bluuebunny/crossref_metadata_2025 huggingface dataset:
236 Increased dietary protein supports key metabolic and intestinal tissue functions in weaned pigs, without increasing gastrointestinal pathogen abundance
Authors: Diether Natalie E , Kommadath Arun , Fouhse Janelle , Zijlstra Ruurd T , Stothard Paul , Willing Benjamin
Published: September 2024

A common dietary strategy to prevent diarrhea in weaned pigs is feeding low protein diets in the period immediately following weaning. The goal of this intervention is to decrease dietary protein sufficiently to reduce pathogen proliferation and protein fermentation without negatively impacting growth performance. One potential alternative to low protein diets is provision of dietary fiber. However, many studies examining the role of protein and fiber on gastrointestinal microbiota and post-weaning diarrhea are complicated by the presence of other substrates, including polyphenols and antinutritional factors in complex ingredients. To assess the role of increased protein and fiber on gut microbiota and host metabolism, semi-purified diets differing in crude protein (CP) and crude fiber (CF) were fed to weaned pigs (n = 40; 28 d of age). Diets with high protein (HP; CP 24.3%, CF 6.4%), high fiber (HF; CP 18.9%, CF 9.4%), or both (HFHP; CP 24.9%, CF 9.5%) were compared with a control (CON; CP 18.1%, CF 6.3%) diet with industry standard crude protein and fiber levels (n = 10/group). Growth performance and diarrhea prevalence were measured alongside gut microbiota composition and metabolites. Pigs fed the HP and HFHP diets had significantly improved feed efficiency compared with both CON and HF diets. Increased protein fermentation, measured through production of biogenic amines, was observed in HP fed animals (P < 0.001). These effects were mitigated by addition of fiber in the HFHP fed pigs. Despite increased markers of protein fermentation, post-weaning diarrhea incidence was not greater in HP fed animals and no increases in gastrointestinal pathogen abundance were detected. Metabolomic and transcriptomic analyses identified critical alterations in host metabolism and cecal transcriptome in the CON compared with the HP fed animals. While all diets were formulated to meet the dietary requirements of weaned pigs, diets with lower protein levels (CON and HF) induced alteration in transcripts from the serine synthesis pathways (P < 0.001) and integrated stress response (P < 0.001) in cecal tissue alongside increases in metabolic pathways related to lysine degradation (P = 0.005). These results challenge the current practice of low protein feeding following weaning by demonstrating a detrimental effect of low protein diets on intestinal cell function and muscle accretion. This suggests that with careful ingredient selection, increased dietary protein post-weaning could better support pig health and performance compared with current industry standard diets.
379 Application of an energy and nutrient matrix to a diet supplemented with a novel phytase achieved a production and sustainability benefit in pigs
Authors: Velayudhan Deepak E E , Remus Janet C , Dersjant-Li Yueming , Vinyeta Ester
Published: September 2024

The capacity of a novel consensus bacterial 6-phytase variant (PhyG) to maintain growth performance and production benefits of pigs when added to an energy and nutrient-reduced mixed cereal diet was assessed. Two experiments were conducted. In Exp. 1 (wean to finish), weaned pigs [n = 192; initial body weight (BW) 7.18 ± 0.38 kg] were randomized to 4 treatments from weaning until market weight. Diets were provided in 5 phases. Treatments included: 1) a nutritionally sufficient positive control (PC); 2) a negative control (NC1) without added inorganic phosphate, reduced (based on specific PhyG dose) in net energy (NE), calcium (Ca), digestible amino acids (AA) and sodium (Na) vs. PC, supplemented with PhyG at 1,000, 1,000, 750, 500 and 500 FTU/kg in each phase, respectively (NC1+low PhyG); 3) a negative control (NC2) as NC1 supplemented with PhyG at 2,000, 2,000, 1,000, 750 and 750 FTU/kg in each phase and further reduced in energy and nutrient based on specific PhyG dose (NC2+high PhyG), and; 4) a negative control (NC3) as 2) and supplemented with xylanase–β-glucanase (XB) to provide 2,400 U/kg xylanase and 304 U/kg β-glucanase, with additional reduction in NE and digestible AA based on the contribution of XB (NC3+low PhyG + XB). In Exp. 2 (nursery), weaned pigs (n = 360; initial BW 8.40 ± 0.78 kg) were assigned to 3 dietary treatments from weaning up to 35 d. Diets were offered in 2 phases. Treatments included a nutritionally adequate positive control (PC) and 2 PhyG-supplemented diets, reduced in digestible phosphorus, Ca, Na, NE and digestible AA vs. PC, according to the expected contribution of PhyG added at 1,000 FTU/kg (NC1) or 2,000 FTU/kg (NC2), respectively. Data were analyzed by ANOVA. Means separation was by Tukey’s HSD test. In Exp. 1, overall growth performance (114 d) in all enzyme-supplemented diets was maintained or improved compared with PC. Compared with PC, feed cost per kg BW gain was significantly reduced by 7.3% and total carbon footprint (CFP; CO2 eq. g/kg BW gain) was reduced by 6.8% with PhyG + XB combination. In Exp.2, overall growth performance (35 d), in all PhyG-supplemented, nutrient-reduced, treatments, were either not different from, or were improved, vs. PC. Total feed costs and estimated CFP per kg BW gain were reduced in all PhyG-supplemented, nutrient- and NE-reduced treatments vs. PC. In conclusion, the application of a full energy and nutrient matrix maintained the overall growth of pigs in both 114- and 35-d studies with the novel phytase. The addition of XB further improved the overall growth of market pigs. Moreover, full matrix application with PhyG achieved reductions in total feed cost and carbon footprint in both studies.
445 Effects of feed restriction on growth, blood chemistry and reproductive performance in replacement gilts
Authors: Holanda Debora M , Stephens Sarah , Lei Huaigang , Sanchez-Osorio Jonatan R , Moroni Julia L , Zak Louisa J , Knol Egbert F , Nyachoti C Martin
Published: September 2024

The practical application of embryo transfer in pigs could benefit from using embryo donors for multiple cycles. Thus, raising the need to investigate feeding strategies for donors which will not be required to recover body condition lost during previous lactation. The objective was to evaluate the effects of temporary feed restriction, from d 6 to 14 of the estrous cycle, on growth, blood variables and reproductive performance in replacement gilts. Replacement gilts (n = 20; TN70, Topigs Norsvin, Oak Bluff, Canada) were assigned equally across 2 feeding regimens following a randomized complete block design where the block was backfat thickness. The feeding regimens were based on the first day of the estrous cycle: CON, recommended feeding levels from d 0 to 14 and a flush feeding (25% above recommended levels) from d 15 until d 21; or RES, CON but with restricted feeding (25% below recommended levels) from d 6 to 14. The CON treatment was based on the recommendations of the Feed Manual TN70 (Topigs Norsvin, 2015). On d 0, 5, 14 and 20 of the cycle, body weight and backfat thickness were measured. On d 21 (detected estrus), gilts were inseminated and on d 27 they were euthanized to collect embryos, ovaries and uterus. The uterus and ovaries were weighed whereas corpora lutea were counted and weighed. Blood serum was collected on d 14, and 20 for chemical analyses. Data were analyzed using the mixed procedure of SAS where each gilt was the experimental unit. Feeding regimens were considered as the fixed effect and backfat block as the random effect. Means were obtained with the LSMEANS statement. No differences (P > 0.05) were observed on growth performance among feeding regimens. However, when comparing the average daily gain (ADG) within feeding regimens between feeding periods, no differences (P > 0.05) were observed among gilts fed CON whereas gilts fed RES showed a decreased (P < 0.05) ADG during d 6 to 14 compared with d 0 to 5 and d 15 to 21. Regarding blood serum variables, gilts fed RES had greater (P < 0.05) total protein and potassium but less (P < 0.05) sodium-to-potassium ratio than gilts fed CON on d 14. On d 20, Gilts fed RES had greater (P < 0.05) cholesterol values than gilts fed CON. No differences (P > 0.05) were observed on the number of corpora lutea, number of embryos collected or on collection efficiency. Similarly, no differences (P > 0.05) were observed on the weight of reproductive organs or on measurements of ovaries among feeding regimens. In conclusion, restricting feed intake of replacement gilts by 25% of the recommendation from d 6 to 14 of the estrous cycle reduced ADG without compromising their reproductive performance.
49 Crossing-talk between micronutrient and macronutrient metabolism: Implication in health and disease
Authors: Lei Xin Gen
Published: September 2024

Recent goals of swine ration formulation have evolved from preventing nutritional deficiency diseases and maximizing growth performance to optimizing immune function and disease resistance with least climate impact. Thus, certain micronutrients such as selenium (Se) are widely considered to be health beneficial at dietary concentrations above nutrient requirements. During the past decade, we have conducted a number of experiments to determine impacts and mechanisms of dietary Se concentrations (0.03 to 1 or 3 mg/kg) on metabolism of carbohydrate, lipid, and protein in pigs from growing to finishing. Strikingly, pigs fed high-Se diets developed hyperinsulinemia and insulin resistance. Those pigs also had increased lipid, protein, saturated fatty acids (myristic, palmitic, stearic, and behenic acids), and aspartic acid, glutamine, and alanine and decreased polyunsaturated fatty acids (dihomo-γ-linolenic, oleic, α-linolenic, and eicosatrienoic acids) in the liver and(or) adipose tissues. The high-Se diets increased and decreased amounts of 5 and 2 selenoproteins, respectively, in tissues of pigs. These effects were associated with down-regulated insulin signaling (INSR and AKT), glycolysis (glucokinase) and gluconeogenesis (PEPCK) and up-regulated lipogenesis (FOXO1, SREBP1, ACC and FAS), and protein synthesis (mTOR and RPS6/S6). In contrast, high dietary fat intakes up- or down-regulated expressions of all selenoproteins except for TXNRD2 and TXNRD3 and showed a strong effect on expressions of DIO2, GPX6, and SELENOK. These induced selenogenome expression changes were associated with increased serum malondialdehyde and plasma concentrations of tumor necrosis factor alpha and interleukin-6, along with risk of obesity and chronic inflammation. Altogether, metabolisms of micronutrients and macronutrients in pigs are coordinated through interdependent and mutually regulated crossing talks at tissue, cellular, biochemical, and signal levels.
98 Differential gene expression of the endocannabinoid system in bovine tissues
Authors: Kent-Dennis Coral , Klotz James L
Published: September 2024

Because of the association with intake and metabolism, there is interest in the endocannabinoid system and how it may be manipulated to benefit livestock. With the recent interest in using industrial hemp as a feedstuff in ruminants, understanding the interaction between phytocannabinoids and the endocannabinoid system is necessary. However, the endocannabinoid system has not been specifically characterized in cattle, especially the gastrointestinal tract (GIT). The objective of this study was to characterize the distribution and transcriptional abundance of genes associated with the endocannabinoid system in cattle. Tissues including brain, spleen, thyroid, lung, liver, kidney, mesenteric vein, tongue, sublingual mucosa, rumen, omasum, duodenum, jejunum, ileum and colon were collected from 10-mo old Holstein steers (n = 6). Total RNA was extracted, and gene expression was measured using absolute quantification real time qPCR. Gene expression of endocannabinoid receptors CNR1 and CNR2, synthesis enzymes DAGLA, DAGLB and NAPEPLD, degradation enzymes MGLL and FAAH, and transient receptor potential vanilloids TRPV3 and TRPV6 was measured. Data were analyzed in R using a Kruskal-Wallis followed by a Wilcoxon rank-sum test. Results are reported as the median copy number/20 ng of equivalent cDNA (CN) with interquartile range (IQR). The greatest expression of CNR1 and CNR2 was in the brain and spleen, respectively. Expression of either receptor was not detected in any GIT tissues; however, there was a tendency (P = 0.095) for CNR2 to be expressed above background in rumen. Expression of endocannabinoid synthesis and degradation enzymes varied greatly across tissues. Brain tissue had the greatest expression at 641 CN (IQR 52; P ≤ 0.05) of DAGLA; however, expression in liver and most of the GIT tissues was below the limit of detection. DAGLB was detected in all tissues, with brain and spleen having the greatest expression (P ≤ 0.05). Expression of NAPEPLD in the GIT was least in tongue and sublingual mucosal. There was no difference in expression between hindgut tissues; however, these tissues collectively had 592% greater expression than rumen and omasum (P ≤ 0.05). While MGLL was found to be expressed in all tissues, expression of FAAH was only above the limit of detection in brain, liver, kidney, jejunum and ileum. TRPV3 was expressed above background in tongue, rumen, omasum and colon, with rumen having the greatest expression (198 CN, IQR 13.3; P = 0.02). Although not difference from each other, thyroid and duodenum had the greatest expression of TRPV6, with 285 (IQR 164) and 563 (IQR 467) CN compared with all other tissues (P < 0.05). These data demonstrate the complex distribution of the endocannabinoid system in cattle. Expression levels suggest that regulatory functions of this system are tissue dependent, providing initial insight into potential target tissues for manipulation of the endocannabinoid system.
100 Impact of luteal blood perfusion and estrus expression on pregnancy rates of beef cows exposed to embryo transfer
Authors: Goncalves Lucas Melo , Burato Samir , Walker Madison , Clements Greg , Morgan Shane , Neira Lucas , Fontes Pedro
Published: September 2024

This study aimed to evaluate the impact of luteal blood perfusion and estrus expression on pregnancy rates of beef cows exposed to fixed-timed embryo transfer (FTET). Postpartum beef cows (n = 763) from 22 locations were exposed to a 7-d Select Synch + controlled internal drug releasing (CIDR) and breeding indicator patches were affixed upon CIDR removal. Estrus expression was assessed twice daily for 72 h and a 100-µg injection of gonadotropin-releasing hormone was administered to cows that failed to express estrus 72 h after CIDR removal. Brightness mode ultrasonography of the corpus luteum (CL) was conducted to select recipients for FTET 9 d after CIDR removal. Suitable recipients were assigned to receive a single fresh or frozen embryo derived from either in vitro (IVF) or in vivo (IVD) method. After embryo recipient selection, CL morphometries and blood perfusion (BP) were then assessed at the time of embryo transfer via transrectal ultrasonography. Embryo recipients were categorized according to CL area [small (< 3 cm²), medium (3 to 4 cm²), or large (> 4 cm²)] and based on the percentage of luteal area with blood perfusion signals [low (< 25%), medium (25 to 45%), or high (> 45%)]. Pregnancy diagnoses were performed between d 60 and 90 of gestation. Cows that failed to express estrus prior FTET had decreased (P ≤ 0.02) luteal area, luteal diameter, and pregnancy rates compared with cows that expressed estrus. Luteal area category had no effect (P = 0.61) on pregnancy rates. Embryo recipients that expressed estrus had similar (P = 0.12) luteal blood perfusion compared with recipients that failed to express estrus. Embryo recipients with high (P = 0.02) and medium (P = 0.05) BP had greater pregnancy rates compared with embryo recipients with low BP. There was no interaction between estrus expression and luteal BP (P = 0.84). In summary, estrus expression and luteal BP positively impacted pregnancy rates to embryo transfer and may be used to facilitate embryo recipient selection.
104 Non-invasive pregnancy diagnosis in Holstein dairy cows using computer vision analysis of thermal images
Authors: Marquez Hector Javier Perez , Schaefer Allan , Bench Clover
Published: September 2024

Thermal visualization of Holstein dairy cattle skin can be indicative of the pregnancy state (cyclic or pregnant) of the cow by observing the size and shape of skin thermal patterns. However, visual assessment of skin thermal patterns can be subjective and laborious. Further, infrared thermography implementation on-farm requires automated analysis to be feasible for dairy producers. The objectives of this study were to implement a machine learning convolutional neural network (CNN) to detect features in thermal images associated with pregnant (Pregnant) and non-pregnant (Cyclic) and to evaluate the accuracy of pregnancy diagnosis in dairy cows. A total of 938 images from 18 Pregnant cows and 982 images from 18 Cyclic were used to build the CNN model, and 120 images from Pregnant (60 images) and Cyclic (60 images) dairy cows were used to validate the model. Pregnant cows were confirmed to be pregnant 90 d after insemination via transrectal ultrasonography. Cyclic cows were confirmed to be non-pregnant using follicular dynamics and corpora lutea presence via transrectal ultrasonography. Images were recorded using a T620s infrared camera at 640 × 480 (307,200) to train the CNN model and images from an E40 FLIR camera at 320 x 240 (76,800 pixels) were used for the validation test. The CNN model was created using TensorFlow in Google Colab to binary classify images into Pregnant or Cyclic using a single output neuron (1: Pregnant and 0: Cyclic) with different Epochs (10, 25, and 100). The diagnosis accuracy (acc) was 0.72 with a validation accuracy (val_acc) of 0.41 for 10 Epochs, acc 0.76 with val_acc 0.37 for 25 Epochs, and acc 0.80 with val_acc 0.63. The acc and val_acc of the training model and validation test were optimized when using images from the T620s exclusively (Epochs 10: acc = 0.70 and val_acc = 0.64; Epoch 25: acc = 0.74 and val_acc = 0.70; Epoch 100: acc = 0.81 and val_acc = 0.80). Greater resolution of thermal images was proven to increase the accuracy of pregnancy diagnosis (307,200 compared with 76,800 pixels) and the greater number of Epoch used to train the model. Machine learning algorithms can diagnose pregnancy using thermal images with an acceptable evaluation accuracy (> 0.70).
225 Kidney function and nitrogen excretion in Brown Swiss and Holstein dairy cows
Authors: Kessler Evelyne C C , Bruckmaier Rupert M M , Gross Josef J
Published: September 2024

The agricultural sector contributes to nitrogen (N) emissions since farm animals excrete considerable N amounts via feces and urine. To reduce N emissions by dairy cattle, methods predicting accurately individual N emissions are of great interest. Recent data showed that Brown Swiss (BS) cows have greater urea concentrations in milk and blood than Holstein (HO) cows. However, it is still unknown if greater BUN concentrations in a particular breed are congruently reflected by concomitantly increased contents of nitrogenous compounds in other media (e.g., urine and saliva). Thus, the present study simultaneously assessed biomarkers for kidney function like urea, and creatinine and symmetric dimethylarginine (SDMA) concentrations in several body fluids (i.e., blood, urine, milk, and saliva) as well as nitrogen excretion in feces in BS and HO cows under identical feeding conditions. Blood, saliva, urine, and feces were sampled in 31 multiparous BS and 46 HO cows kept under identical feeding and management conditions. Samples were collected at different lactational stages after the monthly DHIA control test-day. Concentrations of urea and creatinine were measured in serum, urine, and saliva. Symmetric dimethylarginine was determined in serum, which is an established indicator for glomerular filtration rate (GFR). Feces were analyzed for dry matter content and nitrogen concentrations. Data on milk urea and protein concentrations, and daily milk yield were obtained from the monthly DHIA test-day records. The effects of breed, time, and parity number on blood, saliva, urine, feces, and milk parameters were evaluated with the GLM procedure with breed, time, and parity number as fixed effects. Differences between BS and HO were assessed by the Tukey-corrected t-test at P < 0.05. Dry matter intake and body weight were similar in BS and HO cows (P > 0.05). No differences between BS and HO were observed for milk yield, fecal DM and nitrogen content. BS cows showed greater urea concentration (25.8 ± 0.7 vs 21.8 ± 0.7 mg/dL), and protein content in milk (3.70 ± 0.08 vs 3.45 ± 0.07%) than HO cows (P < 0.01). Concentrations of urea, creatinine, and SDMA in serum, were greater in BS than in HO cows (P < 0.01) with 5.46 ± 0.19 vs 4.72 ± 0.13 mmol/L for urea, 105.96 ± 2.23 vs 93.07 ± 1.50 mmol/l creatinine, and 16.78 ± 0.69 vs 13.39 ± 0.44 µg/dL SDMA, respectively. Urea and creatinine concentrations in urine and saliva did not differ among breeds. Despite greater urea and creatinine concentrations in blood, and milk urea content in BS compared with HO, excretion of these parameters did not differ between breeds in urine. Our results suggest a reduced renal glomerular filtration rate in BS compared with HO. The underlying mechanisms require further investigations.
385 Extracellular vesicle microRNAs in porcine seminal plasma reflect quality status
Authors: Dlamini Notsile H , Feugang Jean M N , Willard Scott T , Ryan Peter L
Published: September 2024

The pig industry relies heavily on artificial insemination as the primary breeding technique, using high-quality semen doses for genetic improvement. Semen consists of seminal plasma, a complex fluid that provides an optimal environment for sperm maturation, viability, and fertilization. Seminal plasma contains membranous structures called extracellular vesicles (EVs), facilitating intercellular communication. These seminal plasma-EVs (SP-EVs) contain microRNAs, which hold promise as predictive markers of semen quality. Thus, we hypothesized that the composition of SP-EVs might reflect the divergent quality status of corresponding spermatozoa. Therefore, this study aimed to explore the microRNA content of SP-EVs isolated from accepted (Passed) or rejected (Failed) boar semen for artificial insemination. Over 8 wk during the hot summer, raw semen was collected (n = 83) from sexually mature Duroc boars at a commercial boar stud (Prestage Farms, MS). Semen samples underwent sperm analysis to evaluate motility and morphology, classified as Passed or Failed quality based on predefined criteria (≥ 70% and < 70%, respectively). Seminal plasma was isolated through serial centrifugation, followed by SP-EV extraction using differential centrifugation. The isolated SP-EVs were characterized using transmission electron microscopy (TEM) for EV morphology and nanoparticle tracking analysis (NTA) for size and concentration. SP-EV miRNAs were extracted and identified via the Illumina NextSeq sequencing platform. Data were analyzed using SPSS software and significance was set at P < 0.05. Both TEM and NTA demonstrated that SP-EVs had a spherical structure with a diameter range of 50 to 300 nm. A total of 437 miRNAs were expressed in the Failed group and 443 miRNAs in the Passed group. MiRNA differential expression analysis revealed 28 downregulated and two upregulated miRNAs in the Passed group compared with the Failed group. Validated miRNA gene targets were associated with signaling pathways, including N-glycan biosynthesis, p53 signaling, pancreatic cancer, and apoptosis. These findings suggest that SP-EVs carry specific microRNAs potentially linked to boar semen quality. Thus, microRNAs from SP-EVs have the potential to serve as biomarkers to assess sperm quality, thereby providing insight into therapeutic approaches to address male infertility. Additionally, seminal plasma-EVs can be useful nanocarriers for further research interventions. Work supported by USDA-ARS grant# 6066-31000-015-00D
71 An electronic device for enteric methane emissions monitoring
Authors: Mazo Sebastian Bedoya , Moreno Pulgarín Luisa Fernanda F , Agudelo John Fredy Ramirez , Guarín Montoya José Fernando , Guarnido-Lopez Pablo , Menendez Hector M
Published: September 2024

It is widely accepted that accumulation of greenhouse gases in the atmosphere, including methane (CH4), is promoting climate change. Cattle contribute significantly to CH4 emissions, mainly generated during ruminal fermentation. Measuring CH4 emissions is expensive and time-consuming, hampering individual, constant, and scalable monitoring at the farm level. Thus, developing innovative methodologies to measure CH4 emissions from cattle is crucial. These methodologies should enable the identification of lower-emitting animals and to assess the effectiveness of various mitigation strategies. This study aimed to develop a low-cost microcontroller-based device to record variations in CH4 concentrations in the air exhaled by animals during indoor intake periods. The device was assembled into a plastic box with an internal compartment for an MQ-4 sensor that measures CH4 concentration (ppm). The device is equipped with an air pump and a plastic tubing with a 4 mm diameter for air flow generation (2 L/min) from the feeder area to the sensor, ensuring individualized measurements. An ESP8266 module collects the sensor signal and sends it to a laptop through a Wi-Fi network. To test the device, emissions from 16 dairy cows were monitored at milking (0500 and 1600 h) during three consecutive days. Variations in CH4 concentration were recorded three times per second in a text file for each animal at milking times. The mean CH4 concentration among the cows was 666 ppm (20.4% CV). Figure 1 compares emissions between two animals: a low-emitter (458 ppm, 4.1% CV) and high-emitter cow (853 ppm, 9.2% CV). The findings reveal the capability of the device for monitoring CH4 emissions on an individual basis, underscoring its value in promoting sustainability at the farm level. Future iterations could benefit from integrating sensors for temperature, humidity, and atmospheric pressure to refine CH4 measurements. Additionally, distance measurement technologies could standardize the proximity of the air sampler to the animals, thereby enhancing the accuracy of the emissions captured. Implementing a CH4 background reader could allow for continuous monitoring of ambient conditions, adjusting the CH4 readings to account for fluctuations that might affect concentrations. Finally, incorporating animal identification tools, such as RFID tags or computer vision identification systems, could automate the process of associating CH4 emission data with specific animals, ensuring consistent data collection. These advancements would not only improve the precision of the device but also offer a more comprehensive understanding of individual enteric CH4 emissions.
67 Precision identification and weight assessment of cattle using supervised machine learning on body surface keypoints
Authors: Menezes Guilherme , Negreiro Ariana , Ferreira Rafael , Higaki Shogo , Casella Enrico , Alves Anderson , Dórea Joao R R
Published: September 2024

Computer vision systems (CVS) offer identification solutions for animals with distinct coat patterns, but are less effective for solid-colored herds. In addition, they can be used to measure critical phenotypes, such as body weight (BW). Providing both BW and identification for solid-colored animals can help farmers make decisions. This study aimed to 1) develop an automatic CVS capable of identifying using the Euclidean distance between keypoints located at specific anatomical landmarks (e.g., bony prominences), and 2) predict the BW using features extracted from these keypoints. The keypoint model was trained to identify seven keypoints per cow, located at the left and right hips, left and right pin bones, tail head, sacral, and cervical vertebrae. These locations remain constant as body condition score of a cow changes. The Euclidean distance between these keypoints was used to generate biometric features for each cow. The keypoint detection model was trained using 3,928 images over 900 epochs with a batch size of 14 and validated using 391 images. This trained model was used to predict keypoints on a different set of 41 cows over 5 d, resulting in a total of 6,944 images which correspond to the dataset for cow identification. The Random Forest (RF) algorithm for cow identification was trained with the first 4 d (5,376 images), and the last day served as the test set (1,568 images). For the cow identification, a RF algorithm was employed on the Euclidean distance of the keypoints. The hyperparameters were determined through a grid search on the training set, utilizing 5-fold cross-validation. The hyperparameters ‘mtry’ (which ranged from 1 to 10) and ‘ntree’ (which ranged from 250 to 500, in increments of 50) were optimized. For the second objective, due to the completely new environment, the keypoint model was fine-tuned using transfer learning for 240 epochs with a batch size of 14, utilizing 310 images. The model predicted keypoints in 1,593 images from different beef-on-dairy animals. This dataset was used to train the BW prediction model. The Euclidean distances from the predicted images and sex were used as features. A RF model was trained using a leave-one-animal-out cross-validation approach. The hyperparameters were determined through a grid search on the training set, using 10-fold cross-validation. The ‘mtry’ parameter ranged from 2 to 16, in increments of 2. For animal identification, the model achieved an accuracy, precision, recall, and F1-score of 92.7%, 89.0%, 90.2%, and 92.7%, respectively. To predict BW, the RF model achieved an R² of 0.86 and a root mean squared prediction error of 36.9 kg, representing 6.7% of the observed values average. These results suggest that keypoints located on the dorsal body surface can identify and weigh individual animals, even those lacking distinct coat color patterns.
185 Effect of synchronized fixed-time AI and non-pregnant heifer delayed feedlot entry on reproductive performance and system economics
Authors: Landblom Douglas G , Hanna Lauren L , Parman Byron , Perry George A , Paisley Steve , Senturklu Songul
Published: September 2024

Heifer reproduction management research is being conducted at the NDSU–Dickinson Research Extension Center. Using crossbred heifers, the objective was to evaluate reproductive performance and economic efficiencies comparing a drylot synchronized fixed-time AI protocol with clean-up bulls to two grazing systems using a fixed-time AI protocol without clean-up bulls. Synchronization protocol:14-d CIDR-PG-GnRH (TAI 66 h ± 2 h). Fixed-time AI treatments: 1) Drylot Control (DLOT) with clean-up bulls, 2) Integrated diverse crop-heifer annual forage grazing (IAF, no clean-up bulls), and 3) Native range grazing (NR, no clean-up bulls). Following pregnancy ultrasound on d 85, non-pregnant heifers continued to bale-graze until late November, when they were transferred to the University of Wyoming SAREC feedlot, finished, harvested at Cargill Meat Solutions packing plant, Ft. Morgan, CO, and grid marketed. Data were analyzed using the MIXED procedure of SAS. Year 1 and 2 grazing days were 121, and 149, respectively. Synchronized TAI pregnancy rates yr 1 and 2 for DLOT, IAF, and NR were 59.4, 43.8, and 62.5%; 68.8, 46.9, and 34.4%, respectively. Total DLOT control pregnancy rates yr 1 and 2 were 90.6 and 100%. Grazing heifer feedlot performance Yr 1 did not differ for starting body weight (BW; 452 vs 436 kg, P = 0.29), ending BW (610 vs 600 kg, P = 0.74), gain (157 vs 164 kg, P = 0.69), average daily gain (ADG; 1.42 vs 1.48 kg, P = 0.70), dry matter (DM) feed intake (15.0 vs 14.7 kg, P = 0.73), F:G (4.81 vs 4.56 kg, P = 0.42), daily feed cost ($7.45 vs $9.47, P = 0.73), feed cost/kg BW gain ($3.11 vs $2.95, P = 0.51), and feed and yardage cost ($3.41 vs $3.24, P = 0.55). Year 2 grazing heifer feedlot performance for the IAF and NR were starting BW (501 vs 456 kg, P = 0.007), ending BW (670 vs 604 kg, P = 0.004), feedlot finishing gain (143 vs 123 kg, P = 0.05), ADG (1.08 vs 0.93 kg/day, P = 0.06), daily DM feed intake (20.1 vs 20.1 kg/d, P = 0.98), feed to gain ratio (7.13 vs 8.22 kg/d, P = 0.11), daily feed cost ($9.61 vs $9.54/d, P = 0.94), feed cost/kg BW gain ($4.05 vs $4.67/kg, P = 0.11), and feed and yardage cost/kg gain ($4.45 vs $5.13/kg, P = 0.092). IAF and NR Yr 1 HCW (P = 0.83), dressing % (P = 0.69), marbling score (P = 0.78) did not differ. Year 2, except for hot carcass weight (HCW; 379 vs 341 kg, P = 0.004), dressing pct (P = 0.99), fat depth (P = 0.29), marbling score (P = 0.94) did not differ. Systems 2-yr mean net return for DLOT, IAF, and NR were $592, $296, $379, respectively. Systems net return profitability was very good for all management comparisons, but reduced for IAF and NR due to IAF farming, finishing, and transportation costs, and NR finishing and transportation costs.
455 Evaluating the effect of a phenology-based timeline on the interpretation of enteric methane emission results
Authors: Husmann Aletta L , Brennan Jameson R , Moreno Elias R Velasquez , Smith Zachary K , Leffler Joshua , Ehlert Krista , Menendez Hector M
Published: September 2024

The methodology of analyzing methane emissions in cattle grazing native rangeland is imperative for producing reliable and repeatable estimations of total enteric emissions on an individual and herd basis. However, due to seasonal differences in climate from year to year, there are distinct differences in forage biomass availability and nutrient composition on extensive rangelands. Thus, our objective was to evaluate the differences in methane emissions using phenological forage phases compared with specific time periods. Yearling Angus steers (n = 127) were allocated to one of six pastures grazed from June to September (2023) at the South Dakota State University Cottonwood Field Station (Cottonwood, SD). Each pasture was equipped with a GreenFeed (C-Lock Inc., Rapid City, SD) pasture system to measure individual animal CH4 emissions. A subset of CH4 data from two cool-season-dominated pastures were aggregated from the overall study. We used two methods to segment CH4 by either 1) month (June, July, August) or 2) phenology (vegetative, reproductive, and senescence) to derive average CH4 (gּ animalּ -1ּ d-1) for each period. Western wheatgrass (WWG), a cool-season native, was used as a proxy for cool season grass development. On May 28th, 2023, the growing degree days (GDD) reached 632, representing the 3.5 leaf stage. WWG has been documented to reach maturity at approximately 1,100 GDD, which occurred on June 20th, 2023. Nutrient content of the forage (i.e., lignin) was used to approximate the start of senescence on August 11th. These developmental markers created estimates of the vegetative, reproductive, and senescence periods within our emissions data. Differences in enteric emissions for each approach were analyzed using a linear mixed effects model in R, and post-hoc contrast between methods was assessed using the lsmeans package. There were no statistical differences in CH4 by month (P > 0.05), and the means for June, July, and August were 217, 214, and 211 ± 4, respectively. By phenological phases, there was a difference (P < 0.05) between maturity and senescence, with means for vegetative, reproductive, and senescence as 214, 219, and 206 ± 4, respectively. Methane intensity (gּ animal-1ּ d-1) per period was then multiplied by the number of days in each month or phase to estimate total emissions for the entire grazing season (86 d). The monthly approach totaled 18,383 g CH4 per animal, while phenology totaled 18,504 g for the grazing season. This is a difference of 0.654% between the same data segmented by month or by phenology. Therefore, because of the dynamic nature of forage and cattle production, it is likely that accounting for phenology will provide greater clarity for GHG on rangeland systems rather than arbitrary periods of time and will require the use of dynamic models to handle the complexity of enteric emissions of grazing animals.
456 Allocating distribution of pasture utilization across the grazing landscape in grazing steers equipped with virtual fencing collars
Authors: Parsons Ira L , Brennan Jameson R , Menendez Hector M , Moreno Elias R Velasquez , Huseman Aletta , Dotts Hadley
Published: September 2024

Spatial utilization of pasture landscapes by grazing animals is often heterogeneous and driven by complex environmental and physiological interactions between plants and animals. Synergistic energy pathways can be modeled using mechanistic relationships describing resource distribution, animal behavior, metabolic energy rate, and pasture utilization using biometric sensors. The objective of this study was to demonstrate the ability to measure the energy landscape by mapping fine-scale contributions to animal energy expenditure, nutrient acquisition, growth, and overall economic profitability. We utilized animal trajectories and location fixes recorded by virtual fencing collars (Vence) daily body weight (BW) using precision livestock scales (Smartscale, C-Lock Inc.) and oxygen consumption (GreenFeeds, C-Lock Inc.) on steers (n = 127), managed as part of a broader project to evaluate environmental synergies in extensive grazing systems. Steers were allocated to one of six native grass pastures assigned to either rotational or continuous grazing strategies, and one of three stocking rates (low, moderate, high) in a 2 x 3 factorial arrangement. Space utilization was quantified as the frequency of fixes located within each cell of a 5 x 5-meter Grid and the distance between grid cells and water was calculated using the Pythagorean theorem. Movement behavior was quantified using Program R to calculate step length, the distance between two temporally continuous fix points utilizing the Pythagorean Theorem, and turn angles calculated as the cosine of the pre- and pro-ceeding step lengths where larger values indicated greater deviation from a straight trajectory. A mixed linear regression model was fitted using the lmer function in the lme4 package. Space utilization decreased with increased distance from water (P < 0.05), with rotational grazing strategies increasing concentration around water sources (P < 0.05). This indicates an opportunity to utilize precision livestock technology to facilitate pasture management and increase space utilization in grazing cattle.
453 Fluxes of greenhouse gases from pastures and methane emissions from beef cattle in Australia
Authors: Shirvan Milad Bagheri , Gonzalez Luciano A , Burgess Jillian E M
Published: September 2024

The carbon footprint of beef cattle production may need to consider both the fluxes of greenhouse gases (GHG) of pasture ecosystems and cattle enteric emissions because these are the largest contributors to the carbon balance. The objective of the present study was to measure the fluxes of greenhouse gases from pastures and enteric methane (CH4) emissions from cattle throughout long periods of time under commercial conditions. The fluxes of CH4, carbon dioxide (CO2), and nitrous oxide (N2O) were measured throughout a period of 3 yr in multiple pasture types ranging from native to sown, and from temperate to summer pastures in New South Wales, Australia. A set of 8 dynamic chambers that automatically close for 10 min every 1.5 h were used for this purpose. The chambers measured the change in the concentration of GHG to allow for the estimation of emissions (positive flux) or sinks (negative flux). All data was then summarized to estimate daily fluxes and the global warming potential (CO2e) was calculated multiplying CH4 by 28 and N2O by 265. The final dataset contained 2,709 d of measurements across the 8 chambers. The GreenFeed system was used to measure CH4 production from cattle under varying conditions fed various diets throughout the same period. Cattle categories included weaners, heifers and steers, bulls and cows under both grazing or pen conditions. Cattle were fed a variety of diets ranging from low quality forages to high quality forages, grain supplementation, and grain-based diets. Data were averaged across many days for each animal and the final dataset contained 1,014 measurements. The CO2 flux from pastures ranged from -855 (uptake) to +339 kg CO2ּ ha-1ּ d-1 with a mean of -10.4 ± 2.19 kg CO2ּ ha-1ּ d-1. The minimum, mean and maximum CH4 fluxes were -192 (uptake), 0.015 ± 0.488, 434 g CH4 ּha-1ּ d-1, respectively, whereas NO2 values -146 (uptake), 17.1 ± 1.23, 1,293 g N2O ּ ha-1ּ d-1, respectively. These fluxes resulted in a GWP ranging from -855 (uptake), -5.83 ± 2.222, 445 kg CO2e ּha-1ּ d-1suggesting that pastures were on average a net sink of GHG throughout the present study. The CH4 production from cattle ranged from 43.6 to 404.6, with an average CH4 production of 192 ± 90.3 g CH4ּ animal-1ּ d-1, which is equivalent to 5.37 kg CO2eqּ animal-1ּ d-1. These results suggest that a hectare of livestock pastures offsets more than the CH4 produced by the average beef cattle in the present study. The fluxes of GHG from vegetation may need to be considered when estimating the contribution of livestock production to global warming.
97 Influence of cashew nutshell extract (CNSE) on enteric methane emission, feeding behavior, and nutrients digestibility in beef steers receiving a finishing diet
Authors: Cuervo Wilmer , Tarnonsky Federico , Fernandez-Marenchino Ignacio , Maderal Araceli B , Fernandez-Lehman Andres , Podversich Federico , Schulmeister Tessa M M , Gonzalez Lucas , Erazo-Mendez Cristian , DiLorenzo Nicolas
Published: September 2024

Feedlots have a crucial role in meeting the increasing global demand for meat. Despite ongoing efforts to improve feed efficiency in finishing diets, cattle in feedlots may experience methane (CH4) losses ranging from 2 to 12% of dietary gross energy (GE). Identifying strategies to mitigate energy losses in finishing diets is imperative for ensuring the sustainability of beef production. Anacardic acid, contained in the cashew nutshell extract (CNSE) has shown promising results in reducing CH4 emissions in forage-based diets; however, its impact on high-grain diets remains to be analyzed. Therefore, this study aimed to evaluate CNSE addition (5 gּ steer-1ּ d-1) in a finishing diet (85:15% grain: forage) on in vivo enteric CH4 emissions, apparent total tract digestibility, and feeding behavior. It was hypothesized that CNSE addition to a finishing diet would reduce enteric CH4 emissions without reducing feed intake or nutrient digestibility. To this aim, Angus crossbred steers (n = 16; 599 ± 40 kg) were used in a crossover design with two periods of 56 d each. Steers were adapted (14 d) to the finishing diet and assigned to receive CNSE or no additive (CON). The diet was offered twice daily as a total mixed ration (TMR) in the feedbunk, while CNSE was independently delivered through the Super SmartFeed system (C-Lock, Inc, Rapid City, SD) using ground corn gluten feed as a carrier. In vivo CH4 emissions, apparent total tract digestibility of nutrients, and feeding behavior were analyzed. Data were recorded during 35 d after the adaptation, followed by 7 d of washout, and analyzed as a crossover design using the MIXED procedure of SAS. Compared with CON, the addition of CNSE increased meal duration (P = 0.03), bunk visit duration (P < 0.01), and dry matter intake (DMI) of TMR (P = 0.03) by 25, 23, and 7%, respectively. Dry matter digestibility was increased (P = 0.02) by CNSE addition. Steers receiving CNSE, had a reduction in enteric CH4 emission rate (g/d; P < 0.001), yield (g/kg of DMI; P < 0.001), and intensity (g/kg of average daily gain; P < 0.01) in 29, 32, and 39% respectively. The loss of dietary GE as CH4 was reduced in CNSE (3.2 vs. 4.7%) compared with CON (P < 0.01). This study showed that CNSE at the evaluated inclusion rate, reduced CH4 yield and emission intensity by more than 31% in beef steers receiving a finishing diet. Moreover, given that CNSE addition promoted a longer feed bunk occupancy and a greater TMR intake, it could be suggested that the observed CH4 mitigation may be linked to shifts in ruminal fermentation rather than changes in DMI.
403 Impact of lysine, methionine, and histidine deficiencies on gene expression and upstream transcriptional regulators in bovine mammary epithelial cells: An RNA-sequencing analysis
Authors: Li Boning , Innes David , Ribeiro Eduardo S , Burgos Sergio , Cant John
Published: September 2024

Essential (E) amino acids (AA) may alter bovine mammary epithelial cell functions by impacting mRNA expression of genes through their upstream transcription factors. The objective of this research was to study the impact of EAA deficiencies on gene expression and to identify upstream transcriptional factors mediating their effects in bovine mammary epithelial cells. Epithelial cells were collected from the mammary glands of lactating dairy cows and cultured in combined media of DMEM/F12 and Medium 170, differentiated for 5 d, and subsequently treated in triplicate for 60 h with a control medium containing all EAA at normal plasma concentrations for cows (CTL), or a medium with 20 μM Lys (LY), 5 μM Met (LM), or 10 μM His (LH), which are each 25% of normal concentration. RNA was isolated from the cells and sequenced on an Illumina NovaSeq 6000 producing 150 base pair paired-end reads with a minimum sequencing depth of 150 million reads. Reads were cleaned with ‘fastp’ (Chen et al., 2018), aligned to the bovine reference genome (ARS-UCD1.2) using ‘STAR’ aligner (Dobin et al., 2013), and genes counted using ‘featureCounts’ (Liao et al., 2014). Differential expression of genes between treatment pairs was determined using the ‘DESeq2’ package (Love et al., 2014) in R. Genes with an absolute log2 fold change ≥ 1 and a false discovery rate of < 0.05 were considered differentially expressed. The number of differentially expressed genes relative to CTL was 780 for LY, 383 for LH, and 536 for LM. QIAGEN Ingenuity Pathway Analysis (IPA) identified four pathways consistently affected across LY, LM, and LH: kinetochore metaphase signaling, mitotic roles of polo-like kinase, cell cycle: G2/M DNA damage checkpoint regulation, and interferon signaling (Figure 1-3). Notably, the kinetochore metaphase signaling pathway was identified as the most significant across all treatments, suggesting a strong link to cell proliferation and apoptosis during EAA deficiency. The interferon signaling might be related to the Janus kinase 2/signal transducer and activator of transcription 5 (Jak2/STAT5) pathway which can promote the expression of genes encoding milk proteins such as β-casein and β-lactoglobulin. Furthermore, the IPA identified upstream transcription factors related to cell proliferation, apoptosis, autophagy, protein translation, endoplasmic reticulum biogenesis, and amino acid metabolism including NUPR1, FOXM1, MYC, CCND1, TP53, DDIT3, and ATF4 across all treatments. The findings suggest that AA deprivation regulates bovine mammary epithelial cell function by instigating amino acid response pathways and altering secretory cell number.