bluuebunny/crossref_metadata_2025 huggingface dataset:
59 A Student Perspective on the Importance of Inclusive Pedagogy
Authors: Tillquist Nicole M
Published: November 2023

Diversity, equity, and inclusion (DEI) in higher education is critical for success of all students including those with marginalized identities. Implementing an inclusive pedagogy involves consideration of all student experiences, backgrounds, and identities. Students who identify within the lesbian, gay, bisexual, transgender, queer plus (LGBTQ+) community can benefit from a more inclusive learning environment. Within the classroom setting and individual courses in particular, including pronouns on course syllabi, using non-binary language, and asking for/respecting preferred names are all examples of simple changes that can be made to create a safe space for LGBTQ+ students. Faculty can also demonstrate a commitment to inclusion outside of the classroom by including pronouns in email signatures or by having DEI training stickers on office doors. These efforts can indicate that faculty are striving to provide a safe space where students can be themselves and that they are committed to being supportive educators that students can trust. Exploring the student perspective offers a unique opportunity to identify potential omissions or oversights in existing curricular and larger systemic factors that can contribute to a lack of inclusion, and to consider potential strategies to ensure promotion of LGBTQ+ inclusive approaches for students in higher education.
4 Hands-On I: Building an Agent-Based Model in Anylogic
Authors: McDonald Wade
Published: November 2023

Livestock farming systems (LFS) have detrimental effects on the environment, associated mainly with feed production, enteric methane and emissions from manure. LFS are complex because they are structured by multiple interactions between biological and human-controlled processes, at various organizational levels. Their behavior and the extent to which feeding strategies can mitigate this environmental burden is not always easily predictable. Dynamic mechanistic models of LFS can simulate the effects of feeding strategies on both animal performance and the associated excretion of nutrients. These models are useful tools to produce the life cycle inventories needed in the second step of a life cycle assessment. In the pig-fattening unit, the effects of multiphase group feeding depend largely on the variability of growth potential among pigs and the farmer has decisions that can target either the group of pigs or each individual (e.g., when choosing pigs to deliver to slaughterhouse). Therefore, simulating the growth trajectory of each individual pig and events like deliveries to slaughterhouse makes it possible to estimate the response of the pig population rather than the average pig to feeding strategies. Individual-based models (IBM) are particularly adequate because they make it possible to simulate each individual and to build the response of the population from the aggregation of individuals. Agent-based models are IBM that rely on self-governing agents made of properties, behavioral rules and resources that allow each agent to make decisions upon the occurrence of an event, which can be triggered randomly or not. This hands-on will focus on a specific example dedicated to the simulation of the response (growth, nitrogen excretion and subsequent gaseous emissions from manure) of a population of fattening pigs to a multiphase feeding strategy. In a first step, we will develop a simplified individual-based model of a pig-fattening pen including pigs and the farmer as agents. In a second step, we will improve this model by introducing interactions between these agents. For both steps, we will work with python language using pre-developed jupyter notebooks.
171 Supplementing Ca Salts of Soybean Oil Via Low-Moisture Molasses-Based Blocks to Improve Reproductive Performance and Overall Productivity of Beef Cows
Authors: Pickett Autumn , Cooke Reinaldo F , Gonçalves Lucas , Burato Samir , Holton Mark , Dias Nicholas Wege , Pancini Stefania , Redifer Tracey , Clark-Deener Sherrie , Currin John , Stewart Jamie L , Fontes Pedro L P , Mercadante Vitor R G
Published: November 2023

This experiment evaluated reproductive and productive responses of beef cows receiving self-fed low-moisture blocks (LMB) enriched or not with Ca salts of soybean oil (CSSO) throughout the breeding season. Non-pregnant, suckling multiparous Angus-influenced cows (n = 554) were assigned to a fixed-time artificial insemination (AI) protocol (day -10 to 0) followed by natural service (day 15 to 70). Cows were managed in 12 groups (46 ± 4 cows/group) maintained in individual pastures, and groups received LMB enriched with 25% (as-fed basis) of CSSO or ground corn (CON) from day -10 to 100. Both treatments were designed to yield a daily LMB intake of 0.454 kg/cow (as-fed basis). Groups were enrolled in an estrus-synchronization + fixed-time AI protocol from day -10 to 0 (AI occurred on day 0) of the experiment and beginning 15 days after AI cows were exposed to mature Angus bulls for 55 d. Pregnancy status was verified on day 55 and 100 of the experiment, and cows that gave birth during the initial two weeks were considered pregnant to fixed-time AI. Calf birthdate and weight was recorded during the subsequent breeding season. All calves were weaned at the same time, and a calf BW and age were recorded. Blood samples were also collected from a subsample of cows on days -10, 0 (fixed-time AI), and 55 (pregnancy diagnosis). All data were analyzed using group as the experimental unit and Satterthwaite approximation to determine the denominator df for the tests of fixed effects. Quantitative data were analyzed with the MIXED procedure of SAS, and binary data analyzed with the GLIMMIX procedure of SAS with a binomial distribution and logit link function. Data were analyzed with group (treatment × location), cow(group), and location as random variables. Significance was set at P ≤ 0.05 and tendencies were determined if P > 0.05 and ≤ 0.10. Cows receiving CSSO had greater (P < 0.01) mean concentrations of ω-6 fatty acids in plasma samples collected on days 0 and 55. Cows receiving CSSO had greater (P = 0.05) pregnancy rate to fixed-time AI (67.2 vs. 59.3%), whereas final pregnancy rate did not differ (P = 0.92) between treatments. Pregnancy loss was less (P = 0.03) in CSSO cows (4.50 vs. 9.04%), which also calved earlier during the calving season (treatment × week; P = 0.04). Weaning rate tended to be greater (P = 0.09) in CSSO (84.8 vs. 79.4%), although calf weaning age and weight did not differ (P ≥ 0.72) between treatments. Kilos of calf weaned/cow exposed was greater (P = 0.04) in CSSO cows (234 vs. 215 kg). Therefore, supplementing CSSO to beef cows via LMB during the breeding season improved their reproductive and overall productivity during a cow-calf cycle.
177 Determining the Body Weight to Body Fat Conversion Factor for Angus, Charolais, and Brahman Growing Steers
Authors: Gonzalez Luciano A , Burgess Jillian , Imaz Augusto , Tedeschi Luis O
Published: November 2023

The profitability of beef feedlot operations depends on accurately predicting the energy and nutrient requirements of the animal to optimize animal growth and carcass quality to meet market specifications. The composition of the gain (i.e., fat and protein) dictates the growth of the animal, and it is highly correlated with the body composition of the mature animal, assuming that the composition of body gain is constant for animals at the same maturity degree. Once the mature weight for a given body composition (i.e., fat) is known, the maturity degree can be estimated, and the equivalent body weight (EqBW) can be used to calculate energy requirements for growth. Several standard feeding systems and nutrition models use the adjusted final body weight (AFBW) at a known fat composition to estimate EqBW. The AFBW is the body weight (BW) at, usually, 28% empty body fat (EBF). Thus, AFBW can be estimated if a given empty BW (EBW) and composition are known, and an EBW-to-EBF factor is used to calculate AFBW from the current BW. Several nutrition models, including the Cattle Value Discovery System, have adopted the 14.26 kg of EBW for each % of EBF. Therefore, this study aimed to determine the amount of body mass deposited per change in body fat content of different breeds commonly used in Australia. We randomly allocated 30 Angus, 30 Brahman, and 29 Charolais into six slaughter groups (6 animals per breed per slaughter group) fed for up to 200 days. Internal organs and carcasses were dissected into physically separable fat, lean, and bones. When we regressed EBW on EBF, the overall regression yielded a slope of 11.2 ± 0.69 kg/%EBF [n = 89, r2 = 0.75, and root of the mean square error (RMSE) = 55.7 kg], likely not different from the 14.26 kg/% EBF. However, slopes were different among breeds (P < 0.001), i.e., there was an interaction between breeds and EBF when the breed was added to the ordinary least-square mean regression as a classificatory variable. The slopes were 16.5 ± 0.84 kg/% for Charolais (n = 29, r2 = 0.933, RMSE = 33.2 kg), 13.2 ± 0.73 kg /% for Angus (n = 30, r2 = 0.921, RMSE = 34.4 kg), and 10.1 ± 1.06 kg/% for Brahman (n = 30, r2 = 0.765, RMSE = 38.3 kg). When we regressed the amount of EBF on EBW, we obtained 0.40, 0.58, and 0.52 kg EBF/kg EBW for Charolais, Angus and Brahman, respectively. This confirms that Charolais deposited less EBF per unit of gain compared with Angus and Brahman. Given the similarity between the 14.26 kg/% to the overall value of 11.2 kg/%, we recommend using the 14.26 EBW-to-EBF factor to estimate AFBW when the genetic group is unknown.
90 Leveraging the Potential of Molecular and Genetic Markers to Improve Feed Efficiency in Beef Cattle
Authors: Lindholm-Perry Amanda
Published: November 2023

Genetic and other molecular markers are powerful tools with the potential to improve livestock production traits, like feed efficiency. Feed efficiency is a complex biological trait mediated by many genes. Molecular based research, including transcriptome studies to evaluate gene expression profiles to determine the genes and pathways that contribute to feed efficiency in beef cattle have been widely performed over the last decade. Despite its widespread use, challenges remain in transcriptomic data analysis, in particular non-reproducibility of results between studies. These discrepancies exist for a number of reasons including small numbers of replicates, technical differences (e.g. sample preparation, sequencing platform), and biological differences (e.g., environmental, management, and genetic effects). Recent developments in technology and analytic tools provide an opportunity to integrate and synthesize the results of existing and future data. The potential to utilize these tools to have greater impact on feed efficiency will also be discussed. USDA is an equal opportunity provider and employer.
192 Evaluation of Textural Characteristics (Texture Profile Analysis and Shear force) on Commercial Training Pet Treats
Authors: Carrera Hilary , Romero Jorge , Berganza Ileana , Dunavant Justin , Abascal-Ponciano Gerardo A , Starkey Jessica D , Starkey Charles , Cho Sungeun
Published: November 2023

Characteristics like scent, flavor, and texture can impact pet treat acceptability. Pet owners rely on personal organoleptic preferences of texture to judge treat quality, and subsequently determine desire to purchase. However, quantitative textural data for commercially available pet treats is currently limited and hard to find since companies that normally measure textural parameters in their products typically keep that information for their own use. This information is important for further investigation regarding product development and sensory evaluation to determine pet preferences and purchasing decisions. The objective of this experiment was to evaluate different textural characteristics of commercially available training treats that serve as a reference to manufacture new pet food products. Six different commercial brands (brand 1, brand 2, brand 3, brand 4, brand 5, and brand 6) were randomly selected from local pet stores. A TA-HDplusC texture analyzer was used to conduct a texture profile analysis (TPA) using a TA-30 probe, while the shear force (SF) test was performed using a TA-42 45° angle chisel blade probe (n = 10 samples per test per product). Data were analyzed as a 1-way ANOVA using the GLIMMIX procedure of SAS ver. 9.4 with mean separation with the PDIFF option at P ≤ 0.05. Significant differences of TPA and SF test parameters were observed among commercial brands of training treats except for chewiness which was similar among all brands. When products were subjected to the TPA test, brand 1 required the maximum force to deform the treats (P < 0.001). Therefore, brands 1 and 2 had the greatest adhesion to the probe (P < 0.001). For resilience, brands 1 and 2 had greater ability to regain the original form, but brand 2 was similar to brands 4 and 6 (P = 0.023). Brands 1 and 2 had cohesiveness values, but these were similar to brand 6 (P = 0.002). For springiness, brands 1, 2, and 6 had greater values (P = 0.0196), but brand 6 was similar to brands 4 and 5. However, brands 1, 2, and 6 had the greatest height recovered after compression among all brands (P = 0.020). Regarding the SF test, brand 2 were firmer and tougher than all other brands (P < 0.001). Textural differences were observed among different training treats brands; however, treats from certain brands shared similar textural characteristics. Overall, brands 1 and 2 typically had the greater values for the textural parameters evaluated. Moreover, textural data on commercially available training treats was generated, so quantitative data of commercially available training treats can be used as a reference to manufacture new pet treats. Likewise, future consumer sensory panel research into preferred textural characteristics by pet owners is warranted.
193 Apparent Total Tract Nutrient Digestibility of Frozen Raw, Freeze-Dried Raw, Fresh, and Extruded Dog Foods and Their Effects on Fecal Characteristics and Metabolites of Adult Dogs
Authors: Geary Elizabeth L , Swanson Kelly S , Templeman James
Published: November 2023

Various pet food diet formats are now available. Processing methods are known to impact nutrient digestibility and are thought to affect pet health but are poorly studied. Therefore, the objective of this study was to determine the apparent total tract macronutrient digestibility (ATTD) of frozen raw, freeze-dried raw, fresh, and extruded dog foods and assess their effects on fecal characteristics, and fecal metabolites of healthy adult dogs. Ten healthy adult spayed female dogs were used in a replicated 5x5 Latin square study to test the following diets: Chicken and Barley Recipe [extruded diet; Hill’s Science Diet (EXT)], Chicken and White Rice Recipe [fresh diet; Just Food for Dogs (FRSH)], Chicken Formula [raw frozen diet; Primal (FRZN)], Chicken and Sorghum Hybrid Freeze-dried Formula [hybrid freeze-dried raw diet; Primal (HFD)], and Chicken Dinner Patties [raw freeze-dried diet; Stella & Chewy (FD)]. The experiment was composed of five 35-day periods. Total feces excreted during a 5-day total collection phase was frozen until analyses and ATTD calculations. On the first day of fecal collections, one fresh fecal sample was collected for measurement of pH, dry matter (DM) content, and bile acid (BA) and fermentative metabolite concentrations. Data were analyzed statistically by Mixed Models using SAS 9.4, with P < 0.05 being significant. Widespread differences were noted among diets. Wet and DM fecal output was greater for EXT than other diets, and wet fecal output was greater for FRSH than FRZN, HFD, and FD. Protein ATTD was greater for FRZN and FD than other diets, and greater for HFD than FRSH and EXT. Fat ATTD was greater for HFD than FRZN and EXT, and less for EXT than other diets. Fecal pH was less in EXT and FRSH than other diets. Fecal scores were greater (looser) in EXT and FRSH than FRZN and FRZDR. Fecal DM% was greater in FD than other diets, and greater in FRZN and HFD than EXT and FRSH. In general, fecal short-chain fatty acids were highest in EXT, intermediate in FRSH and HFD, and least in FRZN and FD. Fecal branched-chain fatty acids were greatest in FDF, intermediate in EXT, FRZN, and FD, and least for FRSH. Fecal phenols and indoles were greatest in HYB and least in FRSH, with others being intermediate. Fecal primary BA were greater in FRSH than other diets, while fecal secondary BA were greater in FRZN than HFD, FRSH, and EXT, greater in FD than FRSH and EXT, and greater in HFD than FRSH. In summary, the diets tested were very different in regard to nutrient digestibility, fecal characteristics, and fecal metabolites. More research is necessary to distinguish how ingredient source, diet processing, macronutrient composition, and other factors may contribute to these differences.
191 Apparent Total Tract Digestibility, Fecal Metabolites, and Feces Quality of Pulse-Based Vegan Dog Foods with Or Without Added Enzymes in Adult Dogs and Comparison to Digestibility from a Pig Model
Authors: Van Straten W P G , Shoveller Anna Kate K , Wang L F , Beltranena E , Vasanthan T , Zijlstra Ruurd T
Published: November 2023

Consumer demand for vegetarian and vegan dog foods is increasing. These specialty diets may rely on alternative plant-based protein sources such as pulses and pulse protein concentrates instead of animal protein to meet amino acid (AA) requirements. Pulses such as field pea and lentil contain more protein than cereal grains, but also contain anti-nutritional factors (ANF) such as phytate and insoluble dietary fiber (IDF) that have the potential to reduce nutrient digestibility. The objectives were 1) to determine if the addition of enzymes before or after extrusion would increase apparent total tract digestibility (ATTD) of pulse-based extruded vegan dog foods; and 2) to compare ATTD of nutrients and gross energy (GE) between dogs and growing pigs fed the same diets. Two formulations were created: low protein (Low) containing 24% crude protein (CP) including 35% field pea flour and 15% lentil flour, and high protein (High) containing 43% CP including 50% pea protein concentrate and 20% lentil protein concentrate. Each formulation was used to prepare 3 diets: control without enzymes (Con), with enzymes added before extrusion (P; X-115 single screw; Wenger, Sabetha, KS) or enzymes added after extrusion (A) for a total of 6 diets. The enzyme blend contained cellulase (480,000 or 510,000 U/kg of diet), xylanase (360,000 or 680,000 U/kg), protease (960,000 or 1,360,000 U/kg), and phytase (12,000 or 17,000 U/kg) for Low and High diets, respectively. Following extrusion, kibbles were ground and 0.5% TiO2 was added to diets. Ten mix breed adult dogs (1.5 - 2yrs; 21-29 kg BW) were fed in a 6 × 6 replicated incomplete Latin square with 10-d periods. Feces were collected during the last 4-d of each period. The ATTD of organic matter (OM) and CP ranged from 77.7 to 86.3% and 74.6 to 87.8%, respectively. The ATTD of OM, CP, crude fat, GE, and ash did not differ between A and Con diets. Feces concentrations of glucose, xylose, acetic and propionic acid was greater (P < 0.05) for A than Con diets, indicating that enzymes hydrolyzed some IDF that was subsequently fermented by gut microbes. Addition of enzymes after extrusion increased (P < 0.05) feces moisture by 1.5% causing loose stools. Addition of enzymes before extrusion reduced (P < 0.05) ATTD of CP due to overheating during drying after wet enzyme processing. The ATTD of nutrients was greater (P < 0.05) for pigs than dogs; Nevertheless, could be a good predictor (R2 = 0.74 - 0.87) for ATTD of OM, CP, and GE. In conclusion, enzyme addition after extrusion did not increase ATTD for the dogs but did impact feces metabolites and fecal quality. Finally, pigs are a good translational model for testing ATTD of dog foods.
203 The Effects of Daily Supplementation of Selected Probiotic and Postbiotic on the Microbiome of Adult Cats
Authors: de Souza Junior Sergio Miranda , de Godoy Maria R C
Published: November 2023

Probiotics, defined as “live microorganisms, which when administered in adequate amounts confer a health benefit on the host” have been shown to beneficially affect health aspects, including body mass index, immune system modulation, and oxidative stress. There are still limited data on the microbiome and the probiotic effects in cats compared with humans. Looking into the feline microbiome could help us understand more about the gut health of these animals. This study was a complete randomized design with 36 cats [mean age = 4.98 1.97 yr; mean body condition score (BCS) = 6.33 1.08] divided into 3 treatments (n = 12/trt). Animals were fed a standard extruded commercial diet. The treatments used were control diet + placebo (maltodextrin carrier; CON), control diet + Probiotic (Bifidobacterium animalis subsp. Lactis CECT8145; daily dosage: CFU/cat; PRO), and control diet + postbiotic (Heat-killed B. animalis subsp. lactis CECT8145; daily dosage: CFU/cat; POST). The objective of this study was to identify and analyze the effects of a selected probiotic and its heat-killed form on the feline microbiome. Fresh fecal samples were collected on days 0 and 90, DNA was extracted and sequenced using the method of ‘Whole Shotgun Sequencing’, abundance comparisons were carried out with the R limma voom package (3.48.3v) to find taxonomic groups and for pathway analysis, it was performed a differential abundance analysis at L3 between day 0 and 90 in each group and abundance comparisons between groups depending on time. Relative abundance of B. animalis increased (P < 0.05) over time in cats in the PRO group, which suggests potential colonization of the B. animalis fed in the live form in the feline gut. Cats in the CON group had an increment abundance of metabolites involved in carbon metabolism pathways and amino acid biosynthesis when compared with PRO and POST, whilst there was a decrease in the abundance of membrane transport, biofilm formation, and bacterial motility pathways in the CON group. In conclusion, the use of the probiotic and postbiotic had a similar effect on the overall feline metabolism, although more studies are needed to determine if B. animalis subsp. Lactis CECT 8145 can induce beneficial outcomes to the feline microbiome.
207 Effect of Sodium Sulfate in Water and Dietary Bismuth Subsalicylate on Feed and Water Intake, Ruminal Hydrogen Sulfide Concentration, and Trace Mineral Status of Growing Beef Heifers
Authors: Evans Mikaela G , Campbell John R , Ribeiro Gabriel O , Henry Darren D H , Waldner Cheryl , Penner Greg B
Published: November 2023

Cattle consuming increased concentrations of sulfur (S) are at an increased risk for depletion of copper (Cu) and or S-induced polioencephalomalacia and there are limited mitigation strategies to alleviate risk for cattle consuming high sulfate water. This study evaluated the effects of feeding growing beef heifers bismuth subsalicylate (BSS; 0.0 vs. 0.4% DM basis) when provided water with a low (LS; 346 ± 13) or high (HS; 4,778 ± 263 mg/L) sulfate concentration on dry matter intake (DMI), water intake, ruminal hydrogen sulfide (H2S) concentration, and trace mineral status. Twenty-four beef heifers (221 ± 41 kg) were stratified based on initial liver copper concentrations collected 13 d before the start of the study, into a completely randomized block design using a high forage diet fed for 98 d. Feed and water intake (weekly), ruminal H2S concentration (d 42 and 91), and liver (pre-study and d 91) and serum trace mineral concentrations (d 1, 28, 56, and 91) were evaluated. Initial liver trace-mineral concentration was used as a covariate in the statistical model. Water intake tended to be reduced with the inclusion of BSS (P = 0.10) but was not affected by water sulfate (P = 0.40). Water sulfate and BSS did not affect DMI (P ≥ 0.89), but total S intake increased (P < 0.01) from LS to HS (17.6 to 51.0 g/d) resulting in diets that contained 0.28 and 0.78% S (DM basis). Heifers consuming HS had 1.58 µg/mL more (P < 0.01) ruminal H2S than LS. The inclusion of BSS reduced (P = 0.04) ruminal H2S concentration by 46%. Regardless of water sulfate concentration, heifers fed BSS had lesser liver Cu (average of 4.08 mg/kg) than heifers not provided BSS, and when not provided BSS, HS had lesser Cu than LS (42.2 vs. 58.3; sulfate × BSS, P = 0.02). Serum concentration of Cu did not differ over time for heifers not provided BSS; whereas heifers provided BSS had less serum Cu on d 91 than d 28 and 55 (BSS × time, P < 0.01). The liver concentration of selenium (Se) was reduced (P < 0.01) with BSS inclusion. The Se concentration in serum was not affected by sulfate, BSS, or time (P ≥ 0.16). Bismuth subsalicylate reduces ruminal H2S concentration, but depletes liver Cu and Se. Moreover, sulfate concentration in water does not appear to affect DMI or water intake but reduces liver Cu concentration.
229 Measuring the Effectiveness of Both Cognitive and Emotional Forms of Instructional Videos Related to the Beef Industry
Authors: Corbitt Katie , Locke Savannah , Hiltbrand Karen A , Shannon David , Rodning Soren P , Sawyer Jason T , Mulvaney Donald , Richburg Darcey
Published: November 2023

US citizenries are becoming detached from the animal agricultural industry, so what is the best way to bridge the knowledge gap? Results of studies have shown that video messaging could be a key factor in decreasing this gap. This study focused on assessing perceptions of young adults about animal agriculture as well as the effectiveness of emotional and cognitive videos featuring local farmers and experts in the industry to alter perception as well as develop and create trust for the beef industry. An invitation to participate was distributed to 10,000 students at Auburn University. Responses were stopped after receiving 500 complete responses. Participants were directed to a survey in Qualtrics. Participants were given a survey with 5-point Likert scale and open-ended questions over aspects of their opinions about animal welfare, diet/health of consumers of red meat and environment/sustainability of the beef industry. After viewing two videos, participants re-took the survey. Data were subjected to paired t-test statistical analysis using SPSS. Results showed the views of the participants about the beef industry improved by 82% after watching the videos. ATLAS was used to code negative and positive key words within open response questions. The emotional video had a greater impact (P < 0.05) on participants perceptions with 190 people choosing that video. In contrast only 99 participants preferred the cognitively designed video. Compared with cognitive messaging, emotional video when used as communication modalities may serve to diminish the knowledge gap relationship between the public and the beef industry.
274 Xylanase Significantly Improves Feed Efficiency in High Fiber Diets
Authors: Metz Mickie , Chamberlin Dave , Remus Janet C , Rozeboom Garrett , Lewton Jaron , Kellesvig Leah M , Polniak Veronica I , Rozeboom Dale W
Published: November 2023

Feed is the greatest expense in pig production and improving efficiency while utilizing lower priced ingredients can help ameliorate this cost. The objective of this experiment was to determine the impact of utilizing a xylanase enzyme (Danisco Xylanase, IFF) on growth performance of pigs fed high fiber diets. We hypothesized that feeding xylanase would improve G:F and ADG when added to a greater fiber diet. To test this hypothesis, 672 PIC 359 x Yorkshire pigs were randomly allotted to pens based on body weight at an average age of 20.8 ± 1.0 d. Pens were randomly assigned to one of the following treatments: Control corn/soy diet (CON), Greater fiber diet (up to 40% dried distillers grains and 10% wheat middlings FIB), and Greater fiber diet plus xylanase (XYL). The CON and the FIB diets were formulated to contain the same net energy. In the XYL treatment, xylanase was added on top of the GF diet with no reformulation or energy release assigned to the xylanase. All pigs were weighed and feed disappearance was measured weekly to calculate ADG, ADFI, and G:F. Growth performance data were analyzed using the PROC MIXED procedure in SAS with pen as the experimental unit. There were 17 pens per treatment for CON and FIB and 16 pens per treatment for the XYL treatment. To increase the number of replicates, the trial was conducted over 3 consecutive turns of pigs. Dietary treatment, repetition, week, and two-way interactions were fixed effects. Results were considered significantly different at P ≤ 0.05. In the 7-week nursery period, the pigs fed CON had increased ADG (CON: 0.52 kg/d, FIB: 0.48 kg/d, XYL: 0.48 kg/d) and ADFI (CON: 0.85 kg/d, 0.81 kg/d, 0.80 kg/d) when compared with FIB and XYL treatments (P ≤ 0.05). There were no differences in growth performance between the pigs fed FIB and the pigs fed XYL in the nursery phase. At the end of the nursery phase, pigs were randomly allotted within treatment to different cohorts in the growing finishing period. In the 12-wk growing finishing period, pigs fed FIB and XYL had decreased ADG compared with pigs fed Control diets (CON: 1.05 kg/d, FIB: 0.97 kg/d, XYL: 0.96 kg/d; P ≤ 0.05). In addition, pigs fed XYL diets had improved G:F when compared with both FIB and CON (CON: 0.402, FIB: 0.400, XYL: 0.414; P ≤ 0.05). This improvement in feed efficiency in the XYL treatment seemed to be driven by a significant reduction in ADFI (P ≤ 0.05), which suggests, adding xylanase to a diet without accounting for energy release, reduces overall feed intake and growing more efficiently, as expected with more available energy.
264 Effects of L-Glutamate and L-Aspartate Supplementation on Growth Performance, Severity of Diarrhea, and Systemic Immunity of Weaned Piglets Challenged with F18 Enterotoxigenic Escherichia Coli
Authors: Wongchanla Supatirada , Park Sangwoo , Kim Kwangwook , Sun Shuhan , Li Xunde , Liu Yanhong
Published: November 2023

L-glutamate (Glu) and L-aspartate (Asp) exhibit multifaceted roles in cellular processes and immunological regulation in pigs. This study aimed to investigate the effects of Glu and Asp on growth performance, diarrhea, and systemic immunity of weaned piglets challenged with an enterotoxigenic Escherichia coli (ETEC) F18. A total of forty-nine weaned pigs (8.18 ± 1.54 kg BW) were randomly assigned to one of seven treatments, with seven piglets per treatment. The treatments included negative control (NC) and positive control (PC) that were fed with control diet without or with ETEC challenge, respectively. The other five dietary treatments were supplemented with either 1% or 2% Glu or Asp, or 50 mg/kg of Carbadox, and were challenged with ETEC. All pigs except for NC were challenged with F18 ETEC orally for three consecutive days at the dose of 1010 CFU/dose/day. The study period lasted for three weeks, with a 7-day adaptation period and 14 days post-inoculation (PI). Pig body weights, feed consumption, and fecal score were recorded throughout the experiment. Fecal samples were collected on d 2, 5, 10, and 14 PI to confirm the presence and dynamics of β-hemolytic coliforms. Blood samples were collected on d 0 before ETEC inoculation, and on d 2, 5, and 14 PI to analyze white blood cell profile. All data were analyzed with ANOVA using the PROC MIXED of SAS with pig as the experimental unit. Frequency of diarrhea was analyzed by Chi-Square analysis. Compared with PC, pigs supplemented with 1% Glu, 2% Asp, or Carbadox had greater (P < 0.05) average daily weight gain and gain:feed ratio from d -7 to 5 PI and d 0 to 5 PI. Pigs fed with 1% Glu had reduced (P < 0.05) percentage of β-hemolytic coliforms in feces on d 14 PI than PC. Compared with PC, pigs fed with NC, 1% Asp, 2% Asp, or Carbadox had decreased (P < 0.05) severity of diarrhea (32.47% vs. 16.23 to 24.68%). The counts of white blood cells, neutrophils, lymphocytes, and monocytes were increased (P < 0.05) on d 2 PI and peaked (P < 0.05) on d 5 PI, and were reduced (P < 0.05) on d 14 PI. Pigs fed with 1% Glu had least (P < 0.05) neutrophils:lymphocytes ratio on d 2 PI, while pigs fed with 2% Glu had greatest (P < 0.05) neutrophils:lymphocytes ratio on d 5 PI among all treatments. In conclusion, results of the present study indicate that dietary supplementation of 1% Glu or 2% Asp enhanced growth performance of ETEC challenged weaned pigs at early stage. Supplementation of 1% or 2% Asp also mitigated severity of diarrhea. Both amino acids modulated the systemic immunity of weaned pigs, which needs to be further investigated.
410 Awardee Talk: Swine Feed Additives: Current and Future Innovation to Achieve Profitable and Sustainable Production
Authors: DeRouchey Joel M , Tokach Mike D , Goodband Robert , Woodworth Jason C , Gebhardt Jordan T
Published: November 2023

Swine feed additives is general terminology used for a wide range of non-nutritive products to help improve growth, health, and carcass characteristics. There are numerous classifications of feed additives that are currently used world-wide. To properly access the value of a feed additive to achieve desired goals, understanding the 1) mode(s) of action, 2) efficacy with different diet formulation strategies, 3) influence of herd health status, and 4) consistency of predicted response are vital. For the swine industry to advance on-farm sustainability for improved carbon, nitrogen and phosphorus efficiency, efficacious feed additives must be a utilized tool. This needs to be done in unison with best management practices already in place (e.g., optimized feed formulation, precise feed manufacturing and processing, advancing genetics, improving herd health) to provide complimentary, not competing results. Also, strategic emphasis must be placed on maintaining efficacious and economical feed additives in the marketplace to prevent loss of their use. Ractopamine hydrochloride is just one example that was routinely fed to most US finishing pigs in diets before marketing but now is not used due to export market access. At the same time, pharmacological levels of Zn and Cu have illustrated clear benefits on pig growth, health and subsequently welfare, but regulatory action based on excretion levels and potential connections to antimicrobial resistance have begun to limit their use in certain countries. These examples highlight the need for correctly designed, unbiased research to provide consumers, human health professionals, and regulatory personnel information to make accurate decisions regarding various feed additives. Finally, innovation to advance the efficacy and predictability of feed additives such as in-feed enzymes, acidifiers, direct feed microbials, yeasts, fatty acids, trace minerals, ionophores, and others is needed. These products must be a component of current and long-term producer profitability, nutritional efficiency, and sustainability.
435 Opportunities for Conservation Research Support, Feed Management Planning and Practice Cost Sharing
Authors: Zwicke Greg , Leech Renee
Published: November 2023

The U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) uses science-based technology to provide conservation planning and assistance to landowners, operators, producers, and others to benefit the soil, water, air, plants, animals, and energy for productive lands and healthy ecosystems. Learn about opportunities for financial and technical assistance for livestock production and conservation as well as grant programs for innovative conservation research and on-farm trials.
313 Efficacy of Vermifiltration to Treat Liquid Cattle Manure to Mitigate Carbon and Nitrogen Emissions
Authors: Monaghan Jera L , Michal Jennifer , Jobson B Thomas , O'Keeffe Patrick , de castro-Nunes Cris , Austin Mackenzie , Johnson Kristen A
Published: November 2023

The objective was to determine the efficacy of a vermifiltration system that treats liquid cattle manure to alter methane (CH4), nitrous oxide (N2O), ammonia (NH3) emissions, and nutrient composition (potassium-K; phosphorus-P; nitrogen-N). Liquid manure was sampled as it entered the worm-bed (influent) and as it exited from the worm-bed (effluent) to measure changes in nutrient composition. Worm-bed surface fluxes of CH4 and N2O were measured in real-time for three distinct environmental temperatures (0 ˚C, 10 ˚C, and 20 ˚C) to examine seasonal variation at several locations in the 3.64 ha worm-bed using isolation chambers and cavity ring-down spectrometry. NH3 flux was measured from the chambers using a ChemComb 3500 Speciation Collection Cartridge and coated honeycomb denuders. NH3 samples were eluted within 4 h of collection and stored at -20 ˚C until colorimetric analysis. Duplicate NH3 measurements were made for each chamber location at each temperature. Examination of the influx and efflux data indicates reductions of 25% in K, 96% in P, 99% in total suspended solids, 92% in volatile solids, and 92% in total Kjeldahl N. Chamber CH4 concentrations at 0 ˚C (0.51 to 1.18 ppm) tended to be less at 10 ˚C (2.17 to 2.67 ppm) and 20 ˚C (1.6 to 2.45 ppm) but were not different across temperatures (P < .077) and reflected ambient concentrations (2.44 ppm). N2O concentrations at 0 ˚C (157.00 to 224.00 ppb) and 10 ˚C (86.3 to 176.5 ppb) were not different than ambient (358.5 ppb), but at 20 ˚C (400.0 to 655.0 ppb) concentrations tended to be greater (P < 0.07). NH3 concentrations at 0 ˚C (0.06 to 0.33 ppm) and 20 ˚C (1.35 and 2.21 ppm) were not different but at 10 ˚C (11.8 to 28.7 ppm) were greater (P < 0.05). Fluxes were calculated for each sampling period. During 0 ˚C flux densities were 1.61 ± 0.17 mg· m-2· day-1 for N2O, 2.5 0.57mg m-2· day-1 for CH4, and 0.007± 0.00 mg m-2· day-1 for NH3. At 20°C flux densities were 1.98± 0.63 mg· m-2day-1 for N2O, 2.88± 0.755 mg m-2· day-1 for CH4, and 25.4 ± 0.0 mg· m-2· day-1 for NH3.Flux calculations and extrapolation of emission rates to the entire system indicates that vermifiltration is an effective strategy to alter nutrient concentrations and reduce CH4 emissions but not emissions of N2O and NH3.
318 The Effect of Developing Heifers to a Lower Percentage of Mature Body Weight at Breeding on Pregnancy Rates and Longevity Within the Herd
Authors: Crouch Josie , Mulliniks Travis , Musgrave Jacki A , Hanford Kathy , McCarthy Kacie L
Published: November 2023

Traditional recommendations suggest that a heifer should be at 65% of her mature body weight (BW) at the time of breeding to obtain optimal production efficiency and achieve the greatest pregnancy rates. The objective of this study was to determine how developing heifers at a decreased percentage of mature BW at breeding impacts heifer performance, stayability, and calf production. Data were collected from cows and heifers (n = 1,434) from the March- and May-calving herds at the University of Nebraska Gudmundsen Sandhills Laboratory (GSL) located near Whitman, NE from 2005 through 2019. Body weights were collected from heifers and cows, percentage of mature BW of heifers was calculated using heifer breeding weight and the average MBW of cows at 5, 6, and 7 years of age. A regression analysis was conducted on percentage of estimated mature BW at breeding in heifers from 50 to 70 % of mature BW. Heifers that were 60% of mature BW at the time of breeding or greater had increased (P < 0.01) pregnancy rates compared with lighter heifers. In contrast, a greater percentage (P = 0.05) of heifers at a mature BW of 60% or less at breeding calved during the first 21 d of the calving season. Calf BW at birth was influenced (P < 0.001) by percent of mature BW at breeding with calves from greater BW heifers being heavier. Subsequent pregnancy rate as a 2-yr old was influenced (P < 0.001) by percentage of mature BW at breeding as a heifer with greater percent mature BW at breeding having greater pregnancy rates than heifers with decreased percent mature BW. However, pregnancy rate as a 3-, 4-, and 5-yr-old were not influenced (P> 0.15) by percentage of mature BW at breeding as a heifer. Overall, greater percentage of mature BW at the time of breeding increased overall pregnancy rate; however, heifers at a decreased percentage of mature BW calved at a greater percentage during the first 21-d of the subsequent calving season. In addition, longevity in the cowherd was not influenced by heifer BW at the time of breeding.
316 Routine Claw Trimming Data Provides Insight into the Occurrence of Claw Lesions Holstein Herds in the Central Region of South Africa
Authors: Joubert Robyn C , Van Marle-Köster Esté , Strydom H F
Published: November 2023

Claw lesions in dairy cows are a primary contributor to lameness, posing severe welfare concerns due to the distress and discomfort experienced by affected cows. Claw disorders have a significant negative impact on herd efficiency, milk yield, reproductive performance, and involuntary culling. Despite increased awareness of the detrimental effects of lameness, its incidence has continued to rise. Reducing the occurrence of lameness remains a major challenge, especially in defining and recording of claw traits. In South Africa (SA), claw data is limited to private hoof trimmers with paper-based recording. The objective of this research was to examine the occurrence and recording of claw lesions in Holstein cattle from the central region of South Africa. Claw-trimming data from five intensively managed dairy farms (average herd size: 1,073) using both dirt lot (DL) and free-stall (FS) housing systems were analyzed over a six-year period (2014 to 2019). The Claw Lesion Identification in Dairy Cattle brochure, co-developed by Zinpro Corporation and the International Lameness Committee, was used as the reference for lesion identification by a local hoof trimmer. Digital dermatitis (D) showed the greatest prevalence (64.02% of all recorded lesions), followed by sole ulcers (U; 8.59%), white line disease (W; 6.27%), and sole hemorrhage (H; 4.28%), with most lesions occurring in the rear feet. A chi-square test of independence between lesion and housing was rejected (P < 0.0001). Correspondence analysis (CA) was then used to explore these dependencies. The first dimension of the graphical display explained 90.7% of the variation in the data. The CA indicated that the prevalence of D and F are strongly associated, and closely associated with U. The prevalence of these lesions is also associated with housing systems DL and FS. The CA also confirmed a close association between W and H, and the prevalence of these lesions in housing system DL+FS. Improving the precision of claw lesion identification and recording, especially with regard to lesions that tend to occur together, can furnish essential data to identify the most prevalent lesions in a population. This will enhance our comprehension of the causal factors behind these significant lesions and offer producers practical recommendations to use these data for prevention, early detection, management, and improvement of lameness.
337 Supplementation of a Kaolin and Yeast-Based Feed Additive on Performance of Feedlot Cattle
Authors: Yang Wenzhu , Schwandt Erin F , Gott Paige N , Levy April W , McAllister Tim A
Published: November 2023

The objective of this project was to examine the effectiveness of feeding a kaolin and yeast-based feed additive on the performance of feedlot cattle. Seventy-five steers (initial BW; 545 ± 42.4 kg) were blocked by BW and randomly allocated into 25 blocks of 3 steers (n = 25 per treatment) in a randomized complete block design with 3 treatments including control, low (10 g/day) and high (15 g/day) kaolin and yeast-based feed additive (FA) supplementation. The steers were fed a finishing diet consisting of 7% corn silage, 1% straw, and 92% corn-based concentrate (DM basis). The duration of the feeding period was 120 days. Supplementation of high grain finishing diet with FA did not affect feed intake (average, 12.4 kg/d), final BW (average, 768 kg), averaged daily gain (average, 1.77 kg/d), carcass traits, and abscessed livers. However, increasing the feeding of FA (0, 10, 15 g/d) to finishing steers linearly (P = 0.05) improved feed efficiency from 0.139 to 0.143 and 0.148 kg gain/kg feed and linearly (P = 0.06) improved net energy for maintenance from 2.05 to 2.10 and 2.15 Mcal/kg and net energy for growth from1.39 to 1.43 and 1.47 Mcal/kg, respectively. Fecal IgA concentration linearly (P = 0.06) increased from 15.0 to 22.7 and 30.1 µg/g with increasing FA addition, suggesting an improvement in nutrient absorption, and potentially better gut health. The increasing addition of FA also linearly (P = 0.03) increased plasma lipopolysaccharide binding protein (LBP) concentration from 46.3 to 56.2 and 64.7 µg/mL but decreased blood total antioxidants from 0.282 to 0.251 and 0.204 mM. These results suggest that the addition of FA may support gut health.
336 Evaluation of a Bacillus Spp. Probiotic on Beef Cattle Performance, Nutrient Digestibility and Enteric Methane Emissions
Authors: Maderal Araceli B , Marenchino Ignacio Fernandez , Vargas Juan , Tarnonsky Federico , Podversich Federico , Cuervo Wilmer , Ramirez-Sepulveda Vanesa , Blanchard Horacio , Gomez-Salmoral Macarena , Schulmeister Tessa M , Queiroz Oscar , Cappellozza Bruno I , DiLorenzo Nicolas
Published: November 2023

Direct-fed microbials have been used in an effort to improve livestock production efficiency and reduce environmental impact. Among other species, spore forming bacteria such as Bacillus spp. present handling and processing advantages to be used as a probiotic. Several studies have demonstrated positive effects of Bacillus spp. on dairy cattle production. However, there is lack of information about its effects on beef cattle. Thus, the objective of this study was to evaluate the effect of a probiotic composed by a mixture of B. subtilis and B. licheniformis on beef cattle performance, nutrient utilization, and enteric methane emissions (CH4). For this purpose, a total of 108 Angus crossbred heifers (318 ± 40.4 kg of BW) were used in a generalized randomized block design. The heifers were fed a sorghum silage-based diet containing 1 of the 2 following treatments: 1) control (CTL, no additive), or 2) Bacillus spp. probiotic (BSL, 310 mg/kg of diet DM), in an attempt to provide an average of 3 g·animal-1·d-1. The experimental period consisted in 7 d of adaptation to the pens, followed by 77 d of performance data collection, 5 d of apparent total tract digestibility measurements, and 5 d of CH4 measurements. No effect of treatment (P > 0.05) was observed for dry matter intake, average daily gain, or gain-to-feed ratio. The inclusion of the probiotic did not affect (P > 0.05) apparent total tract digestibility of dry matter, organic matter, neutral detergent fiber and crude protein, whereas starch digestibility decreased (P = 0.027) with the probiotic inclusion. No differences (P > 0.05) were observed for CH4 between the two treatments. Accordingly, feeding Bacillus spp. did not affect cattle performance, nutrient utilization, or enteric CH4 emissions in beef heifers when included at 310 mg/kg of dietary dry matter.