bluuebunny/crossref_metadata_2025_split huggingface dataset:
PSV-27 Optimizing corn silage utilization in beef feedlot diets: Evaluating the impact of exogenous glucoamylase addition on performance and digestibility
Authors: Schoonmaker Jon P , Nolasco Lester , Vincent Tyler J , Torres Rodrigo 
Published: September 2024

Abstract
The addition of an exogenous glucoamylase enzyme preparation to feedlot diets that contain a high percentage of corn silage may improve digestibility and yield positive outcomes in growth and efficiency. However, it is unclear what concentration of corn silage in the diet would most benefit from exogenous glucoamylase. Crossbred steers [n = 180; body weight (BW) = 459 ± 11.8 kg] were divided into 30 pens (5 pens per treatment; 6 steers per pen) and assigned to one of six treatments arranged as a 3 x 2 factorial investigating 3 forage concentrations (15, 42, and 69% corn silage) and 2 exogenous glucoamylase additions (0 or 183 enzyme units/kg of dry matter per d). Steers were fed 42% corn silage, 30% corn, 23% dried distillers grains with solubles, and 5% supplement at feedlot entry and for 2 wk prior to initiation of the study. Steers on the 15% and 69% corn silage diets were transitioned to treatment diets by wk 3 of the study (d 15), with the first transition occurring on d 0. Diet transitions occurred once weekly. The animals were on feed for 105 ± 10.4 d and had ad libitum access to feed and water. Average daily gain (ADG), dry matter intake (DMI), and gain:feed were assessed both overall and for two distinct periods: d 0 to 50, and d 51 until slaughter. Data analysis was performed using the GLIMMIX procedure of SAS. From d 0 to 50, ADG, DMI, and gain:feed did not differ due to forage concentration or enzyme inclusion and there was no interaction (P ≥ 0.39). For d 51 to slaughter, enzyme inclusion interacted with forage concentration such that the enzyme improved ADG (P = 0.0003) and gain:feed (P = 0.01) for steers fed the 42% corn silage diet but did not effect ADG and gain:feed for steers fed the 15 or 69% corn silage diets. For d 51 to slaughter DMI was not affected by forage concentration, enzyme inclusion, or their interaction (P ≥ 0.21). When calculated for the entire study (d 0 to slaughter), increasing forage concentration decreased ADG and gain:feed (P ≤ 0.0006), but did not effect DMI (P = 0.22). Overall, enzyme addition did not impact ADG, DMI, or gain:feed and did not interact with forage concentration (P ≥ 0.50). Carcass characteristics were not affected by forage concentration, enzyme addition, or their interaction (P ≥ 0.19). Overall results suggest that an exogenous glucoamylase enzyme improves growth and efficiency of heavier feedlot cattle fed moderate amounts of forage later in the feeding period.
PSX-23 Use of time series data in the prediction of beef cattle dry matter intake using machine learning
Authors: Walker Matthew , Blake Nathan , ArunKumar K E , Mata-Padrino Domingo , Holaskova Ida , Wilson Matthew E 
Published: September 2024

Abstract
Improvements in technology that facilitate the estimation of individual animal dry matter intake (DMI) in any setting, whether in confinement or on pasture, will improve beef cattleproduction and management. Big Data approaches could further enhance DMI estimation. In this work, we improved upon our predictive models by developing variable time series features and forgoing the use of full-test Average Daily Gain, a variable that provides unwanted intake information during model training, in DMI prediction. We implemented the improved time series analysis techniques of first differences, moving averages, and seasonal decomposition to create new predictive variables from daily-level data. These new variables were used in k-fold cross-validation to improve the variable selection process and prediction accuracy of the Random Forests Regression (RFR) and Repeated Measures Random Forests (RMRF) models. Reduced models for the RFR and RMRF algorithms were identified, assessed, and compared with estimated DMI calculated using the current NASEM equation for estimation of beef cattle DMI. Data on feed intake, animal weights, and climate conditions were collected from 25 November2019 to 20 February 2020 for bulls and from 19 March 2020 to 7 May 2020 for steers. Feed intakes were recorded using Vytelle Feed Intake Nodes. Animal body weights (BW) and water intakes were measured daily using Vytelle In-Pen-Weighing Positions and metered waterers. Climate data included information on temperature, humidity, precipitation, and wind speed and were recorded at 30-min intervals. We found that seasonally-adjusted and moving averaged features generally outperformed first difference features. The baseline models presented here performed similarly to our previous models, despite using ‘Average Daily Gain to Date’ rather than the ‘Full Test Average Daily Gain’. The range of R2 was 0.44 to 0.69 and the range of RMSE was 0.95 to1.67 kg. Additionally, use of Average Daily Gain to Date in place of full-test Average Daily Gain improves the field deployability of our models. Lastly, while the demonstrated models can both over- or under- predict daily DMI, both RFR and RMRF showed more accurate predictive ability than the current NASEM equation. This study further demonstrates the potential of RFR and RMRF models DMI prediction of beef cattle. Future research will focus on including a wider range of cattle breeds, climatic conditions, and geographic locations, as well as assessment of suitability of RFR and RMRF for DMI prediction of cattle on pasture.
PSXI-7 Effects of selected feed additives on feedlot cattle performance when fed diets containing rehydrated corn grain silage
Authors: Francischinelli André F , Gouvêa Daniel L C G , Ribeiro Vitória A M , Carvalho Victor , Perdigão Alexandre , Pereira Murilo C S , Arrigoni Mário B B , Martins Cyntia L L 
Published: September 2024

Abstract
The use of additives makes it possible to improve body weight (BW) gain and muscle growth, the efficiency of nutrient use, in addition to reducing the incidence of metabolic disorders. The objective of the study was to evaluate the performance, feed intake and carcass production of feedlot Nelore cattle, fed with a high concentrate diet, using different feed additives. Nelore bulls [n = 48; initial BW (BWi = 378.1 kg ± 8.92 kg; 20 mo of age), were used. Bulls were allocated in a collective pen, randomly distributed in two treatments: 1) Sodium Monensin (MON), 26 mg/kg DM; and2) CRINA + RUMISTAR + Hy-D (CRD), blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM + 25 hydroxyvitamin D3, 1 mgּ animal-1ּ d-1
. The experiment lasted 101 d, the animals were weighed fasting (± 16 h) at the beginning and end of the experiment, at the end of the experiment the animals were subjected to carcass ultrasound, dry matter intake (DMI) was measured daily individually using electronic troughs with selector doors (Intergado, PONTA, Betim, MG-Brazil). The initial carcass weight (195.6 kg, P = 1.0) was estimated using the equation HCWi = 0.6587*BWi-53.44 (R² = 0.993), obtained through the reference slaughter of 9 animals, and the final carcass weight measured in the refrigerator. The “step-up” adaptation protocol lasted 15 d, followed by the finishing diet until the end of the experimental period, consisting of ground corn, rehydrated corn grain silage, cottonseed cake, whole cottonseed, sugarcane bagasse, urea and vitamin-mineral supplement. Data were analyzed by SAS PROC ANOVA, using BWi as a covariate when significant. Animals fed CRD had a greater final BW (534.0 vs 515.6 kg, P = 0.003) and increased average daily gain (ADG) by 0.180 kg/d (1.54 vs 1.36 kg/d, P = 0.003). DMI was greater (10.2 vs 9.3 kg/d, P &lt; 0.001) as well as DMI:BW (2.24 vs 2.09 %BW/d, P &lt; 0.001). The feed efficiency did not differ between treatments (P = 0.21). Animals fed CRD presented heavier HCW (305 vs 291 kg, P = 0.004) and ADG carcass (1.08 vs 0.95 kg/d, P = 0.004). The carcass conversion, calculated as kg DM/15 kg carcass produced (143.5 vs 152.6, P = 0.11), carcass yield (P = 0.15), 12th ribeye area (P = 0.52) and 12th rib fat (P = 0.12), were similar among the treatments. Feeding CRD tended to improve marbling (1.67 vs 1.45%, P = 0.08). These results underscore the potential of CRD as an effective alternative to traditional additives in enhancing the performance and carcass quality of feedlot cattle.
PSXI-21 Effect of the inclusion of increasing levels of three tree species on methane production and nutrient digestibility in vitro
Authors: Vazquez-Carrillo Maria Fernanda , López-Varela Jimena Yaxen , Romero-Pérez Atmir , Avilés-Nieto Jonathan Noé , Talamantes-Montes José Moises , Marquez-Mota Claudia Cecilia , Corona-Gochi Luis 
Published: September 2024

Abstract
Beef production is a major contributor to the world’s food system. However, it also represents a significant source of enteric methane (CH4). Currently, the incorporation of plants with increased concentrations of secondary metabolites has been highlighted as a strategy to mitigate enteric CH4. The objective of the present study was to evaluate the effect of increasing levels of three tropical trees in combination with a tropical pasture on total gas production, dry matter (DM) digestibility, neutral and acid detergent fiber (NDF and ADF, respectively) and volatile fatty acid concentration under in vitro conditions. Treatments were arranged in a completely randomized block design with 3 × 4 factorial arrangement, including three tree species [Gliricidia sepium (GS); Guazuma ulmifolia (GU) and Leucaena leucocephala (LL; Table 1)] × four increasing levels of inclusion (0, 15, 30 and 45%). Each experimental treatment was incubated in triplicate in three independent runs (blocks). All experimental units were incubated with 0.5 g of substrate (mixture of arborea with tropical grass) and gas production was measured at different times 0, 2, 4, 6, 8, 8, 10, 12, 14, 16, 20, 24, 30, 36, 48, 60 and 72 h of incubation. Ruminal fermentation was measured by the in vitro gas production technique, using a ruminal inoculum from three bovine donors. The data were analyzed with the MIXED procedure of SAS, and the comparison of means was analyzed with Tukey. The treatments that presented greater NDF digestibility were GS45 (53.79%) and GS15 (51.19%) while for ADF they were GS15 (35.15%) and GU15 (35.28%) and for DM it was GS30 with 71.32% (P &lt; 0.05; Table 2). As for the volume of CH4 produced LL45 presented the least value (10.01%), following the same trend its NDF digestibility with 38.5% (P &lt; 0.0001). While GU45 produced the lowest volume ml CH4 /g DM, NDF and ADF producing 25.83, 52.87 and 109.74 ml (P &lt; 0.0001). Likewise, the tree species that had a reduced response in CH4 production were GU and LL compared with GS (P &lt; 0.0001) also presenting a greater concentration of total and condensed tannins. The incorporation of forage plants with increased concentration of secondary metabolites and the reduced availability of digestible substrate in the present study reduced CH4 production in vitro. This study was partially funded by PAPIIT-DGAPA-UNAM (grant IN212523).
PSXI-29 Effects of Vitamin B6 supplementation on rumen fermentation and branched chain fatty acids content in vitro
Authors: Guo Xin , Zhan Tengfei , Ma Lu , Bu Dengpan 
Published: September 2024

Abstract
Vitamin B6 promotes branched-chain amino acid aminotransferases in branched chain fatty acids (BCFA) synthesis pathways. This study aimed to investigate the effects of Vitamin B6 supplementation in total mixed ration on rumen fermentation characteristics and the rumen BCFA content in vitro. Treatments were set as dose response with 0, 3, 6, 12 and 24 mg/kg dry matter (DM) Vitamin B6. Each incubated with 75 mL of buffered rumen fluid and 0.5 g of fermentation substrate for 24 h at 39°C. Five replicate parallel fermentation flasks were prepared by each level of supplemented Vitamin B6, and incubation was repeated twice. Filtered fluid with Nylon bags were collected from each fermentation flask. The contents of volatile fatty acids (VFA) and BCFA were determined using an Agilent 6890N GC equipped with a flame ionization detector. All data were analyzed using the linear mixed model of nlme Package in R (version 4.3.1). Compared with the control group, the concentration of total branched chain volatile fatty acids, propionic acid, butyric acid, valeric acid, isobutyric acid and isovaleric acid at 3 mg/kg DM Vitamin B6 significantly decreased, while the ratio of acetic acid to propionic acid was significantly increased (P &lt; 0.01). As the dose of Vitamin B6 increased, the concentrations of iso-C14:0, iso-C15:0, anteiso-C17:0 changed quadratically with greatest at 3 mg/kg DM Vitamin B6 (P &lt; 0.05). Compared with the control group, the contents of iso-C13:0, iso-C14:0, iso-C15:0, anteiso-C15:0, anteiso-C17:0, iso, anteiso and BCFA at 3 mg/kg DM Vitamin B6 significantly increased (P &lt; 0.01). The contents of total iso, anteiso and BCFA increased by 18.80 %, 35.37 % and 22.58 %, respectively, compared with the control. In summary, the results of this study indicated that 3 mg/kg DM Vitamin B6 had beneficial effects on increasing BCFA content than other groups.
PSXI-11 In vitro rumen fermentation characteristics of rumen fluid obtained from grain-fed and grass-fed farmed American Bison
Authors: Okoren Claire E , Engle Terry E , Edwards-Callaway Lily N 
Published: September 2024

Abstract
The objective of this pilot study was to examine the impact of diet type on in vitro rumen fermentation characteristics using rumen fluid collected from grain-fed and grass-fed American Bison (Bison bison). Rumen fluid was collected from 6 farmed American Bison at a commercial slaughter facility. At the time of slaughter, 3 grain-fed heifers (&lt; 3 yr) were randomly selected for rumen fluid collection. On a separate day, 3 grass-fed cows (&gt;3 yr) were randomly selected for rumen fluid collection. Rumen fluid was collected from each animal by obtaining rumen contents and filtering the rumen fluid from the digesta. For a given collection day, rumen fluid from the 3 animals was combined with McDougall’s buffering solution to generate rumen fluid buffer solution (RFB). The RFB was added to each pre-weighed digestion vessels (DV) containing no substrate (blanks) or 0.5 g of ground substrate (grain-based diet or forage-based diet). After filling, the DV were capped with one-way valves and incubated for 0, 12, 24, 48, and 72 h. At the end of each incubation period, DV were centrifuged, and supernatant was removed and analyzed for VFA concentrations. The remaining pellet was dried at 60°C for 24 h to determine dry matter digestibility (DMD). Descriptive statistics were used to describe DMD characteristics for rumen fluid collected from bison from each production system. Linear, quadratic, and cubic responses were analyzed for DMD. Linear, quadratic, and cubic contrasts were used to examine DMD over time. In vitro DMD increased quadratically (P &lt; 0.05) for grain-fed bison and linearly (P &lt; 0.05) for grass-fed bison over time. Final 72 h DMD was 84.5% ± 0.05 and 70.0% ± 0.11 for grain-fed and grass-fed bison, respectively. Final molar proportions of acetate, propionate, isobutyrate, and butyrate were 55.3% ± 0.01, 25.8% ± 0.002, 1.9% ± 0.01, and 17.0% ± 0.001 for grain-fed bison and 31.0% ± 0.02, 41.2 ± 0.02, 3.9% ± 0.01, and 23.2% ± 0.01 for grass-fed bison. Molar proportions of all VFA exhibited a cubic response (P &lt; 0.05) over time for rumen fluid collected from both grain-fed and grass-fed bison. These data provide a preliminary insight into in vitro rumen fermentation characteristics of bison from different production systems.
PSXI-17 Comparison of enteric methane production between the respiration chamber and the CO2 method in Holstein heifers
Authors: Lee Jaesung , Bharanidharan Rajaraman , Oh Junseok , Im Seyun , Kim Sang Yeob , Ranaweera Namal , Kim Kyoung Hoon , Baik Myunggi 
Published: September 2024

Abstract
The objective of this study was to validate the carbon dioxide (CO2) method (CO2T) in comparison with the respiration chamber (RC) method for the measurement of enteric methane (CH4) emission. The study was conducted over 108 d with Holstein heifers [n = 10; initial body weight (BW) = 178 kg; and age, 7.7 mo). The study consisted of 3 consecutive measurement periods and each period consisted of 21 d of feed adaptation followed by 15 d of CH4 measurement using the CO2T (3 d) and the RC method (12 d). The 55% timothy hay and 45% concentrate were fed twice daily at 1.2% to 1.5% of BW on an as-fed basis. The CO2T was used for 3 d during the morning and afternoon feeding. For the CO2T, CH4 and CO2 concentrations of exhaled breath from each animal were continuously analyzed by gas analyzers and recorded every 10 sec for 10 min per animal. The CH4:CO2 ratio of the data were calculated and multiplied by daily CO2 production of each animal to determine daily CH4 production. Right after the CO2T measurement, CH4 emission was measured using the RC method by the difference between the inlet and outlet CH4 concentration of the RC. Statistical analyses were performed using the software R version 4.0.4. Differences in dry matter intake (DMI), CH4 production, and CH4 yield between the two methods were tested using the Wilcoxon signed-rank test. DMI was not different between the RC method and the CO2T measurements. The CH4 production (L/d, L/kg BW0.75) and yield (L/kg DMI) determined by two methods were similar (127 vs 120 L/d, 2.05 vs 2.16 L/kg BW0.75, and 23.5 vs 21.6 L/kg DMI for RC vs CO2T, respectively). There was a positive relationship between DMI (kg/d) and CH4 production (L/d) for both of the RC method (R2 = 0.46, P &lt; 0.05) and the CO2T (R2 = 0.72, P &lt; 0.01). Linear regression analysis of CH4 production (L/d) between the RC method and the CO2T showed a moderate positive relationship (R2 = 0.52, P &lt; 0.05). Pearson correlation analyses showed a strong relationship between the RC method and the CO2T for CH4 production (L/d; R2 = 0.72, P &lt; 0.05). In conclusion, the CH4 production of Holstein heifers estimated by the CO2T did not differ from that measured by the RC method, and method agreement indices showed moderate positive correlations. The CO2 method could be used as one of the alternative CH4 measurement techniques comparable to the respiration chamber method.
PSXI-9 Impact of copper dose and soybean oil on in vitro ruminal fermentation products
Authors: Rodezno-Gomez Arturo , Thomas Tyler A , Oliveira Joyce , Loh Huey Yi , Thorndyke Meghan P , Miller Alexandra C , Alves Julia Baroni , Engle Terry E 
Published: September 2024

Abstract
The objective of this experiment was to determine the impact of copper (Cu) dose on microbial fermentation products and biohydrogenation of soybean oil (SBO) using an in vitro rumen fermentation technique. Two heifers [body weight (BW) = 408 and 422 kg] fitted with ruminal canulae were fed a high concentrate diet for 14 d. On d 15, rumen fluid samples were obtained 2 h post-feeding from both animals and combined into one pre-warmed (39°C) container. Anaerobic conditions were maintained by bubbling carbon dioxide (CO2) into McDougall’s buffer, while two volumes of rumen fluid were added to each volume of McDougall’s buffer. The suspension was mixed under CO2 as 30-mL portions were added to pre-weighed vaccine bottles containing 0.5 g of substrate (ground basal finishing diet with no supplemental Cu or SBO). The basal diet contained 4.2 mg Cu/kg dry matter (DM). Treatments were assigned to vaccine bottles in a 2 x 3 factorial arrangement with factors being SBO (0 or 3.5%) and Cu (0, 10, or 20 mg/kg DM) relative to substrate DM. Each treatment was replicated 6 times. Following treatment administration, all vaccine bottles were caped and sealed to maintain anaerobic condition and incubated at 39°C. Vaccine bottles were swirled by hand at the time of gas sample collection at 0, 2, 4, 6, 8, 10, 12, 18, 24, 36, and 48 h post-inoculation. Samples were immediately analyzed for methane (CH4) and CO2. Following every gas sampling timepoint, the vaccine bottles were degassed. At the end of the 48-h incubation, all vaccine bottles were centrifuged, and 2 mL of supernatant were removed and acidified with 25% metaphosphoric acid for volatile fatty acid (VFA) determination, and another 5 mL of supernatant were removed and analyzed for long chain fatty acids. The remaining supernatant was decanted, and the vaccine bottles were dried at 60°C for 72 h to determine DM disappearance (DMD). Data were analyzed as a randomized block design for a 2 x 3 factorial arrangement of treatment using PROC MIXED of SAS. Forty-eight hour DMD, CO2 production, molar percent of acetate, propionate, and butyrate, total mM of VFA, and pH were unaffected by treatment. Methane production per unit of DMD decreased (P &lt; 0.05) in fermentation bottles containing SBO but increased (P &lt; 0.04) in fermentation bottles containing Cu. Soybean oil addition increased C16:0, C18:0, C18:1, C18:2, and C18:3 fatty acids at 48 h. Copper addition tended to decrease C18:0 (P &lt; 0.07) and tended to increased C18:1 (P &lt; 0.06) and C18:3 (P &lt; 0.09) fatty acids. These data suggest that Cu may decrease biohydrogenation in vaccine bottles not containing SBO but increases ruminal biohydrogenation in vaccine bottles containing SBO.
PSXI-27 Supplementing Bovacillus to feedlot cattle finished under heat stress conditions
Authors: Mackey Shea , Cooke Reinaldo F , Pickett Autumn , Cappellozza Bruno I 
Published: September 2024

Abstract
This experiment compared performance, physiological, and carcass responses of finishing cattle receiving a Bacillus-based probiotic under heat stress conditions. Angus-influenced steers (n = 113) were purchased from an auction yard and assigned to the experiment [arrival body weight (BW) = 345 ± 2.7 kg]. On d 0, steers were ranked by initial BW and allocated to 1 of 20 drylot pens (5 or 6 steers/pen). Pens were randomly assigned to receive a finishing diet containing BOV (3 gּ animal-1ּ d-1 Bovacillus) or no additive (CON) until slaughter. Diets contained monensin but not tylosin. Steer BW was recorded on d 0, 28, 56, 84, 112, and at the time of shipping, which was considered final BW. Initial and final BW were used in average daily gain (ADG) calculation. Blood samples were collected immediately after BW assessment on d 0, 28, 56, 112 of the experiment as well as 8 d prior to slaughter. Plasma was analyzed for concentrations of alanine aminotransferase, aspartate transferase, alkaline phosphatase, gamma-glutamyl transferase, bilirubin, and blood urea nitrogen. Real-time temperature and humidity were recorded every hour for the duration of the trial for temperature-humidity index (THI) assessment. Steers were shipped to a packing facility (Tyson; Amarillo, TX) in 3 groups according to BW, which contained an equal number of pens from both treatments. Upon slaughter, hot carcass weight, backfat thickness, Longissimus muscle area, USDA marbling score, USDA yield and quality, and liver abscess score were recorded. The THI during the first and second thirds of the experimental period (79.8 and 78.1, respectively; SEM = 0.22) were substantially above the heat stress threshold (THI = 72). No treatment differences were recorded for BW parameters, ADG, or gain to feed ratio (P ≥ 0.21), despite a 10 kg increase in final BW and a 4 kg increase in hot carcass weight in BOV steers. Dry matter intake did not differ among treatments (P = 0.48). No treatment differences were recorded for carcass quality response, although incidence of liver abscess was reduced in BOV compared with CON groups (7.3 vs 19.0%; P = 0.04). A treatment × day interaction was detected (P = 0.02) for plasma concentration of GGT, which tended (P = 0.08) to be greater for CON vs. BOV steers on d 56. No other treatment differences were detected for plasma metabolites (P ≥ 0.69). Collectively, BOV supplementation mitigated the incidence of liver abscesses in finishing cattle, whereas improvements to steer performance were only numerical.