bluuebunny/crossref_metadata_2025_split huggingface dataset:
15 Influence of early progesterone removal on follicular development, estrus expression, and pregnancy rates in presynchronized beef cows
Authors: Burato Samir , Walker Madison B , Goncalves Lucas M , Oosthuizen Nicola , Zoca Saulo M , Ciriaco Francine M , Henry Darren D , Ranches Juliana , Fontes Pedro L P 
Published: March 2024

Abstract
The objective of this study was to evaluate the impact of early progesterone removal on pregnancy rates to fixed-time artificial insemination (FTAI) in presynchronized beef cows. Postpartum beef cows (n = 922; body condition score = 4.9 ± 0.77; days postpartum = 77.3 ± 20.77 d) from 7 locations were enrolled in a completely randomized design. Within location, cows were stratified by parity and days postpartum before being randomly assigned to 1 of 2 treatments: 1) 7&7 Synch: Cows received a controlled internal drug release insert (CIDR) and a 25-mg injection of prostaglandin F2α (PG1; d 0). Cows received 100 μg of GnRH on d 7 and the CIDR was removed 7 d later, concurrently with a second prostaglandin F2α (PG2) injection (d 14). Cows received a second injection of GnRH and were FTAI 60-66 h after PG2 (d 17); 2) 7&6 Synch: Cows received the same treatment as 7&7 Synch cows; however, CIDR removal and PG2 were performed on d 13, and cows were FTAI 60-66 h after CIDR removal. Ovarian ultrasonography was performed to determine follicle diameter and CL presence at PG2 and FTAI in a subset of cows (n = 40). Estrus detection patches were utilized to evaluate estrus expression between PG2 and FTAI. Pregnancy diagnosis was performed 28-35 d after FTAI. Cows exposed to the 7&7 Synch tended to have larger follicle diameter at PG2 compared with 7&6 Synch cows (P = 0.09); however, there were no differences in follicle diameter at FTAI. Cows that expressed estrus tended to have larger follicle diameter at FTAI compared with cows that failed to express estrus (P = 0.10). Follicular growth between PG2 and FTAI, percentage of cows with a corpus luteum at PG2, and ovulation rate were not impacted by treatment (P ≥ 0.56). No differences were determined between treatments for estrus expression (7&7 Synch: 77.1 ± 5.91; 7&6 Synch: 74.6 ± 6.28; P = 0.50) or pregnancy rates to FTAI (7&7 Synch: 60.1 ± 4.32; 7&6 Synch: 58.2 ± 4.26; P = 0.69). In conclusion, early removal of progesterone did not impact pregnancy rates in presynchronized beef cows. Thus, the 7&6 Synch protocol described herein may be used as an alternative to the conventional 7&7 Synch protocol without compromising fertility.
28 Investigating the effects of Chromium Propionate supplementation on reproductive performance of beef cows
Authors: Vidlund Trinity , Craun Hannah , Mitchell Camille , Currin John , Stewart Jamie L , Clark Sherrie , Redifer Tracey , Mercadante Vitor R G 
Published: March 2024

Abstract
The objective of this study was to explore the effects on reproductive performance of beef cows supplemented with Chromium Propionate during the post-partum and breeding periods. A total of 955 multiparous suckled beef cows located at eight locations were enrolled in the study. Within location cows were stratified based on parity, body condition score (BCS), and days postpartum (DPP) and randomly assigned to one of two treatments: 1) Control- supplementation of a mineral product at 113 g animal/d (n = 484 cows; 16 experimental units); or 2) CrP - supplementation of mineral product at 113 g animal/d containing Chromium Propionate (0.4% animal/d, KemTRACE, Kemin Industries; n = 471 cows; 16 experimental units). Mineral supplementation was offered starting at 45 d pre-breeding, during the breeding season, and until weaning for a total of approximately 150 d. Cows were enrolled in a fixed-time artificial insemination (TAI) using the 7-d CO-Synch+CIDR protocol followed by natural service with clean-up bulls 7 d after TAI, for a 70-d total breeding season. Pregnancy diagnosis was performed by ultrasonography 55 d after TAI and again approximately 40 d after the end of the breeding season. Cow body weight (BW) and BCS were recorded at the beginning of the experiment (d -45), at the initiation of the TAI protocol (d -10), at each pregnancy diagnosis (d 55 and 110), and at weaning (d 150). Mineral intake was estimated based on the difference in weight between offered mineral and refusals. Data were analyzed using the GLIMMIX, for binomial data, and MIXED, for continuous data, procedures of SAS. Cow initial BW and DPP were similar (P &gt; 0.10) between treatments (584 ± 198 kg and 78 ± 3 d, respectively). Estimated mineral intake was similar (P = 0.52) between treatments (119.6 ± 10.3 g and 124.5 ± 10.4 g animal/d, for Control and CrP, respectively). Supplementation of CrP did not influence estrus expression (58.3% vs 61.0% ± 2.5 %; P = 0.45), TAI pregnancy rates (63.1% vs 60.1 % ± 2.9 %; P = 0.56), or final breeding season pregnancy rates (94.2% vs 94.7% ± 2.9 %; P = 0.86), for CrP and Control, respectively. Chromium Propionate supplementation did not affect (P &gt; 0.10) final cow BCS and BW (5.2 ± 0.03; 562.9 ± 169.93 kg). In conclusion, Chromium Propionate supplementation delivered via an oral mineral supplement during the pre-breeding and breeding periods did not influence reproductive performance and changes in BW and BCS of beef cows.
137 Impacts of heat stress on the accuracy of an ear-tag sensor for detection of eating and rumination behavior in cattle
Authors: Weinert-Nelson Jennifer R , Werner Jessica , Jacobs Alayna A , Anderson Leslie H , Hamilton Tracy A , Williams Carey A , Davis Brittany E 
Published: March 2024

Abstract
Ear-tag accelerometers are used for precision livestock management, but little is known regarding effects of varying environmental conditions on sensor performance. The objective was to evaluate accuracy of a commercially available ear-tag sensor (CowManager SensOor, Agis Automatisering BV, Harmelen, the Netherlands) in quantifying feeding behaviors under varying temperature-humidity indices (THI). RumiWatch System (RW) noseband sensors (Itin+Hoch GmbH, Liestal, Switzerland) were utilized as a benchmark. Nine Holstein-Angus steers (body weight: 488 ± 9 kg) were fitted with CowManager (CM) sensors and RW halters, with continuous monitoring during two 14-d phases: thermoneutral (TN: 21.0 ˚C, 64.0% humidity, THI = 67) and heat stress (HS: cyclical daily temperatures to mimic diurnal patterns; HS: 23.2 ˚C – 33.6 ˚C, 39.5 – 70.0% humidity, THI = 70.3 – 83.5). Steers were individually-housed (3×3 m) and provided ad libitum access to a mixture of corn silage and dried distillers grains with solubles. Hourly summaries of eating time (ET) recorded by CM were compared with EAT1TIME (head down) and EAT2TIME (head up) parameters from RW (v.7.3.36) as well as total ET (EAT1TIME + EAT2TIME); rumination time (RT) was also compared. Agreement was evaluated (R; v.4.3.1) over the full 24-h day (FULL) and a 6-h period from afternoon to early evening (AFT; 1400 – 2000 h) when HS effects would be most pronounced. Across both 14-d phases, agreement between CM and EAT1TIME was moderate to high (concordance correlation coefficient [CCC] = 0.69 to 0.77), whereas agreement with EAT2TIME and total ET was poor to moderate (CCC = 0.41 – 0.61). Bland-Altman analysis demonstrated significant underestimation of total ET by CM, with biases of -8.98 (-10.88, -7.09) to -6.44 (-7.51, -5.38) min h-1. Agreement for EAT1TIME was high for TN (CCC = 0.74), but only moderate during HS (CCC = 0.69) for the FULL dataset. Similarly, agreement for total ET was moderate for TN but poor for HS over FULL and during AFT, respectively (CCC: TN – 0.53, 0.54; HS – 0.47, 0.41). CowManager significantly underestimated EAT1TIME during HS (bias: FULL = -1.45 [-2.60, -0.30]; AFT = -2.14 [-3.93, -0.35] min h-1), but not TN (bias: FULL = -1.38 [-2.82, 0.06]; AFT = -1.83 [-3.68, 0.02] min h-1). Agreement for RT was high regardless of environmental conditions and time period analyzed (CCC = 0.74 – 0.81). However, during the critical AFT period, CM significantly overestimated RT under HS (bias: 4.42 [2.06, 6.79] min h-1) but not TN conditions (bias: -0.47 [-2.42, 1.47] min h-1). These results indicate that ET reported by CM is more reflective of time eating with the head down than the total time engaged in eating behaviors. Results of this study also suggest accuracy of ear-tag accelerometers may be impaired when cattle are subjected to heat stress.
136 Evaluation of internal parasite burden in grazing beef cattle in North Carolina over a production lifecycle
Authors: Williams Katherine G , Pickworth Carrie L , Weaver Andrew R , Poole Daniel H 
Published: March 2024

Abstract
Gastrointestinal nematode (GIN) parasite infections can be detrimental to not only cattle health and immunity, but also result in economic loss and poor performance. Cattle grazing in the southeast are challenged even further by the favorable environmental conditions for parasite development, especially those animals who have yet to develop an immunity to combat parasitism. To diminish potential economic and performance-based losses, many beef producers treat animals for GIN parasites with anthelmintics on a regular basis without proper diagnosis. Anthelmintic resistance(AR) develops when deworming products are overused and misused. To minimize the development of AR, selective deworming and sustainable management practices should be implemented. However, the severity of parasite burden over the production cycle needs to be better understood in beef cattle herds before recommendations can be made. Thus, the objective was to investigate the rates of GIN parasite infections through fecal egg counts (FEC) and the impact on body weight (BW) and body condition score (BCS). Angus-based cattle (6 mo-13 yr, n = 1,154) on a were utilized from five different research and educational herds across North Carolina. Cattle were categorized based on their age at the start of the project as either calves (n = 446), yearling heifers (n = 205), 2 year old (n = 260), 3-5 year old (n = 501), or 6+ year old (n = 206). Starting in September, FEC, BW, and BCS were collected and analyzed every 90 d at critical production timepoints (calving, breeding, weaning, and 90d post-weaning) to monitor the severity of GIN parasite challenge. Cattle on study were not treated with anthelmintics regardless of parasite load, with the exception of calves at four of the locations at the time of weaning. All data were analyzed using Proc MIXED in SAS with repeated measures. Statistical significance was declared at P ≤ 0.05 and a trend at 0.10 &gt; P &gt; 0.05. Age of cattle had an impact on FEC overall (P &lt; 0.05), however, there was no difference between FEC of mature cattle over 3 yr (4.29 ± 4.9 eggs/gm). Calves had the greatest FEC (120.59 ± 4.2 eggs/gm) while cattle 6+ yr had the least (3.68 ± 4.5 eggs/gm). Cattle age at each location affected BCS and BW (P &lt; 0.05). Between age groups across locations, time had an impact on FEC, BW, and BCS (P &lt; 0.05). There was also a tendency (P = 0.6) for location to impact FEC. Calf sex did not affect (P &gt; 0.05) FEC. Further FEC analysis of cattle under 2 yrof age is required to better understand when a natural immune response to GIN parasite infections develops.
144 Utilizing invasive pigweed (Amaranthus Spinosus) as a novel methane mitigation strategy in beef cattle feed: A sustainable approach
Authors: Cuervo Wilmer , Gomez Camila , Fernandez-Marenchino Ignacio , Maderal Araceli B , Tarnonsky Federico , Erazo-Mendes Cristian , Schulmeister Tessa M , DiLorenzo Nicolas 
Published: March 2024

Abstract
By 2050, the US beef industry must produce an extra 40 million tons of beef to satisfy the global demand, while reducing methane (CH4) emissions. This surplus of cattle will be provided mostly by cow-calf operations, which rely primarily on grazing. Those pastures are often infested with weeds such as pigweed (Amaranthus spinosus), one of the most invasive in the US, known for its increased polyphenols concentration. Despite the known effect of polyphenols on CH4 reduction, few studies have explored pigweed as a feed additive. Our objective was to evaluate the effect of in vitro addition of pigweed on ruminal fermentation, digestibility, and CH4 production. We collected ruminal fluid from three American Aberdeen steers (374 ± 21 kg) receiving a backgrounding diet (80:20% corn silage:cotton gin trash, as fed). We incubated (24 h, 39°C) diet (0.7 g) plus the inclusion of 0, 2.5, 5, or 10% (of diet DM) of roots, stems, leaves, seeds, or the whole pigweed plant (WHO). Volatile fatty acids (VFA), CH4 (mmol g-1 organic matter), ammonia, pH, gas, in vitro dry matter, and organic matter digestibility (IVDMD and IVOMD) were determined. Using the MIXED procedure of SAS, data were analyzed as a randomized complete block design with a 5 × 4 factorial arrangement of treatments with plant part (n = 5) and inclusion level (n = 4) as fixed main factors. Incubation and bottle within incubation were random effects. Polynomial orthogonal contrasts were used to determine linear, quadratic, and cubic effects of inclusion level. Plant × level interactions were detected in acetate, propionate, and butyric molar proportion, total VFA, CH4 production, and IVDMD (P &lt; 0.01). Increasing levels of stems increased acetate concentration (P = 0.03), while those from WHO led to a linear reduction of acetate (P &lt; 0.01). The inclusion of 2.5% of leaves, seeds, and WHO increased propionate concentration (P = 0.05), but greater levels decreased it (P &lt; 0.01). Increasing levels of all parts decreased acetate:propionate proportion (P &lt; 0.001). Increasing levels of WHO resulted in a linear reduction of CH4 production (P &lt; 0.05), while increasing inclusion of roots and stems increased CH4 production (P &lt; 0.01). Quadratic reductions in CH4 production were observed after increasing the addition of leaves, seeds, and WHO (P &lt; 0.001). Increasing levels of leaves and roots decreased ammonia concentration (P &lt; 0.01) while stems increased it (P = 0.01). Except for stems and roots, there was a linear decrease in IVDMD with increasing levels of all parts (P &lt; 0.001). The inclusion of low levels of seeds, leaves, and WHO promoted ruminal changes leading to a reduction of CH4 production without significantly compromising the digestibility.
148 Supplementing Bovacillus to newly weaned beef steers during a 90-d grazing period
Authors: Cooke Reinaldo F , Mackey Shea , Pickett Autumn , Colombo Eduardo , Cappellozza Bruno I , Karisch Brandi B , Harvey Kelsey M 
Published: March 2024

Abstract
This experiment compared performance, health, and physiological responses of high-risk stocker cattle receiving a Bacillus subtilis derivative during a 90-d grazing period. Crossbred steers (n = 120) were obtained from an auction yard and transported to the experimental facility. Steer shrunk body weight (BW) was recorded at arrival (d -1). This value was averaged with BW recorded on d 0 to represent initial BW (236 ± 2 kg). On d 0, steers were ranked by BW and allocated to 1 of 12 pastures (4-ha pastures; 10 steers/pasture). Pastures were randomly assigned to receive daily supplementation with dried distillers’ grains at 1% of BW containing either: 1) Bacillus licheniformis and B. subtilis ingredient (BOV; 2 g/steer daily of Bovacillus, Chr Hansen A/S, Horsholm, Denmark) or 2) no additive (CON). Cattle received treatments from d 0 to 90 while housed in pastures containing stockpiled grass forage, as well as free-choice access to water and a commercial mineral + vitamin mix without ionophores. Steers were assessed for bovine respiratory disease (BRD) signs daily, and shrunk BW recorded on d 91. Blood samples were collected, and BW recorded on d 0, 14, 28, 56, and 90. No treatment differences were detected (P ≥ 0.19) for glucose, non-esterified fatty acids, β-hydroxybutyrate, haptoglobin, or insulin-like growth factor 1, whereas a treatment × day interaction indicated increased cortisol in BOV cattle on d 56 (P &lt; 0.01). A treatment × day interaction was detected for serum concentrations of parainfluenza type 3 antibodies, which was greater in BOV steers on d 90 (P &lt; 0.01). No treatment differences were detected (P ≥ 0.23) for serum concentrations of antibodies against other BRD pathogen. Average daily gain (ADG) tended to be increased (P = 0.09) in BOV compared with CON steers from d 56 to d 90 (0.858 and 0.760 kg/d, respectively, although did not impact overall ADG (P = 0.48). No treatment differences were detected for steer final BW (P = 0.43). Total BW change per pasture was greater in BOV compared with CON (790 vs. 550 kg BW change; P = 0.02). No treatment differences were detected (P = 1.00) for BRD incidence, although steers removed from the experiment for health reasons tended to be increased in CON compared with BOV (P = 0.08). Despite lacking differences in health or physiological responses, B. licheniformis and B. subtilis supplementation increased overall production of BW in high-risk stocker steers during a 90-d grazing period.
2 Number of spot samples required when using the GreenFeed System in grazing beef cows
Authors: Dressler Elizabeth , Bormann Jennifer M , Weaber Robert , Rolf Megan M 
Published: March 2024

Abstract
Methane (CH4) production from beef cattle occurs through a natural digestive process called enteric fermentation. This has increasingly become an area of focus due to environmental and efficiency concerns. There are several techniques to quantify gas fluxes from beef cattle such as an open circuit gas quantification system (OCGQS). The GreenFeed (C-Lock, Inc.) is an OCGQS, which has been validated in previous literature, that is capable of quantifying CH4, carbon dioxide (CO2), and oxygen (O2) from grazing beef cattle. However, few studies have reported the minimum number of spot samples to quantify gas fluxes from an individual animal, particularly in a grazing environment. No recommendations have been made to evaluate the number of spot samples for the calculation of metabolic heat production, using the gas fluxes quantified by an OCGQS. A minimum of 100 spot samples each were collected from 17 grazing animals using an OCGQS. The mean gas fluxes were computed starting from the first 10 visits (forward) and increasing by increments of 10 until 100 visits was reached and also from visit 100 moving back in time in increments of 10 (reverse). Mean gas fluxes were used to calculate individual animal metabolic heat production for each interval with both the forward and reverse approach. Pearson and Spearman correlations were computed between the full 100 visits and each shortened visit interval. Mean forward and reverse gas fluxes and metabolic heat production were also computed starting at 30 visits and increasing by 2 until 40 visits and vice versa. The minimum number of spot samples was determined when correlations with the full 100 visits were greater than 0.95. The minimum number of spot samples needed for accurate quantification of CH4, CO2, O2, and metabolic heat production were 38, 40, 40, and 36, respectively. Simultaneous collection of gas fluxes for the calculation of metabolic heat production would require at least 40 spot samples given the recommendations for gas flux components. Animals had an average of 1.2 visits/day to the OCGQS in this study. Therefore, animals met the required number of spot samples for quantification of metabolic heat production, CH4, CO2, and O2 in 29.5 ± 8.7, 30.5 ± 9.1, 31.8 ± 9.2, and 31.8 ± 9.2 d, respectively. There was large variation in the number of days needed to achieve the recommended number of spot samples. For this reason, protocols for the OCGQS should be based on the total number of spot samples, rather than a test duration. These recommendations can be applied to grazing cattle that typically have more infrequent visits. More research is needed to establish if the minimum number of spot samples would be fewer if animals have more frequent visits, although this is difficult in grazing settings.
4 Utilizing SmartFeed Pro and SuperSmart Feeders for applied beef cattle research
Authors: DelCurto Timothy , Wyffels Sam 
Published: March 2024

Abstract
Designing research for applied beef cattle production systems has always presented challenges for Land Grant University and USDA Scientist. Specifically, creating study designs that have enough replication for statistical inference has often prompted scientists to use designs that do not closely replicate actual production systems. Past research has often used multiple replications (pens/paddocks/pastures) that utilize replication (group averages; 4 – 8 animals) means as the experimental unit. While effective in measuring average treatment responses, these types of study designs do little to describe the actual individual animal behavior and performance in a more practical production environments. Approaches to increasing statistical observations in actual production environments will be discussed in this presentation. Embracing new technologies such as GPS, activity monitors, EID tags, and feed intake monitors (C-Lock Inc, GrowSafe) combined with multiple regression modeling tools can aid in designing and publishing beef cattle production research in actual beef production environments. Research at Montana State University has utilized SmartFeed Pro and SuperSmart Feeders for strategic supplementation research on extensive rangelands and dry-land pastures for the past seven years. Results of these studies have evaluated self-fed (salt-limited; loose, pelleted, and baked molasses blocks) as well as hand-fed supplements where daily intakes are limited by the locking gate on the feeder. This presentation will summarize these studies with a focus on research designs that were successful and/or unsuccessful in respect to characterizing beef cattle performance in production settings. Our goal will be to assist the audience in the application of feed intake technology in designing future applied beef cattle research.
52 Evaluation of linseed meal on ovarian follicular development after synchronization in preovulatory small ruminants during seasonal anestrus
Authors: Poole Cameron A , Meyer Audrey G , Runyan Chase 
Published: March 2024

Abstract
Seasonal estrous of small ruminants can hinder overall reproductive efficiency of holistic management strategies involving sheep and goats. The objective of this study was to quantify the effect of increased melatonin containing feed ingredients on ovarian function during seasonal anestrus. Ovarian follicle number and follicle sizes were evaluated on Spanish × Boer cross does and Rambouillet ewes amounts of lineseed meal in the treatment diet (P30DIET) or an isocoloric and isonitrogenous control diet (CON). The P30DIET contained 2.5% linseed meal which contained increased melatonin (Manchester et al. 2000). At d -18 ewes and does were stratified by age into treatment groups and the P30DIET and CON diets were supplemented (0.91 kg and 0.68 kg per animal per day for sheep and goats, respectively). Synchronization protocols were administered at d 0 for both groups and ovarian ultrasound measures were collected 48 h after the removal of the controlled internal drug release device (CIDR). Mixed model procedures of SAS were used to analyze the number of dominant follicles that were present following the synchronization protocols. The number of dominant follicles observed in the P30DIET goats was significantly greater than the CON consuming goats (P &lt; 0.05). Least Squares Means estimates (LSMEANS) in the P30DIET were 1.5 ± 0.20 as compared with CON goats (0.91 ± .21). These data suggest that flushing small ruminants with greater linseed meal during the seasonal anestrus period can increase the number of dominant follicles therefore implying an improvement in reproductive efficiency in holistic management strategies of small ruminants.