bluuebunny/crossref_metadata_2025 huggingface dataset:
218 Methane and Carbon Dioxide Emissions from Crossbred Beef Cattle Fall-Grazed on Native Aspen Parkland Pastures
Authors: Behrouzi Amir , Ewasiuk Mikayla , Bork Edward , Basarab John A , Fitzsimmons Carolyn J
Published: November 2023

Over 20 M ha of grazing land is utilized for beef production in western Canada, significantly contributing to the Canadian economy. Cattle are recognized for contributing to methane (CH4) and carbon dioxide (CO2), and individual animal contribution varies with several factors, one of them being feed efficiency as measured using residual feed intake adjusted for off-test backfat thickness (RFIfat). Given that commercial cattle spend a large portion of their production lifecycle grazing on diverse pastures in western Canada, understanding whether and how RFIfat measured in drylot and CH4 emissions reflect animal performance on pasture remains essential. This study quantified CH4 and CO2 production from beef cattle while grazing diverse diets on open-range aspen parkland pastures during fall. Cattle had been previously measured for RFIfat in drylot. Production of CH4 and CO2 (g/day) from crossbred beef cows (n = 22, with a range of -2.2 to +1.3 kg DM/day in RFIfat) and replacement heifers (n = 15; with a range of -2.6 to + 3.0 kg DM/day in RFIfat) were monitored using the GreenFeed emissions monitoring system over 40 days while grazing on native rangeland (70 ha) in the fall of 2022. Fall grazing was divided into two 20 ± 1 day' grazing periods; 20 days in September (SEP) vs. 20 days in October (OCT). Total spot measurements of CH4 and CO2 emissions in SEP and OCT were 1,096 vs. 1,054 for cows and 644 vs. 571 for heifers, respectively. The average number of daily visits per animal to the GreenFeed unit for cows and heifers were 2.8 ± 0.1 vs. 2.5 ± 0.1 in SEP, and 2.5 ± 0.1 vs. 2.0 ± 0.1 in OCT, respectively. Cows had greater average daily CH4 (SEP: 268.4 ± 6.1 vs. 196.1 ± 4.3; OCT: 243.9 ± 6.1 vs. 185.0 ± 4.3 g/day) and CO2 emission (SEP: 9,105.0 ± 143.1 vs. 6,485.3 ± 108.6; OCT: 8,544.3 ± 143.2 vs. 6,308.7 ± 108.9 g/day) than heifers (all P < 0.01). A negative relationship was evident between the CH4 emission and RFIfat in heifers (SEP: R2 = 0.043 vs. OCT: R2 = 0.014; P < 0.01), as well as CO2 emission and RFIfat (SEP: R2 = 0.083 vs. OCT: R2 = 0.020; P < 0.01), although the amount of variation explained by RFIfat is very small and is in disagreement with previous data. We speculate that the decline in CH4 and CO2 emissions from cattle in Oct might be due to various factors, including but not limited to changes in overall intake, daylight hours, air temperature, plant community, feeding and ruminating patterns, and rumen microbial profiles. Further analysis of forage quality, step counts, and GPS location, as well as rumen bacterial community, may shed more light on methane production in the fall.
82 Critical Comparison of Water Buffalo (Bubalus bubalis) and Cattle on Growth Performance and Carcass Traits: a Review
Authors: Rodas-Gonzalez Argenis
Published: November 2023

The multipurpose water buffalo (Bubalus bubalis) has been exploited mostly for dairy purposes while being poorly utilized for meat production. However, in the marketplace, a prejudice exists against Buffalo carcasses due to most of the carcasses coming from animals at the end of their productive life on the dairy farm. Unfortunately, scarce literature establishes comparative biological endpoints between water buffaloes and cattle (Bos indicus or Bos taurus) as meat producers. Furthermore, the literature has not considered the effects of gender (i.e., male castration) for any interspecific comparison. Many unknown answers remain regarding Buffalo growth performance, carcass traits and composition with respect to cattle. Therefore, this review will discuss the pros and cons of water buffalo meat production with respect to cattle, particularly research carried out in tropical conditions, regarding the production traits indicated previously. In a few studies, water buffaloes have proven to be adaptable to tropical grazing conditions and have shown consistently faster body weight gains; but, under confinement conditions, water buffalo have shown a slower growth rate performance than cattle, requiring more days than cattle to reach a comparable body weight. Water buffaloes present heavier carcasses but ldecreased dressing percentages than cattle at different ages which are explained by their significantly greater body proportions of the head, hide and internal organs at the post-weaning ages than cattle. Additionally, under similar grazing or confinement conditions, water buffalo had abundant fat cover distribution and back fat thickness than cattle. Consequently, their carcasses yielded greater percentages of trimmed fat, with a reduced proportion of total cuts. Based on the observed growth and carcass traits, water buffalo offers a promising alternative for meat production, a specialty under tropical grazing conditions.
411 Awardee Talk: Fetal Programming and Molecular Characterization of the Skeletal Muscle Development in Ruminants
Authors: Costa Thais C , Gionbelli Mateus P
Published: November 2023

Three experiments were developed aiming to investigate the effects of maternal nutrition on the skeletal muscle development and metabolism of the offspring. The first study was designed to evaluate the protein restriction during mid-gestation on the skeletal muscle growth of beef cattle offspring. Our results revealed that maternal protein restriction at this stage of gestation caused a decreased number of muscle fibers in the offspring. The second and third studies aimed to elucidate the effects of maternal feed restriction during different stages of gestation on the transcriptome and proteome profile in the skeletal muscle of the newborn. In these experiments, pregnant goats were feed-restricted (at 50% maintenance requirements) either during the first or second half of gestation. Transcriptome analysis revealed that feed restriction at first half of gestation upregulated genes involved with the maintenance of satellite cells, and fatty acid oxidation in skeletal muscle of the newborn. On the other hand, restriction at the second half of gestation upregulated genes related with the balance of glucose metabolism, in addition to protective mechanisms against the oxidative stress in the skeletal muscle of the newborn. Through the proteomic analysis, we observed enriched biological processes (BP) and signaling pathways (SP) related with the energy-investment phase of glycolysis, in addition to the increase in the usage of glycogen and fatty acids storages in the skeletal muscle of the newborn due to feed restriction at the first half of gestation. We also observed that when feed restriction occurs at second half of gestation there is an enrichment in BP and SP associated with the energy-generation phase of glycolysis, and an enhancement in the biosynthesis of glutamine in skeletal muscle of the newborns. Overall, the results of these studies bring insights that help to develop nutritional strategies during early life development aiming to improve postnatal performance.
247 In Vitro Characterization of Equine Fore- and Midgut Digestion
Authors: Cargo-Froom Cara L , Nosworthy Matthew , Darani Priska , Cieslar Scott , Ellis Jen L
Published: November 2023

Considerable advancements can be made in the field of equine nutrition and diet formulation, by improved feed characterization and the development of nutritional models, including in vitro models, to describe nutrient degradation. Methodologically, literature values for in vitro small intestine incubation times are widely variable ranging from 2 to 18 h. While some incubation times are selected to represent approximate mean retention times, conversely, insufficient in vitro incubation times and sampling time points could prohibit or result in inaccuracies characterizing nutrient degradability characteristics, ultimately affecting both degradability and digestion values and their use. The objective of this trial was to assess whether macronutrient degradability plateaus when digested for 2 h in a simulated gastric environment plus 8, 12, or 16 h in a simulated small intestinal environment. To replicate in vivo digestion, a pepsin-pancreatin approach was selected. The first step of this method replicates the gastric environment. Ten g of each test ingredient are weighed into beakers containing 60 mL hydrochloric acid (HCl; 0.1 M) and 0.4 g pepsin (~2,500 U/g) solution. Beakers are then covered and incubated for 2 h at 39 ℃ under constant stirring. One mL aliquots of the digestion liquid are sampled at 0, 5, 10, 20, 30 60, 90 and 120 min after the start of the gastric simulation. Before replicating intestinal digestion, samples are neutralized with sodium hydroxide and the pH is increased to 7. The second step of this method replicates the small intestinal environment. Fifty mL of pancreatin-phosphate buffer (350 U/g protease, 6,000 FIP U/g lipase, 7,500 U/g amylase) is added to the beakers, which are then covered and incubated for either 8, 12, or 16 h at 39 ℃ under constant stirring. One mL aliquots of the digestion liquid are sampled at 0, 5, 10, 20, 30 60, 90, 120, 150, 180 min and thereafter hourly up until the end of digestion (480, 720, or 960 min). Aliquot samples are analyzed for starch via a glucose assay, protein via o-phthalaldehyde assay, and lipids via gas chromatography. A model will is fit to the time point data to determine degradation rates and degradable fractions of the digested samples. Results from these analyses go beyond estimating gross nutrient and digestible nutrient values and inform on the rate of degradation of nutrients of equine feedstuffs and the impact of in vitro methodology. The resulting degradability values will be used in a mechanistic model of equine digestion which will inform precision feeding. Ultimately this will improve how we feed horses to reduce nutrient excretion into the environment and reduce the risk of metabolic conditions such as laminitis.
253 Understanding the Health Benefits of Feeding Treated Wheat Straw for Weanling Pigs
Authors: Polniak Veronica I , Lewton Jaron , Michael Medhat A , Thelen Kyan M , Moeser Adam J , Rozeboom Dale W
Published: November 2023

Two experiments were conducted to understand the growth and health benefits of including treated wheat straw in weanling pig diets. The first experiment evaluated feeding treated versus untreated wheat straw on young pig growth performance and localized immunological markers. One hundred and ninety-two (PIC 359 x Yorkshire) pigs were weaned at 26.8 ± 1.1 d old (8.3 ± 1.1 kg) and randomly allotted to 24 pens with 8 pigs per pen. Three dietary treatments were fed over a 28-d period, control (CON), control plus 5% untreated wheat straw (UWS), and control plus 5% treated wheat straw (TWS). Diets were formulated to meet or exceed all nutrient requirements of NRC, 2012. Growth performance data was recorded on a weekly basis. One pig per pen (equal number of males and females) was randomly selected for sacrifice and sample collection on d 28. The second experiment evaluated the impact of 5% dietary TWS on the local and systemic health of nursery pigs experiencing a vaccination-induced immune challenge. Twenty barrows (PIC 800 x Yorkshire) were weaned at 27.7 ± 0.75 d (8.6 ± 1.2 kg) and assigned to four pens, with 5 pigs per pen. A heavy and light-weight pen for each treatment (CON and TWS) resulted. All pigs were sacrificed for sample collection on d 42. In both experiments, before euthanasia, blood was collected to assess plasma immunoglobulin A (IgA) and intestinal fatty acid binding protein (iFABP) concentration. Upon sacrifice, segments of the distal ileum and ascending colon were removed to collect mucosal scrapings for the analysis of localized immunological markers interleukin (IL) 6 , IL-10, IL-12, and tumor necrosis factor-alpha (TNF-α). In experiment one, overall ADG and ADFI were similar among treatments. Gain-to-feed ratio of TWS pigs was greater (P < 0.05) than that of UWS pigs and tended to be greater (P = 0.07) than that of CON pigs (0.70, 0.67, and 0.68, respectively; SEM = 0.01). Both straw treatments decreased the expression of ileal and colonic mucosa IL-6, in addition with less expression of ileal IL-12. Plasma IgA concentrations in UWS pigs were greater than those in CON and TWS pigs (P < 0.05). In experiment two, TWS pigs had greater gene expression of colonic TNF-α and IL-6 (P < 0.05). Ileal gene or protein expression of markers did not differ, nor did amounts of plasma IgA or iFABP. Overall, feeding 5% treated wheat straw in the nursery pig diet does not negatively impact growth and results in increased feed efficiency. Nursery diets with 5% treated wheat straw can impact the expression of immune markers in the gut, but the question of how this is related to performance and overall health needs further elucidation.
282 Dynamics of Mitochondrial Adaptation and Energy Metabolism in Rainbow Trout (Oncorhynchus mykiss) in Response to Sustainable Diet and Temperature
Authors: Idenyi John N , Eya Jonathan , Adeyemi Abigeal , Hadimundeen Abdallah
Published: November 2023

Impacts of plant-based ingredients and temperature regimens on energy metabolism and mitochondrial function in rainbow trout were investigated. Two hundred and eighty-eight fish weighing 45.6 ± 0.05 g (average ±SD) were evenly allocated to 24 tanks. For 150 days, fish were fed four isocaloric, isolipidic and isonitrogenous diets containing 40% crude protein and 20% crude lipid and formulated as 100 % animal-based protein (AP) and a blend of 50% fish oil (FO) and 50% camelina oil (CO), 100% AP and 100% CO, 100% plant-based protein (PP) and a blend of 50% FO and 50% CO or 100% PP and 100% CO at 14 or 18 °C twice daily. Main effect of diet or temperature, or diet x temperature interaction did not significantly affect percentage weight gain (PWG), condition factor (CF) or specific growth rate (SGR) (P > 0.05), but diet significantly impacted both feed efficiency (FE) and feed intake (FI). Only temperature had a significant impact on whole-body ash content. Furthermore, temperature did not influence protein efficiency ratio (PER), lipid efficiency ratio (LER), protein productive value (PPV), energy productive value (EPV), and lipid productive value (LPV); however, diet had significant major effects on PER, LPV, and PPV (P < 0.05). Temperature regimens induced increased activities of mitochondrial complexes I, II, III, IV, V, and citrate synthase in all tissues (liver, muscle and intestine). Similarly, dietary composition affected the same enzyme activities except complex III activity. Diet x temperature interaction impacted citrate synthase activity at 18 °C. Overall, comparing partial to full dietary substitution of FO with CO, partial dietary replacement showed similar effects on complex activities. Hence, aquaculture could economically benefit from a 40:20 plant protein/lipid dietary composition.
433 Leveraging Feed Technologies to Reduce Methane Emissions from Livestock
Authors: Place Sara E
Published: November 2023

Multiple promising approaches to reducing enteric methane emissions from livestock have evolved over the past decade, including animal and feed management, dietary interventions, and feed additives. Explore methods and technologies that have potential to transform livestock production for broader and greater economic and environmental impacts, and the opportunities that lie ahead to propel conservation to the next level.
299 The Effectiveness of Subjective Fetal Aging as a Predictor of Calving Date
Authors: Richardson Katylyn J , Perkins Tommy L , Arnold Chelsea J , Cowey Garrett A , Walker Zoë P
Published: November 2023

Fetal aging (FA) is an assisted reproductive technique in which fetal measurements collected via transrectal ultrasonography are used to estimate the day of gestation of a fetus. These estimations can then be used to generate calving date predictions, which allow producers to capitalize on the management of both pregnant and non-pregnant females to improve reproductive efficiency and profitability. Previous literature supports the accuracy of calving date predictions when fetometry is used to generate fetal age. However, there is little published research validating the accuracy of fetal aging based on technician evaluation of the fetus at the time of ultrasound. The objectives of this study were to evaluate the accuracy of calving dates predicted with subjective FA compared with the accuracy of calving dates predicted using estrus detection methods (ED). Breeding cows (n = 130) ranging in both breed composition and parity were observed for visual signs of estrus twice daily from December 2021 through February 2022. Cattle were bred via natural service, and all observed signs of estrus and copulation were recorded and used to generate calving date predictions. Cattle were palpated for pregnancy via transrectal ultrasound in April 2022, at which time subjective estimations of fetal age were recorded by ultrasound technicians and used to generate calving date predictions. Data were analyzed using SAS version 9.4 with prediction method serving as the fixed effect. Of the cattle enrolled in this study, calving date predictions were generated from 91 cows using ED and 130 cows using FA. Data analysis indicated a strong positive correlation (Spearman) between FA calving date predictions compared with reported calving dates (r = 0.79, P ≤ 0.01), as compared with a moderately positive correlation between ED calving date predictions and reported calving dates (r = 0.59, P ≤ 0.01). When stratified according to estimated fetal age, analysis indicated a moderately positive correlation between FA calving date predictions and reported calving dates for short- (r = 0.58, P = 0.01) and mid- (r = 0.60, P ≤ 0.01) bred groups, and a weak positive correlation for the long-bred group (r = 0.17, P = 0.16). Data in this study indicates that FA calving date predictions were more accurate than ED calving date predictions. Further analysis will be conducted to quantify the economic value of FA as a method of calving date prediction for producers.
405 The Effects of Disease-Induced Inflammation on Reproductive Neuroendocrinology: Evidence from Sheep
Authors: Renwick Allison
Published: November 2023

Reproduction is dictated by the cohesive functioning of the organs of the hypothalamic-pituitary-gonadal (HPG) axis. As the name suggests, reproduction starts within the hypothalamus through the production and pulsatile secretion of gonadotropin releasing hormone (GnRH) followed by subsequent secretion of luteinizing hormone (LH) from the anterior pituitary and then steroidogenesis and gametogenesis in the gonads. Additionally, the HPG axis is tightly regulated by internal and external cues and, over the last twenty years, kisspeptin has been identified as a key modulator for reproduction through its stimulatory actions on GnRH neurons to secrete GnRH and subsequently LH. Growing evidence indicates that these kisspeptin expressing neurons are negatively affected by stressors (e.g., inflammation, social stress, metabolic stress) resulting in impaired reproduction. Inflammation caused by lipopolysaccharide (LPS, endotoxin), a component of the cell membrane of Gram-negative bacteria (e.g., Escherichia coli), is of particular interest due to its relationship with common livestock ailments, such as mastitis and metritis, and its suppression of GnRH and LH secretions. However, there is limited information about the influence disease-induced inflammation has on kisspeptin expressing neurons. In rats, acute endotoxin inflammation will cause about a 50% decrease in the number of kisspeptin immunopositive cells in the arcuate nucleus along with a suppression in LH secretion. In ewes, an acute dose will decrease the proportion of activated kisspeptin neurons in the ARC and POA. However, the mechanisms by which inflammation affects reproduction are not completely understood, especially in domestic livestock. Through a series of experiments, we aim to elucidate these mechanisms and effects of endotoxinemia in both an acute and a chronic model. To accomplish these goals, we administered endotoxin acutely to ewes. Overall, the suppression of LH secretion at the level of hypothalamus is possible, however, more research is required to further elucidate the mechanism. To evaluate a chronic model of systemic inflammation, we evaluated routes of endotoxin administration by randomly assigning twenty two castrated male sheep into one of five groups - control (CON), single acute IV dose (SAD; 400 ng/kg BW LPS) administered on Day 1, daily acute IV dose (DAD; 400 ng/kg BW LPS), daily increasing IV dose (DID; starting with 400 ng/kg BW LPS and increasing 20% each day), or steady subcutaneous dose (SSD; 20 µg/kg BW LPS over 24 hours), all administered during a one-week study period. Chronic inflammation, induced by a daily rising dose of IV administered LPS, suppresses LH secretion through effects on kisspeptin protein expression in the middle arcuate nucleus of the hypothalamus of sheep. Taken together, systemic inflammation associated with infection and disease likely impairs reproduction in part through suppression of kisspeptin-expressing neurons.
303 Accuracy of the Smartscale In-Pen Weighing System
Authors: Harrison Meredith A , Zimmerman Scott
Published: November 2023

The Beef Improvement Federation recommends repeated body weight (BW) measures in a 70-d test period for accurate assessment of average daily gain (ADG) in growing animals. In-pen automated scale systems enable daily monitoring of BW and ADG without the additional labor, time, and animal stress that is associated with recording static chute BW. The objective of the current study was to determine the utility of partial body weight (pBW) for estimating full BW and average daily gain (ADG) in growing steers. SmartScales (C-Lock Inc.) were positioned in front of water troughs and used to measure front-quarter pBW while animals were drinking. Partial body weight was used to estimate full BW using an internally developed slope-intercept equation. The dataset consisted of pBW, estimated BW, and recorded BW for 300 steers in a 50-d feed performance test. Single-day chute BW were recorded on days 14, 28, 35, and 50. Relationships and errors between estimated BW and recorded BW were evaluated. Individual animal ADG estimates were calculated and compared using estimated and recorded BW measurements. Steers in the study visited the water trough an average of 4.3 ± 2.6 times per day. On average, pBW explained 96.1% variation in recorded BW. Average predicted BW and recorded BW differed by 8.3 ± 6.4 kg, or 0.15 ± 3.0 %-units. Average daily gain calculated from pBW and recorded BW were strongly correlated (r = 0.83). On average, ADG calculated using pBW and recorded BW differed by 0.14 ± 0.12 kg, or 8.8 ± 8.0 %-units. Real-time pBW collected using in-pen weighing systems can be used to accurately estimate full BW and ADG.
317 Characterizing Foot and Leg Scores for Montana Registered Angus Cattle
Authors: Sitz Taylre , DelCurto Timothy , DelCurto-Wyffels Hannah , Van Emon Megan L , Wyffels Sam , Peterson Jeremiah , Hamilton Thomas , Retallick Kelli J , Tarpoff Esther , Garcia Andre , Kangas Kurt
Published: November 2023

The objectives of this study were to increase the amount of phenotypic data available for enhancing the foot and claw EPDs of Montana sires and evaluate factors that could impact foot angle and claw set scores. Specifically, this study evaluated the interaction of sex and age on claw set and foot angle scores of front or hind legs. Researchers used the American Angus Association (AAA) Foot Scoring Guidelines to subjectively analyze claw set and foot angle on a series of Montana Angus herds, scoring a total of 4,723 cattle: 1,475 yearling bulls, 992 yearling heifers, 1,044 two- and three-year-old cows, and 1,212 cows that were four years of age and older. The AAA Foot Scoring Guidelines require breeders to score the combined “worst foot” for both the claw set and foot angle traits on a hard, flat surface. Yearling bulls had a 0.12 and 0.20 greater mean foot angle and claw set score compared with yearling heifers (P < 0.01). The proportion of scores that differed from 5 (ideal foot score) were greater (P < 0.01) for front feet as compared with hind feet, with 61.5 and 74.5% of the scores not equal to 5 being front feet issues for yearling heifers and bulls, respectively. Foot angle scores increased linearly (P < 0.01) with advancing cow age, ranging from 5.15 to 5.80 for heifers versus cows 4 years and older, respectively. Likewise, claw set scores increased quadratically (P < 0.01) as a function of cow age. The location of the “worst foot” also changed quadratically with age (P < 0.01) with the majority of problem feet in two- and three-year old cows and cows 4 years and older being hind feet issues (70.5 and 77.1%, respectively). The proportion of foot angle and claw set scores not equal to 5 also increased quadratically with age (P < 0.01) with heifers having the lowest proportion of scores not equal to 5 (15.8 and 31.7%, respectively) compared with 4 year and older cows (66.0 and 68.0%, respectively). In analysis of progeny of sire lines, the range between the progeny of the sire line with the greatest foot angle score and that of the least was 0.60 for foot angle. Likewise, for claw set, a similar range 0.57 was observed. Sire lines did have an effect on progeny claw set (P < 0.05) and foot angle scores (P < 0.05), as well as variation of progeny foot scores. In summary, progress is being made by utilizing the AAA foot scoring guidelines, as well as foot angle and claw set EPDs. Additional improvements may be possible with continued model refinement and improvements with scoring guidelines specific to age and sex effects.
347 Effects of Inoculation Period on the Nutritive Value of Pleurotus Ostreatus Treated Corn Stover
Authors: Olagunju Lydia K , Isikhuemhen Omonanghe S , Dele Peter A , Shaw Yasmine , Brice Rosetta M , Orimaye Oluteru E , Wuaku Michael , Ike Kelechi A , Anele Uchenna Y
Published: November 2023

The objective of the study was to optimize and improve the feeding value of corn stover. Despite the documented ability of Pleurotus ostreatus to selectively delignify crop residues, it is not widely used for ruminant fiber digestion partly due to extended pretreatment time. Optimization of crop residues is influenced by enzymatic activities of fiber degrading enzymes and dependent on the stage of P. ostreatus growth. Thus, optimizing the inoculation period for lignin removal by P. ostreatus is important to improve and increase success on lignocellulose feed resources utilization. Therefore, we hypothesized a difference in nutritive value for different inoculation periods for P. ostreatus spent substrates. Two ruminally cannulated dairy cows were used in an in vitro study arranged in a 3 x 5 factorial design with 4 replicates to evaluate the effects of inoculation period [0 (control), 2, 4, 6 and 8 wk] on P. ostreatus spent substrates at 6, 24 and 48 h of fermentation on chemical composition, dry matter disappearance (DMd) and volatile fatty acid (VFA) production. Significant (P < 0.001) non-linear treatment effect across the inoculation period was observed in the treated samples (Table 1). An increase of 44.4 to 59.1% and 20.6 to 78.6% was noted for the crude protein and ash contents, respectively. Also, significant (P < 0.001) incubation time effect across the inoculation period resulted in a wide variation (22.6 - 755%) in the microbial mass with greater values for 2- and 4-wk treatments. Neutral detergent fiber and hemicellulose were significantly (P < 0.001) reduced with a range between 7.29 to 18.7% and 26.6 to 40.8%, respectively (Table 3). Inconsistent positive and negative outcomes across the periods in acid detergent fiber, lignin and cellulose resulted in significant (P < 0.001) 116 and 121% increment in non-fiber carbohydrates for 2 and 4-wk treatments, respectively. Consequently, both DMd and total VFA were significantly (P < 0.001) greater, ranging between 238 to 242% and 13.9 to 15.1% respectively for these treatments (Table 2). Additionally, the rumen fermentation pathway favored production of propionate with significant (P < 0.001) treatment and time effect that resulted in 7.46 and 8.30% increment in propionate production after 2 and 4 wk, respectively. Consequently, significant (P < 0.001) reduction was observed in acetate with 4.44 and 3.58%, and 11.7 and 11.1% in A:P ratio for 2 and 4 wk, respectively. High butyrate production was observed for 2 wk in comparison with 4 wk resulting in 18.3 and 9.86% increment, respectively, when compared with control (Table 4). The study showed that 2 wk of inoculation is sufficient to provide bio-transformed cow-calf feed resource from P. ostreatus treated corn stover, which is contrary to 30 days (4 wk) previously recommended.
341 Effect of Multispecies Fungal Culture Extract Supplementation on the Growth Performance and Carcass Characteristics of Feedlot Cattle
Authors: Pittaluga Alejandro , Relling Alejandro E
Published: November 2023

To evaluate the effect of supplementing feedlot cattle with a multispecies fungal culture extract (MFE; Aspergillus flavus, Aspergillus niger, Aspergillus oryzae, Aspergillus terreus, Phlebia radiata, Pyricularia oryzae, Stropharia coronilla, Thanatephorus cucumeris, Trichoderma longibrachiatum, Trichoderma reesei, Trichoderma viride) in growth performance and carcass characteristics, Angus × SimAngus-crossbred steers (n = 14) and heifers [n = 46; body weight (BW) 344 ± 21 kg] were used in randomized complete block design. Cattle were blocked by BW and housed in 4 feedlot pens (randomly assigned 2 pens per treatment) where a hay-based diet was fed for 84 d (backgrounding), followed by a ground corn-based finishing diet. Subsequently, cattle were harvested upon reaching desired 12th rib fat thickness (2.0 cm). Diets were offered ad libitum and with (MFE) or without (CON) the inclusion of the multispecies fungal culture extract supplement. Steers were weighed at 28-d intervals throughout the experimental period and carcass data were provided by a USDA grader. All data were analyzed using the PROC MIXED procedure of SAS considering the fixed effect of treatment and sex, and the random effect of block and pen (block). During the 84-d period of the backgrounding phase, feeding MFE increased (P = 0.05, Table 1) the average daily gain (ADG) by ~10%, and tended to increase (P = 0.06, Table 1) the dry matter intake (DMI). No differences were observed in the gain to feed ratio (G:F) between treatments (P = 0.67, Table 1). At the conclusion of the 84-d period, cattle fed MFE were heavier (P = 0.04, Table 1) than cattle in the CON treatment. In the finishing phase, no treatment differences were observed (P ≥ 0.36) for the ADG, DMI, and G:F. At the end of the experiment, cattle supplemented with MFE were heavier (P = 0.04, Table 1) than cattle in the CON treatment. The quantity of days on feed in the finishing diet required to reach harvesting target was not different (P = 0.60) among treatments. For the carcass characteristics, dietary inclusion of the MFE tended to increase the hot carcass weight (P = 0.10, Table 2) and increased the marbling score (P = 0.01, Table 2). No treatment effect was detected (P ≥ 0.25, Table 2) for the dressing, longissimus muscle area, 12th rib fat thickness, kidney-pelvic-heart fat content, and yield grade. Results from this study suggest that dietary inclusion of a multispecies fungal culture extract might improve the growth performance of beef cattle fed forage-based diets, as well as their carcass characteristics after conclusion of the feedlot finishing phase.
332 Effects of Ruminal Lipopolysaccharides on Primary Bovine Ruminal Epithelial Cells
Authors: Sarmikasoglou Efstathios , Chu Leah , Yue Feng , Faciola Antonio P
Published: November 2023

The objective of this study was to investigate the immunopotential of mixed ruminal lipopolysaccharides (LPS) on cultured primary bovine ruminal epithelial cells (RECs). Primary bovine RECs were isolated from 6 yearling steers and grown in culture for 3 experiments. In Exp. 1 the objective was to determine the immunopotential of ruminal LPS, in Exp. 2 the objective was to assess tolerance to chronic LPS exposure, and the objective of Exp. 3 was to evaluate antagonistic interactions between ruminal and E.coli LPS. In exp. 1 & 2, RECs were exposed to nonpyrogenic water (CON), 20 μg/mL of E. coli LPS (E. COLI), 10 μg/mL of mixed ruminal-LPS (RUM10), 20 μg/mL of mixed ruminal-LPS (RUM20) and 40 μg/mL of mixed ruminal-LPS (RUM40) either continuously or intermittently. For the continuous exposure, RECs underwent a 6 h exposure, while for the intermittent exposure, the procedure was 1) a 12 h continuous exposure to treatments followed by LPS removal for 24 h and then another 12 h of exposure (RPT), and 2) a 12 h continuous exposure to treatments followed by LPS removal and a recovery period of 36 h (RCV). In exp 3, RECs were exposed to nonpyrogenic water (0:0), 1 μg/mL E. coli LPS (0:1), 1 μg/mL mixed ruminal-LPS:1 μg/mL E. coli LPS (1:1), 10 μg/mL mixed ruminal-LPS :1 μg/mL E. coli LPS (10:1) and 50 μg/mL mixed ruminal-LPS :1 μg/mL E. coli LPS (50:1). Each experiment was done as a complete randomized block design with 6 REC donors. The REC donor was used as a blocking factor. Each treatment had 2 technical replicates, and treatment responses for all data were analyzed with the MIXED procedure of SAS. For all exp., total RNA was extracted from RECs and real-time quantitative PCR was performed to determine the relative expression of genes for toll-like receptors (TLR2 & TLR4), proinflammatory cytokines (TNFα, IL1β, and IL6), chemokines (CXCL2 & CXCL8), growth factor-like cytokines (CSF2 & TGFβ), and a lipid mediator (PTGS2). In exp. 1, the targeted genes were upregulated in response to E. COLI (P<0.01), while all ruminal LPS treatments resulted in a lower transcript abundance (P<0.01). Regarding RPT and RCV condition, in Exp. 2, the expression of targeted genes was downregulated or not affected in response to ruminal LPS treatments. Lastly, in Exp. 3 all targeted genes resulted in decreased transcript abundance on all ruminal LPS ratios (P<0.01). Overall, our results indicate that ruminal LPS have a limited capacity to activate the TLR4/NF-κB pathway and to induce the expression of inflammatory genes.
331 Investigating the Ruminal Metagenome of Grass and Forage-Fed Bison to Uncover Metabolic Activities That Impact the Efficiency of Plant Fiber Utilization
Authors: Fresno Rueda Anlly M , Kruse Carter , St-Pierre Benoit
Published: November 2023

The ability of bison to thrive on grass and forage-based diets is of great interest for the bison industry. However, raising bison on pasture presents challenges, including longer finishing times. While some producers overcome this by feeding grain or concentrate to bison, this practice conflicts with the concept of natural production. Considering that bison maintain better on feed of poor quality compared with domesticated grazers, it can be inferred that there is great potential for improving their productivity on pastures. Because ruminants rely on symbiotic microorganisms to break down and ferment plant polysaccharides into nutrients they can absorb and assimilate, the metabolic capabilities of rumen microbial communities in bison would likely have an important role in contributing to the efficiency of their host. To gain further insight, we investigated the ruminal metagenome of six grass-fed bison. Raw sequence reads generated using an Illumina Miseq (2x250) platform from ruminal microbial genomic DNA were assembled into genomic contigs using custom written Perl scripts. A total of 6,297 contigs, representing a combined total length of 23,822,104 nucleotides, were obtained for all samples. Coding sequences were identified and annotated using RAST (Rapid Annotation using Subsystem Technology), which was followed by assignment to metabolic pathways using references from KEGG (Kyoto Encyclopedia of Genes and Genomes), with a particular focus on carbohydrate metabolism and amino acid synthesis. This analysis resulted in the identification of nine of the ten enzymes necessary for glycolysis, indicating the capacity to metabolize glucose into pyruvate. Two outcomes were predicted for pyruvate: conversion to lactate through lactate dehydrogenases (EC 1.1.1.27, EC 1.1.1.28), as well as the production of acetate through the sequential activity of pyruvate-flavodoxin oxidoreductase (EC 1.2.7.1), phosphate acetyltransferase (EC 2.3.1.8), and acetate kinase (EC 2.7.2.1). Propionate and butyrate were also predicted as end-products being produced in bison rumen, as well as synthesis of precursors for aromatic amino synthesis through the Chorismate-Shikimate pathway. In addition, enzymes involved in the fermentation of five-carbon sugars, such as arabinose (EC 5.1.3.4, EC 2.7.1.16, and EC 5.3.1.4) and xylose (EC 2.7.1.17 and EC 5.3.1.5), were also identified. Characterization of the metabolic potential of ruminal bacteria from pasture-fed bison, such as the utilization of glucose and pentose sugars that form the backbone of structural polysaccharides to produce short chain fatty acids and essential amino acids, will provide further insight on the use of forage and grass-based diets by these animals.
378 Genetic Parameter Estimates of Post-Weaning Growth and Gastrointestinal Nematode Infection Traits of Katahdin Lambs
Authors: Hess Andrew , Murphy Tom W , Miller Jim E , Burke Joan M
Published: November 2023

The objective of this study was to estimate heritability of, and genetic correlations between lamb growth and gastrointestinal nematode (GIN) infection. Lambs were weighed and weaned at ~60 days of age and body weight (BW), fecal egg count (FEC), FAMACHA score (FAM) and packed cell volume (PCV) were recorded at ~90, 120, and 150 d of age. Lambs were not dewormed and FEC was transformed as: LFEC = log10(FEC+25). Average daily gain (ADG) was calculated from weaning to 90 days of age (ADG90) as well as 90 to 120 (ADG120) and 120 to 150 days (ADG150). Each trait (ADG, LFEC, PCV and FAM) was analyzed separately within each timepoint. The number of records per time point ranged from 1,980 (ADG90) to 1,283 (LFEC at 150 days of age). Traits were analyzed using a univariate model fitting fixed class effects of sex, birth/rear type, and season/system (fall or winter/conventional or organic), and fixed covariate of actual age at 90 days. Random effects included contemporary group, birth year, and an additive genetic effect whereby genetic relationships were captured through pedigree data. The heritability of FEC was 0.09 ± 0.03, 0.12 ± 0.03, and 0.07 ± 0.04, at 90, 120 and 150 days, respectively. PCV estimates were 0.22 ± 0.04, 0.32 ± 0.05, and 0.29 ± 0.06, at 90, 120 and 150 days, respectively. The heritability estimates of ADG were 0.09 ± 0.03, 0.12 ± 0.04, and 0.20 ± 0.04, at 90, 120 and 150 days, respectively and FAM were 0.15 ± 0.04, 0.10 ± 0.04, and 0.19 ± 0.05. Genetic and phenotypic correlations between GIN infection traits and ADG at the same time point were estimated using a bivariate model. The genetic correlation of LFEC with ADG was low for all timepoints analyzed and ranged from -0.07 ± 0.28 (150 days) to 0.07 ± 0.19 (90 days). Phenotypic correlations were similarly low and ranged from -0.02 ± 0.07 (120 days) to -0.16 ± 0.07 (150 days). LFEC showed a consistent negative genetic and phenotypic correlation with PCV at all timepoints, ranging from -0.17 ± 0.17 (90 days) to -0.57 ± 0.18 (150 days) and -0.32 ± 0.05 (90 days) to -0.20 ± 0.06 (150 days), respectively. Conversely, FAM was positively correlated with LFEC, with genetic correlation estimates ranging from 0.21 ± 0.22 (120 days) to 0.54 ± 0.20 (150 days) and phenotypic correlations ranging from 0.08 ± 0.06 (150 days) to 0.22 ± 0.05 (90 days). The genetic and phenotypic correlations of PCV with ADG increased over time, going from -0.17 ± 0.15 to 0.19 ± 0.18 and 0.08 ± 0.06 to 0.10 ± 0.06, respectively. The correlations of FAM with ADG were more variable, but generally low, ranging from -0.14 ± 0.06 (150-day phenotypic correlation) to 0.09 ± 0.18 (90-day genetic correlation). We showed that selection on PCV may be more effective than selection on LFEC to reduce the burden of GIN infection, although further investigation into its correlation with growth is warranted. This dataset will be used to investigate resistance, resilience, and susceptibility traits in Katahdin lambs.
375 Effects of Breed Type and Gender on Performance, Feeding Behavior, and Feed Efficiency in Growing goats
Authors: Irvin Merrick E , Kidane Negusse F , Carstens Gordon E , Foxworth William B , O'Reilly Keara , Horner Scott
Published: November 2023

The objectives of this study were to examine the effects of gender and breed type on performance, feed efficiency, and feeding behavior traits in growing goats. The trial was conducted with 36 intact male (n = 16) and female (n = 20) goats of 4 breed types;12 purebred Spanish, 12 F1 Spanish x Boer (dam-sire), 8 F1 Boer x Spanish, and 4 purebred Boer. Goats with initial BW of 30.9 ± 6.0 kg and 38.8 ± 7.4 kg for females and males, respectively, were fed a concentrate diet in pens equipped with electronic feed bunks (GrowSafe System). Individual dry matter intake (DMI) and feeding behavior traits were collected daily for 44 d and BW measured weekly. Residual feed intake (RFI) was calculated as the residual from the regression of DMI on ADG and mid-test BW0.75. Feeding behavior traits evaluated were frequency and duration of bunk visit (BV) events, head-down (HD) duration, BV eating rate (BVER), and day-to-day variation of these traits, defined as the root mean squared error (RMSE) from linear regression of each trait on the day of trial. A mixed model (JMP) with fixed effects of gender, breed type, and gender x breed type interaction with pen as a random effect was used. Gender x breed type interactions were not significant for any traits. Male goats had heavier (P < 0.01) initial and final BW, but similar ADG during the trial. Male goats consumed more (P < 0.05) DMI, but had similar F:G and RFI compared with female goats. Gender did not affect feeding behavior traits, but male goats had greater BVER and more (P < 0.05) day-to-day variation in DMI than female goats. Purebred Boer goats had heavier (P < 0.05) initial and final BW and greater ADG than purebred Spanish and both F1 crosses. However, DMI and RFI were not affected by breed type. G:F was greater (P < 0.05) in Boer and Boer x Spanish goats (0.183, 0.153) than Spanish goats (0.115), with Spanish x Boer (0.132) goats being intermediate. Breed type did not affect feeding behavior traits in this trial. Minimal effects of gender and breed type on feed efficiency were detected in growing goats in this trial. Further research is warranted to examine effects of breed type on life-cycle feed efficiency including growing goats and female goats during pregnancy and lactation.
386 Effects of Different Soy Protein Sources on Gut Microbiome Composition and Relationship with Performance in Pigs in Regular Nursery and F4 Enterotoxigenic Escherichia Coli (ETEC) Challenged Conditions
Authors: Hu Qiong , Sardi Maria I , Naqvi S Ali , Hackenhaar Leandro , Pluk Patricia , de Laat John , Newcomb Mark D , Khafipour Ehsan
Published: November 2023

Provisoy, produced by hydro, thermal, and mechanical process using soybean meal (SBM) has been shown to improve both post-weaning pig growth and gut health compared with SBM. It was hypothesized that Provisoy could improve the utilization of both protein and fiber fractions along the gastrointestinal tract of a nursery pig resulting in a more balanced nutrient environment and robust microbiome in the hindgut compared with SBM. A total of 268 weaned pigs (body weight, 6.82 ± 0.85 kg) were allotted to either a regular nursery condition (5 pigs/pen, 10-11 pens/treatment) or subjected to ETEC challenge (3 pigs/pen, 12 pens/treatment, 1 pig per pen was orally gavaged with O149:K91:K88 strain on d 5 post-weaning). Pigs received one of the following diets: SBM, Provisoy or HP300 (soy protein from Hamlet Protein, used as a benchmark). A standard wheat-barley-SBM based diet was used, and test soy products were added to replace SBM in the treatment diets during the first three weeks of nursery program. All diets were isocaloric with the same standardized ileal digestible lysine level in a three-phase (38 days) nursery program. Fecal samples were collected on d 13 or d 14 post-weaning and subjected to DNA extraction and Nanopore shotgun sequencing. Data were center-log-ratio transformed and subjected to statistical analysis. Microbiome composition was affected by dietary treatment (P < 0.01) and challenge (P < 0.05), but their interaction was not significant. In regular nursery condition, both Provisoy and HP300 tended (P < 0.10) to have greater microbiome alpha-diversity compared with SBM, but no difference was observed between these two treatments. Only SBM fed pigs subjected to ETEC challenge had greater (P = 0.02) alpha-diversity compared with their non-challenged counterparts. Compared with the SBM treatment, pigs that received Provisoy in the regular condition had greater abundance of Coprococcus and Dialister, which were positively correlated with greater average daily gain (ADG; r = 0.53, P < 0.01, and r = 0.45, P = 0.01, respectively). Under ETEC challenge, an increase in abundance of Dialister was observed in pigs that received Provisoy treatment with a positive correlation with ADG (r = 0.42, P = 0.01). In conclusion, dietary inclusion of Provisoy or HP300 improved microbiome alpha-diversity compared with SBM. Provisoy helped promote the growth of beneficial bacteria in the hindgut of nursery pigs which were positively correlated with gain.