Search

Introduction: Targeted single nucleotide polymorphisms (SNPs) have been used in genomic prediction methodologies to enhance the accuracy of associated genetic transmitting abilities in Holstein cows. The objective of this study was to identify and validate SNPs associated with fertility traits impacting early embryo mortality. Methods: The mRNA sequencing data from day 16 normal (n = 9) and embryo mortality (n = 6) conceptuses from lactating multiparous Holstein cows were used to detect SNPs. The selection of specific genes with SNPs as preliminary candidates was based on associations with reproductive and fertility traits. Validation of candidate SNPs and genotype-to-phenotype analyses were conducted in a separate cohort of lactating primiparous Holstein cows (n = 500). After genotyping, candidate SNPs were filtered using a quality control pipeline via PLINK software. Continuous numeric and binary models from reproductive traits were evaluated using the mixed procedure for a generalized linear model-one way ANOVA or logistic regression, respectively. Results: Sixty-nine candidate SNPs were initially identified, but only 23 passed quality control procedures. Ultimately, the study incorporated 466 observations for statistical analysis after excluding animals with missing genotypes or phenotypes. Significant (p <0.05) associations with fertility traits were identified in seven of the 23 SNPs: DSC2 (cows with the A allele were older at first calving); SREBF1 and UBD (cows with the T or G alleles took longer to conceive); DECR1 and FASN (cows with the C allele were less likely to become pregnant at first artificial insemination); SREBF1 and BOLA-DMB (cows with the T allele were less likely to be pregnant at 150 days in milk). It was also determined that two candidate SNPs within the DSC2 gene were tag SNPs. Only DSC2 SNPs had an important allele substitution effect in cows with the G allele, which had a decreased age at first calving by 10 days. Discussion: Candidate SNPs found in this study could be used to develop genetic selection tools to improve fertility traits in dairy production systems. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) infections cause USD 1.5–2 billion in losses annually. Maternal BVDV after 150 days of gestation causes transient fetal infection (TI) in which the fetal immune response clears the virus. The impact of fetal TI BVDV infections on postnatal growth and white blood cell (WBC) methylome as an index of epigenetic modifications was examined by inoculating pregnant heifers with noncytopathic type 2 BVDV or media (sham-inoculated controls) on Day 175 of gestation to generate TI (n = 11) and control heifer calves (n = 12). Fetal infection in TI calves was confirmed by virus-neutralizing antibody titers at birth and control calves were seronegative. Both control and TI calves were negative for BVDV RNA in WBCs by RT-PCR. The mean weight of the TI calves was less than that of the controls (p < 0.05). DNA methyl seq analysis of WBC DNA demonstrated 2349 differentially methylated cytosines (p ≤ 0.05) including 1277 hypomethylated cytosines, 1072 hypermethylated cytosines, 84 differentially methylated regions based on CpGs in promoters, and 89 DMRs in islands of TI WBC DNA compared to controls. Fetal BVDV infection during late gestation resulted in epigenomic modifications predicted to affect fetal development and immune pathways, suggesting potential consequences for postnatal growth and health of TI cattle. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article regarding the use of abortifacient, a modified-live virus (MLV) vaccines, in pregnant cattle.

Objective--To assess the impacts of the introduction of foot-and-mouth disease (FMD) and various FMD control programs in southern Thailand. Animals--A native population of 562,910 cattle and 33,088 buffalo as well as 89,294 animals legally transported into southern Thailand. Procedures--A quantitative risk assessment was used to ascertain the probability of FMD introduction, and an intrinsic dynamic model was used to assess impacts. Value for the transmission rate (β) was estimated. Five scenarios created to assess the impacts of nonstructural protein (NSP) testing, mass vaccination, and culling were examined. Impacts were assessed through an examination of the estimated annual cumulative incidence (ACI) of FMD. The ACls of various scenarios were compared by use of the Tukey Studentized range technique. Results--β was estimated at 0.115. Approximately 35,000 cases of FMD would be expected from the baseline situation. A 30% reduction of ACI was detected with the introduction of NSP antibody testing. Prophylactic vaccination resulted in an 85% reduction of ACl. Concurrent use of NSP antibody testing and vaccination reduced the ACl by 96%, and the addition of an eradication policy resulted in a slightly greater decrease in the ACl (98%). Conclusions and Clinical Relevance--The study used epidemiologic models to investigate FMD control interventions. Results suggested that vaccination has more impact than the use of NSP testing. Use of the NSP test reduced ACl during peak seasons, whereas vaccination diminished the underlying incidence. The best mitigation plan was an integrated and strategic use of multiple control techniques. [ABSTRACT FROM AUTHOR]

Objective--To assess the likelihood of an introduction of foot-and-mouth disease (FMD) into the Malaysia-Thailand-Myanmar (MTM) peninsula through terrestrial movement of livestock. Animals--89,294 cattle and buffalo legally moved into the MTM peninsula. Procedures--A quantitative risk assessment was conducted by use of a stochastic simulation. Patterns of livestock movement were ascertained through review of relevant governmental records and regulations and by interviewing farmers, traders, and local officers when the records did not exist. Parameters identified in the process were the probabilities of livestock having FMD and of FMD infection going undetected during import processes. The probability of an animal accepted for import having FMD was also assessed. Sensitivity analysis was performed to determine the effects that each parameter had on the model. Results--The simulation yielded an average consignment prevalence of 10.95%. Typically, each animal in a quarantine facility had a 2.7% chance of having an inapparent form of FMD infection; hence, it was likely an animal would not be identified as infected. Findings revealed that the mean probability of an animal accepted for import having FMD was 2.9%, and the risk was as high as 11%. Conclusions and Clinical Relevance--Results of the model allowed for the evaluation of movement regulations currently imposed in the MTM peninsula. Evidence from the study suggested that current practices in animal movement were far from efficient in preventing introduction of FMD-infected animals into the MTM region, and additional measures will be necessary. [ABSTRACT FROM AUTHOR]

Introduction: Targeted single nucleotide polymorphisms (SNPs) have been used in genomic prediction methodologies to enhance the accuracy of associated genetic transmitting abilities in Holstein cows. The objective of this study was to identify and validate SNPs associated with fertility traits impacting early embryo mortality. Methods: The mRNA sequencing data from day 16 normal ( n = 9) and embryo mortality ( n = 6) conceptuses from lactating multiparous Holstein cows were used to detect SNPs. The selection of specific genes with SNPs as preliminary candidates was based on associations with reproductive and fertility traits. Validation of candidate SNPs and genotype-to-phenotype analyses were conducted in a separate cohort of lactating primiparous Holstein cows ( n = 500). After genotyping, candidate SNPs were filtered using a quality control pipeline via PLINK software. Continuous numeric and binary models from reproductive traits were evaluated using the mixed procedure for a generalized linear model-one way ANOVA or logistic regression, respectively. Results: Sixty-nine candidate SNPs were initially identified, but only 23 passed quality control procedures. Ultimately, the study incorporated 466 observations for statistical analysis after excluding animals with missing genotypes or phenotypes. Significant ( p <0.05) associations with fertility traits were identified in seven of the 23 SNPs: DSC2 (cows with the A allele were older at first calving); SREBF1 and UBD (cows with the T or G alleles took longer to conceive); DECR1 and FASN (cows with the C allele were less likely to become pregnant at first artificial insemination); SREBF1 and BOLA-DMB (cows with the T allele were less likely to be pregnant at 150 days in milk). It was also determined that two candidate SNPs within the DSC2 gene were tag SNPs. Only DSC2 SNPs had an important allele substitution effect in cows with the G allele, which had a decreased age at first calving by 10 days. Discussion: Candidate SNPs found in this study could be used to develop genetic selection tools to improve fertility traits in dairy production systems., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Gonzalez Berrios, Bowden, Saad, Bishop, Van Campen, Pinedo, Hansen and Thomas.)

Conceptus-derived interferon-tau (IFNT) initiates maternal recognition of pregnancy in ewes by paracrine actions on the endometrium and endocrine action on the corpus luteum (CL). To examine the effect of IFNT on the CL without inducing IFN stimulated genes (ISGs) in the endometrium, recombinant ovine IFNT (roIFNT) or bovine serum albumin (BSA) was delivered directly into CLs via osmotic pumps at a rate of 10, 50 or 100 ng/h from days 9 to 12 of the estrous cycle. Endometrial and CL samples were collected on day 12. Fifty ng/h of roIFNT induced ISG15 in the CL on day 12 without affecting endometrial ISG15 concentrations. In a second experiment, roIFNT (50 ng/h) was infused into the CL from days 10 to 17 of the estrous cycle and serum samples were collected daily. Serum progesterone concentrations were significantly higher on days 15 to 17 in roIFNT-infused ewes compared to controls. Levels of LHCGR, STAR, CYP11A1, HSL, OPA1 and PKA mRNA and proteins were higher in the roIFNT-infused CLs compared to the controls. Levels of ISG15 and MX1 mRNA increased in the CLs of roIFNT-infused ewes but not in the endometrium. Endometrial ESR1 mRNA and protein concentrations were higher in the controls compared to roIFNT-infused ewes. In conclusion, intra-luteal delivery of roIFNT induced ISGs, stabilized steroidogenesis in the CL and delayed luteolysis without inducing endometrial ISGs. Inhibition of ESR1 in the endometrium of roIFNT-infused ewes was observed suggesting that direct delivery of IFNT to the CL has an additional anti-luteolytic effect on the endometrium., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Two methods for the extraction of RNA of vesicular stomatitis virus (VSV) Indiana1 and New Jersey and their simultaneous amplification by one-step polymerase chain reaction using reverse transcriptase were evaluated. A guanidine-thiocyanate-based RNA extraction (Qiagen RNeasy Mini Kit, Qiagen, Valencia, CA ) followed by column-based purification coupled with one-step RT-PCR proved to be a simple, safe, practicable, and reliable tool for rapid, highly sensitive, and specific differential diagnosis of both types of VSV in cell lysate and spiked tissue samples as compared with the tri-phasic extraction method (Tri-reagent method). When RNA was extracted either from VSV cell culture stock or from VSV spiked bovine lymph nodes by using Qiagen RNeasy Mini Kit, the detection limit in the multiplex RT-PCR was as low as 0.505 to 2.84 TCID(50) for VSV-IND and VSV-NJ, respectively. The multiplex RT-PCR consistently detected VSV-IND and NJ RNA in as little as 0.1-1.0  fg of total RNA from spiked BHK-21 cell suspension when Qiagen RNeasy mini kit was used. The multiplex RT-PCR assay was capable of detecting both types of VSV in a one-step reaction tube. The minimum sensitivity of this assay in various experiments was 0.1683 TCID(50) (IND), 0.0946 TCID(50) (NJ), and 0.057  fg (IND and NJ) per 2  µl PCR sample, which is significantly more sensitive than reported previously (0.28-2.8 TCID50/1  µl). So the present study improved the sensitivity of previously reported multiplex RT-PCR for the detection and differentiation of VSV-IND and VSV-NJ in a single assay., (© 2011 Wiley-Liss, Inc.)

Objective: To develop a method for percutaneous collection of fetal fluid from cattle in the late stages of gestation and determine whether bovine viral diarrhea virus (BVDV) can be isolated from such fluids., Design: Case series., Animals: 169 pregnant beef cattle., Procedure: Animals were restrained in a squeeze chute, and hair was clipped from a region of the right flank. Pregnancy was confirmed, and fetal fluids were identified by means of abdominal ultrasonography. Fetal fluid was collected with a spinal needle. Virus isolation was performed on fetal fluids, WBC lysates from 160 live calves, and tissues from 12 calves that died or were aborted. Blood samples collected from adult cattle were assayed with an immunoperoxidase monolayer assay., Results: Fourteen animals aborted or delivered premature calves within 3 weeks after fetal fluid collection; however, it could not be determined whether this was a complication of the procedure or attributable to other factors. Results of BVDV isolation from fetal fluid samples were negative for 168 animals. However, a noncytopathic BVDV was isolated from fetal fluid obtained from a 2-year-old heifer; results of the immunoperoxidase assay of serum from this heifer were also positive, and a noncytopathic BVDV was isolated from tissue specimens from a stillborn calf produced by this heifer., Conclusions and Clinical Relevance: Results suggest that fetal fluids can be collected percutaneously from cattle in the late stages of gestation and that virus isolation performed on fetal fluids can be used to identify fetuses infected with BVDV in utero. However, safety of the procedure could not be evaluated.