bluuebunny/crossref_metadata_2025 huggingface dataset:
196 The Effect of Hydrolyzed Protein on Fecal Microbiota in Adult Dogs
Authors: Hsu Clare , Marx Fabio , Guldenpfennig Ryan , Valizadegan Negin , de Godoy Maria R C
Published: November 2023

Research on protein hydrolysates has observed various properties and functionalities of these ingredients depending on the type of hydrolysate. The objective of this study was to evaluate the effect of hydrolyzed chicken protein that was incorporated into diets on gut health in healthy adult dogs. Five complete and balanced treatment diets were manufactured: 1) CONd: chicken meal diet; 2) 5% CLHd: 5% substitution of chicken liver hydrolysate of chicken meal diet; 3) CLHd: chicken liver hydrolysate diet; 4) 5% CHd: 5% substitution of chicken hydrolysate of chicken meal diet; and 5) CHd: chicken hydrolysate diet. A 5×5 Latin square design was used which included 10 neutered adult beagles. Each of the 5 periods consisted of a 7-d washout time and a 28-d treatment period. All diets were well accepted by the dogs. For fecal metabolites, there was greater fecal butyrate concentration as well as reduced isovalerate, 4-ethylphenol, and indole in dogs fed CLHd than CONd (P < 0.05). Regarding the overall microbiota composition, Firmicutes, Bacteriodota, Fusobacteriota, Actinobacteriota, and Proteobacteria were the top 5 most abundant phyla. At the class level, samples from CHd group had greater relative abundances of Bacteriodia and Fusobacteriia as well as less Bacilli. On the other hand, CLHd group had greater abundances of Bacilli and Actinobacteria with less Fusobacteriia. At the level of order, CHd group had greater Bacteriodales and Fusobacteriales while CLHd group had greater Bifidobacteriales. At the family level, CHd group showed a greater abundance of Muribaculaceae and a decreased abundance of Bifidobacteriaceae when compared with the other groups. Alternatively, CLHd group demonstrated a greater abundance of Bifidobacteriaceae together with reduced abundance of Fusobacteriaceae, Muribaculaceae, Sutterrellaceae, and Ruminococcaceae. Fecal microbiota was shifted by CLHd with greater differential abundance in Ruminococcus gauvreauii group as well as reduced Clostridium sensu stricto 1, Sutterella, Fusobacterium, and Bacteroides compared with CONd (P < 0.05). There was also a difference in beta diversity of fecal microbiota between CLHd and CHd (P < 0.05). However, no difference was observed in alpha diversity among treatment groups (P < 0.05). Fecal butyrate concentration was negatively correlated with the genera Blautia, Phascolarctobacterium, Sutterella, Faecalibacterium, and Bacteriodes. Conversely, Allobaculum and Bifidobacterium were positively correlated with butyrate concentration. In conclusion, the test chicken protein hydrolysates may have potential to support gut health by modulating microbiota.
84 Advances, Challenges and Prospects for the Sustainable Use of the chigüiro in Colombia
Authors: López Arévalo Hugo Fernando , Mesa Elizabeth , Montenegro Díaz Olga Lucía , Sánchez Pedro , Quiroga Guillermo , Mora Catherine , Serrano Hernán , Cáceres Rocío , Cáceres Carlos
Published: November 2023

The sustainable use of chigüiro or capybara is a strategy proposal to prevent the decline of the species population by maintaining and conserving appropriate habitats, reducing illegal capture, promoting its recognition, and achieving a better distribution of its benefits and its environmental services. The objective of this work is to present the progress made toward the sustainable use of capybaras in Colombia. The biological information compiled during the last 15 years indicates that the density of the populations of this species is heterogeneous throughout the flooded savannahs with space-time variations between < 1 individual/ha, and up to 6 individual/ha. These variations are associated with strong climatic variations, changes in habitat quality, and the impact of a series of conditioning factors, both natural (water availability over time) and anthropogenic origin (hunting, land use, eventual competition with cattle, and the incidence of burning). Commercial hunting as a sustainable strategy includes the identification of various products and by-products of the species, as well as its linkage in Bioeconomy projects (Figure 1) through the compliance of associated normative, the reinforcement of environmental authorities, an effective communication strategy and user commitment. Capybara meat is characterized by having a low-fat content and a protein ratio greater than 20%; and its carcass meat performance is between 44% and 53%. In addition to the training in the preparation of various meat by-products and the analysis and processing of the fur, there is an updated market study that includes an interview phase, a pilot test of exploitation, yields and tastings for approach to the actor of the commercial chain and meet future investors or buyers. With these results, a financial model was formulated with all the necessary costs to make use of the Chigüiro products. Additionally, a prototype processing plant was designed and it has three mobile components (A, B, C); two complementary fixed structures (D, E) and a module for the processing of by-products and waste (Figure 2). Finally, linking capybara population concentration points within ecotourism activities will expand the options for its use and conservation of the Chigüiro population and its habitats. Among the actual limitations for Chigüiro use we have the delay in issuing the resolution for the allocation of the global utilization quota, and the modification of the closure to increase the period of use. These resolutions will encourage the participation of other users and local investors, which is expected to reduce the transformation of natural ecosystems and their associated biodiversity.
408 Awardee Talk: Team Approach to Beef Cattle Extension Programming
Authors: Lehmkuhler Jeffrey
Published: November 2023

Over 100 years ago, the Smith Lever Act created the Cooperative Extension Service in conjunction with the land grant institutions. Extension has seen much change with a never-ending list of challenges presenting themselves. Graduate training programs are typically discipline focused, answering questions using the scientific method. Most new hires have limited exposure to Extension educational program development and likely have not received training in curriculum planning, program assessment or logic model development. The learning curve can be even steeper when one accepts a position with multiple disciplinary responsibilities or outside their industry sector focus (i.e., cow/calf verses feedlot nutrition). Success is often determined by developing relationships with experienced faculty both at their institution and others in the region. Guidance can be sought from these experienced individuals, knowledge can be gained from their successes and failures, and one can learn the Extension arm of the land grant system quickly from these relationships. Relationships should not be limited to the home department of the individual but should reach across disciplines to engage others to work with and learn from to aid in developing a system-wide view of agricultural production. Regional research and extension groups are key contributors to building multi-state programming of new Extension specialists. Access to funds is critical for the implementation of Extension programming and these networks increase funding opportunities. My success in Extension is a shared success with all those that were kind enough to take the time to teach me a little of their area of expertise. Having the willingness to be part of a team in developing Extension programming for beef cattle has resulted in a rewarding career. New hires in the Extension specialist role will find building a team to work with to develop effective beef programs will ease their transition from graduate student to Extension specialist.
422 Mineral Content of Invaded Grassland Forages Is Affected By Precipitation and Management
Authors: Christensen Rachael G , Hendrickson John R , Toledo David L
Published: November 2023

Mineral content of grazed forage influences overall health, growth and reproduction of cattle and promotes maximum cattle productivity. However, grassland mineral content may not always meet cattle requirements throughout the grazing season and can be affected by precipitation of the season. Most of the Northern Great Plains grassland is invaded by exotic perennial grass species that have a uniform growth habit and response to precipitation. Growth habitat can be controlled by grazing or mowing, which may alter mineral content. No studies have examined the combined effects of mowing and drought on forage mineral concentration of invaded grassland. Therefore, the objective of this study was to determine mineral concentration of forage in rangeland pastures in seasons of low compared with normal precipitation and mowing status and model recommendations for mitigating low mineral content. This study was conducted at the Northern Great Plains Research Laboratory in Mandan, North Dakota USA. Pastures were sampled across several years and pasture locations, with enclosed plots mowed or not mowed in April, to simulate early season mobgrazing or clipping. Quarter- meter quadrats were taken every two weeks of the grazing seasons from plots in each pasture, one year dry and the other normal. Samples were analyzed for macrominerals and trace minerals via ICP-aa spectroscopy. Forage mineral content was analyzed as a completely randomized design using the MIXED procedure of SAS (SAS 9.4, Cary, NC). Total ash content was different by year (P = 0.0053) but not affected by mowing (P = 0.21). Potassium and phosphorus were not different due to mowing, nor effected by precipitation. Calcium was affected by mowing (P = 0.0065) and tended be affected by precipitation (P = 0.11). Zinc, copper, molybdenum, manganese and iron were all found to be significantly affected by precipitation (P < 0.001). When applied to a beef nutrient requirement model, Ca and P were generally adequate to meet recommended amounts for lactating cows based on a May-calving 1,200-pound cow most months of the season but did not meet needs of a 1400 lb. cow and calf. Forage phosphorus content was significantly less in June of each year, but adequate the rest of the season, suggesting targeting phosphorus supplementation for only the least months would save on mineral costs. Understanding forage mineral fluctuations across the grazing season may provide producers with tools to make the best supplementation strategies and use the most appropriate mineral formulations to maximize performance and reduce input cost.
240 Prolonged Maternofetal Inflammation in the Pregnant Ewe at Mid-Gestation Increases Subsequent Fetal Inflammatory Tone and Disrupts Skeletal Muscle Growth and Glucose Metabolism Near Term
Authors: Hicks Zena M , Gibbs Rachel L , Beer Haley N , White Melanie R , Lacey Taylor A , Grijalva Pablo Cesar C , Most Micah S , Schmidt Ty B B , Peterson Jessica L L , Yates Dustin T
Published: November 2023

Chronic maternofetal inflammation in late gestation (i.e., peak fetal growth) causes fetal intrauterine growth restriction (IUGR) in sheep, which was associated with deficits in growth, body composition, and metabolic function before and after birth. However, the impact of sustained maternofetal inflammation during mid-gestation (i.e., peak placental growth and development) has not been explored. Therefore, our objective was to determine the effects of sustained maternofetal inflammation during this critical window on subsequent fetal inflammatory tone, metabolism, and myoblast (i.e., muscle stem cell) function. Pregnant ewes were injected every 3rd day from the 50th to 65th d of gestational age (dGA; term = 150 dGA) with saline (control; n = 12) or bacterial lipopolysaccharide endotoxin to induce maternofetal inflammation and IUGR (MI-IUGR; n = 12). Fetuses were surgically catheterized on dGA 118 to collect blood samples, and a hyperinsulinemic-euglycemic clamp (HEC) was performed on dGA 123. Fetuses were necropsied on dGA 125 to collect semitendinosus muscle samples. Fetal plasma TNFα concentrations tended to be greater (P = 0.07) for MI-IUGR fetuses (440 ± 45 pg/m l) than for controls (348 ± 24 pg/mL). Fetal blood O2 partial pressures were 12% less (P < 0.05) and maternofetal O2 gradients tended to be 11% greater (P = 0.08) for MI-IUGR fetuses than for controls. Hindlimb-specific glucose uptake rates did not differ between fetal groups, but hindlimb-specific glucose oxidation rates were reduced (P < 0.05) by 15% under basal conditions and by 27% under hyperinsulinemic conditions for MI-IUGR fetuses compared with controls. Semitendinosus glycogen content and β2 adrenoceptor content did not differ between fetal groups, but semitendinosus content of the TNFα receptor, TNFR1, was 41% greater (P < 0.05) for MI-IUGR fetuses than for controls. Immunohistochemistry revealed 18% fewer (P < 0.05) proliferating myoblasts (pax7+/Ki67+) and 38% fewer (P < 0.05) differentiated myoblasts (myogenin+) in semitendinosus from MI-IUGR fetuses compared with controls, which coincided with 13% smaller (P < 0.05) muscle fibers. From these findings, we conclude that sustained maternofetal inflammation during peak placental development at mid-gestation resulted in enhanced fetal inflammatory tone near term, which in turn impaired myoblast function, muscle fiber hypertrophy, and muscle glucose metabolism.
242 Methionine and Guanidinoacetic Acid Supplementation During the Periconceptual Period of Gestation Shifts Methionine Metabolism of Fetal Bull Calves at D 63 of Gestation
Authors: Crouse Matthew S , Hauxwell Kathlyn , Caton Joel S , Ward Alison , Dahlen Carl R , Amat Samat , Freetly Harvey C , Lindholm-Perry Amanda , Neville Bryan W , Oliver William T , Thorson Jennifer , Snider Alexandria P , Miles Jeremy R , Cushman Robert A
Published: November 2023

Recent research has demonstrated that feeding rumen protected methionine (MET) products increases circulating methionine while feeding guanidinoacetic acid (GAA) may result in a methyl deficiency. Therefore, we hypothesized that maternal MET or GAA supplementation from 63 days before breeding until d 63 of gestation would increase fetal hepatic methyl donors or result in a fetal hepatic methyl donor deficiency, respectively. Eighty MARC II heifers (n = 20 per treatment; initial BW = 344 ± 8 kg; day -63) were weighed and assigned to one of four breeding groups and four treatments stratified by age and starting weight. Heifers were fed a total mixed ration to gain 0.68 kg/d and received 100 g of one of four treatments top dressed: control supplement of ground corn (CON), MET (10 g/d) in a ground corn carrier, GAA (40 g/d) in a ground corn carrier, or MET + GAA (10 g/d MET + 40 g/d GAA) in a ground corn carrier. At breeding (d 0), all heifers were bred to a single sire using male sexed semen. At d 63 of gestation, 35 heifers (CON n = 10, MET n = 8, GAA n = 7, MET + GAA, n = 10) confirmed pregnant with bull calves were humanely slaughtered and fetal liver tissues were collected and sent to Metabolon Inc. for global metabolomics analysis. Data were analyzed as a 2 x 2 factorial with 2 levels of GAA and 2 levels of MET with breeding group included in the model. For this abstract, only metabolites from the methionine cycle and adjacent pathways will be reported and only metabolites with significant P-values will be discussed (P ≤ 0.05). There were no main effects or interactions for the abundance of methionine, GAA, creatine, SAM, SAH or homocysteine. Glycine was decreased and sarcosine increased in fetuses from MET supplemented dams. Serine was affected by a MET x GAA interaction being decreased in livers of CON, MET, and MET + GAA fetuses compared with GAA. Cystathione, S-methylcysteine, s-methylcysteine sulfoxide, and hypotaurine were greater in fetuses of MET supplemented heifers and pyridoxal phosphate was reduced in fetal liver of MET supplemented heifers. The abundance of urea was greater in GAA supplemented fetuses. These results indicate that fetuses from dams fed methionine may be able to maintain balance in methionine supply by shunting methionine through adjacent pathways including the transsulfuration pathway. We also interpret these data to imply that excess methionine is not utilized by the fetus and is metabolized to products that can be excreted. Lastly, GAA did not alter the fetal methyl supply. USDA is an equal opportunity provider and employer. Funded by (USDA-NIFA-AFRI # 2022-67015-36196).
281 Modeling How the Inclusion of Fibrous By-Products to the Feed Improves the Net Protein Contribution of Pork Meat
Authors: Marbà Berta Llorens , Remus Aline , Pomar Candido
Published: November 2023

Animal meat provides high-quality protein to the human food industry, but often uses feed ingredients that could also be used to feed humans. The objective of this study was to model how the inclusion of by-products in pig diets would improve the net protein contribution (NPC) of pig meat within an individual precision feeding (IPF) program. The InraPorc model was used to simulate the animal response to pigs fed two different feeding treatments. In both cases, there was feed A (rich-), and B (poor in all nutrients). Feeds were mixed daily to each pig to meet individual requirements. Treatment 1 (BY0) was free of by-products, consisting of traditional ingredients (corn, wheat, and soybean meal). Treatment 2 (BY20) included canola meal and oat hulls in addition to conventional ingredients. These inclusions accounted for nearly 10% of changes in feed A and nearly 20% in feed B. The consumed HeP in pig-fed was estimated from the beginning of the growing-finishing phase to slaughter. Total pig HeP included the carcass meat, fancy meats such as heart, liver, kidney, and tongue, and 25% blood. HeP conversion efficiency was calculated based on the HeP profiles for initial (23 kg) and final body weight (120 kg) in both treatments. Digestible indispensable amino acid score (DIAAS) was calculated based on a 3-year-old-child protein requirements, the same score being attributed to adolescents or adults. The HeP conversion efficiency was 0.28 and 0.32 for BY0 and BY20 respectively, and the protein quality ratio (PQR, calculated as DIAAS of the meat vs. DIAAS of the feed) was equal to 2 for both diets, indicating that protein quality in pig meat is greater than in animal feed. Finally, the NPC of both treatments, calculated by multiplying the HeP conversion efficiency with the PQR, was below 1. Therefore, neither treatment contributed positively to the net protein contribution of pork meat to the human protein supply. However, the NPC of BY0 and BY20 were 0.58 and 0.64, respectively. Thus suggesting that adding by-products, such as oat hulls, to feed formulas reduces feed-to-food competition.
33 Identification of How Future Climates May Impact the Reproductive Herd and What This May Mean for Nutrition
Authors: Cottrell Jeremy J , Green Mark P , Dunshea Frank R , Liu Fan , Plush Kate J , Zhao Weicheng
Published: November 2023

Changes in our climate with global warming will translate to an expansion in the seasons and an increased incidence of extreme heat events, such that heat stress (HS) will become a major management issue. This poses particular challenges to the reproductive herd, as by virtue of their increased physical size and pregnancy, they are less resilient to environmental challenges. Recent work from our laboratory has quantified the performance of summer mated piglets on productivity, demonstrating that these litters are lighter at birth, have a lighter placenta weight and are more likely to be stillborn. These piglets also take longer to reach market weight and have increased carcass backfat, which can trigger market penalties. Collectively our studies demonstrate that summer conditions result in developmental abnormalities in piglets, potentially through placental insufficiency. Additionally, HS was challenging sows during the periparturient period, resulting in more stillbirths. Two subsequent climate-controlled studies quantified the effects of HS (cyclic 28 to 33 oC) during early to mid-pregnancy (d 40 to 60), when the placenta is undergoing rapid growth, as well as the effects of HS (cyclic 28 to 30 oC) in the periparturient period (d 110 of pregnancy to farrowing). In the first study, gestational HS did not influence the number or size of the piglets at mid-gestation but increased placental mass by 22% and reduced Longissimus muscle fiber hyperplasia by 16%. The apparent enlargement of the placenta at mid-gestation may reflect an adaptation to a reduction in uterine blood flow. In other species, HS is known to reduce blood flow to the splanchnic bed and reproductive tract organs, as blood is redistributed to the periphery and upper respiratory tract to augment heat dissipation. Therefore, the prioritization of placental growth by the piglet may represent an adaptation against a backdrop of insufficient nutrient supply. Whilst reductions in muscle fiber hyperplasia were associated with reduced vascularity, although it is not clear if this was a cause or effect. In the second study, the effects of periparturient HS resulted in a 30% increase in stillbirths, with surviving piglets having lower umbilical vein blood oxygen saturation and increased meconium staining. This supports the likelihood of HS restricting uterine and umbilical blood flows, resulting in increased periparturient fetal stress. Collectively these studies emphasize the challenges that climate change poses to swine production and that addressing these challenges will require a whole farm approach. In the near term, it is likely that advances in nutrition will form an important component in adjusting to a changing climate and minimize production losses.
292 Tandem Administration of Prostaglandin F2α and Gonadotropin-Releasing Hormone in Beef Heifers and Cows as a Convergent Presynchronization Method in the 7 & 7 Synch Protocol
Authors: Palcheff Lucas J , VanWye Genevieve M , Ricardo Kimberly R , Spinka Christine M , Poock Scott E , Thomas Jordan M
Published: November 2023

An experiment was designed to evaluate modifications to the 7 & 7 synch protocol with the hypothesis that tandem administration of prostaglandin F2α (PG) and gonadotropin-releasing hormone (GnRH) during the presynchronization portion of the protocol would generate a convergent ovarian response among anestrous and estrous cycling females. Nulliparous (n = 153), primiparous (n = 92), and multiparous (n = 413) Angus-cross females across four locations were blocked based on parity and pre-treatment cyclicity status (presence or absence of a corpus luteum) as assessed via transrectal ovarian ultrasonography. Within block, females were randomly assigned to one of three treatments. Females assigned to the 7 & 7 Synch treatment received an intravaginal progesterone-releasing insert (CIDR) and administration of PG on day 0, administration of GnRH on day 7, and administration of PG coincident with CIDR removal on day 14. Females assigned to 7 & 7 Synch + G received the same treatment schedule with the modification that GnRH was administered in tandem with the PG on day 0. Females assigned to 7 & 7 Synch + G + P received GnRH in tandem with PG on both day 0 and day 7 of the treatment schedule. Fixed-time artificial insemination (FTAI) was performed at 54 h after CIDR removal for nulliparous females and at 66 h for primiparous and multiparous females. Transrectal ovarian ultrasonography was performed on day 7 and day 14 to characterize the largest follicle diameter (LFD) as well as the presence/absence and number of corpora lutea (CL). Expression of estrus before FTAI was characterized in three locations using estrus detection patches (Estrotect. Approximately 75 to 90 days after FTAI, pregnancy status was determined via transrectal ultrasonography. Day 7 CL status was affected by treatment (P = 0.002), with a greater proportion of females presenting with CL on Day 7 when treated with the modified treatments (64%) as compared with the 7 & 7 Synch treatment (31%). Day 14 LFD was affected by treatment (P = 0.002), with a larger average LFD among females treated with 7 & 7 Synch + G + P (12.0 mm) as compared with 7 & 7 Synch (11.4 mm) or 7 & 7 + G (10.7 mm). Pregnancy rate to FTAI was affected by pre-treatment cyclicity status (P < 0.0001) and semen type (P = 0.0003) and tended to be affected by treatment (P = 0.09) with 7 & 7 Synch + G + P tending to result in a greater proportion pregnant (58.86%) as compared with 7 & 7 Synch (49.17%) and 7 & 7 Synch + G (48.79%). Tandem administration of GnRH and PG on days 0 and 7 of the 7 & 7 Synch protocol effectively generated a convergent ovarian response among anestrous and estrous cycling beef females and tended to result in increased pregnancy rates to FTAI.
293 Impact of Late Embryonic and Early Fetal Mortality on Overall Productivity of Suckled Beef Cows
Authors: Goncalves Lucas Melo , Zoca Saulo Menegatti , Neira Lucas , Burato Samir , Holton Matthew Patrick , Walker Madison , Fontes Pedro L P
Published: November 2023

The objective of this study was to evaluate the effect of late embryonic and early fetal mortality (LEEFM) on the performance of beef cows exposed to fixed-timed artificial insemination (TAI). Postpartum cows (n = 207) from three locations were exposed to a 7-d CO-Synch+CIDR protocol followed by TAI (day 0) and natural service breeding starting 14 days after TAI. Two pregnancy diagnoses were performed on days 29 and 100 and cows were classified as: 1) Maintained (MAINT): cows were pregnant on day 29 and the same pregnancy was confirmed on day 100; 2) LEEFM: cows were diagnosed as pregnant on day 29 but non-pregnant or pregnant by natural service on day 100; and 3) Non-pregnant (NP): cows were diagnosed as non-pregnant to TAI on both days 29 and 100. Cows were evaluated until calves that were a product of the breeding season described herein were weaned. Final pregnancy rates were decreased (P < 0.01) for LEEFM compared with MAINT and NP. Calving (P < 0.01) and weaning rates (P < 0.01) were also decreased for LEEFM compared with MAINT and NP. Average calving day was decreased (P < 0.01) in MAINT cows compared with both NP and LEEFM; however, no differences were observed between NP and LEEFM (P = 0.46). Weaning weight was increased (P ≤ 0.05) for MAINT compared with both NP and LEEFM; however, there were no differences between NP and LEEFM ( P = 0.52). Cows that experienced LEEFM had decreased (P < 0.01) weaning weights per cow exposed compared with both MAINT and NP. In summary, that conceive to TAI and experience LEEFM have decreased performance compared not only to MAINT cows, but also cows that failed to conceive to TAI (NP).
30 Central Regulation of Kndy Neurons During Undernutrition in Sheep
Authors: Nestor Casey
Published: November 2023

Adequate energy intake is essential for reproduction. While we have known for decades that feed restriction inhibits gonadotropin-releasing hormone/luteinizing hormone (GnRH/LH) secretion, the central mechanisms that govern this reduction during undernutrition remain to be fully elucidated. The past few years, we have focused on examining central mechanisms whereby chronic feed restriction in young sheep results in the inhibition of LH secretion. This presentation will focus on our current understanding of how feed restriction impacts kisspeptin/neurokinin B/dynorphin (KNDy) neurons in young sheep and will give a glimpse into our next few years as we examine how input to KNDy neurons could play a key role in regulating reproduction during undernutrition.
302 Incremental Variables in Predicting Beef Cattle Dry Matter Intake
Authors: Blake Nathan , Walker Matthew , Holaskova Ida , Mata-Padrino Domingo , Wilson Matthew E
Published: November 2023

The great strain of increasing climate variability on animal agriculture necessitates improvement of current production processes, the development of methods to measure individual feed and water intakes, and the improvement of feed and water use efficiency in cattle. The use of machine learning (ML) approaches in predicting beef cattle dry matter intake (DMI) have provided groundwork for improvement of beef cattle production using big data and ML. However, despite wide variation between daily feed intakes, typical variables in animal intake-based ML approaches are not incremental, not allowing for daily prediction of intake. Our work introduces first-differenced intake, climate, and animal performance variables into a ML algorithm to predict beef cattle DMI and increase the immediacy of prediction applications. A total of 745 animals were evaluated in eight test groups from 11/25/2019 to 9/2/2021 in a dry lot equipped with In-Pen Weighing Positions and Feed and Water-Intake Nodes. Relationships among average daily gain (ADG), DMI, residual feed intake (RFI), water intake (WI), residual water intake (RWI), animal performance variables, and environmental variables at the individual animal level were investigated on a first test group of 125 Angus bulls and 53 crossbred steers. Out-Of-Bag root mean square error (OOB RMSE), an internal measure of Random Forest (RF) prediction accuracy, was used as a measure of error between model-predicted and observed DMI. Input variables were first-differenced by differencing a variable’s value between sequential test days for the entire test period. Two models were run using the RF package in R (ntree = 500, mtry = 11), with the first model (M1) using a standard test-train data split and the second model (M2) using all first-differenced and non-incremental observations to train the model. The model incorporating the test-train split performed marginally better than M2 (OOB RMSE = 1.39 and 1.44, respectively), indicating that first-differenced input variables can be used to predict daily individual DMI by within 1.39 kg by using M1. Using percent-increase in MSE (%IncMSE), first-differenced variables were found to be of less overall predictive value than non-incremental variables, with incremental daily gain and first-differenced water intake being ~55 and 45% less predictive than ADG and overall water intake in both M1 and M2. Though first-differenced variables were less predictive than non-incremental variables, inclusion of first-differenced variables allowed for prediction of individual DMI by within 1.39 kg. Our work demonstrates critical preliminary steps in the development of a deployable algorithm for the efficient prediction of DMI and the improvement of beef cattle intake efficiencies for the continued sustainability of animal agriculture.
320 Effects of Sorting Strategy on Within-Pen Variation and Profitability
Authors: Harrison Meredith A , Oltjen James W
Published: November 2023

Decreasing variation in a pen of feedlot cattle reduces overfeeding, increases carcass quality and uniformity, and improves economic returns. The objective of this study was to evaluate the effect of sorting by body weight (BW) or expected days on feed (DOF) on pen performance and profitability. Ninety-six Angus-cross steers (initial BW = 360 ± 28 kg) were randomly assigned to sorting by BW or DOF determined using the Davis Growth Model and initial body measurements for BW, hip height, back fat thickness (BF), and ribeye area. Steers within BW and DOF sort groups were randomly assigned to one of two replicates. Within replicate, BW groups were divided into light and heavy pens (initial BW = 323 and 366 kg, respectively), and DOF groups were divided into short and long pens (DOF = 119 and 160 d, respectively), for a total of 8 pens with 12 steers in each pen. Pen feeding was managed using the slick bunk method and time of marketing was determined based on observation of an average pen BF of 1.1 cm. Steers were harvested at a commercial abattoir and individual carcass characteristics were recorded. Profit was calculated as carcass value minus feed costs. For comparison of sorting treatments, pen was the experimental unit, and treatment means and variances were compared using a t-test and F-test, respectively. Steers were harvested in three groups: both heavy-BW sort pens and both short-DOF sort pens were harvested after 84 d, both long-DOF sort pens and one light-BW sort pen were harvested after 104 d, and the final light-BW sort pen was harvested after 116 d on the finishing ration. There were no differences in mean initial BW (P = 0.95) or initial percent empty body fat (EBF; P = 0.28), but variation in initial BW was reduced (P < 0.01) for the BW sort group. Final mean BW did not differ between sort groups (P = 0.54), but variance in final BW and hot carcass weight was less (P < 0.01) for the group sorted by BW. Final percent EBF also did not differ between groups (P = 0.41), but percent EBF variance was 2.4 %-units for DOF and 2.9 %-units for BW sorted pens, although differences were not statistically significant. There were no differences in average daily gain or feed conversion rate between sort groups. Variation in yield grade, BF, and marbling score were numerically reduced for the DOF group; however, differences were not statistically significant (P > 0.10). Average profit per steer was $ 321.42 and $ 235.05 for DOF and BW sorted groups, respectively. Sorting by DOF increased profitability by 26% by increasing harvest BW, improving uniformity, and decreasing overweight carcasses.
321 Rancher Motivations for Joining Sustainability Programs
Authors: Klopatek Sarah C , Oltjen James W , Roche Leslie , Stackhouse-Lawson Kim R , Cantwell Allison
Published: November 2023

Livestock’s environmental footprint has become a pivotal concern for both consumers and investment corporations. To stay competitive in the sustainable foods movement, the beef industry has sought to improve sustainability within their own supply chains. However, before system sustainability can be achieved, more sustainability practices must be adopted and implemented by the foundation of the system. Therefore, to gain insight into motivations of ranchers for adopting new sustainable practices we administered an online multi-state survey to cattle ranchers in collaboration with state Cattlemen’s Associations. In total, the survey consisted of 45 questions and was divided into four sections including: 1) rancher demographics, 2) ranching educational resources, 3) current best management practices, and 4) willingness to join new rancher sustainability program. Of the survey participants (n = 884), when asked what made them trust/ believe in a ranching educational program, 64% of ranchers stated they trusted (very or extremely) science, 55% or ranchers stated they trusted a ranching educational program if the program was partnered with state cattlemen’s associations, and 32% of ranchers stated they trusted the program if other ranchers they knew were currently enrolled in the program. When survey participants were asked who they trusted most to dispense ranching educational information 79% trusted veterinarians (very or extremely), 63% trusted extension agents/ farm advisors, 57% trusted professors (very or extremely), and 54% trusted other cattle producers. In regards to where cattlemen acquired ranching information 94% utilized trade publications or magazines, 90% utilized university or extension, 70% utilized state or national cattlemen’s meetings, and 52% utilized social media. The top three reasons why survey participants would choose to adopt a new ranching practice included increases profitability 79%, improves animal health 78%, and expected benefits greatly outright the cost or effort to implement 51%. Meanwhile, only 18% of ranchers selected improving environmental health as one of their top 3 reasons for adopting a new ranching practice. In terms of best management practices, 77% of producers stated they had a grazing management practice, however only 29% had their plane written down. Finally, the survey indicated that ranchers who were male, had been through the Beef Quality Assurance training, and were enrolled in a land assistance program were more likely to state that joining a sustainability program would be beneficial to their operation (P < 0.05). Overall, this survey provides the necessary insight into why and how ranchers learn about new ranching practices and provides a possible framework for how to develop successful ranching educational and sustainability programs in the future.
351 Effects of Replacing Soybean Hulls with Molasses During the Receiving Period of Feedlot Steers
Authors: Raudales Quijada Angel A , Henry Darren D H , Pagoada Romero Alejandro A J , Fontes Pedro L P , Burato Samir , Messias Ciriaco Francine M
Published: November 2023

An experiment was conducted to evaluate the effects of replacing soybean hulls with molasses in the receiving diets of weaned feedlot steer-calves on growth performance, nutrient digestibility, enteric methane emissions, and blood inflammatory marker. Eighteen growing Angus crossbred steers (293 ± 11 kg body weight) were used in a completely randomized design with two diets, which were considered treatments. Diets consisted of (DM basis): 1) 46% corn silage, 25% dried distillers grains with solubles, 27% molasses, 0.5% limestone, and 1.5% vitamins and mineral packet (MOL), and 2) 46% corn silage, 22% dried distillers grains with solubles, 30% soybean hulls, 0.5% limestone and 1.5% vitamins and mineral packet (SBH). The experiment consisted of a 42-d period. On d -2 and -1, steers were weighed, and the average was considered initial body weight. On day -1, after weighing, steers were transported via truck and trailer for 12 h (6 h in one direction then 6 h back to the facility) to induce stress experienced by calves when shipped to another location as is standard in the beef industry. Steers were provided hay the evening they returned to the facilities. Steers were stratified by initial body weight and randomly assigned to individual pens, which were randomly assigned to one of the two treatments (MOL or SBH; n = 9 steers/treatment). Dietary treatments started on d 0. Other body weight measurements were recorded on d 7, 14, 21, 28, 35, 41 and 42. Final body weight was considered the average of two consecutive weights recorded on d 41 and 42. Blood samples were collected via venipuncture on days corresponding to body weight measurements. Feed intake data was collected daily by measuring dry matter of feed offered and orts refused. From d 14 to 20, breath samples were collected, using the sulfur hexaflouride technique, to determine enteric methane production, and feces were collected to determine apparent total tract nutrient digestibility. Data were analyzed using the MIXED procedure of SAS and steer as the experimental unit. The model included the fixed effect of treatment. Initial (P = 0.82) and final body weight (P = 0.64) were not affected by treatment. Additionally, no effects of treatment were observed on dry matter intake (P = 0.80) or average daily gain (P = 0.48). Data on enteric methane emissions, nutrient digestibility, and plasma LPS binding protein are still being analyzed. Preliminary data indicate that molasses can replace soybean hulls as an energy source in feedlot receiving diets without affecting animal performance.
342 Effectiveness of Liver Abscess-Controlling Antibiotic on Rumen Kinetics of Beef Steers Consuming a High-Grain Diet
Authors: Batista Luiz Fernando Dias , Rivera Madeline E , Mendes Egleu D M , O'Reilly Keara , Tedeschi Luis O
Published: November 2023

Virginiamycin (VM) possesses antimicrobial properties due to its blocking of protein synthase in Gram-positive bacteria, allowing it to reduce lactic acidosis and the incidence of liver abscesses in ruminants. Ruminal acidosis is a common metabolic disorder that affects feedlot and dairy cattle and occurs when the supply of organic acids from fermentation exceeds its absorption and degradation, accumulating acid content in the rumen. The objective of this study was to evaluate the effects of three different doses of VM administration on in vivo and in vitro ruminal digestion kinetics of beef steers consuming a high-grain diet [metabolizable energy (ME): 2.99 Mcal/kg; Crude Protein (CP): 15.2 % dry matter basis (DM)]. Nine ruminally cannulated British-crossbred steers (596 ± 49 kg) were assigned to this experiment. Animals were housed in three pens (n = 3/pen) equipped with a Calan gate feed system and water trough. Pens were enrolled in a 3×3 Latin square design containing three periods of 16 d, and a 5-d washout interval between periods. Dietary treatments consisted of VM administration at 0 mg/d (VM0), 180 mg/d (VM180), and 240 mg/d (VM240). During d 15 and 16 of each period, about 600 mL of rumen fluid was collected before (0 h) and at 4, 8, 12, and 16 h relative to the morning feed (0730 h) pH and redox potential (Eh) measurements were taken immediately after collection using a portable pH and redox meter, and subsamples were taken for volatile fatty acids (VFA), and NH3-N analyses. During the 4-h post-morning feed rumen collection, rumen inoculum was utilized to perform in vitro gas production (IVGP) measurements. All statistical procedures were performed using SAS software where steer was considered the experimental unit, and period and square were included as random. Acetate, propionate, and total VFA did not differ among treatments (P ≥ 0.50), whereas butyrate increased linearly (P = 0.033) as the VM dose increased. Acetate:propionate ratio did not differ among treatments (P = 0.273). Lactate concentration decreased linearly (P = 0.027) as the VM dose increased; likewise, pH increased linearly (P = 0.019) as the VM dose increased. Branched-chain VFA and NH3-N concentrations increased linearly (P ≤ 0.056) as the VM dose increased. The total and rate of gas production were similar among treatments (P ≥ 0.161). However, second-pool gas production increased linearly as VM inclusion increased (P = 0.023). The in vitro neutral detergent fiber digestibility did not differ among treatments (P = 0.984). The provision of VM altered the rumen dynamics in a dose-dependent manner. Animals consuming high-grain diets will likely promote rumen health through a more stable pH and fermentation profile.
403 Awardee Talk: Characterization of Rumen Microbiome and Immune Genes Expression of Crossbred Beef Steers with Divergent Residual Feed Intake Phenotypes
Authors: Taiwo Godstime A , Ogunade Ibukun M
Published: November 2023

We investigated whole blood and hepatic mRNA expressions of immune genes and rumen microbiome of crossbred beef steers with divergent residual feed intake (RFI) phenotype to identify relevant biological processes underpinning feed efficiency in beef cattle. Low-RFI beef steers (n = 20; RFI = - 1.83 kg/d) and high-RFI beef steers (n = 20; RFI = + 2.12 kg/d) were selected from a group of 108 growing crossbred beef steers (average BW = 282 ± 30.4 kg) fed a high-forage total mixed ration after a 70-d performance testing period. At the end of the 70-d testing period, liver biopsies and blood samples were collected for total RNA extraction and cDNA synthesis. Rumen fluid samples were also collected for analysis of the rumen microbial community. The mRNA expression of 84 genes related to innate and adaptive immunity was analyzed using pathway-focused PCR-based arrays. Differentially expressed genes were determined using P-value ≤ 0.05 and fold change (FC) ≥ 1.5 (in whole blood) or ≥ 2.0 (in liver). Gene ontology analysis of the differentially expressed genes revealed that pathways related to pattern recognition receptor activity, positive regulation of phagocytosis, positive regulation of vitamin metabolic process, vascular endothelial growth factor production, positive regulation of epithelial tube formation and T-helper cell differentiation were significantly enriched (FDR < 0.05) in low-RFI steers. In the rumen, the relative abundance of PeH15, Arthrobacter, Moryella, Weissella and Muribaculaceae was enriched in low-RFI steers, while Methanobrevibacter, Bacteroidales_BS11_gut_group, Bacteroides and Clostridium_sensu_stricto_1 were reduced. Our study found that low-RFI beef steers exhibit increased mRNA expression of genes related to immune cell functions in whole blood and liver tissues, specifically those involved in pathogen recognition and phagocytosis regulation. Additionally, these low-RFI steers showed differences in relative abundance of some microbial taxa which may partially account for their improved feed efficiency compared with high-RFI steers.
428 Awardee Talk: Can the Ruminal Microbiome Ever Answer All the Questions That Nutritionists have?
Authors: Callaway Todd
Published: November 2023

The rumen microbial consortium has long been viewed as a “black box”, where we recognize what goes in, and most of what comes out, but the ruminal catabolic and anabolic activity remains shrouded in uncertainty. Microbiologists from the 1940s through the early 2000s identified microbes responsible for ruminal feedstuff degradation, highlighted animal-important fermentation endproducts (such as volatile fatty acids, VFA), and examined how microbes interacted with each other (e.g., interspecies hydrogen transfer), and with the host animal. However, our knowledge was dependent on our ability to grow anaerobic microbes in pure or mixed cultures, but it became apparent that our limiting factor was that we could culture <10% of the ruminal microbes. In the past 15 years, there has been a proliferation of new techniques to identify what is occurring in the rumen of live ruminants such as, culturable and unculturable microorganism populations, microbial biochemical pathways and important metabolic intermediates, potential interactions between microbes, and biologically relevant endproducts that impact host animal physiology, health, and production efficiency. As Next Generation Sequencing (NGS) has become increasingly affordable, there has been a surge in research examining the “microbiome” with a resultant influx of massive datasets. However, without the ability to connect microbial populations to biochemical degradative pathways, endproducts, microbial interactions or animal production parameters, this information is of limited impact in ruminant nutrition. Ruminant nutrition is on a precipice where we can finally fully integrate microbiology with metabolomics and animal performance and nutrition. Advancements in ruminal microbiology will allow us to fully grasp the functional nature of the microbial ecosystem and where it fits within ruminant nutrition, which will improve animal productivity and ruminant-derived protein food production sustainability.