bluuebunny/crossref_metadata_2025_split huggingface dataset:
PSV-30 Effects of divergent residual feed intake on performance, feed efficiency, feeding behavior and gaseous exchange in replacement beef heifers
Authors: Adcock Zoe , O’Reilly Keara , Carstens Gordon E , Tedeschi Luis O , Pinchak William E , Walker Ryon S 
Published: September 2024

Abstract
The objective of this study was to examine the differences in performance, feed efficiency, feeding behavior and gaseous exchange (methane, carbon dioxide and oxygen) in replacement beef heifers with divergent phenotypes for residual feed intake (RFI). Crossbred beef replacement heifers [n = 63; initial body weight (BW) = 277 ± 21 kg] were blocked by BW and assigned to 1 of 2 pens each equipped with electronic feed bunks (GrowSafe Systems) and GreenFeed gaseous-exchange measurement systems (GEM; C-Lock). Heifers were fed a corn-silage based ration twice daily. Individual dry matter intake (DMI), feeding behavior, and gas flux data were collected for 70 d and BW measured weekly. Carcass ultrasound data were collected at the beginning and end of the study. Residual feed intake was calculated as the residual from the regression of DMI on ADG and mid-test BW0.75 and heifers assigned to low-, medium-, and high-RFI classes (± 0.5 SD from the mean RFI). A mixed model with RFI class as fixed effect and pen as a random effect was used for data analysis. There were no differences due to RFI class in BW and ADG. However, low-RFI heifers consumed 16% less (P &lt; 0.001) DMI and had more favorable gain to feed (G:F) then high-RFI heifers. High-RFI heifers had a greater (P &lt; 0.05) backfat gain during the 70-d study, with backfat gain accounting for an additional 4.2% of the variation in DMI. Low-RFI heifers exhibited more favorable feeding behavior, with 10.4% fewer (P = 0.057) bunk visit events and spent numerically less time at the feed bunk (103 vs 122 min/d) compared with high-RFI heifers. Methane emissions (g/d) did not differ between heifers with divergent RFI (P = 0.138; 129 vs 140 g/d in low- and high RFI heifers respectively), however, methane yield (g/kg DMI) was 9% greater (P &lt; 0.05) in low- compared with high-RFI heifers. Additionally, low-RFI heifers produced 7.9% less (P &lt; 0.05) carbon dioxide (g/d) and consumed 6.9% less (P &lt; 0.05) oxygen than high RFI heifers. Further research is warranted to investigate the biological mechanisms influencing RFI and the effects of selection for RFI as a strategy to mitigate reduce greenhouse gas emissions from cattle production systems.
PSVII-24 Backgrounding carryover nutritional effects on nitrogen metabolism and water requirements onto grain or forage-fed finished cattle
Authors: da Silva Aghata Elins Moreira , Franco Arturo Macias , da Silva Gleise Medeiros , Fonseca Mozart A 
Published: September 2024

Abstract
The objective of this study was to examine how different backgrounding and finishing systems might affect nitrogen (N) metabolism, and consequently water requirements of cattle. Further, we investigated if the previous plane of nutrition might affect the results obtained in the subsequent phase. Cattle (n = 24) were randomly distributed into either a moderate (MP; crude protein (CP): 9.10%) or high (HP; CP: 12.62%) plane of nutrition during the background phase for 85 d. Animals were then blocked by their previous plane of nutrition and were moved onto a 105-d finishing phase. The forage-finished group received only high-quality alfalfa hay (CP: 21.3%), whereas the grain-finished group received a high grain diet (80% whole corn and 20% alfalfa hay; CP: 10.8%). Animals on MP diets excreted less N through urine (P &lt; 0.01) and feces (P &lt; 0.01), while retaining more N (P &lt; 0.01), which resulted in an increased N efficiency (P &lt; 0.01) when compared with HP animals. No differences were observed for water intake or microbial N being observed (P &gt; 0.05). Grain-fed animals consumed less N and water (P &lt; 0.01), but still had a greater amount of N being digested when compared with forage-fed animals (P &lt; 0.01), as well as the least excretion of N through feces (P &lt; 0.01) and urine (P &lt; 0.01), and consequently a greater rate of N being retained (P &lt; 0.01) and a greater efficiency on utilizing the ingested N (P &lt; 0.05). Further interaction was also observed between treatment and previous plane of nutrition, where animals coming from a MP had the least dry matter intake, greatest amount of N being digested and least N excretion, fecal output, and excretion of N through the feces (P &lt; 0.05). These results indicate that animals receiving MP will reduce their excretion of N without modifying the required amount of water while producing the same amount of microbial N due to more efficient N recycling. Extremely important is the fact that efficiency is carried over after these animals are transitioned to grain-fed finishing systems.
PSX-17 Effects of Saccharomyces cerevisiae fermentation product on methane production of steers fed a finishing diet
Authors: Dhungana Anjan , Odunfa Oluwaseun , Blair Jansen , Yoon Ilkyu , Ogunade Ibukun M , Altman Alexander , McLeod Kyle R , Harmon David L , Jiang Yun 
Published: September 2024

Abstract
Saccharomyces cerevisiae fermentation product (SCFP), a postbiotic feed additive, has been reported to improve ruminal pH in cattle fed a high-starch diet. Given that higher ruminal pH was associated with greater methane production, SCFP may affect enteric methane production. However, no research has investigated the effect of SCFP on methane production in finishing cattle. This study assessed the effects of SCFP on enteric methane production of steers fed a high-concentrate finishing diet. Holstein steers (n = 12) were blocked based on their initial body weight (BW; 294 ± 12.7 kg) to 3 groups and enrolled in a randomized block design study. The 4 steers in each block were randomly assigned to two treatments and fed ad libitum a finishing diet consisting of 20% corn silage and 80% concentrate on a DM basis. The treatments were CON (Control, basal diet only) and SCFP (basal diet, top dressed with 12 gּ animal-1ּ d-1 SCFP, NaturSafe, Diamond V, Cedar Rapids, IA). After 29 d, steers were transferred to head-boxes for respiratory measurement for 72 h. The first 24 h was used as adaptation. During the last 48 h, respiratory samples were collected every 21 min and analyzed with gas sensors to determine O2 consumption and CO2 and CH4 production. Data were analyzed with the GLIMMIX procedure of SAS 9.4. The BW of steers was similar (342.5 vs. 338.8 kg for SCFP and CON respectively, P = 0.65) between two treatments before the respiratory measurement. Steers fed SCFP tended to have an overall greater dry matter intake (DMI; 7.26 vs. 6.76 kg/d, P = 0.10) and had graeter DMI during the 48-h respiratory measurement (6.58 vs. 5.45 kg/d, P = 0.03). The amount of O2 consumed was not affected by SCFP (35.6 vs. 34.4 Lּ kg BW.75/d, P = 0.45). Similarly, CO2 production was not affected by SCFP (36.5 vs. 34.8 Lּ kg BW.75/d, P = 0.36). Supplementing SCFP did not affect daily CH4 production per unit of metabolic BW (1.82 vs 1.80 Lּkg BW.75/d, P = 0.94), but it numerically reduced hourly methane emissions per unit of DMI (1.00 vs. 1.29 L/kg DMI, P = 0.39, Figure 1). Our results suggest that SCFP did not lead to greater methane production but instead showed a trend toward reduced methane emission per kilogram of DMI. This is likely driven by greater DMI by feeding SCFP during the respiratory chamber measurements. Further studies using larger experimental units are needed to confirm this observation.
PSX-22 Boosting techniques for prediction of dry matter intake of cattle in confinement settings and SHAP analysis on the models’ output
Authors: ArunKumar K E , Blake Nathan , Walker Matthew , Holaskova Ida , Mata-Padrino Domingo , Wilson Matthew E 
Published: September 2024

Abstract
Measurement of individual dry matter intake (DMI) is critical to improving the management of the beef herd and is necessary to determine the feed efficiency of individual cattle. Combining machine learning models and proxies for DMI (e.g., water intake, body weight, climatic variables) has the potential to replace the need for dedicated feed intake equipment. It would also open the possibility of measuring DMI in situations like grazing where quantifying DMI directly is not possible. In this study, we examined the relationship between DMI, animal variables and environmental variables. In this study, we developed and tested machine learning models based boosting techniques to develop approaches to predict DMI in cattle, using the same data we have previously published results from Random Forest techniques in the past. The dataset included both bulls and steers. The developed models include both regular boosting regression models and random effects boosting models. The regular boosting technique models such as gradient boosting regression, light gradient boosting regression, extreme gradient boosting regression. Similarly, random effects boosting machine learning model Gaussian process boosting (GPBoost) was developed to consider the random effects associated with the intake behavior of the animals. The extreme gradient boosting model outperformed other regular boosting regression models with a r2 of 0.81 and 0.48 on training and testing datasets respectively. However, it does not consider the random effects associated with the longitudinal nature of the animal intake and weather variables and prone to overfitting. GPBoost model variants were tested and developed to avoid overfitting and to incorporate a random effects model, which we propose as the overall best performing model. The GPBoost generalized well on the training and testing datasets with r2 scores of 0.55 and 0.54 respectively. To further understand the model’s performance on the unseen dataset, we used SHAP analysis on the GPBoost. The SHAP analysis revealed that water intake, full body weight and age of the animals contributed significantly to predicting unseen data.
PSXI-16 Increased copper concentrations in liver and duodenum tissues in Rambouillet-crossbred sheep receiving copper supplementation
Authors: Loh Huey Yi , Thorndyke Meghan P , Quevedo Alejandro , Gibbons Ashlee , Baer Brecken , Gleckler Leala , Engle Terry E 
Published: September 2024

Abstract
Rambouillet-crossbred wethers (n = 8; approximately 7 mo of age) were stratified by body weight (BW) into 4 BW blocks to examine the impact of copper (Cu) supplementation on plasma, bile, liver, duodenum, jejunum, and ileum tissue Cu concentrations. On d 0 of the experiment, liver biopsies and plasma samples were collected from each animal and analyzed for Cu concentrations. Animals were housed in individual pens and received a total mixed ration (dry matter basis: 30.0% cracked corn, 33.3% grass hay, 33.3% alfalfa hay, 3.4% soybean meal) once daily in amounts to allow ad libitum access to feed over a 24 h period. Wethers were paired by BW and assigned to 1 of two treatments (n = 4 wethers/treatment). Treatments consisted of 1) no supplemental Cu (control), and 2) +Cu: 12 mg of supplemental Cu/kg DM from CuSO4∙5H2O. Ground corn was used as a carrier for each treatment and fed in a separate feed container daily. On d 28 of the experiment, all wethers were transported to an USDA inspected abattoir and harvested. Following harvest, blood, bile, liver, duodenum, jejunum, and ileum samples were collected. Digestive tract samples were thoroughly washed with phosphate-buffered saline to remove all feed particles. Blood samples were collected in heparinized trace mineral free vacutainer tubes and centrifuged at 2,000 x g for 15 min at room temperature. Plasma, bile, and gastrointestinal tissue samples were stored in acid-washed storage vials at -20 ºC until analyzed for Cu concentrations. Data were analyzed as a randomized block design using the MIXED procedure in SAS with individual animal as the experimental unit. Liver (P &lt; 0.05) and duodenum (P &lt; 0.04) Cu concentrations were greater and ileum Cu concentrations were less (P &lt; 0.04) in sheep receiving supplemental Cu compared with controls. Plasma, bile, and jejunum Cu concentrations were similar across treatments. These data suggest that Cu absorption takes place primarily in the duodenum and accumulates in the liver in sheep fed a diet containing 18 mg Cu/kg dry matter. Although total bile production was not measured in this experiment, the accumulation of Cu in the liver in +Cu sheep coupled with no treatment effect on bile Cu concentrations suggests an inability of sheep to excrete excess Cu from the liver via bile. Future research examining the impact of Cu supplementation on the molecular mechanisms associated with Cu absorption from each segment of the small intestine and storage and excretion mechanisms in the liver is warranted.
PSXI-23 Development of sub-models to estimate protein requirements and supply of lactating dairy cows using machine learning algorithms
Authors: Lee Mingyung , Seo Seongwon , Tedeschi Luis O 
Published: September 2024

Abstract
The objectives of this study were to develop sub-models for predicting protein requirements and supply, encompassing 1) net protein for maintenance (NPm), 2) lactation (NPl), 3) rumen undegradable protein (RUP), and 4) duodenal microbial nitrogen (MicN) from the feed protein. The dataset used in this study was constructed by integrating in vivo experimental data collected from open databases (the National Animal Nutrition Program) and articles (Journal of Dairy Science), which includes a total of 1,779 observations from 436 publications. In the development of the model, animal information and feed chemical components were used as candidate variables, and two types of machine learning algorithms, Random Forest Regression (RFR) and Support Vector Regression (SVR) were employed. After testing, the following predictors were selected for predicting: 1) NPm: body weight (BW) and dry matter intake (DMI), 2) NPl: BW, DMI, days in milk (DIM), and dietary organic matter (OM) and crude protein (CP) contents, 3) RUP: DIM, DMI, dietary DM content, and CP fraction intake (B and C), and 4) MicN: DIM, DMI, DM, dietary neutral detergent fiber (NDF) content, CP fraction intake (A, B, and C). The selected models were assessed using a cross-validation method with the following statistical metrics including the coefficient of determination (R2), root-mean-square error of prediction (RMSEP), residual analyses, and concordance correlation coefficient (CCC). For the RUP and MicN models, they were compared with the NASEM (2021) model. In predicting NPm, both SVR and RFR algorithms demonstrated increased precision (R2 = 0.965 vs. 0.969) and accuracy (RMSEP = 9.7 vs. 9.2 g/d); however, during residual analysis, the RFR model showed a statistically significant slope bias (P &lt; 0.05). In the NPl prediction, the RFR algorithm showed slightly greater performance compared with SVR (R2 = 0.864 vs. 0.814 and RMSEP = 86.7 vs. 98.5 g/d). However, similar to the NPm prediction, the RFR model displayed a statistically significant slope bias (P &lt; 0.05). In the supply model, the RFR model exhibited the greatest precision and accuracy in predicting RUP (R2 = 0.60, RMSEP = 0.326 kg/d, and CCC = 0.71) without any biases. This model achieved a 2.37-fold increase in R2 and a decrease of 0.111 kg/d in RMSEP compared with the NASEM model. As for MicN prediction, the SVR model performed the best (R2 = 0.76, RMSEP = 42.4 g/d, and CCC = 0.86) without biases. This model attained a 19-times improvement in R2 and a reduction of 38.7 g/d in RMSEP when compared with the NASEM model. In conclusion, the models developed using machine learning algorithms can be helpful for accurately and precisely predicting protein requirements and supply based on animal information and the chemical composition of feed.
PSXI-15 Effect of different levels of dry distillers bran plus solubles on performance of Nellore bulls finished on pasture receiving high supplementation
Authors: de Souza Gilyard Angelo Pinheiro , Ferreira Igor Machado Machado , de Almeida Saulo T Teixeira Rodrigues , Garcia Anna Lidia Francino Francino , Andrade Antonio Henrique , Inácio de Abreu Mateus José Inácio José , de de Resende Flávio Dutra Dutra , Siqueira Gustavo Rezende Rezende 
Published: September 2024

Abstract
This study was carried out to evaluate the performance of Nellore bulls finished on pasture receiving high supplementation containing different inclusion levels of dry distillers bran plus solubles (DDBS). Nellore bulls [n = 832; body weight (BW) = 390 ± 30 kg; 20 mo of age] were distributed in a randomized block design and allocated to 12 paddocks (Urochloa brizantha cv. Marandu; 7 or 8 animals/ha) measuring 10 ha (n = 6) and 8 ha (n = 6). The treatments consisted of four levels of DDBS inclusion: supplement without DDBS (S0) or containing 250 g/kg (S250), 500 g/kg (S500) or 750 g/kg (S750) of inclusion in the supplement dry matter (DM; Table 1). The DDBS used in the experiment was produced by FS Fueling Sustainability, Lucas do Rio Verde, Brazil, and had 90.8% dry matter (DM), 20.5% crude protein (CP), 38.6% neutral detergent fiber (NDF), and 6.5% ether extract (EE). The supplements were provided ad libitum daily. The finishing period lasted 103 d, from October/2023 to January/2024 (wet season). The animals were weighed fasting (16 h) on the first and last day of the experiment. The supplement DM intake (DMIs) was measured daily. All data were analyzed using the MIXED procedure of SAS. The means were compared using orthogonal polynomial contrasts (linear and quadratic). Significance was set at P ≤ 0.05 and trends were declared when 0.05 &lt; P ≤ 0.10. A quadratic effect was observed for both final BW and average daily gain (ADG; P = 0.01 and P = 0.04, respectively). Animals kept in the S250 treatment had greater BW gain and were heavier at the end of the experimental period than the other treatments. The DMIs tended to be quadratic (kg/d, P = 0.06; and %BW, P = 0.07), with the greatest supplement intake for S250 (7.88 kg/d) and the least for S750 (7.01 kg/d). Supplement feed conversion [DMIs:average daily gain (ADG] did not differ (P ≥ 0.23) between treatments (Table 2). The DDBS inclusion also had a quadratic response in hot carcass weight (HCW; P = 0.01), where animals kept in the S250 treatment had greater carcass weight than the other treatments. However, there was no effect of including DDBS on dressing percentage (P ≥ 0.32). The inclusion of DDBS at 250 g/kg of the supplement DM improves the performance of cattle finished on pasture receiving high supplementation.
PSXI-12 Effects of Flint corn with or without high concentration of amylase and particle size on in vitro fermentation parameters, gas production and methane emission
Authors: De Oliveira Daiana Dos Santos , Brixner Bárbara Martins , Abdalla Adibe Luiz , Polizel Daniel Montanher , Drouillard James S S , Santos Flávio Augusto Portela 
Published: September 2024

Abstract
The objective of this trial was to evaluate the fermentation parameters, gas production and dry matter (DM) disappearance in vitro of two corn hybrids with two particle sizes. A 2 × 2 factorial design study was carried out to evaluate two types of Flint corn with or without high amylase concentration (Enogen flint or Tropical Flint, respectively), and two particle sizes (1.5 or 2.5 mm). Incubations were carried out for a total period of 24 h using the automatic gas pressure system (ANKOM, RF). The ruminal liquid was combined with buffer in a 1:4 ratio respectively and each bottle received 150 mL of this mixture plus 1.5 g of DM corn sample. At the end of the 24-h period, a gas sample was taken for methane analysis, a sample was taken for short chain fatty acid (SCFA) analysis, and DM was performed on the final residue from the bottles to estimate the disappearance of DM. Data were analyzed using SAS Proc Mixed (9.4). There was no interaction effect between corn hybrid and particle size for the variables evaluated. Enogen Flint corn increased the proportion of propionate (30.7 vs. 28.1 mM/100 mM; P = 0.03) and reduced isovalerate (1.23 vs. 1.65 mM/100 mM; P = 0.01), and acetate:propionate ratio (1.85 vs. 2.11; P = 0.04), with no effect on the other fermentation variables evaluated. The particle size affected the pH of the fluid, with lower pH observed when using 1.5 mm particle size (6.64 vs. 6.70; P &lt; 0.01). Regarding the disappearance of DM, Enogen Flint corn increased disappearance compared with Tropical Flint (80.8 vs. 77.5%; P &lt; 0.01), and the 1.5 mm particle size also resulted in an increase in DM disappearance (81.9 vs. 76.4%; P &lt; 0.01), with no interaction between the factors studied. (P = 0.80). Corn hybrids did not affect total gas production and methane production. However, the 1.5 mm particle size increased the total gas production (117.5 vs. 103.2 mL/24 h; P &lt; 0.01), with no effect on methane production. In conclusion, Enogen technology optimizes the rumen fermentation process and increases corn dry matter degradability, and 1.5 mm particle size of the corn grain also increases degradability.
PSXI-16 Using a multi-omics approach to decipher trans-10 shift biomarkers in ruminants
Authors: Alves Susana P , Vitor Ana Cristina , Garrine Carmen , Fernandes Tatiane , Nanni Paolo , Roschitzki Bernd , Attwood Graeme , Grossmann Jonas , Laczko Endre , de Almeida André M , Bessa Rui J B 
Published: September 2024

Abstract
The trans-10 shift is a recognized deviation from the normal ruminal biohydrogenation (BH) pathways of the dietary polyunsaturated fatty acids (FA) in the rumen. This phenomenon leads to the formation of the harmful t10-18:1, which is detrimental to the health of the animal, instead of the beneficial t11-18:1, which has positive effects. The phenomenon known as the t10-shift has been observed in animals consuming diets that are high in starch but low in forage. Although consuming such similar diets, there exists a significant variability in t10-shift expression among animals. The reasons behind the t10-shift are not well understood. With the aim of finding biomarkers associated with t10-shift, this study utilized multiple levels of information, including lipidomics, metabolomics, and proteomics of ruminal contents. Rumen contents from male lambs (n = 16) distributed by two diets with distinct forage:concentrate ratios (20:80 and 80:20) were collected after 42 d on ad libitum feed. FA from rumen contents were prepared and analyzed by gas chromatography, metaproteomics analyzes were performed from rumen bacterial pellets using LC-MS/MS-based label-free quantification, and metabolomics analyzes were performed from rumen fluid supernatants using IMS-TOF technology. Multivariate analyses and correlations were performed using the Metaboanalyst R package. Several fatty acids, proteins, and metabolites showed a strong correlation with the proportion of t10-18:1 in rumen contents. Among fatty acids, 17:0, 14:0, a-15:0, and t15-18:1 were positively correlated, while t11-18:1, t11,c13-CLA and c9,t11-CLA showed negative correlation. The metabolites, thiamine aldehyde, mevinolinic acid, 2-hydroxy-2H-benzo[h]chromene-2-carboxylate, or biotin were positively correlated with t10-18:1, as well as proteins associated with gluconeogenesis, stress response or amino acid metabolism. This work provides, for the first time, a multi-level integrated view of t10-shift phenomena in sheep. Fundação para a Ciência e a Tecnologia (FCT) provided financial support through the research projects PTDC/CAL-ZOO/29654/2017 (RumOmics), PTDC/CAL-ZOO/4515/2021 (Gene2Rumen), UIDB/00276/2020 (CIISA), UIDB/04129/2020 (LEAF), and LA/P/0059/2020 (AL4Animals).