Dataset Information

Evaluation of age, weaning weight, body condition score, and reproductive tract score in pre-selected beef heifers relative to reproductive potential.

ABSTRACT: Background:Artificial insemination is a preferred breeding method for beef heifers as it advances the genetic background, produces a predictive and profitable calving season, and extends the heifer's reproductive life span. As reproductive efficiency in heifers is key for the success of beef cattle production systems, following artificial insemination, heifers are exposed to a bull for the remainder of the breeding season. Altogether, up to 95% of heifers might become pregnant in their first breeding season. Heifers that do not become pregnant at the end of the breeding season represent an irreparable economical loss. Additionally, heifers conceiving late in the breeding season to natural service, although acceptable, poses serious losses to producers. To minimize losses due to reproductive failure, different phenotypic parameters can be assessed and utilized as selection tools. Here, we tested the hypothesis that in a group of pre-selected heifers, records of weaning weight, age at weaning, age at artificial insemination, and age of dam differ among heifers of varied reproductive outcomes during the first breeding season. Results:None of the parameters tested presented predictive ability to discriminate the heifers based on the response variable ('pregnant to artificial insemination', 'pregnant to natural service', 'not pregnant'). Heifers categorized with body condition score?=?6 and reproductive tract score ??4 had the greatest proportion of pregnancy to artificial insemination (49% and 44%, respectively). Furthermore, it was notable that heifers presenting body condition score?=?6 and reproductive tract score?=?5 presented the greatest pregnancy rate at end of the breeding season (89%). Heifers younger than 368?d at the start of the breeding season did not become pregnant to artificial insemination. Those young heifers had 12.5% chance to become pregnant in their first breeding season, compared to 87.5% if the heifers were older than 368?days. Conclusion:Our results suggest that beef heifers with body condition score?=?6 and reproductive tract score ??4 are more likely to become pregnant to artificial insemination. Careful assessment should be undertaken when developing replacement heifers that will not reach 12?months of age by the beginning of the breeding season.

SUBMITTER: Dickinson SE

PROVIDER: S-EPMC6390375 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Evaluation of age, weaning weight, body condition score, and reproductive tract score in pre-selected beef heifers relative to reproductive potential.

Dickinson Sarah E SE Elmore Michelle F MF Kriese-Anderson Lisa L Elmore Joshua B JB Walker Bailey N BN Dyce Paul W PW Rodning Soren P SP Biase Fernando H FH

Journal of animal science and biotechnology 20190226

<h4>Background</h4>Artificial insemination is a preferred breeding method for beef heifers as it advances the genetic background, produces a predictive and profitable calving season, and extends the heifer's reproductive life span. As reproductive efficiency in heifers is key for the success of beef cattle production systems, following artificial insemination, heifers are exposed to a bull for the remainder of the breeding season. Altogether, up to 95% of heifers might become pregnant in their f ...[more]

PMID: 30891236

Similar Datasets

Project description:Reproductive failure of replacement breeding animals is one of the leading causes of loss to the beef production industry. The losses are further increased due to the inability to diagnose the reproductive potential of the beef heifer prior to the breeding season until the pregnancy outcome. To overcome this problem, a system to discriminate beef heifers with varying reproductive potential as early and accurately as possible is demanded. The omics technologies, such as transcriptomics, could predict the future reproductive potential of beef heifers. Therefore, this manuscript provides the gene expression profile dataset using RNA-Seq identified from peripheral white blood cells (PWBC) of beef heifers at weaning. To accomplish this, the blood samples were collected at the time of weaning, processed to extract the PWBC pellet and stored at – 80 °C until further processing. After the breeding protocol (artificial insemination (AI) followed by natural bull service) and pregnancy diagnosis, the heifers that were pregnant to AI (n = 8) or remained open (n = 7) were utilized for this study. Total RNA was extracted from PWBC collected at the time of weaning from these samples and subjected to sequencing using the Illumina Nova-Seq platform. High-quality sequencing data was analyzed using a bioinformatic workflow based on FastQC and MultiQC for quality control, STAR for read alignment, and DESeq2 for differential expression analysis. Genes were considered significantly differentially expressed after adjustment with Bonferroni correction (padj ≤ 0.05) and absolute (log2 fold change) ≥ 0.5. Raw and processed RNA-Seq data were deposited and made publicly available on the gene expression omnibus database (GEO; GSE221903). To our knowledge, this is the first dataset investigating the change in the gene expression level as early as weaning to predict the future reproductive outcome in beef heifers. Interpretation of the main findings based on this data is reported in a research article titled “mRNA Signatures in Peripheral White Blood Cells Predicts Reproductive Potential in Beef Heifers at Weaning” [1].

Project description:The present study evaluated the growth and puberty attainment of Bos indicus heifers administered recombinant bovine somatotropin (bST) or saline injections during preweaning and/or postweaning. On day 0, 177 suckling Nellore heifers were stratified by initial age and body weight (BW) (80 ± 10 d; 97 ± 16 kg), and randomly assigned, in a 2 × 2 factorial design (n = 44 to 45 heifers/treatment), to receive s.c. injections of saline (5 mL 0.9% NaCl) or sometribove zinc (Posilac; Elanco, Greenfield, IN; 6.14 mg/kg of BW0.75) on days 0 and 10 (PRE) and/or days 167 and 177 (POS). All heifers were managed as a single group in Brachiaria decumbens pastures from day 0 until 24 d postweaning (day 191), and then provided a corn silage-based TMR from days 191 to 380 to achieve 65% to 70% of mature BW at the end of the study (day 380). Heifer full BW was collected on days 0, 10, 167, 177, and monthly from days 191 to 380. Transrectal ultrasonography of ovaries was performed on days 1 and 10 of each month from days 229 to 380 to assess the percentage of pubertal heifers. Liver biopsies and blood samples from jugular vein were collected on days 0, 10, 167, 177, and 380. Additional blood samples were collected monthly from days 259 to 380 (n = 10 to 15 heifers/treatment). No interactions among day of the study, PRE, and POS injections of saline or bST were detected (P ? 0.11). Preweaning bST injections increased heifer average daily gain (ADG) from days 0 to 10 and plasma IGF-1 on day 10 (P ? 0.03), did not affect ADG from days 0 to 177, plasma IGF-1 from days 259 to 380, and any liver gene mRNA expression (P ? 0.19), but tended to decrease ADG from days 191 to 380 (P = 0.07) and percentage of pubertal heifers on days 349 (P = 0.07), 359 (P = 0.002), and 380 (P = 0.0001) compared with saline injections. Postweaning bST injections increased plasma IGF-1 on day 177 and overall liver mRNA expression of GHR-1A (P ? 0.05), decreased plasma IGF-1 from days 259 to 380 (P = 0.03), tended to decrease liver mRNA expression of GHR-1B on day 177 (P = 0.08), but did not affect ADG from days 167 to 177 and 191 to 380, and puberty attainment from days 229 to 380 (P ? 0.12) compared with saline injections. Thus, preweaning and postweaning injections of bST successfully increased heifer plasma IGF-1 concentrations 10 d after first injection. Postweaning injections of bST had no impact on puberty attainment, whereas preweaning bST injections of bST impaired puberty attainment of Nellore beef heifers.

Project description:BackgroundCompared to national evaluations, international collaboration projects further improve accuracies of estimated breeding values (EBV) by building larger reference populations or performing a joint evaluation using data (or proxy of them) from different countries. Genomic selection is increasingly adopted in beef cattle, but, to date, the benefits of including genomic information in international evaluations have not been explored. Our objective was to develop an international beef cattle single-step genomic evaluation and investigate its impact on the accuracy and bias of genomic evaluations compared to current pedigree-based evaluations.MethodsWeaning weight records were available for 331,593 animals from seven European countries. The pedigree included 519,740 animals. After imputation and quality control, 17,607 genotypes at a density of 57,899 single nucleotide polymorphisms (SNPs) from four countries were available. We implemented two international scenarios where countries were modelled as different correlated traits: an international genomic single-step SNP best linear unbiased prediction (SNPBLUP) evaluation (ssSNPBLUPINT) and an international pedigree-based BLUP evaluation (PBLUPINT). Two national scenarios were implemented for pedigree and genomic evaluations using only nationally submitted phenotypes and genotypes. Accuracies, level and dispersion bias of EBV of animals born from 2014 onwards, and increases in population accuracies were estimated using the linear regression method.ResultsOn average across countries, 39 and 17% of sires and maternal-grand-sires with recorded (grand-)offspring across two countries were genotyped. ssSNPBLUPINT showed the highest accuracies of EBV and, compared to PBLUPINT, led to increases in population accuracy of 13.7% for direct EBV, and 25.8% for maternal EBV, on average across countries. Increases in population accuracies when moving from national scenarios to ssSNPBLUPINT were observed for all countries. Overall, ssSNPBLUPINT level and dispersion bias remained similar or slightly reduced compared to PBLUPINT and national scenarios.ConclusionsInternational single-step SNPBLUP evaluations are feasible and lead to higher population accuracies for both large and small countries compared to current international pedigree-based evaluations and national evaluations. These results are likely related to the larger multi-country reference population and the inclusion of phenotypes from relatives recorded in other countries via single-step international evaluations. The proposed international single-step approach can be applied to other traits and breeds.

Project description:The gene expression profiles were measured using RNA-Seq beef heifers sampled at weaning and retrospectively classified as pregnant through artificial insemination (AI-P, n = 8) or non-pregnant (NP, n = 7). In brief, crossbred heifers (Angus-Simmental) were used in this study. At the time of weaning (~238 days after birth), blood samples (10 mL) were collected from the jugular vein into vacutainers containing EDTA. The blood was processed to extract PWBC and was stored at -80 until further processing. During the breeding season, all the heifers followed the same breeding protocol, estrus synchronization, and fixed-time artificial insemination (AI). Fourteen days following the fixed-time AI, the non-pregnant heifers were exposed to fertile bulls for 60 days. Depending on the presence or absence of conceptus at 75 days following AI, heifers were classified as pregnant to AI (AI-P), pregnant to natural breeding (P-NB) or non-pregnant (NP). Heifers that were pregnant to AI (N = 8) and non-pregnant (N = 7) were considered for the study. Total RNA was extracted from peripheral white blood cells of 15 samples (AI-P and NP) and was subjected to sequencing. The RNA-Seq data were subjected to quality control and mapped with STAR aligner to Ensemble’s ARS UCD1.2 Bos taurus reference genome. Read quantification was performed using a STAR aligner to obtain raw counts per gene. Genes with low counts were filtered out. After filtering, the read counts were analyzed using DESeq2 v 1.26.0 to identify differentially expressed genes (DEGs). The DEGs with padj < 0.05 and absolute (log2 fold change) > 0.5 were considered significant. The NP heifers were considered as the reference group, and the DEGs up or downregulated were classified based on the log2 fold change direction. We identified 92 DEGs between AI-P and NP groups. The top pathways identified with DEGs were the immune system, cytokine production and defense response, hematopoietic cell lineage, positive regulation of reactive oxygen species metabolic process, and negative regulation of cysteine-type endopeptidase activity involved in the apoptotic process.

Project description:The miRNA profiles were measured using small-RNA sequencing in beef heifers sampled at weaning that was retrospectively classified as fertile or subfertile following the breeding protocol. To accomplish this, the miRNA profiles were generated from the blood samples (10 mL) collected from crossbred heifers (Angus-Simmental) at the time of weaning (~238 days after birth). Peripheral white blood cells (PWBC) were extracted from the blood samples and stored at -80°C until further processing. During the breeding season, all the heifers followed the same breeding protocol, estrus synchronization, and fixed-time artificial insemination (AI). Fourteen days following the fixed-time AI, the non-pregnant heifers were exposed to fertile bulls for 60 days. Depending on the presence or absence of conceptus at 75 days following AI, heifers were classified as fertile for those who were pregnant through artificial insemination, pregnant to natural breeding (P-NB), or subfertile for those who were not pregnant. Heifers from fertile (n = 7) and subfertile (n = 7) groups were considered for the study. Total RNA was extracted from the PWBC of 14 samples and was subjected to small RNA library preparation and sequencing. After quality control, adapter trimming, and alignment, mature miRNAs were used for differential expression analysis. The read counts were transformed to counts per million (CPM), and raw counts with CPM < 1 in 50% of the samples were filtered out. The filtered raw counts were analyzed using DESeq2 v 1.26.0 to identify differentially expressed miRNAs (DEMIs). The DEMIs identified with a p-value < 0.05 and absolute (log2 fold change) > 0.5 were considered significant. With the subfertile heifers as the reference group, we identified 16 DEMIs between fertile and subfertile groups. To determine the genes targeting the DEMIs, we downloaded the target genes for each DEMI and retained only those genes expressed in the PWBCs. For the miRNA-gene correlation, we used the partial correlation and information theory (PCIT) approach to identify the significant gene-miRNA correlated pairs. The significant genes correlated with the miRNAs identified pathways including MAPK, ErbB, HIF-1, FoxO, p53, mTOR, T-cell receptor, insulin and GnRH signaling, apoptosis, and pathways regulating pluripotency of stem cells in the fertile group while cell cycle, p53 signaling pathway and apoptosis pathways in the subfertile group.

Project description:A 3 yr study evaluated the effects of three preweaning injections of bovine ST, administered 14 d apart, on growth and reproductive performance of Bos indicus-influenced beef heifers. On d 0 of each year, suckling Angus × Brangus heifers (n = 15 heifers/treatment/yr) were stratified by BW (147 ± 20 kg) and age (134 ± 11 d) and randomly assigned to receive an s.c. injection of saline (SAL; 5 mL; 0.9% NaCl) or 250 mg of sometribove zinc (BST; Posilac, Elanco, Greenfield, IN) on d 0, 14, and 28. Heifers and respective dams were managed as a single group on bahiagrass (Paspalum notatum) pastures from d 0 until weaning (d 127). From d 127 to 346, heifers were grouped by treatment, allocated to bahiagrass pastures (1 pasture/treatment/yr) and fed a molasses-based supplement (2.9 kg/heifer daily; DM basis) until d 346. Blood samples were collected on d 0, 14, 28, 42, and then every 9-10 d from d 179 to 346. In yr 3, liver biopsy samples were collected on d 0, 42, and 263. Heifers were exposed to mature Angus bulls from d 263 to 346. Growth performance and physiological parameters were analyzed using the MIXED procedure, whereas reproductive variables were analyzed using the GLIMMIX procedure of SAS. Effects of treatment × year and treatment × year × time were not detected for any variable measured in this study (P ? 0.14), except for calving percentage (P = 0.03). Heifers assigned to BST injections had greater overall plasma concentrations of IGF-1 and ADG from d 0 to 42 (P ? 0.05), less ADG from d 42 to 127 (P = 0.04), but had similar BW at weaning and postweaning ADG (P ? 0.25) compared to SAL heifers. Heifers assigned to BST tended to achieve puberty 26 d earlier (P = 0.10), had greater percentage of pubertal heifers on d 244, 263, 284, and 296 (P ? 0.04), tended to have greater overall pregnancy percentage (P = 0.10), and had greater (P ? 0.05) calving percentages in yr 1 and 2 (but not yr 3; P = 0.68) compared to SAL heifers. Liver mRNA expression of GHR-1B and IGF-1 on d 0 and 42 did not differ between treatments (P ? 0.15), but was greater for BST vs. SAL heifers on d 263 (P ? 0.02). Hence, administering three injections containing 250 mg of sometribove zinc at 14 d intervals before weaning (between 135 and 163 d of age) induced long-term impacts on liver gene expression and may be a feasible management practice to enhance puberty and pregnancy attainment in B. indicus-influenced replacement beef heifers.

Project description:This experiment evaluated the effects of postweaning body weight (BW) gain of replacement beef heifers on their reproductive development and productivity as primiparous cows. Seventy-two Angus × Hereford heifers were ranked on day -6 of experiment (17 d after weaning) by age and BW (218 ± 1.6 d of age and 234 ± 3 kg of BW), and assigned to receive 1 of 3 supplementation programs from days 0 to 182: 1) no supplementation to maintain limited BW gain (LGAIN), 2) supplementation to promote moderate BW gain (MGAIN), or 3) supplementation to promote elevated BW gain (HGAIN). Heifers were maintained in 2 pastures (36 heifers/pasture, 12 heifers/treatment in each pasture) with free-choice alfalfa-grass hay, and supplements were offered individually 6 d per week. Heifer shrunk BW was recorded on days -6 and 183 for average daily gain (ADG) calculation. Blood samples were collected for puberty evaluation via plasma progesterone weekly from days 0 to 182. On day 183, heifers were combined into a single group and received the same nutritional management until the end of the experimental period (day 718). From days 183 to 253, heifers were assigned to a fixed-time artificial insemination program combined with natural service. Average daily gain from days 0 to 182 was greater (P < 0.01) in HGAIN vs. MGAIN and LGAIN (0.78, 0.60, and 0.37 kg/d, respectively; SEM = 0.02), and greater (P < 0.01) in MGAIN vs. LGAIN heifers. Puberty attainment by the beginning of the breeding season was also greater in HGAIN vs. MGAIN and LGAIN (87.5%, 62.5%, and 56.5%, respectively; SEM = 7.1) but similar (P = 0.68) between MGAIN vs. LGAIN heifers. A treatment × day interaction was detected (P < 0.01) for calving rate, as HGAIN heifers calved earlier compared with MGAIN and LGAIN heifers. Ten heifers per treatment were assessed for milk production via weigh-suckle-weigh at 56.8 ± 1.5 d postpartum, followed by milk sample collection 24 h later. No treatment differences were detected (P ≥ 0.16) for milk yield and composition. However, mRNA expression of GLUT1 in milk fat globules was less (P ≤ 0.02) in LGAIN vs. MGAIN and HGAIN heifers, and expression of GLUT8 mRNA was also less (P = 0.04) in LGAIN vs. HGAIN heifers. No treatment differences were detected (P ≥ 0.44) for offspring weaning BW. Collectively, results from this experiment indicate that HGAIN hastened the reproductive development of replacement heifers, without negatively affecting their milk productivity and offspring weaning weight as primiparous cows.

Project description:In beef cattle maternally influenced traits, estimates of direct-maternal genetic correlations (rdm) are usually reported to be negative. In international evaluations, rdm can differ both within countries (rdm_WC) and between countries (rdm_BC). The rdm_BC are difficult to estimate and are assumed to be zero in the current model for international beef cattle evaluations (Interbeef). Our objective was to investigate re-ranking of international estimated breeding values (IEBVs) in international beef cattle evaluations between models that either used estimated values for rdm or assumed them to be 0. Age-adjusted weaning weights and pedigree data were available for Limousin beef cattle from ten European countries. International EBVs were obtained using a multi-trait animal model with countries modeled as different traits. We compared IEBVs from a model that uses estimated rdm_BC (ranging between -0.14 and +0.14) and rdm_WC (between -0.33 and +0.40) with IEBVs obtained either from the current model that assumes rdm_BC to be 0, or from an alternative model that assumes both rdm_BC and rdm_WC to be 0. Direct and maternal IEBVs were compared across those three scenarios for different groups of animals. The ratio of population accuracies from the linear regression method was used to further investigate the impact of rdm on international evaluations, for both the whole set of animals in the evaluation and the domestic ones. Ignoring rdm_BC, i.e., replacing estimated values with 0, resulted in no (rank correlations > 0.99) or limited (between 0.98 and 0.99) re-ranking for direct and maternal IEBVs, respectively. Both rdm_BC and rdm_WC had less impact on direct IEBVs than on maternal IEBVs. Re-ranking of maternal IEBVs decreased with increasing reliability. Ignoring rdm_BC resulted in no re-ranking for sires with IEBVs that might be exchanged across countries and limited re-ranking for the top 100 sires. Using estimated rdm_BC values instead of considering them to be 0 resulted in null to limited increases in population accuracy. Ignoring both rdm_BC and rdm_WC resulted in considerable re-ranking of animals' IEBVs in all groups of animals evaluated. This study showed the limited impact of the current practice of ignoring rdm_BC in international evaluations for Limousin weaning weight, most likely because the estimated rdm_BC was close to 0. We expect that these conclusions can be extended to other traits that have reported rdm values in the range of rdm_WC values for weaning weight in Limousin.

Project description:BackgroundBovine genital campylobacteriosis (BGC) is a globally important venereal disease of cattle caused by Campylobacter fetus subspecies venerealis. Diagnosis of BGC is highly challenging due to the lack of accurate diagnostic tests.MethodsTo characterise the biomarkers for C. fetus venerealis infection, a total of twelve cycling heifers were selected and categorised as vaccinated (n = 6) with Vibrovax® (Zoetis™) and unvaccinated (n = 6). All heifers were oestrous synchronised with a double dose of prostaglandin (PGF2α) 11 days apart and when in oestrous intravaginally challenged with 2.7 x 109 CFU live C. fetus venerealis. DNA extracted from vaginal mucus samples was screened using a C. fetus qPCR and 16S rRNA was characterised using Illumina sequencing (V5-V8 region). Relative abundances of serum proteins were calculated using sequential window acquisition of all theoretical fragment ion spectra coupled to tandem mass spectrometry (SWATH-MS) for all heifers at three timepoints: pre-challenge, post-challenge and post-recovery.ResultsIn 16S rRNA sequencing of vaginal mucus, Campylobacter spp. appeared two days following challenge in unvaccinated compared to 14 days in vaccinated animals, consistent with the qPCR results. Increased relative abundances of Firmicutes and Campylobacterota were identified after C. fetus venerealis challenge and were associated with C. fetus venerealis in vaccinated and unvaccinated heifers. Greater relative abundance of Streptococcus spp. was observed during oestrous rather than dioestrous. In both vaccinated and unvaccinated heifers, Acinetobacter spp. increased after challenge with higher abundance of Corynebacterium spp. in the vaccinated group. A total of 130 unique proteins were identified in SWATH analysis of the serum samples, and the number of differentially abundant proteins found was higher in the vaccinated group after recovery from infection compared to pre-and post-challenge (adjusted P < 0.05 and Log2FC > 0.2).ConclusionCoglutinin, clusterin, HP homologs, vitamin D binding protein and fetuin B were identified as potential biomarkers for C. fetus venerealis infection and need further study to validate their efficiency as immune biomarkers for BGC.

Dataset Information

Evaluation of age, weaning weight, body condition score, and reproductive tract score in pre-selected beef heifers relative to reproductive potential.

Publications

Evaluation of age, weaning weight, body condition score, and reproductive tract score in pre-selected beef heifers relative to reproductive potential.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets