bluuebunny/crossref_metadata_2025_split huggingface dataset:
200 Improving efficiency of embryo transfer (ET) programs by optimizing fertility and management of recipients
Authors: Wiltbank Milo , Garcia-Guerra Alvaro , Sala Rodrigo V , Fosada Meliton , Carrenho-Sala Luciana , Moreno Juan F 
Published: July 2019

Abstract
Multiple experiments were performed to optimize efficiency and fertility in recipients of fresh in vitro produced (IVP) embryos. In experiment 1, heifers (n = 520) were synchronized and received an embryo on d 6–8 after estrus or 6–8 d after GnRH in a fixed time ET (FTET) program using modified 5-d CIDR-Synch protocol (d-8: CIDR inserted; d-3: CIDR removed and PGF2α treatment; d-2: second PGF2α; d0: GnRH to induce ovulation). Pregnancy per ET (P/ET) at d 32 and d 60 were similar but pregnancy per treated potential recipient (efficiency of recipient utilization) was greater for FTET than estrus (+49.7%). Subsequent experiments sought to optimize FTET protocol by analyzing whether CIDRs could be used multiple times (up to 4 uses similar P/ET) and whether multiple PGF2α treatments were needed at end of program (no difference when no GnRH given at start of protocol). Thus, a simple, inexpensive FTET program has similar fertility as ET after estrus but is more efficient at recipient utilization. A large retrospective analysis (n = 12,569 ET) was performed using FTET program. Embryo stage and quality were major embryo factors impacting P/ET. Transfer of d 7 fresh embryo to d 7 or d 8 recipient was better than d 6 (+24.4%). Two experiments (GnRH or CIDR treatment) evaluated increasing circulating P4. In GnRH experiment, heifers (n = 1,562) on d5 received GnRH (200 μg) or Control (untreated). On D12, P4 was greater (P < 0.001) in GnRH-treated (7.2 ± 0.1ng/ml) vs Controls (6.0 ± 0.1ng/ml). There was greater P/ET at D33 and D60 of pregnancy for Stage 7 than 6 embryos. Treatment with GnRH did not alter P/ET but decreased pregnancy loss between D33 and D60 in heifers receiving Stage 7 embryos (11.6 vs 27.6% in recipients with accessory CL on d 33). In CIDR experiment, treatment with 2 CIDRs (from d 13; one new CIDR each 7 d) elevated circulating P4 and tended to decrease pregnancy loss (d 27 to 62; 25.9 vs 11.9%) and increase P/ET (40.4 vs 53.6% on d 62). Thus, elevating P4 decreased pregnancy loss during FTET program using fresh IVP embryos.
204 Genomics of age at puberty in gilts
Authors: Ciobanu Daniel 
Published: July 2019

Abstract
Our previous research demonstrated that age at puberty is characterized by moderate heritability and is an early pre-breeding indicator of sow fertility. Early selection of gilts, based on genomic prediction of age at puberty and fertility in general, is considered a potential approach to reduce sow culling. Phenotypes, genotypes and tissues from UNL resource population (n > 1,700) were used in initial genome-wide association to identify regions of the genome associated with age at puberty. The proportion of phenotypic variation for age at puberty explained by the Porcine SNP60 BeadArray was 27.3%, with top genomic regions responsible for relatively small effects. The top 1-Mb windows (1%) explained 6.7% of the genetic variation with one window located on SSC2 (12–12.9 Mb) displaying pleiotropic features, affecting both age at puberty and litter size. These top genomic regions were oversaturated with new genetic variants discovered by deep genomic and RNA (arcuate nucleus) sequencing, which were integrated in SowPro90, a custom Affymetrix SNP array. Using a subset of sows representing extremes of the distribution for age at puberty (n = 283) and genotyped with the SowPro90 led to identification of a SNP in the proximal promoter of the UBE2L6 (SSC2, 13.3Mb; F = 13.39; P = 0.0003), a gene known to modulate function of ISG15, a marker for pregnancy. This novel SNP, which exceeded the effect of the original top SNP in the region (DIAS0004771; F = 6.98), explained 6.8% of the proportion of phenotypic variance. Identification of functional polymorphisms that influence age at puberty could lead to improvements in the accuracy of genomic prediction while reducing sow replacement rates. This project was supported by AFRI Competitive Grant no. 2013-68004-20370 from the USDA-NIFA.
208 Molecular mechanisms through which heat stress compromises reproduction in pigs
Authors: Ross Jason W , Hale Benjamin J , Seibert Jacob T , Romoser Matthew R , Adur Malavika K , Keating Aileen F , Baumgard Lance H 
Published: July 2019

Abstract
Seasonal variations in environmental temperatures impose added stress on domestic species bred for economically important production traits. These heat-mediated stressors vary on a seasonal, daily, or spatial scale, and negatively impact behavior and reduce feed intake and growth rate, which inevitably leads to reduced herd productivity. The seasonal infertility observed in domestic swine is primarily characterized by depressed reproductive performance manifesting as delayed puberty onset, reduced farrowing rates, and extended weaning-to-estrus intervals. Understanding the effects of heat stress at the organismal, cellular, and molecular level is a prerequisite to identifying mitigation strategies that could reduce the economic burden of compromised reproduction. Additionally, hyperthermia experienced in utero influences industry-relevant postnatal phenotypes. Understanding tissue-specific molecular mechanisms through which heat stress confers suppressed reproductive ability is essential to the development of mitigation focused hypothesis driven solutions. This work was supported by the National Pork Board and the Iowa Pork Producers Association.
209 Effects of heat stress on the intestinal tract of poultry
Authors: Rostagnos Marcos 
Published: July 2019

Abstract
Stress is a biological adaptive response to restore homeostasis, and occurs in every animal production system, due to the multitude of stressors present in every farm. Heat stress is one of the most common environmental challenges to poultry worldwide. It has been demonstrated that heat stress negatively impacts the welfare and productivity of broilers and laying hens. However, our knowledge of basic mechanisms associated to the reported effects, as well as related to poultry behavior and welfare under heat stress conditions is in fact scarce. The adaptive response of poultry to a heat stress situation is complex and intricate in nature, and it includes effects on the intestinal tract. Intervention strategies to deal with heat stress conditions (e.g., management practices, feed additives, diet formulation, and others) have been the focus of most published studies. Nevertheless, effectiveness of most of the interventions has been variable or inconsistent. This review focuses on the scientific evidence available on the effects of the heat stress response on different facets of the intestinal tract of poultry, including its integrity, physiology, immunology and microbiology.
218 Effect of GnRH injection at -72 h in MGA-PG estrus synchronization protocol
Authors: Erickson McKay , Funston Rick N 
Published: July 2019

Abstract
Beef heifers (n = 1524) from two operations in central Nebraska were randomly assigned to one of two treatments [0 or 5 μg GnRH at prostaglandin F2α (PGF) administration 72 hrs before insemination]. Both locations utilized MGA-PG fixed-time AI (TAI) estrus synchronization protocol. The first location (L1, n = 1076, 382 ± 3 kg) processed heifers 72 hours prior to insemination and every third heifer was assigned to receive an injection of GnRH (5 ug) (TRT) and an injection of PGF. The remaining heifers received PGF and 0 μg GnRH. At insemination all heifers received 100 ug GnRH. Heifers were then observed for estrus behavior from 10–21 days post TAI and re-inseminated if estrus was detected. Heifers pregnant from the second breeding were added to final pregnancy rate. The second location (L2) utilized estrus detection patches and performed only TAI (n = 448, 363 ± 7 kg) following MGA-PG synchronization protocol outlined above without the estrus observation period. Treatment did not significantly (P > 0.20) improve TAI pregnancy rates [L1 TAI 56.3% (TRT) vs 57.3%; L1 AI Total 78.3% (TRT) vs 73.9%; L2 TAI 58.5% (TRT) vs 52.5%] among the two herds. The administration of 5 μg GnRH at PGF tended to increase (P = 0.12, 74% vs 63%) pregnancy rates for those inseminated during the follow up heat detection period at L1. The treatment did not (P > 0.20) improve pregnancy for the time-AI heifers. In addition, TAI pregnancy rates were similar (P > 0.20) at L2. There were greater (P < 0.20) effect of pen on pregnancy rate.
215 Influence of BVDV exposure on AI conception and breeding season pregnancy success in beef herds
Authors: Epperson Kaitlin M , Rich Jerica J J , Zoca Saulo Menegatti , Perkins Stephanie D , Northrop Emmalee J , Daly Russell F , Walker Julie A , Rhoades Jim R , Perry George A 
Published: July 2019

Abstract
Bovine Viral Diarrhea Virus (BVDV) causes reproductive and economic losses in cattle. The objective of this study was to evaluate the influence of BVDV exposure on reproductive success (AI and breeding season conceptions). Well vaccinated cows (n = 367) and heifers (n = 540) from 9 different herds were synchronized using the 7-d CO Synch + CIDR protocol and were fixed-time AI (FTAI). On d 28 following insemination, blood samples were collected, and pregnancy status was determined by transrectal ultrasonography and the IDEXX Rapid Visual Pregnancy Test. Non-pregnant animals were resynchronized and FTAI a second time. In six herds bulls were comingled with females beginning 10-15 d after the second AI. Final pregnancy status was determined 33–80 d following the first pregnancy diagnosis. Blood samples were tested for the presence of BVDV antigen using the IDEXX BVDV PI X2 Kit. Positive samples were indicative of animals with an active infection. Herds were determined as having BVDV exposure by the presence of at least one animal having a positive test for active antigen (n = 4 exposed herds, n = 5 non-exposed herds). Statistical analyses were performed using the GLIMMIX procedure of SAS. Herds that had BVDV exposure during the breeding season had significantly decreased (P < 0.01) first service AI conception rates compared to herds that had no exposure (34 ± 2.3% vs. 54 ± 2.3%). Additionally, breeding season pregnancy rates were decreased (P < 0.01) in herds that had BVDV exposure compared to non-exposed herds (69 ± 3.4% vs. 80 ± 3.6%). There was no significant effect of BVDV exposure on embryonic loss (P = 0.42) or percentage of animals which lost a pregnancy and rebred by the end of the breeding season (P = 0.63). In conclusion, BVDV exposure in well vaccinated herds still had a negative effect on both first service AI conception rate and overall breeding season pregnancy success.
217 Influence of daily temperature fluctuations on estrus activity determined by an electronic estrus detection system and conception to artificial insemination in cross-bred beef heifers
Authors: Cushman Robert A , Chase Chadwick C , Rich Jerica J J , Northrop Emmalee J , Thallman R Mark , Snelling Warren M , Kuehn Larry A , Brown-Brandl Tami M , Perry George A 
Published: July 2019

Abstract
Behavioral estrus occurs in response to estradiol, and the intensity of activity registered in some electronic estrus monitoring systems is greater in dairy cows that conceive to artificial insemination compared to cows that do not conceive. Ambient temperature may influence estrus activity and follicular development. Therefore, we hypothesized that differences in temperature would associate with peak activity and conception to artificial insemination in cross-bred beef heifers. Heifers (n = 346) in south central Nebraska were observed twice daily for 21 d for behavioral estrus and artificially inseminated between June 4 and June 25, 2018. Onset of estrus and peak activity were extracted from the electronic system. Ambient temperature was merged with onset of estrus, and data were analyzed using the MIXED procedure of SAS with pregnancy status to artificial insemination as a class effect. There was no difference in peak activity between heifers that conceived to artificial insemination and heifers that did not conceive to artificial insemination (P = 0.45). The ambient temperature at onset of estrus was greater for heifers that did not conceive to artificial insemination than for heifers that conceived to artificial insemination (P < 0.05). Time of onset significantly influenced peak activity (P < 0.01), with the greatest peak activity occurring in the early morning hours and in the early evening hours. Daily temperatures increased until 1600 h and decreased thereafter (P < 0.01). Differences in peak activity do not associate with conception to artificial insemination in beef heifers as in dairy cows, but temperature at onset of estrus influenced conception to artificial insemination. Based on increased peak activity in the evening when temperatures were still greater than the early morning hours, the perceived trajectory of temperature may influence behavioral estrus more than the actual temperature. USDA is an equal opportunity provider and employer.
226 Impact of corn silage level on finishing cattle nutrient digestion, ph characteristics, and feeding behavior
Authors: Wilson Hannah C , Jolly-Breithaupt Melissa L , Watson Andrea K , MacDonald James C , Erickson Galen E 
Published: July 2019

Abstract
When used as a roughage source in a finishing diet, corn silage can have different effects on digestion compared to hay because of the presence of additional corn grain. The objective of this study was to determine the effects of corn silage inclusion level on cattle digestion and feeding behavior. In a digestion study, 3 ruminally cannulated steers (430 kg ± 0.20 kg) were utilized in a generalized randomized block design with 8 periods. Treatments consisted of 3 levels of corn silage included at 0, 7.5 and 15% of the diet DM and a control treatment with 15% alfalfa. Results showed DMD, OMD, NDF digestibility, and ADF digestibility were greatest for cattle fed CS0 followed by CS7.5, CS15, and Alf (P < 0.01). Average ruminal pH was least for CS0, CS7.5 was intermediate, followed by Alf and CS15 with the greatest pH (P < 0.01). Total VFA production was greatest in cattle fed CS0 followed by CS7.5 and Alf with CS15 having the least. Acetate to propionate ratio was least for cattle fed CS0, intermediate for CS7.5 and CS15 and greatest for Alf. Cattle ate the same number of meals which were similar in size as a % of total DMI (P ≥ 0.60). However, cattle fed Alf and CS0 spent more time eating compared to cattle fed CS7.5 and CS15 (P = 10). The rate of intake (kg/hr) was greatest for CS15 (9.55) and decrease linearly for CS7.5 (9.44), Alf (8.12) and least for CS0 (7.68; P = 0.04). These data suggest that cattle, typically at high risk for reduced performance, are susceptible to negative effects of high grain diets, like acidosis, when fed no or low inclusion of roughage. Feeding silage at 15% was similar to feeding alfalfa at 7.5%.
223 Effects of high protein DDGS in SFC or DRC-based diets on nutrient digestibility and ruminal fermentation characteristics
Authors: Ovinge Lauren , Norman Mitch , Wheeler Kaylee , Erickson Galen E 
Published: July 2019

Abstract
The effect of high protein dried distillers grains plus solubles in steam flaked corn (SFC) or dry rolled corn (DRC)-based diets on rumen fermentation and nutrient digestion was evaluated. Six ruminally and duodenally cannulated heifers were utilized in a 6×6 Latin Square experiment using a 2×3 factorial treatment design. One factor was SFC or DRC-based diets, and the other factor was a control with no DGS (CON), regularly produced DDGS (DDGS), or High Protein DDGS (HiPro) included at 30% in the diet (DM basis). Data were analyzed using the MIXED procedure of SAS, with individual steer within period as the experimental unit. There was an interaction of apparent total tract starch digestibility (P 0.01), as including either DDGS or HiPro reduced starch digestibility in DRC-based diets and tended (P = 0.06) to reduce starch digestibility in SFC-based diets. Digestibility of starch was greater (P < 0.01) for SFC versus DRC-based diets across distillers treatments. Dry matter and OM apparent total tract digestibility was lowest (P < 0.01) for HiPro and DDGS was intermediate. There was no difference in molar acetate proportions (P > 0.43) between treatments. Dry rolled corn tended (P = 0.08) to have greater propionate proportion than SFC (44 vs 38%; respectively). Ammonia concentration was greater (P < 0.01) for DRC-based diets, and greatest for CON (P < 0.01) over DDGS and HiPro treatments. Average ruminal pH was unaffected by treatment (P > 0.16). Digestible energy (Mcal/kg) tended (P = 0.08) to be greater for CON over HiPro and DDGS. The use of HiPro did not affect apparent total tract nutrient digestibility as compared to DDGS in SFC or DRC-based diets. The use of either distillers product did result in a reduction in energy intake and digestibility, without affecting ruminal metabolic parameters.
222 Effect of corn stalk inclusion rate on performance and rumination behavior in beef steers
Authors: Jennings Jenny S , Lockard Catherine L , Lawrence Ty E 
Published: July 2019

Abstract
Coarse roughage, such as corn stalks, in feedlot diets aids in the formation of a fibrous mat within the rumen. The fibrous mat supports rumen health, buffers pH, and reduces acidosis risk in cattle consuming high-concentrate diets. Excess roughage can increase physical fill, thus lowering the animal’s ability to consume enough energy for efficient growth. The objective of this experiment was to quantify feedlot growth performance, rumination, ruminal pH and carcass quality and yield outcomes of cattle consuming a finishing diet with increasing levels of roughage. Fifty-one steers (initial BW = 295 + 11 kg) were randomly allocated to 1 of 3 dietary treatments; 5% (5CS; n = 18), 10% (10CS; n = 17), or 15% (15CS; n = 16) corn stalks (DM basis) in a steam-flaked-corn based finishing diet. Steers were fitted with a sensory collar that recorded rumination (min/d) and one-half of the steers (n = 27) received a rumen bolus that continuously monitored pH. The experiment was conducted using a randomized complete block design. Data were analyzed using a mixed model; treatment was a fixed effect and block was a random effect. As CS inclusion increased, we observed increased DM intake (P = 0.01; 7.7, 8.2, and 8.5 kg/d, respectively), decreased gain efficiency (P < 0.01; 0.18, 0.16, and 0.14 kg/kg DM, respectively), and a tendency for decreased ADG (P = 0.09; 1.34, 1.33, and 1.22 kg/d, respectively). Ruminal pH was highest (P < 0.01) for 15CS (6.28) and similar for 5CS and 10CS (6.10). Steers spent more time ruminating (P < 0.01) when consuming the 10CS diet (361 min/d) and least with 5CS diet (279 min/d). Increasing CS to 15% decreased rib fat thickness (P = 0.01), decreased calculated YG (P = 0.02), and decreased marbling score (P < 0.01) compared with the 5CS and 10CS treatments. Feeding excess corn stalks (≥ 15%) may prevent adequate energy intake, thus diminishing feedlot growth performance and carcass merit.
229 Characterization of the rumen bacterial communities of bison heifers maintained on a pasture-based diet
Authors: Fresno Rueda Anlly M , Griffin Jason , Kruse Carter , St-Pierre Benoit 
Published: July 2019

Abstract
The North American bison has evolved to thrive on a diverse range of habitats and climate. As a ruminant, it is dependent on the metabolic activities of symbiotic microorganisms to digest the plant fibers that make up the majority of its diet. To gain further insight into the bison rumen environment, which has remained largely unexplored, the primary objective of this study was to determine the diversity and composition of ruminal bacteria in bison fed a pasture-based diet. Ruminal content from 19 heifers maintained on pasture at the Standing Butte Ranch (North Stanley, South Dakota, USA) was collected by stomach tubing. Following extraction of microbial genomic DNA, PCR was performed to amplify the V1–V3 region of the 16S rRNA gene, then amplicons were sequenced using an Illumina MiSeq(2×300) platform. Next-generation sequence data was then analyzed using a combination of custom Perl scripts, publicly available software (Mothur v. 1.40) and online tools (RDP classifier and NCBI Blast). Bacteroidetes and Firmicutes were found to be the dominant phyla in the rumen environments analyzed, together representing 85.3% to 96.6% of sequence reads in individual samples. In contrast, the ratio of Bacteroidetes to Firmicutes showed a much broader range (0.57 to 3.90), suggesting that the rumen bacterial communities of the sampled animals exhibited a wide array of distinct composition patterns. However, Pearson correlation analysis did not support an association between the Shannon alpha diversity index and the abundance of either Bacteroidetes or Firmicutes (P > 0.05). Interestingly, Pearson correlation analysis supported a positive association between Bacteroidetes and Fibrobacteres (P < 0.05), as well as between Firmicutes and Planctomycetes (P < 0.05). Together, these results suggest that at least two rumen enterotypes, Bacteroidetes-Fibrobacteres and Firmicutes-Planctomycetes, can be distinguished in the rumen of North American bison heifers maintained on a pasture-based diet.
332 Young Scholar Presentation: regulation of immune signaling by extracellular vesicles
Authors: Ylioja Caroline M , Mamedova Laman K , Bradford Barry J 
Published: July 2019

Abstract
Exosomes and other extracellular vesicles traffic a variety of protein and nucleic acid cargo throughout the body. Immune cells especially utilize these vesicles for communication, and they are being studied in clinical settings for their potential to act as disease markers, but also to serve as drug delivery systems. In animal science, a large part of the research around exosomes has centered around their presence in milk, as well as their bioavailability and potential impact for the neonate and for humans; milk-derived exosomes are enriched with immune-related proteins and microRNA that may relate to maternal health, mammary function, or neonate development. We sequenced miRNA isolated from colostrum of dairy cows predicted to feature either moderate or high degree of immune suppression, but found minimal differences (2 differentially expressed miRNA of 343 miRNA analyzed) between the two groups. Immune suppression exhibited during early lactation may also be related to altered exosome-mediated communication between immune cells. We studied the ability of bovine exosomes to alter immune responses of primary bovine monocyte-derived macrophages and found that exosomes alone or in combination with LPS were able to stimulate cytokine production to a greater extent than LPS alone. The ability of exosomes to transport cytokine, bioactive lipid, and regulatory RNA cargo suggests potential involvement in transition cow health. Altered exosome content and function have been associated with uterine infection, mastitis, and metabolic dysfunction; future studies with exosome signaling may help clarify the complexities of transition cow immune function and point to strategies to support immunity.