bluuebunny/crossref_metadata_2025 huggingface dataset:
267 Comparison of methods to process remotely collected body weight in feedlot steers
Authors: Gonzalez Luciano A , Burgess Jillian E M , Shirvan Milad Bagheri
Published: September 2024

New technologies such as automatic in-pen weighing of cattle offer great opportunities to monitor, improve and control livestock production. The large amount of raw BW data recorded must be processed to estimate BW minimizing the impact of erroneous records and the large variability due to various factors such as fill of the gastrointestinal tract. The objective of the present study was to compare two data processing methods of remotely collected body weight (BW) in feedlot steers against traditional weighing measured in central handling facilities. The BW data were collected from a serial slaughter trial with 26 steers of each Angus, Brahman, and Charolais slaughtered at 50, 100, 150, and 200 DOF (initial BW = 345 ± 29.9 kg). Body weight was measured every 50 d in the central handling facilities (stationary BW in a weighing box) and then using an in-pen weighing system setup in front of the water trough to record animal BW linked to RFID while drinking water. The remotely collected BW data were processed with two smoothing: 1) penalized b-splines (BWpbs) and 2) natural cubic splines (BWncs). After fitting the data from each animal to each smoothing algorithm, datapoints greater or less than the estimated BW × 1.5 residual error were deleted. The BW estimated from remotely collected data with each method was regressed against traditional BW. The former algorithm resulted in a linear regression of the form BWpbs = -13.1 (± 1.46) + 1.04 (± 0.003) BW (R2 = 0.996; RMSW = 6.46 kg). The natural cubic spline algorithm resulted in a linear regression of the form BWncs = -11.0 (± 3.02) + 1.04 (± 0.007) BW (R2 = 0.985; RMSW = 12.88 kg). Both algorithms had acceptable accuracy and precision although the penalized b-spline algorithm was more sensitive because it better detected sudden changes in BW. The intercept showed that both algorithms estimated heavier BW compared with traditional BW, likely because of BW loss due to defecation and urination during yarding. In conclusion, penalized b-splines smoothing algorithm is recommended over natural cubic splines to process remotely collected BW because of decreased error and greater precision.
365 Feeding Cattle – Optimal Days on Feed: Rates of change of economically important performance and carcass characteristics
Authors: Galyean Michael
Published: September 2024

Feedlot research data from 7 experiments with beef steers, 6 experiments with beef heifers, and 2 experiments with Holstein steers, representing a total of 687 pen observations, were analyzed to determine the rate of change in selected performance and carcass measurements over extended feeding periods. All cattle were fed high-grain diets and managed under typical industry conditions. The 15 experiments included extended days on feed as a factor (steers: 0 to 62 d; heifers: 0 to 42 d; and Holsteins: 0 to 56 d), with several experiments including beta-agonist and implant program comparisons. Variables of interest were dry matter intake, average daily gain, final shrunk body weight, hot carcass weight, and measures of carcass fatness, yield, and quality. Beta-agonist and implant programs effects and their interaction with extended days on feed, as well as the overall rate of change in performance and carcass measurements with extended days on feed were evaluated using mixed-model statistical methods adjusting for random intercept effects of studies. Effects of zilpaterol or ractopamine and implant programs were consistent with the published literature, and for analyses across steer and heifer data, interactions between beta-agonist/implant program and extended days on feed were detected for only 2.5% of the variables evaluated. Slope values in the overall analyses for all 3 classes of cattle were generally significant (P ≤ 0.03 for 85% of the variables analyzed), reflecting increased final shrunk body weight and hot carcass weight, greater carcass fatness, and shifts toward higher quality and yield grades with extended days on feed. Producers marketing cattle on a carcass basis could use the slope data from these analyses to estimate changes in carcass weight along with potential premiums and discounts for use in economic projections.
12 Differences in pregnancy loss between Bos indicus and Bos taurus cattle
Authors: Mercadante Vitor R G , Vidlund Trinity , Pancini Stefania , Smith Damon , Moorey Sarah , Ealy Alan , Biase Fernando , Pohler Ky G , Lamb Cliff C
Published: September 2024

Infertility due to pregnancy loss is a major issue leading to economic losses in cow-calf beef production. Furthermore, undernutrition is linked to infertility in cattle and is of most concern during times of extended drought periods and ever-increasing feed costs, such as today. Approximately 30% of cattle in the U.S. contain a portion of their genetic background of Bos indicus origin, and approximately 40% of beef cows and 50% of the cow-calf producers in the country are located in the southern U.S. where Bos indicus cattle and their crosses are located. Our research group has investigated differences in fertility and conceptus development between Bos indicus and Bos taurus cattle and there is evidence for differences in embryonic development and pregnancy establishment processes between Bos taurus and Bos indicus. In similar studies performed in Brazil and in the U.S., d 15 Bos indicus embryos averaged at 2.4 cm in length, while Bos taurus d 15 embryos averaged 11.4 cm in length. In addition, we determined that cows containing primarily Bos taurus genetics had larger fetuses at d 53 of pregnancy than cows with at least 20% Bos indicus genetics. These differences highlight the importance of performing controlled studies with direct comparisons between the two subspecies. Recent findings from our group indicate that Bos indicus cattle have improved fertility and embryonic survival under nutritional restriction when compared with Bos taurus cattle. Angus embryo transfer recipients submitted to a 70% nutritional restriction have increased pregnancy failure compared with Angus recipients in a maintenance diet and Brangus recipients in both restricted and maintenance diets. In addition, embryo recipients in the restricted diet that received an Angus embryo experienced greater pregnancy failure than recipients in the restricted diet receiving Brangus embryos, regardless of the recipient breed. Collectively, our results indicate that the magnitude of the detrimental effect of nutrient restriction differs between Bos taurus and Bos indicus cattle. Bos taurus genotype in both maternal and fetal systems decreased the probability of pregnancy when nutrient restriction was superimposed, indicating that Bos taurus cows were more susceptible to experience embryonic loss when exposed to the same negative plane of nutrition. There is a critical need to understand how the fetal-maternal crosstalk during early stages of pregnancy as well as the uterine environment differ between Bos taurus and Bos indicus cattle.
9 Contributions of sire diet to pregnancy establishment in cattle
Authors: Fontes Pedro
Published: September 2024

The first weeks of pregnancy represent a pivotal period for pregnancy establishment and have considerable implications to fertility and beef production efficiency. While fertilization rates are considerably high in beef cattle, early embryonic mortality occurs in a large proportion of females between fertilization and the first pregnancy diagnosis. Most research efforts to address early pregnancy loss in cattle have focused on female-related factors that influence embryonic mortality. However, research from other animal models has shown that in addition to its genetic contributions, sperm-derived factors are involved in many post-fertilization events, such as syngamy, cleavage, and epigenetic regulation of the developing embryo. Large-scale field fertility studies have shown differences in pregnancy rates between sires with similar sperm parameters based on industry-standard semen analyses. However, few studies have investigated the paternal contributions to early embryonic development in cattle. In rodents, embryos sired from obese fathers had reduced cleavage and blastocyst development rates compared with embryos sired from control fathers. While bull over conditioning is a common phenotype observed in the beef industry, the impact of paternal nutrition on embryo and conceptus development remains poorly understood in cattle. Our group has recently evaluated the effect of paternal high energy diets on semen parameters and embryo development during in vitro embryo production. When compared with a control treatment, bulls exposed to a highly anabolic diet had similar sperm motility, but partially decreased semen quality based on computer-assisted sperm analyses and flow cytometry, respectively. In addition, while a highly anabolic diet resulted in similar cleavage rates compared with a control diet, decreased blastocyst rates as a percentage of cleaved oocytes were observed in bulls fed a highly anabolic diet. These results corroborate with reports in other species; however, further research is required to better understand the contributions of paternal diets to conceptus development and pregnancy loss.
10 Awardee Talk: Pregnancy losses in Bos indicus-influenced cowherds
Authors: Cooke Reinaldo F , Vasconcelos Jose
Published: September 2024

Pregnancy loss is recognized as a major reproductive challenge in beef cattle operations. Most pregnancy losses are associated with early embryonic mortality, but limited research evaluated pregnancy losses throughout the gestation period. Research is warranted to address this gap in knowledge, particularly fetal losses in Bos indicus-influenced females. This subspecies predominates in tropical regions of the planet, which contain more than 80% of the world’s cattle population and supply a major portion of the global demand for beef products. Our group recently evaluated pregnancy losses from d 30 of gestation to calving in 4,926 Nelore females assigned to an ovulation synchronization + fixed-time artificial insemination (FTAI) protocol. Pregnancy loss was greater (P < 0.01) from d 60 to 150 of gestation (10.2%) compared with d 30 to 60 of gestation (6.0%) and with d 150 of gestation to calving (7.4%) and differed (P = 0.04) between these latter two periods. Pregnancy loss from d 30 to 60 of gestation did not differ (P = 0.26) among cow parities (nulliparous, primiparous, and multiparous), whereas total pregnancy losses (d 30 to calving) were greater (P < 0.01) in precocious (28.4%) and conventional (27.1%) heifers compared with primiparous (16.4%) and multiparous (13.0%) cows. In a second experiment, pregnancy losses from fixed-time embryo transfer (FTET) to calving were evaluated in 4,366 FTET events using Nelore × Angus recipient heifers. Pregnancy losses were greater (P < 0.01) from FTET to d 32 of gestation compared with d 32 to 100 and with d 100 to calving (58.7, 39.5, and 36.7%, respectively), and did not differ (P = 0.56) between these latter periods. Recipients that lost the pregnancy from FTET to d 32 gained less (P < 0.01) body condition score after FTET compared with recipients that maintained the pregnancy. Pregnancy losses from d 32 to calving were greater (P < 0.01) in recipients reared in drylots and moved to pastures on d 32 compared with recipients reared on pasture. Collectively, these results provide novel information about pregnancy losses in Bos indicus females, with a substantial proportion of losses occurring as fetal mortality.
438 DNA methylation patterns and transcriptional regulation during pig fetal skeletal muscle development
Authors: Ernst Catherine W
Published: September 2024

Fetal development is controlled by a complex cascade of highly regulated and coordinated gene expression patterns. Epigenetic mechanisms have important roles in regulating development and differentiation. Among such mechanisms, DNA methylation exhibits context-specific associations with gene expression and has been shown to be highly dynamic during developmental processes. We performed whole-genome bisulfite sequencing (WGBS) to assess DNA methylation in pig longissimus dorsi muscle at 41- and 70-d gestation (dg), as well as RNA- and small RNA-sequencing to identify coordinated changes in methylation and expression between myogenic stages. We identified 45,739 differentially methylated regions (DMRs) between stages, and the majority (n = 34,232) were hypomethylated at 70 vs. 41 dg. Developmental DMRs exhibited feature-specific enrichment in gene regulatory regions, as well as in regions proximal to micro-RNAs (miRNAs) that have known roles in myogenesis. Integration of methylation and transcriptomic data revealed strong associations between differential gene methylation and transcript abundance. We surveyed myogenic regulatory factor (MRF) genes to determine if differential methylation was present in expected genomic regions. Within the MYF5 and MYF6 locus, MYF5 was significantly promoter-hypermethylated at 70 dg, whereas MYF6 was significantly hypomethylated upstream of its transcription start site. MYF5 is the earliest MRF to be expressed and primarily functions in myoblast proliferation and determination, while MYF6 functions in muscle cell differentiation. Thus, these patterns were consistent with expected downregulation of MYF5 and upregulation of MYF6 as muscle development progresses and demonstrate that differential methylation is evident at myogenic transcription factors. Differential miRNA methylation was significantly negatively correlated with abundance, and dynamic expression of assayed miRNAs persisted postnatally. Motif analysis revealed significant enrichment of myogenic regulatory factor motifs among hypomethylated regions, suggesting that DNA hypomethylation may function to increase accessibility of muscle-specific transcription factors. We also show that developmental DMRs are enriched for GWAS SNPs associated with muscle physiology and meat quality traits, demonstrating the potential for epigenetic processes to influence phenotypic diversity. Our results enhance understanding of DNA methylation dynamics in pig fetal skeletal muscle and reveal putative cis-regulatory elements governed by epigenetic processes during porcine myogenesis.
439 Bovine embryo epigenetic analysis according to periconceptional conditions and new information on postnatal phenotypes
Authors: Sirard Marc Andre A
Published: September 2024

In the field of animal reproduction, the environment associated with gametes and embryos refers to the condition of the parents as well as conditions surrounding gametes and embryo in vivo or in vitro. This environment is now known to influence not only the functionality of the early embryo but potentially the future phenotype of the offspring. Using transcriptomic and epigenetic molecular analysis, and the bovine model, recent research has shown that both the female and the male metabolic status, for example age, can affect gene expression and gene programming in the embryo. Evidence demonstrates that milking cows losing body weight at the time of conception generates compromised embryos and offsprings with a unique metabolic signature. A similar phenomenon has been associated with different culture conditions and the IVF procedure. The general common consequence of these situations is an embryo behaving as “economy” mode where translation, cell division and ATP production is reduced, potentially to adapt to the perceived future environment. New epidemiologic studies in bovine to assess if these changes result in a different phenotype especially with animals created by IVF which shows consequences later in life.
296 Saccharomyces cerevisiae derived postbiotic modulates inflammatory response and gut microbiota in large breed dogs exposed to endurance exercise and transport stress
Authors: Timlin Claire L , McCracken Fiona B , Dickerson Sarah M , Skaggs Patrick M , Fowler Jason W , Jalukar Sangita , Coon Craid N
Published: September 2024

Postbiotic supplements have been used in various livestock species to mitigate the negative effects of stress. This study aimed to determine if similar responses are seen in canine companion animals. We evaluated the effects of a Saccharomyces cerevisiae (S. cerevisiae) postbiotic supplement on inflammatory biomarkers, cortisol, and microbiota dysbiosis index in Labrador Retrievers exposed to exercise and transport stress. Dogs [n = 36; 3.52 ± 0.21 yr old and body weight (BW) = 27.6 ± 2.97 kg] were blocked by sex, age, and BW and assigned to receive 1 of 3 daily top-dressed treatments: 1) 15 g ground corn germ (Control, n = 12); 2) 7.5 g S. cerevisiae yeast postbiotic (Low, n = 12); or 3) 15 g of S. cerevisiae yeast postbiotic (High, n = 12). Dogs were given 1 wk to acclimate to treatments before beginning a 7-wk exercise regimen consisting of twice weekly 4.8 km guided runs. Dogs were exposed to a transportation stressor in wk 8. Fecal samples from d 0 and 56 were analyzed for calprotectin, calgranulin C (S100A12), α1-protease inhibitor, immunoglobulin A, and microbiota dysbiosis index. Blood was collected on d 0 and 63 for serum chemistries and complete blood counts. Blood collection was also performed prior to and 18 to 20 h after first and final runs of the exercise regimen for analysis of inflammatory cytokines. The Four Rivers Kennel (FRK) Gait Inflammation Index score was assessed prior to and 24 hours after the first and last exercise runs with the Gait4Dogs pressure mat system. Saliva cortisol was measured before and after transportation. Blood chemistry did not differ among treatments (P ≥ 0.19), but Control dogs had increased eosinophils (P = 0.01) and tended to have increased white blood cells (P = 0.08) and lymphocytes (P = 0.08) compared with dogs receiving postbiotic. Dogs fed Low dose had elevated monocyte chemoattractant protein-1 (P = 0.01) and maintained Interleukin (IL) -8 after the initial run (P = 0.03). Males in the Low group had increased IL-10 (P = 0.02). Fecal biomarkers and microbiota dysbiosis index score did not differ among treatments by d 56 (P ≥ 0.19). Blautia abundance was decreased in High (P = 0.04). Fusobacterium abundance tended to be reduced in High and increased in Control and Low (P = 0.07). Clostridium hiranonis tended to be greater in Low compared with Control (P = 0.07). The FRK Total Gait Inflammation Index scores decreased over time with acclimation to running (P < 0.01). Saliva cortisol concentrations did not differ among treatments (P ≥ 0.20). The Saccharomyces cerevisiae-based postbiotic tested in this study has potential as a functional ingredient to modulate immune function, improve muscle recovery shortly after exercise and positively change diversity of the gut microbiome in canine companion animal diets.
293 Impact of black soldier fly larvae meal in a dry extruded food on nutritional quality and health in adult cats
Authors: Bosch Guido , Loureiro Bruna , Schokker Dirkjan , Kar Soumya , Sluczanowski Nicky
Published: September 2024

Insects like the black soldier fly larvae (Hermetia illucens; BSFL) have been proposed as protein-rich feed ingredients to support the growing demand for meat. The BSFL hold also promise for use as a protein source in pet foods and, as such, it has been studied for palatability, nutritional quality and health effects in dogs and cats. This study aimed to evaluate the effects of including BSFL meal in a dry, extruded food on nutritional quality and health in healthy adult cats. Two similar compositions of dry, extruded foods were formulated to meet the FEDIAF nutrition guidelines for adult cats of which one was chicken meal-based (control, with 34.3% chicken meal) and the other BSFL meal-based (inclusion of 37.5% BSFL meal). BSFL meal contained 95.0% dry matter, 53.1% crude protein, 14.3% crude fat, 6.0% ash (Protix, Dongen, The Netherlands). Two groups of four cats were each fed one of the two foods for two 28-d periods in a crossover design, with sample collection during the last 7 d of each period. Cats were housed in groups of the same sex during the first 21 d of each period. Both foods were well-accepted by the cats. No health problems (including coat and skin condition) were noted throughout the study. Food type did not impact body weight (P = 0.850). Food intake was greater when cats were fed the BSFL-based food (P < 0.001). Consistency scores of fresh feces were optimal and did not differ between the foods. Compared with the control food, the food with BSFL meal had decreased apparent fecal digestibility values for dry matter, organic matter, nitrogen, and gross energy (P < 0.05) although all values were high. Digestibility values for acid-hydrolyzed fat were similar for both foods (P = 0.628). Diets resulted in changes in fermentation product concentrations, like fecal ammonia was less when cats fed this food compared with the control food (P < 0.001), but the fecal concentrations of the short-chain fatty acids and biogenic amines were generally increased (P < 0.05). Moreover, reduced fecal bacterial diversity and affected bacterial relative abundance suggested that inclusion of BSFL meal steered the microbial composition in the distal gut of cats. It was observed increased relative abundance of bacteria genus considered beneficial for host health like Bifidobacterium (P < 0.001) and Megasphaera (P < 0.036); and inhibition of genus Negativibacillus and Lachnoclostridium (P < 0.001), previously associated to digestive issues and negative for gut health. Overall, the data gathered in this study suggests that BSFL meal is an adequate alternative ingredient for extruded dry cat foods and may exert a prebiotic effect on intestinal microbiota.
299 Impact of antimicrobial bathing on canine dermal microbiota regrowth
Authors: Discepolo Dakota , Bender Kelly , Crowell Cierra N , Watson Adrian , Perry Erin B
Published: September 2024

Recent public health concerns have heightened concerns regarding the potential for contact transfer of bacteria from dogs to humans. Pathogenic bacteria including strains of Staphylococcus are of specific concern and have raised the question regarding the use of antimicrobial based bathing methods for potential mitigation. Common veterinary antimicrobial cleansers such as chlorhexidine gluconate have been suggested as possible decontamination cleansers. Chlorhexidine gluconate bathing has been well studied in humans. However, its use beyond surgical preparation is not well examined in canines. Therefore, the objective of this work was to identify the time frame associated with dermal microbial regrowth following an antimicrobial bath designed to mimic a decontamination procedure using chlorhexidine gluconate. Labrador Retrievers (n = 10) were assigned to treatment group (control = CON; chlorhexidine gluconate = CHX) and were bathed by a single trained technician using either water (CON) or chlorhexidine gluconate (CHX). Baths included the application of 280 mL of treatment (CON = water; CHX = 4% chlorhexidine diluted 1:4). Three dermal swabs were collected at the shoulder blades at baseline (prior to bathing) and across the following timepoints after the bathing procedure: 1 h, 12 h, 24 h, 36 h, and 48 h. Swab solutions were diluted to 108. All dilutions were plated on nutrient agar and incubated at 30° C for 44 to 50 h. Colony counts were measured to calculate final cells/mL concentration of samples. Mean concentration per timepoint for each canine was used for analysis using SAS on Demand with significance determined at P = 0.05. Mean concentration values over time compared with baseline were analyzed for effects of time, treatment group, and sex via PROC GLM between by within ANOVA. Time following bathing, treatment and sex significantly impacted bacterial regrowth (P < 0.0001). Bacterial growth did not differ significantly until 24 h following bathing at which point the CON group regrowth began. Dogs in the CHX group had reduced regrowth through the 48 h following bathing and failed to completely recover by 48 h post bathing. Males had increased regrowth compared with females in both CHX and CON groups. These results indicate a surprising time delay associated with antimicrobial bathing. The antimicrobial effect of chlorhexidine gluconate was not fully evident until 24 h and had differing impacts based on sex in the studied canines. Future studies should examine these findings in larger research cohorts with different breeds to identify impacts associated with coat type, sex, and more frequent sampling intervals.
300 Awardee Talk: Elisabeth Huff-Lonergan
Authors: Huff-Lonergan Elisabeth
Published: September 2024

The science of pet food processing is an emerging area of interest for many companion animal scientists. Pet food science has an essential role in ensuring the health and well-being of companion animals, and in the sustainability and viability of the animal agriculture industry. Many ingredients used in pet foods are co-products of human food production. Meat products, including whole meats, mechanically deboned meat, and rendered protein meals, are often used as a principal source of highly digestible, well-balanced proteins and, vitamins and minerals. These products are transported, stored, and processed under various means. Many of these processes can have a detrimental impact on the nutrient and functionality of the protein component. Proteins are susceptible to many changes during processing that can impact their functionality, nutritional quality, and digestibility - including oxidative degradation. Oxidation of proteins is critical to understand as it can affect the functionality and quality of the diet. However, protein oxidation, from exposure to oxygen, heat, and light, has often not been well explored. Oxidized proteins may lead to reduced palatability, decreased digestibility, and other aspects of product quality of pet foods. Understanding protein oxidation mechanisms and their impact on product quality can help develop effective mitigation strategies for producing and maintaining high-quality pet food. There is a need for ongoing work to identify antioxidants, processing techniques, and storage conditions that minimize protein oxidation. Another critical need for the industry is to educate future pet food scientists to answer new problems and capitalize on innovative solutions. However, despite the growing demand for high-quality pet food, there remains a gap in specialized education for aspiring pet food professionals. Traditional animal science programs often lack dedicated coursework on companion animal nutrition and formulation, specifically pet food processing. On both the science of processing and the education of the next generation of scientists and industry professionals, there is a need to continue to draw on perspectives from the human food industry. As the pet food industry continues to evolve, it faces several challenges related to product quality, innovation, and the need for scientists who understand the pet food industry.
305 Factors influencing palatability of wet cat food
Authors: Beer Lesleigh C , LePore Angela , Stutsman Pauline Morin , Lambrakis Leah K , White Brittany L
Published: September 2024

Mouthfeel and piece shape are important to feline palatability preference; however, the impact of these attributes on wet pet food palatability has not yet been well established. Moreover, food acceptance is a primary decision factor for cat parents while flavor, ingredients, and brand are key selection contributors when buying wet cat food. The objective of this study was to evaluate consumption preference of adult cats for different formats of wet pet foods. Formulations were created in a commercial pet food manufacturing facility and included five product formats: paté, minced, shreds, standard cuts in gravy, and flaked. The primary protein source was chicken, and equivalent ingredients were used to maintain format as the variable. Pairs of formats were fed in a series of two-bowl feeding studies (n = 9). Each feeding panel (n = 20 cats) was fed for 3 d with bowls presented for 2 h. Bowl position was reversed daily, and both bowls were removed if one format was fully consumed before 2 h elapsed. Significance was determined at P < 0.05. Paté performed at parity (P > 0.05) to minced, standard cuts in gravy, and flaked formats. Similarly, both the minced and the standard cuts in gravy format performed at parity (P > 0.05) to flaked or shreds format, respectively. The overall consumption ratio of shreds was significantly greater (P < 0.05) as compared with the paté (1.85:1) and the minced (1.67:1) format. Similarly, minced was significantly preferred (P < 0.05) to the standard cuts in gravy format (2.07:1). Interestingly, a subsequent feeding study demonstrated that cats consumed a significantly greater (P < 0.05) ratio of a minced format containing 4% extra gravy (46% minced:54% gravy) as compared with a typical minced with gravy format (50% minced:50% gravy; 1.93:1). In conclusion, these data suggest shreds or minced formats with additional gravy could lead to enhanced palatability of wet pet food for cats. This presentation will further investigate how various factors such as processing conditions, nutrient composition, palatants, ingredient selection, and freshness influence the palatability of wet cat food.
32 Biotics: Are there differences?
Authors: Swanson Kelly S
Published: September 2024

In companion animals, the search for dietary ingredients and supplements that may promote health and longevity continues. Because stool quality issues and gastrointestinal diseases are common, substances addressing gastrointestinal health are of interest and some of the most heavily studied. Given the importance that microbiota have on host health and disease, many strategies function by directly or indirectly influencing the microbial species that inhabit the gut. Dietary fibers may impact gut health by maintaining stool quality, providing laxation, reducing fecal odor, and modulating fermentative end-products. A variety of biotic substances may also be used to promote gastrointestinal health. Four primary biotic substances exist, namely probiotics, prebiotics, synbiotics, and postbiotics. Over the past decade, the International Scientific Association for Probiotics and Prebiotics (ISAPP) has sponsored expert consensus panels to update the biotic definitions, offer criteria for qualification, outline guiding principles for research and development, and provide implications for a variety of stakeholders (scientists; media; regulators; industry). In 2014, Hill et al. defined probiotics as “live microorganisms that when administered in adequate amounts confer a health benefit”. Gibson et al. (2017) defined prebiotics as “substrates that are selectively utilized by host microorganisms conferring a health benefit.” Probiotics and prebiotics have been widely used in pet products over the past few decades. Swanson et al. (2020) updated the synbiotic definition to be a “mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confer a health benefit”. Synbiotics may contain components that operate independently (complementary synbiotic) or in together (synergistic synbiotic) to promote host health. In 2021, Salminen et al. defined postbiotics as “preparations of inanimate microorganisms and/or their components that confer a health benefit.” Yeast and bacteria-based mixtures falling under this definition have become more popular in pet nutrition as of late, but the postbiotic definition is often misused. This presentation will discuss each biotic substance category in regard to their use in dogs and cats. Mechanisms of action, potential benefits of consumption, evidence of successful use in companion animals, and ideas for the future of biotics will be presented.
163 Affecting the senses: Impacts of pharmaceuticals and nutraceuticals on olfactory acuity
Authors: Singletary Melissa
Published: September 2024

Evolutionary pressures have driven species-specific sensory system modifications resulting in a diversity of capabilities and adaptations. The sense of smell, olfaction, is an important sensory system in companion animals for communication, modulating behavior and influencing biological fitness. The enhanced olfactory acuity of companion animals relative to humans, and in particular domestic dogs, has led to employment of these animals in modern society as highly capable biological sensors. The use of pharmaceuticals and nutraceuticals in companion animals may directly or indirectly impact olfactory acuity. Identifying knowledge gaps, exploring capabilities, and addressing limitations associated with pharmaceutical and nutraceutical interventions is important in optimizing outcomes and maintaining minimal side effects, especially in working animals performing olfactory-based tasks.
162 The role of functional amino acids in optimizing nutrition and health
Authors: Shoveller Anna K , Columbus Daniel A
Published: September 2024

The ability of a diet or an individual protein-containing ingredient to satisfy the indispensable amino acid (IAA) requirements of an individual is a reflection of protein quality. In human nutrition, the concept of PQ is well recognized and widely applied to facilitate guidance on the extensive range of food items we consume. In the pet food industry, the concept of PQ is gaining recognition as a way in which to identify ideal candidate ingredients for diet formulation and our laboratory has recently completed a large data base of PQ estimates of typical ingredients used in the pet food industry to compliment the emerging PQ ingredient data. Our laboratory has also used more advanced methodologies, specifically the IAAO technique, to measure the dietary Phe, Trp, Met, Thr, and Lys requirements for adult dogs of small, medium and large breed dogs. The role of AA beyond support of protein turnover (adults) or protein deposition (growth) is being explored, such as the role of certain AA in behavior, immune function and inflammation. For example, the ratio of tryptophan to the large neutral amino acids of 0.75:1.0 in contrast to 0.46:1.0 resulted in better indices of gut health and may reduce agonistic behaviors both of which are underpinned by improved serotonergic status. The role of the sulfur AA in the development of dilated cardiomyopathy further highlights the role of IAA as sources for secondary metabolites, such as taurine and glutathione in supporting animal health. Indeed, many AA are becoming referred to as functional AA and the requirement of these AA may differ in healthy and challenged animals and deserve attention in dog and cat nutrition as well. Overall, the pattern of AA that defines the requirement of healthy dogs and cats, may not be the pattern that would support the animal under challenging conditions. Research into supporting different physiological challenges and how these may affect amino acid requirements is warranted.
164 Combining in silico, in vitro, and in vivo approaches for studying taste perception and preferences of domestic cats and dogs
Authors: McGrane Scott J
Published: September 2024

Developing food products for pet cats and dogs is an important and challenging area of the food industry. The diet offered must be both balanced and palatable to ensure the amount of food eaten meets their nutritional requirements. The taste perception of pets is different from humans in many cases (Li et al., 2005) and therefore species-specific research is necessary. Hence, understanding the flavor preferences of cats and dogs is an important area of research and requires multiple disciplines and scientific approaches. We have developed a range of complimentary methods for studying taste perception and preferences of domestic cats and dogs In silico: homology models of the pet taste receptors have been developed. These models are used to identify candidate compounds and elucidate the mechanisms of taste perception of pets. In vitro: cell-based high throughput screening assays of pet taste receptors have also been developed. These assays are used to identify taste-active compounds and confirm response to those identified via the in silico method to refine the model. In vivo: finally, a two-bottle choice test for cats has been developed. This test is used to confirm hedonic responses and determine optimum concentrations of single compounds and mixtures identified by the in silico and/or in vitro methods. Using this novel approach, we now have a deeper understanding of the taste perception and preferences of pets, with specific examples including Umami (McGrane et al., 2023) and Kokumi (Laffitte et al., 2021) taste perception of cats and bitter taste perception of dogs (Gibbs et al., 2022). This approach has also enabled us to reduce the number of in vivo tests required, so implementing the 3Rs, by prioritizing the most promising tastants using the in silico and in vitro methods. Gibbs, M., Winnig, M., Riva, I., Dunlop, N., Waller, D., Klebansky, B., Logan, D.W., Briddon, S.J., Holliday, N.D., McGrane, S.J. 2022. Bitter taste sensitivity in domestic dogs (Canis familiaris) and its relevance to bitter deterrents of ingestion. PLoS One. 17:e0277607. Laffitte, A., Gibbs, M., Hernangomez de Alvaro, C., Addison, J., Lonsdale, Z.N., Giribaldi, M.G., Rossignoli, A., Vennegeerts, T., Winnig, M., Klebansky, B., Skiles, J., Logan, D.W., McGrane, S.J. 2021. Kokumi taste perception is functional in a model carnivore, the domestic cat (Felis catus). Sci Reports 2021 111. 11:1–17. Li, X., Li, W., Wang, H., Cao, J., Maehashi, K., Huang, L., Bachmanov, A.A., Reed, D.R., Legrand-Defretin, V., Beauchamp, G.K., Brand, J.G. 2005. Pseudogenization of a sweet-receptor gene accounts for cats’ indifference toward sugar. PLoS Genet. 1:0027–0035.McGrane, S.J., Gibbs, M., Hernangomez De Alvaro, C., Dunlop, N., Winnig, M., Klebansky, B., Waller, D. 2023. Umami taste perception and preferences of the domestic cat (Felis catus), an obligate carnivore. Chem Senses. 48.
166 Development of non-model organoids in animal research: A paradigm shift in in vitro models
Authors: Zdyrski Christopher , Nicholson Hannah , Catucci Michael , Elbadawy Mohamed , Ralston Abigail , Feauto Ryan , Barko Patrick , Williams David , Chakrabarti Jayati , Zavros Yana , Orbay Maru , Rawlings Emily , Saba Corey , Mochel Jonathan , Allenspach Karin
Published: September 2024

For decades, two-dimensional (2D) cell cultures have been used as the gold standard in vitro models for basic research, drug discovery and preclinical screening applications. However, since 2009, the field has quickly shifted towards the use of three-dimensional (3D) stem cell-derived organoids. Organoids offer a variety of advantages compared with conventional 2D models, including being self-organized, retaining their cellular polarity, and being simplified versions of organs in vitro. Adult stem cells can self-renew, differentiate into multiple cell types, and are genomically stable over multiple passage lines, providing a variety of technical benefits and offering the closest recapitulation of the in vivo environment. Our laboratory has focused on expanding, characterizing, and utilizing animal-derived 3D organoid models, specifically focusing on canines; but also including other animals such as swine, turtles, snakes, and squirrels to study their unique adaptations. Practically, we can use 3D canine colonoids for the screening of anti-inflammatory candidates using our tumor necrosis factor (TNF)-α stimulation model. Additionally, we have grown and used swine lung organoids as a model for studying H1N1 viral uptake. Furthermore, we have grown and bio-banked tumor organoids/spheroids from a variety of canine cancers, including urothelial carcinoma (derived from urine and biopsies) and nasal carcinoma, among others, with future applications in precision veterinary medicine and comparative oncology. To accomplish this goal, we have carried out in vitro screening of a variety of chemotherapies and combination therapies at different concentrations across patients to predict in vivo responses and demonstrate the predictive ability of the organoid model. Finally, our laboratory has derived and characterized a variety of healthy organoid lines from canines including the pancreas, lung, liver, bladder, colon, and pituitary to act as healthy controls in mechanistic studies looking at disease pathogenesis and for uses in basic biology. In summary, in vitro organoid models from various animal species and tissues can be used in a variety of basic and applied research fields, including virology, toxicology, and oncology, with the potential to broaden our scientific understanding of disease and overall improve human and veterinary medicine.
167 Using ‘omics’ to optimize nutrition and health outcomes
Authors: Slupsky Carolyn M
Published: September 2024

It is clear that diet is linked with health outcomes, yet we are still far from fully understanding the impact of diet on systemic metabolic health. In the new era of ‘omics’ technology, the ability to optimize nutrition across the lifespan of companion animals is within reach. We have been using ‘omics’ technologies to understand how changes in diet composition impact metabolism using a neonatal piglet model. By measuring the composition of sow milk over the first week of lactation, we created an optimized pig milk replacer, and studied the impact of varying the whey protein composition of the milk replacer using a combination of metabolomics on blood, urine, liver, and brain tissue, as well as transcriptomics of intestinal, liver and brain tissue. Our results revealed a substantial impact of the type of whey protein on piglet metabolism that included differences in cortisol, blood and tissue amino acid profiles, and immunity. This work paves the way for additional studies to optimize animal nutrition in the neonatal period and beyond.
324 Use of organoids as in vitro model to study intestinal function
Authors: Saqui-Salces Milena
Published: September 2024

Organoids are tridimensional structures cultured in the lab from stem cells. Organoids have been developed for many different organs, particularly those with Lgr5+ stem cells. The organs of the digestive system belong to this group of organs and to date, organoids have been established from all the digestive tract tissues and organs including liver, gall bladder and pancreas. Although most protocols to generate organoids have focused on human and mouse organs, organoids from domestic and production animals like dogs, cats, rabbits, pigs, chickens, turkeys, and horses are actively used in research. In this presentation, the principles of developing intestinal organoids will be covered, along with a summary of how they have been used to address intestinal function and disease in our lab and by others. In our lab, we use swine enteroids (intestinal organoids) to study the intestinal epithelial responses to nutrients and pathogens. We have explored differential responses of the intestinal epithelium to organic and inorganic sources of dietary zinc, and we are currently investigating the mechanism of pathogenesis of Lawsonia intracellularis, the causative agent of porcine intestinal adenopathy. We will also discuss methods for modeling intestinal physiology using enteroids, and the advantages and challenges of working with swine enteroids.
321 Application of the Fick Principle for the study of visceral nutrient absorption and metabolism
Authors: Harmon David L , Huntington Gerald B
Published: September 2024

In 1870, Adolf Fick introduced the concept for the calculation of cardiac output by measuring gas exchange in the lungs at a meeting of the Würzburg Physiology and Medical Society. It was not until around 1930 after the development of cardiac catheterization that it was fully verified. Fick’s equation also serves as the basis for all indicator dilution methods for measuring blood flow and has been applied to several tissues throughout the body. By measuring the blood concentration of nutrients supplying and draining a tissue bed, coupled with the flow of blood, the net nutrient exchange can be calculated. Researchers first began investigating the movement of nutrients into the portal system of ruminants in the 1950s and the first method for measuring nutrient exchange in small ruminants was published in the 1960s. This approach requires the implantation of vascular catheters into an artery and the hepatic portal vein which drains the stomach, intestines, and spleen. An additional catheter is implanted upstream in a mesenteric vein for infusion of a blood flow marker, and the addition of a catheter in a hepatic vein allows the measure of blood flow and nutrient transfer in the liver. These methods were adapted for calves and dairy cows in the 1970s. The 1980s brought further refinement of the methodologies such as improved catheter materials allowing animals to be maintained for extended periods and, several researchers published data from cattle, sheep, and goats. These methods have been coupled with measures of ruminal and intestinal disappearance as well as isotopic tracers to examine nutrient exchange and metabolism by tissues. The goal of this presentation is to review the development of this approach for studying nutrient absorption in vivo, and to highlight specific advancements in its application.
173 The who, what, and why of Scope 3: The corporate animal agriculture sustainability journey
Authors: Klopatek Sarah C
Published: September 2024

The drive for companies to reduce emissions from their Scope 3 inventories, particularly from livestock production, is relatively well known within the academic community. What is less well known are the pressure origins of the Scope 3 reductions and the process companies undergo to ensure greenhouse gas (GHG) reductions can come to fruition. Principally, before a reduction can be recognized GHG inventories must first be established. For these inventories to be recognized by the financial institutions, companies are required to follow rigorous reporting standards. Although these standards are vital to help ensure accounting accuracy, they have also revealed many tribulations animal agricultural faces in meeting Scope 3 reduction goals. These obstacles include limited traceability in supply chains, lack of consensus on empirical data collection, and the inability to recognize real time industry progress when using lagging emission factors. These obstacles are not insurmountable but there does need to be an academic and industry consensus on how reductions and removals can be evaluated within supply chains. Once this gap is alleviated companies have a greater opportunity to enact scalable, cost effective GHG removal and reduction strategies within their value chains.