mark
Published: November 2020

By-products, such as distillers’ and brewers’ dried grains, are used in livestock rations as a source of important nutrients, cheapen feed costs, and reduce the cost of production. Olive pomace is the by-product from the production and milling of olive oil, and is a possible source of protein and energy for livestock. The objective of this study was to determine if Mozambique tilapia would consume olive pomace when mixed with commercial feed. Sixty tilapia of similar size were divided into two separate tanks, each with its own aquaponic filtration system. Ammonia, pH, nitrates, nitrites, and chlorine levels were monitored to ensure optimum water environment. Olive pomace, from a two-phase mill, has a slurry-like constancy containing approximately 50% moisture. Due to its high moisture content, the pomace was offered to the fish in a dried state and mixed with a commercial feed at a 1:1 ratio. The dried pomace immediately sank to the bottom of the tank while the commercial feed remained on the water surface and consumed by the fish. The rate of consumption of the dried pomace could not be separated from the tank sediment, and therefore was not measurable. To deter the pomace from sinking, wet pomace was mixed at a 1:1 ratio with the floating commercial feed. The wet pomace, mixed well with the commercial feed and yielded a consistent blend of pomace and feed. The moist pomace:feed blend was molded by hand into 2 ½ centimeter spheres, each weighing approximately 9.1 grams. Four spheres were dropped into each tank allowing multiple fish to feed at once. Although, the wet blended feed mixture did not float, the fish ate the feed spheres as they sank. This preliminary research illustrates the willingness of tilapia to consume olive pomace and its potential use as a feed.
27 Defining Grazing Recommendations for Alfalfa-Bermudagrass Mixtures in the Southeastern U.S
Authors: Groce Kaylyn , Tucker Jennifer J , Mason Katie , Marks Landon , Mullenix Mary K
Published: November 2020

Recently there has been growing interest in interseeding high-quality legumes, like alfalfa, into existing bermudagrass stands as a step towards improving forage, animal, and ecosystem sustainability in the Southeast. Current work evaluating these mixtures has focused on management and production of stored forages, and limited work has evaluated the use of alfalfa-bermudagrass mixtures under grazing conditions. It is known that both grazing intensity and frequency impact overall alfalfa stand production over time. The objective of this research is to evaluate the effect of harvest height and frequency on alfalfa interseeded into bermudagrass to develop grazing management recommendations. In 2018 thirty-six alfalfa-bermudagrass plots were established at 4 locations across Alabama and Georgia in a randomized complete block design with four replications at each location. Alfalfa varieties utilized were selected for suitability to location and were either ‘Bulldog 505’ or ‘Bulldog 805’ interseeded into existing hybrid bermudagrass sods. Treatments included combinations of harvest frequency (2, 4, or 6 weeks) and harvest height (5, 10, 15 cm) and plots were evaluated to determine the optimum interval in relation to sward yield, alfalfa persistence, stand density, botanical composition, nutritive value, and change over time. Forage yield was affected by the interaction of location with harvest frequency and height (P < 0.05). At three of the four locations, overall seasonal yield from the 5cm cutting height was greatest; however, alfalfa persistence declined in these treatments throughout the season and was less than 10% at the northern locations when 2019 data collection began. Additionally, crude protein (CP) and in-vitro digestibility (IVDMD) declined throughout the season as the alfalfa presence decreased. This study is supported by funding from the USDA-NIFA-Alfalfa Forage Research Program (2017).
92 Health and Performance of Ewes in Woodland and Silvopasture Systems
Authors: Ellis Nevershi , Karki Uma , Paneru Bidur , Karki Lila B
Published: November 2020

The health and performance of small ruminants can be influenced by the type of vegetation available in the grazing lands, which are evolving from conventional sole pastures to other systems containing browse species, such as pastures incorporated with browse, silvopastures, and woodlands. However, how the type of grazing lands would impact animal performance and health is not documented well. The objective of this study was to determine the health and performance of ewe lambs in southern-pine silvopastures and woodlands. The study site consisted of pine silvopastures (3 plots, 0.4-ha each) planted with different cool- and warm-season forages, and woodlands (3 plots, 0.4-ha each) having numerous understory shrubs and herbaceous species. Katahdin-St. Croix-cross ewe lambs (n = 20; live weight – 29.4±1.03 kg., 5–6 months old) were rotationally stocked in study plots (10 animals/system) from May to August 2019. Both silvopasture and woodland systems consisted of 14-year-old longleaf (Pinus palustris Mill.) and loblolly pine (Pinus taeda L.) trees. Animal performance data [live weight (LW), body condition score (BCS), FAMACHA score, and fecal egg count] were collected every 14 days and blood samples collected at the beginning and on day 80 after they were stocked in the study plots. Blood samples were analyzed for PVC using centrifuge machine and other parameters in IDEXX. Data were analyzed using the multivariate analysis of variance in SAS 9.4. The silvopasture ewes gained more weight versus the woodland ewes (P < 0.0001). Fecal egg count was correlated negatively with live weight and BCS and positively with FAMACHA score in both groups (P < 0.05). Woodland ewes showed greater levels of RBC, hemoglobin, and lymphocyte, but less blood urea nitrogen (BUN), monocyte, and basophil than silvopasture ewes (P < 0.05). Results indicate that woodland ewes may need some supplement to improve their weight gain and BUN.
24 Condensed tannins: structure, activity and characterization
Authors: Zeller Wayne
Published: November 2020

As a class of plant polyphenolic compounds contained in some forages [i.e., sainfoin (Onobrychis viciifolia Scop.), big trefoil (Lotus pedunculatus Cav.), birdsfoot trefoil (Lotus corniculatus L.)], condensed tannins (CTs) exhibit a variety of biological effects on ruminants. The potential positive impact of CTs on the agricultural industry stems from their ability to modulate proteolysis during forage conservation and ruminal digestion, to prevent bloat, to reduce intestinal parasite burdens, and to abate methane and ammonia emissions from ruminants. How CTs exert these effects on ruminants focuses on the interaction of CTs with proteins. The structure-activity relationship in CT–protein interaction is not well understood but is known to be dependent on the structure and properties of both the CT and the protein. The objectives of this presentation are fivefold. First, examples of the structural diversity of CTs will be provided to enable the audience members to appreciate that not all CTs are the same. Second, examples of how CTs structural diversity affects their interaction with the protein, which in turn, dictates the biological response from the animal will be discussed. Third, the presentation will outline hurdles in obtaining highly pure and well-characterized CTs from natural sources for use in CT structural analysis and in vitro experiments. This will be followed by brief descriptions of improved and emerging techniques for CT analysis and, finally, the presentation concludes with questions to address in future investigations and a list of recommendations for CT researchers to follow.
28 Defining Grazing Recommendations for Alfalfa-Bermudagrass Mixtures in the Southeastern U.S
Authors: Groce Kaylyn , Tucker Jennifer J , Mason Katie , Marks Landon , Mullenix Mary K
Published: November 2020

Recently there has been growing interest in interseeding high-quality legumes, like alfalfa, into existing bermudagrass stands as a step towards improving forage, animal, and ecosystem sustainability in the Southeast. Current work evaluating these mixtures has focused on management and production of stored forages, and limited work has evaluated the use of alfalfa-bermudagrass mixtures under grazing conditions. It is known that both grazing intensity and frequency impact overall alfalfa stand production over time. The objective of this research is to evaluate the effect of harvest height and frequency on alfalfa interseeded into bermudagrass to develop grazing management recommendations. In 2018 thirty-six alfalfa-bermudagrass plots were established at 4 locations across Alabama and Georgia in a randomized complete block design with four replications at each location. Alfalfa varieties utilized were selected for suitability to location and were either ‘Bulldog 505’ or ‘Bulldog 805’ interseeded into existing hybrid bermudagrass sods. Treatments included combinations of harvest frequency (2, 4, or 6 weeks) and harvest height (5, 10, 15 cm) and plots were evaluated to determine the optimum interval in relation to sward yield, alfalfa persistence, stand density, botanical composition, nutritive value, and change over time. Forage yield was affected by the interaction of location with harvest frequency and height (P < 0.05). At three of the four locations, overall seasonal yield from the 5cm cutting height was greatest, however alfalfa persistence declined in these treatments throughout the season and was less than 10% at the northern locations when 2019 data collection began. Additionally, crude protein (CP) and in-vitro digestibility (IVDMD) declined throughout the season as the alfalfa presence decreased. This study is supported by funding from the USDA-NIFA-Alfalfa Forage Research Program (2017).
145 Stocker gains on diverse summer annual pastures
Authors: Mercier Kelly , Teutsch Chris , Smith Ray , Vanzant Eric , Burdine Kenny , Ritchey Edwin
Published: November 2020

The objective of this study was to determine if increasing forage botanical diversity improved stocker gains on warm-season annual (WSA) pastures. An opportunity exists to add extra gain on fall-born calves by grazing summer pastures after spring weaning and selling at a more favorable late summer market. However, cool-season perennial pastures in the Mid-South often have insufficient quality and yield to support desired summer gains. Therefore, the improved production and nutritive value of WSA forages shows promise in this system. A study was conducted near Princeton, KY, where calves (329, 366, and 297 kg in 2017, 2018, and 2019, respectively) grazed one of three WSA forage treatments without supplementation in a randomized complete block design with three replications. Treatments included 1) sorghum-sudangrass monoculture (MONO), 2) simple mixture (SIMPLE = sorghum-sudangrass, pearl millet, soybean), and 3) complex mixture (COMPLEX = SIMPLE + sudangrass, corn, crabgrass, cowpea, sunflower, sunn hemp, daikon radish, forage rape, Korean lespedeza). In 2017, MONO and SIMPLE calves had higher average daily gain (ADG) than COMPLEX calves (0.79 kg/day vs. 0.66 kg/day, P < 0.03). In 2018, no differences in ADG were detected among treatments (P > 0.3); however, calves only gained 0.01 kg/day. In 2019, MONO and SIMPLE calves again had higher ADG than COMPLEX calves (0.59 kg/day vs. 0.43 kg/day, P < 0.03). The exceptionally low 2018 ADG was likely due to the higher nutritional demand of heavier calves and the lower nutritive value of mature forages compared to other years. In conclusion, complex WSA forage mixtures did not offer any improvement in animal performance, and proper management of all WSA forages (maintaining a vegetative state) is paramount to achieving adequate gains on stockers without supplementation; however, supplementation may be necessary to improve WSA forage utilization in the rumen, potentially leading to more favorable gains.
89 Fermentation Kinetics of Different Cool-Season Annual Mixtures With or Without Silage Inoculant
Authors: Shoup Sarah L , Mullenix Mary K , Dillard Sandra L , Muntifering Russ B
Published: November 2020

High moisture feeds such as baleage are becoming a more practiced feed storage method in the Southeast due to the ability for more timely harvests and consistent forage quality compared with dry hay. The objective of this study was to determine the nutritive quality and fermentation kinetics of three different cool-season annual mixtures stored as baleage. The forage treatments were wheat (Triticum aestivum) + T-Raptor (Brassica rapa × napus; WT), wheat + crimson clover (Trifolium incarnatum; WC), and annual ryegrass (Lolium multiflorum Lam.) + oats (Avena sativa) + crimson clover (ROC) which were planted at the E.V. Smith Research Center in Shorter, AL, as a 3 × 2 × 8 factorial design (n = 3). Forage was either inoculated (I) or not inoculated (N) with a cereal/grass silage inoculant to determine its efficacy in promoting proper fermentation. Samples were taken at 8 different days after ensiling to determine fermentation kinetics and quality. Crude protein of WC was greater (P ≤ 0.005) than all other forage treatments (17.1%) and wheat + crimson clover-I was greater (P = 0.024) than WC-N (17.7 and 16.4%, respectively). However, ROC–N had greater (P = 0.033) CP than ROC–I (16.5 and 15.0%, respectively). Wheat + T-raptor ensiled with the lowest (P ≤ 0.003) pH while ROC had the greatest (P ≤ 0.001; 4.5 and 5.4, respectively). Forage treatments WC and WT did not differ (P = 0.140) in lactic acid concentration (3.7%); however, both were greater (P ≤ 0.001) than ROC (0.9%). There were no differences (P ≥ 0.128) in acetic acid concentration among all forage treatments (3.5%). The results of this study indicate that WC had the greatest nutrient quality, but do not indicate that silage inoculants offer benefits to baleage fermentation kinetics.
109 Metabolic and endocrine indicators in male goats differing in genetic propensity to consume juniper
Authors: Tolleson Douglas R , Welsh Thomas H , Walker John W
Published: November 2020

We sampled Spanish goats selected for their propensity to consume above (H) or below (L) the population average for proportion of juniper/monoterpenes in the diet (as determined by fecal near infrared spectroscopy) to determine the effect of juniper/monoterpenes on metabolic/endocrine indicators in adult male goats (Y: 2-year-old and O: 3-5-year-old). Body weight (kg) and serum samples were collected from 20 animals [n = 5 of each age (i.e. length of exposure to monoterpenes) and juniper consumption combination] maintained solely on pastures inhabited by juniper. Differences in serum analytes between groups were determined by analysis of variance. Body weight was not different between juniper groups (~71.1 ± 3.4 each) but was greater in O (76.0 ± 3.7) than Y (66.3 ± 1.9). Glucose (mg/dL) was numerically higher (P = 0.15) in H (82.3 ± 7.3) than L (69.5 ± 3.8) and in O (81.9 ± 1.9) than Y (69.9 ± 2.3). Serum urea nitrogen (mg/dL) was 10.5 ± 1.0 in both H and L (P > 0.1) but was significantly higher (P < 0.004) in O (12.9 ± 1.3) compared to Y (8.2 ± 0.5). NEFA (mEq/L) was significantly higher (P < 0.02) in H (0.33 ± 0.04) than L (0.26 ± 0.02), but not in O (0.30 ± 0.04) versus Y (0.29 ± 0.03). Total globulin (g/dL) was significantly higher (P < 0.007) in L (4.34 ± 0.35) than H (3.40 ± 0.16), and in O (4.29 ± 0.38) than Y (3.45 ± 0.12). Gamma glutamyl transferase was significantly higher (P < 0.0001) in H (59.2 ± 2.1) than L (44.3 ± 2.2), and in Y (55.3 ± 2.9) than O (48.2 ± 3.2). Length of exposure (via advancing age) and preference for juniper may incur a cost of fitness in goats selected for higher than average consumption of monoterpenes.
132 Proportional tissue weights in male goats differing in genetic propensity to consume juniper
Authors: Tolleson Douglas R , Welsh Thomas H , Garza Nick , Hollingsworth Kaylee , Walker John W
Published: November 2020

Metabolic and endocrine tissues of goats (Capra hircus) consuming juniperus species containing monoterpenes were evaluated. Monoterpenes have toxicological and pharmacological effects. We sampled Spanish goats selected for their propensity to consume above (H) or below (L) the population average for proportion of juniper in the diet as determined by fecal near infrared spectroscopy. Our objective was to determine the effect of divergent propensity to consume juniper on various tissues in adult male goats [young (2-year-old) and old (3-5-year-old)] grazing pastures containing juniper at the Texas A&M AgriLife Sonora Research Station. In June 2019, 20 animals (n = 5 of each age and juniper consumption combination) were slaughtered at the Angelo State University Meats Lab. Body weight was recorded 2 days prior to harvest. Tissue samples (i.e. liver, kidney, heart, adrenal, testicle, epididymis) were collected and weighed at the time of harvest. Tissue weights were analyzed as a proportion of body weight. Differences in proportional tissue weights between young (Y) and old (O), H and L animals were determined by analysis of variance. Body weights (kg) were 75.5 ± 4.2, 76.5 ± 6.2, 63.5 ± 1.9, and 69.0 ± 2.8 for HO, LO, HY and LY respectively. Body weight for O (76.0 ± 3.72) was greater (P < 0.03) than Y (66.3 ± 1.9). Total paired testicle, epididymal, adrenal, and heart proportional weight (g/kg) was not affected (P > 0.1) by age nor juniper consumption group. Total paired proportional weight was significantly greater (P < 0.05) in H (2.53 ± 0.09) than L (2.19 ± 0.08) for kidneys and greater (P = 0.15) in H (15.80 ± 0.75) than L (14.58 ± 0.39) for liver. High apparent consumption of juniper was associated with an increase in mass of tissues typically involved in metabolism, biotransformation, and elimination of plant secondary compounds.
121 Physiological effects of low level laser therapy on exercised horses
Authors: Rosenkrans Ashley , Freeman Carson , Oberhaus Erin L , Morse Palika Dias , Rosenkrans Charles
Published: November 2020

Low level laser therapy (LLLT) is a form of phototherapy, which may stimulate healing of injuries and lesions from exercise. Our objective was to determine effects of LLLT before or after exercise on equine serum concentrations of cortisol, lactate, and cytochrome P450 (CYP) inhibition. Twelve quarter horses were randomly assigned to one of three groups: (A) received no laser therapy, (B) received six minutes of laser therapy before exercise, and (C) received six minutes of laser therapy after exercise. Laser (635 nm) treatment was with a class II handheld low-level laser with constant wave modulation. Horses were exercised using a walker for 30 min five days a week for three weeks. Within 30 min after exercise blood was collected on day 7, 14, and 21; blood was collected on day 0 prior to exercise as a reference point. Serum was collected, frozen; and cortisol, lactate, and CYP inhibition were determined via validated assays. Data were analyzed by ANOVA with horse as the experimental unit; an interaction (P < 0.05) between treatment group and day of study affected serum concentrations of cortisol, lactate, and CYP inhibition. For group B horses, cortisol concentrations decreased (P < 0.001) from day 14 to day 21 (31 vs 20 ± 2.9 ng/mL). Serum lactate concentrations increased (P < 0.0001) during the three weeks of training (2700, 2773, 3064, and 6061 ± 232 μM; respectively for day 0, 7, 14, and 21); whereas, inhibition of CYP decreased (P < 0.01) from day 0 to day 21. Interaction of main effects on lactate can be explained by larger increases in lactate concentrations for horses treated with LLLT during the trial; conversely, CYP inhibition decreased for horses treated with LLLT after exercise. Our results suggest that LLLT may be useful in improving performance of equine athletes.
14 Characterization of adipose tissue extracellular matrix component mRNA expression during porcine adipogenesis using real-time PCR
Authors: Reeves Maegan A , Charlton Courtney E , Brandebourg Terry D
Published: November 2020

Given adipose tissue is histologically classified as connective tissue, we hypothesized expression of extracellular matrix (ECM) components are significantly altered during adipogenesis. However, little is known about the regulation of the ECM during adipose tissue development in the pig. Therefore, the objective of this study was to characterize expression of ECM components during porcine adipogenesis. Primary cultures of adipose tissue stromal-vascular cells were harvested from 3-day-old neonatal pigs (n=6) and preadipocytes induced to differentiate in vitro for 8 days in the presence of insulin, hydrocortisone, and rosiglitazone. Total RNA was extracted from these cultures on days 0 and 8 post-induction. Real-time PCR was then utilized to determine changes in mRNA expression for collagen type I alpha 1 chain (COL1A), collagen type I alpha 2 chain (COL2A), collagen type I alpha 3 chain (COL3A), collagen type I alpha 4 chain (COL4A), collagen type I alpha 6 chain (COL6A), biglycan, fibronectin, laminin, nitogen-1 (NID1), matrix metallopeptidase 2 (MMP2), matrix metallopeptidase 9 (MMP9), metallopeptidase inhibitor 3 (TIMP3). The mRNA abundances of COL1A, COL3A and MMP2 were significantly downregulated 2.86-fold (P < 0.05), 16.7-fold (P < 0.01) and 3.1-fold (P < 0.05) respectively in day 8 (differentiated) compared to day 0 (undifferentiated) cultures. Meanwhile, mRNA abundances were significantly upregulated during adipogenesis for the COL2A (2.82-fold; P < 0.05), COL4A (2.01-fold; P < 0.05), COL6A (2.8-fold; P < 0.05), biglycan (49.9- fold; P < 0.001), fibronectin (452-fold; P < 0.001), laminin (6.1-fold; P < 0.05), NID1(47.4-fold; P < 0.01), MMP9 (76.8- fold; P < 0.01), and TIMP3(3.04-fold; P < 0.05) genes. These data support the hypothesis that significant changes in ECM components occur during porcine adipogenesis. Modulating adipose tissue ECM remodeling might be a novel strategy to manipulate adiposity in the pig.
137 Randel Lecture: Genetic control of thermotolerance in cattle at the whole-animal and cellular level
Authors: Hansen Peter J
Published: November 2020

Research by Randel and others has revealed the extensive genetic diversity in thermotolerance existing in cattle. Genetic differences in resistance to heat stress involve genes that affect body temperature regulation and that stabilize cellular function during hyperthermia. There are large differences between breeds in ability to regulate body temperature during heat stress. There is also genetic variation in thermoregulatory ability within breeds that arose in cold climates – the estimate of heritability of rectal temperature during heat stress in Holsteins is 0.17. Efforts are underway to identify genes conferring increased thermoregulatory ability in thermotolerant breeds and transfer these to thermosensitive breeds. One such gene is the prolactin receptor gene (PRLR). Several mutations in PRLR exist in criollo-type B. taurus that result in formation of a truncated receptor protein. Cattle with this mutation, which is dominant, have a short sleek hair coat and are referred to as “slick”. The slick mutation has been introduced into Holsteins by crossbreeding with Senepol cattle and in Red Angus by gene editing. Slick Holsteins are less affected by heat stress than wild-type Holsteins with respect to rectal temperature, milk yield and reproduction. Genetic variation also exists in cellular responses to elevated temperature (i.e., heat shock). Exposure of preimplantation embryos to heat shock, for example, causes a greater reduction in subsequent development of Angus, Holstein, Angus x Holstein or Jersey embryos than embryos from Brahman or Nelore (B. indicus) or Romosinuano (criollo). One gene with alleles affecting cellular resistance is the heat shock protein 70 gene HSPA1A. A mutation in the promoter region of HSPA1Ais associated with increased transcription of the encoded protein and enhanced survival of lymphocytes exposed to heat shock. Identification of other genes conferring thermotolerance will result in the increased ability to produce thermotolerant lines of cattle via genetic selection or gene transfer.
86 Evaluation of the effect of prenatal transportation stress on endocrine and immune tissues of neonatal Brahman calves
Authors: Earnhardt Audrey L , Wellman Catherine L , Hairgrove Thomas , Cardoso Rodolfo C , Long Charles R , Riley David G , Randel Ron , Welsh Thomas H
Published: November 2020

The objective of this experiment was to evaluate whether prenatal transportation stress (PNS) affects the weight of endocrine and immune tissues of calves. Mature Brahman cows inseminated to a single Brahman sire in 2018 were assigned to be either Control (n = 35; not transported) or PNS (n = 37; 2 h of transportation at 60, 80, 100, 120, and 140 ± 5 d of gestation). Of the calves born in 2019, 16 Control (8 bulls and 8 heifers) and 16 PNS (8 bulls and 8 heifers) calves were studied. Pen score, body weight, and blood samples were obtained from calves at 25 ± 2 d of age. At that time, calves were euthanized by barbiturate overdose in order to collect tissues (brain, pituitary and adrenal glands, spleen and thymus). Tissues were trimmed and weighed. Serum cortisol was determined by RIA. Data were analyzed using ANOVA, GLM, and CORR procedures of SAS with body weight at sample collection as a covariate. Whole pituitary weight tended (P = 0.08) to be greater in females compared to males, whereas anterior pituitary weight tended (P = 0.06) to be greater in PNS. Whole brain weight was greater (P < 0.01) in males. The interaction of treatment and sex on whole brain weight of PNS tended (P = 0.09) to fall between that of the Control females and Control males. Whole pituitary weight was positively correlated with total adrenal weight (r = 0.32; P = 0.08). Total thymus weight positively correlated with whole brain and total adrenal weight (r = 0.43 and 0.41, respectively; P < 0.05). Serum cortisol was negatively correlated with spleen weight and total immune tissue weight (r = -0.37 and -0.38, respectively; P < 0.05). Results suggest next steps should include a closer look at function of immune tissues by studying PNS effect on thymus response to immunization.