A fresh look at inter-service intervals in UK dairy herds

Good heat detection is essential for good reproductive performance in the modern dairy herd using artificial insemination. Veterinary surgeons and farmers use a variety of tools to monitor heat detection including the analysis of inter-service intervals (ISIs). The aim of this study was to explore the distribution of inter-service intervals in a large sample of UK dairy herds and establish targets for use by practitioners when interpreting ISIs. In this study service records from 167 dairy herds from across the UK were used to generate ISI profiles for each calendar year of each herd. Intervals between serves were categorised as short irregular (2-17 days), short regular (18-24 days), long irregular (25-35 days), long regular (36-48 days) or extended (>48 days). Herd years were ranked by oestrus detection efficiency, the mean of the top quartile of herd-years had 6%, 40%, 16%, 19% and 19% of intervals in each interval category respectively. There was no correlation between the percentage of serves falling in the short regular and short irregular category for a given herd-year (Spearman rho magnitude <0.01, p=0.84), suggesting little direct correlation between the sensitivity and specificity of a herd’s heat detection. The results show a substantial difference to accepted targets and will be of use when interpreting herd data and target setting for UK dairy herds

A fresh look at inter-service intervals in UK dairy herds

Good heat detection is essential for good reproductive performance in the modern dairy herd using artificial insemination. Veterinary surgeons and farmers use a variety of tools to monitor heat detection including the analysis of inter-service intervals (ISIs). The aim of this study was to explore the distribution of inter-service intervals in a large sample of UK dairy herds and establish targets for use by practitioners when interpreting ISIs. In this study service records from 167 dairy herds from across the UK were used to generate ISI profiles for each calendar year of each herd. Intervals between serves were categorised as short irregular (2-17 days), short regular (18-24 days), long irregular (25-35 days), long regular (36-48 days) or extended (>48 days). Herd years were ranked by oestrus detection efficiency, the mean of the top quartile of herd-years had 6%, 40%, 16%, 19% and 19% of intervals in each interval category respectively. There was no correlation between the percentage of serves falling in the short regular and short irregular category for a given herd-year (Spearman rho magnitude <0.01, p=0.84), suggesting little direct correlation between the sensitivity and specificity of a herd’s heat detection. The results show a substantial difference to accepted targets and will be of use when interpreting herd data and target setting for UK dairy herds

Associations between dairy cow inter-service interval and probability of conception

Recent research has indicated that the interval between inseminations in modern dairy cattle is often longer than the commonly accepted cycle length of 18–24 days. This study analysed 257,396 inseminations in 75,745 cows from 312 herds in England and Wales. The interval between subsequent inseminations in the same cow in the same lactation (inter-service interval, ISI) were calculated and inseminations categorised as successful or unsuccessful depending on whether there was a corresponding calving event. Conception risk was calculated for each individual ISI between 16 and 28 days. A random effects logistic regression model was fitted to the data with pregnancy as the outcome variable and ISI (in days) included in the model as a categorical variable. The modal ISI was 22 days and the peak conception risk was 44% for ISIs of 21 days rising from 27% at 16 days. The logistic regression model revealed significant associations of conception risk with ISI as well as 305 day milk yield, insemination number, parity and days in milk. Predicted conception risk was lower for ISIs of 16, 17 and 18 days and higher for ISIs of 20, 21 and 22 days compared to 25 day ISIs. A mixture model was specified to identify clusters in insemination frequency and conception risk for ISIs between 3 and 50 days. A “high conception risk, high insemination frequency” cluster was identified between 19 and 26 days which indicated that this time period was the true latent distribution for ISI with optimal reproductive outcome. These findings suggest that the period of increased numbers of inseminations around 22 days identified in existing work coincides with the period of increased probability of conception and therefore likely represents true return estrus events

Variation in the inter-service intervals of UK dairy cows

An understanding of the normal estrous cycle length of the cow is important when managing and monitoring dairy herd fertility. Whilst the normal inter-ovulatory interval is widely considered to be 21 days, some studies have found alternative intervals to be more prevalent; previously most of the variation in interval length was expected to be between cows. The aim of this study was to assess the time between inseminations (inter-service interval, ISI), in a large number of dairy cows and to explore possible associations between cow factors and estrous cycle length. The study used ISI data from 42,252 cows in 159 herds across England and Wales. Univariate analysis of the subset of 114,572 intervals between 15 and 30 days (a range covering the increased frequency of ISIs occurring at the expected time of the first return to estrus) following an insemination revealed a modal ISI of 22 days. Primiparous heifers had a modal ISI of 21 days. There were significant differences between the distribution of ISIs for different yield groups, parity numbers and the number of inseminations. Multilevel regression modelling was used to evaluate the associations between cow factors and ISI, whilst accounting for clustering at the herd and cow level. This revealed significant associations between predicted ISI and insemination number, days in milk, lactation 305 day milk yield, and month and year of insemination. Variance partition coefficients indicated that only 1% of variation in ISIs was at the herd level, 12% at the animal level and 87% at the insemination level, indicating that cycle length varies substantially more between cycles within a cow than between cows or herds. These findings suggest the “normal” range of ISI for modern UK dairy cows is longer than expected and that there is a large amount of unexplained variation in cycle length within individual animals over time

Are you as important as me? Self-other discrimination within trait-adjective processing

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.bandc.2020.105569. © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Healthy adults typically display enhanced processing for self- (relative to other-) relevant and positive (relative to negative) information. However, it is unclear whether these two biases interact to form a self-positivity bias, whereby self-positive information receives prioritized processing. It is also unclear how a blocked versus mixed referent design impacts reference and valence processing. We addressed these questions using behavioral and electrophysiological indices across two studies using a Self-Referential Encoding Task, followed by surprise recall and recognition tasks. Early (P1) and late (LPP) event-related potentials were time-locked to a series of trait adjectives, encoded relative to oneself or a fictional character, with referent presented in a blocked (Exp. 1) or mixed (Exp. 2) trial design. Regardless of study design, participants recalled and recognized more self- than other-relevant adjectives, and recognized more positive than negative adjectives. Additionally, participants demonstrated larger LPP amplitudes for self-relevant and positive adjectives. The LPP self-relevance effect emerged earlier and persisted longer in the blocked (400–800 ms) versus mixed design (600–800 ms). The LPP valence effect was not apparent in the blocked design, but appeared late in the mixed design (600–1200 ms). Critically, the interaction between self-relevance and valence appeared only behaviorally in the mixed design, suggesting that overall self-relevance and valence independently impact neural socio-cognitive processing.This work was supported by grants from the Natural Sciences and Engineering Research Council of Canada (NSERC Discovery Grant #418431), the Canada Foundation for Innovation (CFI, #213322), and the Canada Research Chair program (CRC #230407) awarded to RJI, and by the Social Science and Humanities Research Council (SSHERC Insight grant #435-2016-0494) awarded to HAH

Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares

The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature and density sensitive line ratios, Doppler shifted emission lines and nonthermal broadening, abundance measurements, differential emission measure profiles, and continuum temperatures and energetics, among others. In this paper I shall review some of the advances made in recent years using these techniques, focusing primarily on studies that have utilized data from Hinode/EIS and SDO/EVE, while also providing some historical background and a summary of future spectroscopic instrumentation.Comment: 34 pages, 8 figures. Submitted to Solar Physics as part of the Topical Issue on Solar and Stellar Flare

Use of early lactation milk recording data to predict the calving to conception interval in dairy herds

Economic success in dairy herds is heavily reliant on obtaining pregnancies at an early stage of lactation. Our objective in this study was to attempt to predict the likelihood of conception occurring by d 100 and 150 of lactation (days in milk, DIM) by Markov chain Monte Carlo analysis using test day milk recording data and reproductive records gathered retrospectively from 8,750 cows from 33 dairy herds located in the United Kingdom. Overall, 65% of cows recalved with 30, 46, and 65% of cows conceiving by 100 DIM, 150 DIM, and beyond 150 DIM, respectively. Overall conception rate (total cows pregnant/total number of inseminations) was 27.47%. Median and mean calving to conception intervals were 123 and 105 d, respectively. The probability of conception by both 100 DIM and 150 DIM was positively associated with the average daily milk weight produced during the fourth week of lactation (W4MK) and protein percentage for test day samples collected between 0 to 30 and 31 to 60 DIM. Butterfat percentage at 0 to 30 DIM was negatively associated with the probability of conception by 100 DIM but not at 150 DIM. High somatic cell count (SCC) at both 0 to 30 and 31 to 60 DIM was negatively associated with the probability of conception by 100 DIM, whereas high SCC at 31 to 60 DIM was associated with a reduced probability of conception by 150 DIM. Increasing parity was associated with a reduced odds of pregnancy. Posterior predictions of the likelihood of conception for cows categorized as having “good” (W4MK >30 kg and protein percentage at 0 to 30 and 31 to 60 DIM >3.2%) or “poor” (W4MK <25 kg and protein percentage at 0 to 30 and 31 to 60 DIM <3.0%) early lactation attributes with actual observed values indicated model fit was good. The predicted likelihood of a “good” cow conceiving by 100 and 150 DIM was 0.39 and 0.57, respectively (actual observed values 0.40 and 0.59). The corresponding values for a “poor” cow were 0.28 and 0.42 (actual observed values 0.26 and 0.37). Predictions of the future reproductive success of cows may be possible using a limited number of early lactation attributes