Novel genetic parameters for genetic residual feed intake in dairy cattle using time series data from multiple parities and countries in North America and Europe.

Residual feed intake is viewed as an important trait in breeding programs that could be used to enhance genetic progress in feed efficiency. In particular, improving feed efficiency could improve both economic and environmental sustainability in the dairy cattle industry. However, data remain sparse, limiting the development of reliable genomic evaluations across lactation and parity for residual feed intake. Here, we estimated novel genetic parameters for genetic residual feed intake (gRFI) across the first, second, and third parity, using a random regression model. Research data on the measured feed intake, milk production, and body weight of 7,379 cows (271,080 records) from 6 countries in 2 continents were shared through the Horizon 2020 project Genomic Management Tools to Optimise Resilience and Efficiency, and the Resilient Dairy Genome Project. The countries included Canada (1,053 cows with 47,130 weekly records), Denmark (1,045 cows with 72,760 weekly records), France (329 cows with 16,888 weekly records), Germany (938 cows with 32,614 weekly records), the Netherlands (2,051 cows with 57,830 weekly records), and United States (1,963 cows with 43,858 weekly records). Each trait had variance components estimated from first to third parity, using a random regression model across countries. Genetic residual feed intake was found to be heritable in all 3 parities, with first parity being predominant (range: 22-34%). Genetic residual feed intake was highly correlated across parities for mid- to late lactation; however, genetic correlation across parities was lower during early lactation, especially when comparing first and third parity. We estimated a genetic correlation of 0.77 ± 0.37 between North America and Europe for dry matter intake at first parity. Published literature on genetic correlations between high input countries/continents for dry matter intake support a high genetic correlation for dry matter intake. In conclusion, our results demonstrate the feasibility of estimating variance components for gRFI across parities, and the value of sharing data on scarce phenotypes across countries. These results can potentially be implemented in genetic evaluations for gRFI in dairy cattle.

Latencies of click-evoked auditory responses in a harbor porpoise exceed the time interval between subsequent echolocation clicks.

Most auditory evoked potential (AEP) studies in echolocating toothed whales measure neural responses to outgoing clicks and returning echoes using short-latency auditory brainstem responses (ABRs) arising a few ms after acoustic stimuli. However, little is known about longer-latency cortical AEPs despite their relevance for understanding echo processing and auditory stream segregation. Here, we used a non-invasive AEP setup with low click repetition rates on a trained harbor porpoise to test the long-standing hypothesis that echo information from distant targets is completely processed before the next click is emitted. We reject this hypothesis by finding reliable click-related AEP peaks with latencies of 90 and 160 ms, which are longer than 99% of click intervals used by echolocating porpoises, demonstrating that some higher-order echo processing continues well after the next click emission even during slow clicking. We propose that some of the echo information, such as range to evasive prey, is used to guide vocal-motor responses within 50-100 ms, but that information used for discrimination and auditory scene analysis is processed more slowly, integrating information over many click-echo pairs. We conclude by showing theoretically that the identified long-latency AEPs may enable hearing sensitivity measurements at frequencies ten times lower than current ABR methods.

Transdiscal instrumentation in single-level lumbosacral fusion for high-grade isthmic pediatric spondylolisthesis: Technical note and review of the literature.

Pediatric spondylolisthesis is a common cause of back pain in children, typically managed conservatively with bracing and non-steroidal anti-inflammatory drugs. When posterolateral fusion is performed for refractory pain, pseudarthrosis and implant failure may occur, necessitating reoperation. To improve patient outcomes, there is a need for alternative surgical techniques to effectively manage high-grade isthmic slips. Here, the authors report the case of a child with Meyerding grade III anterolisthesis of L5 on S1 who was treated with a single-level, instrumented fusion using bilateral S1-L5 transdiscal screws, supported with L5-S1 posterolateral instrumentation and arthrodesis. Postoperatively, there was improvement in the patient's symptoms with good clinical and radiographic outcomes. The patient continues to be symptom free with radiographic evidence of hardware stability and bony fusion across the segment. The authors detail a novel surgical technique in children as well as a review of lumbosacral transdiscal screw fixation. Further evidence is required to definitively establish the safety, outcomes, and biomechanical strength of this technique.

Non-targeted metabolomics of saliva to explore potential biomarkers for gastric ulceration in pigs fed hemp.

Gastric ulceration is a common disease in pig production worldwide and is associated with economic losses as well as animal health and welfare issues. The aim of this study was to explore potential salivary biomarkers for gastric ulceration in pigs. In addition, the aim was to study the effect of hemp on the incidence of gastric ulcers. Approximately 440 growing-finishing pigs in the period from 30 to 110 kg BW were allocated to four different diets: meal feed (Meal); pelleted feed (Pellets); pelleted feed added 4% hempseed cake (Hemp Cake); pelleted feed added 4% hempseed hulls (Hemp Hulls). The day before slaughter, saliva samples from each pig were collected. After slaughter, the stomachs were emptied to assess the consistency of the stomach content and examined for gastric ulceration using an index scale (0-10). Noticeable changes of the gastric mucosa (total index score ≥ 6) were observed in 291 pigs. The odds of having index scores 0-5 relative to index scores 6-8 and 9-10, respectively, were higher (P < 0.001) for pigs fed Meal compared to pigs fed Pellets. The odds of suffering from severe gastric ulcers tended (P = 0.08) to be lower in pigs fed Hemp Hulls compared to pigs fed Pellets. A non-targeted liquid chromatography mass spectrometry based metabolomics analysis was performed on saliva samples to determine any separation between pigs with healthy stomachs and those with gastric ulcers and to examine a possible correlation between gastric ulcer index and potential biomarkers. Partial least-squares discriminant analysis showed a separation between pigs with ulcers and those with healthy stomachs/hyperkeratosis (HK). Metabolites contributing to the separation between groups were identified. Levels of oxylipins deriving from linoleic acid were lower (P < 0.001) in pigs with ulcers compared to healthy/HK pigs. This may indicate a shift in the metabolic pathways towards more pro-inflammatory arachidonic acid-derived eicosanoids, which might reflect an increased inflammatory response. Thus, reduced levels of oxylipins derived from linoleic acid seemed to be associated with active gastric ulcers, and thereby they might function as biomarkers for gastric ulceration in pigs. In addition, supplementation of hempseed hulls had a beneficial effect on severe gastric ulcers, as hempseed hulls changed the consistency of the gastric content by conferring more solidness. However, it was not possible to observe any reliable separation between pigs fed pellets supplemented with hemp products and pigs fed non-supplemented pellets according to the identified salivary metabolites.

Cardiovascular function in 8- to 9-year-old singletons born after ART with frozen and fresh embryo transfer.

STUDY QUESTION: Do 8- to 9-year-old singletons conceived after frozen embryo transfer (FET) or fresh embryo transfer (Fresh-ET) have increased arterial stiffness compared to naturally conceived (NC) children? SUMMARY ANSWER: The process of FET or Fresh-ET is not associated with altered cardiovascular function in 8- to 9-year-old singletons, including arterial stiffness, as compared to NC children. WHAT IS KNOWN ALREADY: ART has been suggested to influence cardiovascular risk factors (i.e. endothelial dysfunction, increased arterial blood pressure and insulin resistance). It is not known if ART procedures alter arterial stiffness in singletons. STUDY DESIGN, SIZE, DURATION: A cohort study was carried out, including 8- to 9-year-old singletons conceived after FET, Fresh-ET and NC children (50 children in each group). This study was conducted between November 2018 and August 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS: In total, 150 singletons were identified through the Danish IVF Registry and the Medical Birth Registry. They underwent cardiac magnetic resonance imaging (CMR) and anthropometric measurements. Parental data were collected using questionnaires. NC children were matched by sex and birth year with FET/Fresh-ET children. Exclusion criteria were congenital heart disease, maternal gestational diabetes or maternal diabetes mellitus. Our primary outcome was arterial stiffness, which is assessed from noninvasive arterial blood pressure and aortic ascendens distensibility. The secondary outcome was the pulse wave velocity of total aorta and exploratory outcomes were left ventricular ejection fraction, mean arterial pressure, cardiac output and total peripheral resistance. Measurements and analyses were performed blinded to the child group. MAIN RESULTS AND THE ROLE OF CHANCE: Aortic ascendens distensibility of children conceived after FET and Fresh-ET did not differ from NC children (mean (SD): FET 11.1 (3.6) 10-3 mmHg-1, Fresh-ET 11.8 (3.0) 10-3 mmHg-1, NC 11.4 (2.8) 10-3 mmHg-1, P > 0.05). Multivariate linear regression was performed to adjust for potential confounders (i.e. child sex and age, maternal BMI at early pregnancy and maternal educational level). Data showed no statistically significant differences between study groups and aortic ascendens distensibility. However, the fully adjusted model showed a non-significant tendency of lowered aortic ascendens distensibility in children born after FET compared to Fresh-ET (ß estimate (95% CI): -0.99 10-3 mmHg-1 (-2.20; 0.21)) and NC children (ß estimate (95% CI): -0.77 10-3 mmHg-1 (-1.98; 0.44)). Lastly, secondary and exploratory outcomes did not differ between the groups. Primary and secondary outcomes showed good intra-rater reliability. LIMITATIONS, REASONS FOR CAUTION: This study is possibly limited by potential selection bias as the participation rate was higher in the ART compared to the NC group. Also, in some variables, the study groups differed slightly from the non-participant population. The non-participant population (n = 1770) included those who were excluded, not invited to CMR scan, or declined to participate in this study. WIDER IMPLICATIONS OF THE FINDINGS: Our findings indicate that children born after FET or Fresh-ET do not have altered cardiovascular function, including arterial stiffness. This is reassuring for the future use of ART. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Novo Nordisk Foundation (grant reference number: NNF19OC0054340) and The Research Foundation of Rigshospitalet. All authors declared no conflict of interests. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT03719703.

Echolocation click parameters of short-finned pilot whales (Globicephala macrorhynchus) in the wild.

Short-finned pilot whales (Globicephala macrorhynchus) are large, deep-diving predators with diverse foraging strategies, but little is known about their echolocation. To quantify the source properties of short-finned pilot whale clicks, we made 15 deployments off the coast of Tenerife of a deep-water hydrophone array consisting of seven autonomous time-synced hydrophone recorders (SoundTraps), enabling acoustic localization and quantification of click source parameters. Of 8185 recorded pilot whale clicks, 47 were classified as being recorded on-axis, with a mean peak-to-peak source level (SL) of 181 ± 7 dB re 1 µPa, a centroid frequency of 40 ± 4 kHz, and a duration of 57 ± 23 µs. A fit to a piston model yielded an estimated half-power (-3 dB) beam width of 13.7° [95% confidence interval (CI) 13.2°-14.5°] and a mean directivity index (DI) of 22.6 dB (95% CI 22.5-22.9 dB). These measured SLs and DIs are surprisingly low for a deep-diving toothed whale, suggesting we sampled the short-finned pilot whales in a context with little need for operating a long-range biosonar. The substantial spectral overlap with beaked whale clicks emitted in similar deep-water habitats implies that pilot whale clicks may constitute a common source of false detections in beaked whale passive acoustic monitoring efforts.

The largest of August Krogh animals: Physiology and biomechanics of the blue whale revisited.

The blue whale is the largest animal ever. This gigantism probably evolved to exploit seasonal krill blooms, where massive feasts allow for accumulation of large blubber reserves that can fuel their low mass specific metabolism during prolonged periods of fasting. Until recently, the physiology and biomechanics of blue whales could only be inferred from anatomical inspections, but the recent development of biologging tags now provide unique insights into how these ocean giants function and interact with their environment. Their mandibles, the largest bones ever to evolve, along with a highly expandable buccal cavity, enable an extreme and dynamic bulk feeding behavior. During a lunge feeding event, blue whales accelerate up to 5 m/s to engulf a volume prey laden water that is commensurate with the whale's gigantic body size. Perhaps due to the costs of such extreme foraging, their dive times of 10-15 min are much shorter than scaling would predict for their size. Like other diving animals, blue whales display a dive response with heart rates down to 4 BPM to prolong dive times and perhaps mitigate decompression sickness. Blue whales make the lowest and most energetic calls of any mammal with ocean traversing potential under natural ambient noise conditions. However, communication space may be severely reduced due to pervasive shipping noise. We hope that an increasing ability to study the physiology and behavior of blue whales and other marine megafauna will enable informed decisions and ensure our permanent co-existence in the face of increasing human encroachment into marine habitats.

Why whales are big but not bigger: Physiological drivers and ecological limits in the age of ocean giants.

The largest animals are marine filter feeders, but the underlying mechanism of their large size remains unexplained. We measured feeding performance and prey quality to demonstrate how whale gigantism is driven by the interplay of prey abundance and harvesting mechanisms that increase prey capture rates and energy intake. The foraging efficiency of toothed whales that feed on single prey is constrained by the abundance of large prey, whereas filter-feeding baleen whales seasonally exploit vast swarms of small prey at high efficiencies. Given temporally and spatially aggregated prey, filter feeding provides an evolutionary pathway to extremes in body size that are not available to lineages that must feed on one prey at a time. Maximum size in filter feeders is likely constrained by prey availability across space and time.

Danish experience of meticillin-resistant Staphylococcus aureus eradication with emphasis on nose-throat colonization and supplementary systemic antibiotic treatment.

This study aimed to evaluate the Danish Board of Health's guidance for treating the carriage of meticillin-resistant Staphylococcus aureus (MRSA), focusing on nose-throat carriage and use of supplementary systemic antibiotics. The results of MRSA eradication treatment among 358 patients were analysed, focusing on those with nose (N=58) or throat (N=183) MRSA colonization. The Danish guidance for MRSA treatment was found to be more successful in patients with nose colonization (66%) compared with throat colonization (41%), despite the fact that the cumulative eradication rates were equal after three treatment cycles (71% vs 73%). This study found that supplementation of colonization treatment with systemic antibiotics does not have a positive effect.

Why still in hospital after laparoscopic colorectal surgery within an enhanced recovery programme?

AIM: Enhanced recovery after surgery programmes in elective colorectal surgery have been developed and implemented widely, but a subgroup of patients may still require longer hospital stays than expected. The aim of this study was to identify and describe factors compromising early postoperative recovery by asking 'why is the patient still in hospital today?' after laparoscopic colorectal cancer surgery within an enhanced recovery after surgery programme. METHOD: Patients undergoing elective laparoscopic colorectal cancer resection were evaluated postoperatively with predefined potential reasons for still being in hospital. The primary outcome was 'reason for still being in hospital' on postoperative day 0-4 and secondarily length of stay with a focus on differences between patients with and without a stoma. RESULTS: Ninety-six patients having colorectal cancer surgery were included. The median length of stay for the whole group was 3 days (range 1-14). The four dominant causes for patients without a stoma to be in hospital were lack of gastrointestinal function, lack of early mobilization, lack of normal micturition and nausea. Patients with a stoma stayed in hospital due to stoma training, lack of gastrointestinal function, lack of free micturition and a miscellaneous 'others' group. CONCLUSION: Delayed gastrointestinal function, insufficient mobilization, poor urinary function and stoma care training have been characterized as dominant compromising factors for postoperative recovery. Together with a focus on frailty, future studies should focus on improving early mobilization, prevention and treatment of postoperative urinary retention and improved stoma care training, in order to minimize delay in postoperative recovery and discharge.

Hypoxaemia during recovery after surgery for colorectal cancer: a prospective observational study.

Episodic and ongoing hypoxaemia are well-described after surgery, but, to date, no studies have investigated the occurrence of episodic hypoxaemia following minimally-invasive colorectal surgery performed in an enhanced recovery setting. We aimed to describe the occurrence of postoperative hypoxaemia after minimally-invasive surgery in an enhanced recovery setting, and the association with morphine use, incision site, fluid intake and troponin increase. We performed a prospective observational study of 85 patients undergoing minimally-invasive surgery for colorectal cancer between 25 August 2016 and 17 August 2017. We applied a pulse oximeter with a measurement rate of 1 Hz immediately after surgery either until discharge or until two days after surgery, and recorded the oxygen saturation. We measured troponin I during the first four days after surgery, or until discharge. The median (IQR [range]) length of stay was 3 (2-4 [1-38]) days. Thirty-six percent of patients spent more than 1 h below an oxygen saturation of 90% (4.2% of the day), and with a median (IQR [range]) proportion of 1.3 (0.2-11.1 [0.0-21.4])% of the day spent with an oxygen saturation below 88%. We found no associations between time spent below an oxygen saturation of 88% and morphine use (p = 0.215), fluid intake (p = 0.446), complications (p = 0.808) or extraction site (p = 0.623). Postoperative increases in troponin I were associated both with time spent below an oxygen saturation of 88% (p = 0.026) and hypopnoea episodes (p = 0.003). Even with minimally-invasive surgery and enhanced recovery after surgery, episodic hypoxaemia and hypopnoea episodes are common, but are not associated with morphine use, fluid intake or incision site. Further studies should investigate the relationship between hypoxaemia and troponin increase.

Low energy expenditure and resting behaviour of humpback whale mother-calf pairs highlights conservation importance of sheltered breeding areas.

Understanding the behaviour of humpback whale mother-calf pairs and the acoustic environment on their breeding grounds is fundamental to assessing the biological and ecological requirements needed to ensure a successful migration and survival of calves. Therefore, on a breeding/resting ground, Exmouth Gulf, Western Australia, we used animal-borne DTAGs to quantify the fine-scale behaviour and energetic expenditure of humpback whale mothers and calves, while sound recorders measured the acoustic environment. We show that: (i) lactating humpback whales keep their energy expenditure low by devoting a significant amount of time to rest, and their use of energy, inferred from respiration rates, is ~half than that of adults on their foraging grounds; (ii) lactating females mainly rest while stationary at shallow depths within reach of the hull of commercial ships, thus increasing the potential for ship strike collisions; (iii) the soundscape is dominated by biological sources; and (iv) even moderate increases of noise from vessels will decrease the communication range of humpback whales. Planned commercial infrastructure in Exmouth Gulf will cause a substantial increase in shipping traffic with the risk of ship strikes and acoustic disturbance potentially compromising energy reserves for the southern migration of humpback whales.

Basin-wide contributions to the underwater soundscape by multiple seismic surveys with implications for marine mammals in Baffin Bay, Greenland.

Seismic surveys increasingly operate in deeper Arctic waters with propagation conditions and marine mammal fauna different from the better-studied temperate, or shallow-water, regions. Using 31 calibrated sound recorders, we quantified noise contributions from four concurrent seismic surveys in Baffin Bay, Greenland, to estimate their potential impacts on marine mammals. The impact was cumulative as the noise level rose in response to the onset of each survey: on a minute-by-minute scale the sound-exposure-levels varied by up to 70 dB (20 dB on average), depending on range to the seismic vessel, local bathymetry effects and interference patterns, representing a significant change in the auditory scene for marine mammals. Airgun pulse energy did not decrease to ambient before arrival of the next pulse leaving very little low-frequency masking-free time. Overall, the measured values matched well with pre-season-modeling, emphasizing the importance of noise-modeling in impact assessments, if responses of focal marine mammals are known.

Short communication: Multivariate outlier detection for routine Nordic dairy cattle genetic evaluation in the Nordic Holstein and Red population.

It is of practical importance to ensure the data quality from a milk-recording system before use for genetic evaluation. A procedure was developed for detection of multivariate outliers based on an approximation for Mahalanobis distance and was implemented in the Nordic Holstein and Red population. The general target of this procedure is based on the Nordic Cattle Genetic Evaluation yield model, which is a 9-trait model for milk, protein, and fat in the first 3 lactations. The procedure is based on the phenotypic correlation structure as a function of days in milk (DIM) and on computation of trait means and standard deviations within a production year, lactation, and DIM. For each record in the data, a Mahalanobis distance value was computed based on the trait mean and the covariance matrix for the actual production year, lactation, and DIM. A set of cutoff values, ranging from 10 to 100 with steps of 10, for discarding multivariate outliers was investigated. Prediction accuracy was calculated as the Pearson correlations between estimated breeding values predicted by full data set and estimated breeding values predicted by reduced data set for cows without records in the reduced data set and with 1 or more records deleted due to the editing rules on Mahalanobis distance. The results showed that, averaged over all scenarios, gains of 0.005 to 0.048 on prediction accuracy have been obtained by deleting the multivariate outliers. The improvements were more profound for progeny of young bulls compared with progeny of proven bulls. It is easy to implement this multivariate outlier-detection procedure in the routine genetic evaluation for different dairy cattle breeds; however, an optimal cutoff value for Mahalanobis distance needs to be defined to achieve an acceptable compromise between genetic evaluation accuracy and data deletion.

Short communication: Genomic prediction using different single-step methods in the Finnish red dairy cattle population.

Single-step genomic prediction models utilizing both genotyped and nongenotyped animals are likely to become the prevailing tool in genetic evaluations of livestock. Various single-step prediction models have been proposed, based either on estimation of individual marker effects or on direct prediction via a genomic relationship matrix. In this study, a classical pedigree-based animal model, a regular single-step genomic BLUP (ssGBLUP) model, algorithm for proven and young (APY) with 2 strategies for choosing core animals, and a single-step Bayesian regression (ssBR) model were compared for 305-d production traits (milk, fat, protein) in the Finnish red dairy cattle population. A residual polygenic effect with 10% of total genetic variance was included in the single-step models to reduce inflation of genomic predictions. Validation reliability was calculated as the squared Pearson correlation coefficient between genomically enhanced breeding value (GEBV) and yield deviation for masked records for 2,056 validation cows from the last year in the data set investigated. The results showed that gains of 0.02 to 0.04 on validation reliability were achieved by using single-step methods compared with the classical animal model. The regular ssGBLUP model and ssBR model with an extra polygenic effect yielded the same results. The APY methods yielded similar reliabilities as the regular ssGBLUP and ssBR. Exact prediction error variance of GEBV could be obtained by ssBR to avoid any approximation methods used for ssGBLUP when inversion left-hand side of mixed model equations is computationally infeasible for large data sets.

The evolution of foraging capacity and gigantism in cetaceans.

The extant diversity and rich fossil record of cetaceans provides an extraordinary evolutionary context for investigating the relationship between form, function and ecology. The transition from terrestrial to marine ecosystems is associated with a complex suite of morphological and physiological adaptations that were required for a fully aquatic mammalian life history. Two specific functional innovations that characterize the two great clades of cetaceans, echolocation in toothed whales (Odontoceti) and filter feeding in baleen whales (Mysticeti), provide a powerful comparative framework for integrative studies. Both clades exhibit gigantism in multiple species, but we posit that large body size may have evolved for different reasons and in response to different ecosystem conditions. Although these foraging adaptations have been studied using a combination of experimental and tagging studies, the precise functional drivers and consequences of morphological change within and among these lineages remain less understood. Future studies that focus at the interface of physiology, ecology and paleontology will help elucidate how cetaceans became the largest predators in aquatic ecosystems worldwide.

Click communication in wild harbour porpoises (Phocoena phocoena).

Social delphinids employ a vocal repertoire of clicks for echolocation and whistles for communication. Conversely, the less social and acoustically cryptic harbour porpoises (Phocoena phocoena) only produce narrow-band high-frequency (NBHF) clicks with properties that appear poorly suited for communication. Nevertheless, these small odontocetes likely mediate social interactions, such as mate choice and mother-calf contact, with sound. Here, we deployed six tags (DTAG3) on wild porpoises in Danish waters for a total of 96 hours to investigate if the patterns and use of stereotyped NBHF click trains are consistent with a communication function. We show that wild porpoises produce frequent (up to 27 • min-1), high-repetition rate click series with repetition rates and output levels different from those of foraging buzzes. These sounds are produced in bouts and frequently co-occur with emission of similar sounds by nearby conspecifics, audible on the tags for >10% of the time. These results suggest that social interactions are more important to this species than their limited social encounters at the surface may indicate and that these interactions are mediated by at least two broad categories of calls composed of short, high-repetition rate click trains that may encode information via the repetition rate of their stereotyped NBHF clicks.

Treatment of acute myocardial infarction in the sub-arctic region of Norway. Do we offer an equal quality of care?

Patients, relatives, healthcare workers and administrators are concerned about the quality of care offered. We aimed to explore the treatment of acute myocatrdial infarction (AMI) in Northern Norway, compare it with the national figures, and document whether there is an equal quality of care or not. The retrospective study included data on patients' treatment for AMI. The following sources were employed. The Norwegian Patient Registry, National Quality of Care Database, Norwegian Myocardial Infarction Registry and data from the National Air Ambulance Services of Norway. The period 2012-2014/15 was studied and the variables were: incidence of AMI, gender and age adjusted rates of AMI and revascularization (PCI, CABG) based on patient's place of living (according to hospital catchment area) and 30-day survival rate. The annual incidence of AMI was 9% higher in the northern region. Significant incidence variations (2.7-5.9 AMI/1000 inhabitants) between the hospitals' catchment areas were revealed. The 30-day survival rate varied between 85.1-92.1% between hospitals. The variation in revascularization/AMI rate was 0.72-1.54. Air amublance services' availability varied through the day. In conclusion, significant variations in the AMI rate and an unequal service within the region was revealed.

Estimation of genetic parameters and heterosis for longevity in crossbred Danish dairy cattle.

Crossbreeding has been shown to improve the longevity of dairy cattle in countries across the world. The aim of this study was to estimate heterosis, breed effects, and genetic parameters for longevity in crossbred dairy cattle among Danish Holstein (DH), Danish Red (DR), and Danish Jersey (DJ) breeds. Data were provided from 119 Danish commercial herds that use systematic crossbreeding (i.e., rotational crossbreeding). Additional data from 11 mixed-breed herds with DH and DJ were included to estimate reliable breed effects for DJ. Survival information on 73,741 cows was analyzed with a linear animal model using the artificial insemination-REML algorithm in the DMU package. Five longevity (L) traits were defined: days from first calving until the end of first lactation or culling (L1), days from first calving until the end of second lactation or culling (L2), days from first calving until the end of third lactation or culling (L3), days from first calving until the end of fourth lactation or culling (L4), and days from first calving until the end of fifth lactation or culling (L5). Heritabilities ranged between 0.022 and 0.090. Additive breed effects in units of days were estimated relative to DH for DR as -0.5 (L1), +10.5 (L2), +18.5 (L3), +11.9 (L4), and +28.6 (L5), and corresponding figures for DJ were +2.0, +0.5, +14.2, +27.7, and +44.0. Heterosis effects in L1 were low (1.2%) but favorable in crosses between DH and DR, whereas negative heterosis effects were estimated for crosses between DH and DJ (-2.5%) and DR and DJ (-1.2%). The largest heterosis effects for L2, L3, L4, and L5 were found in DH × DR and were favorable (+3.3, +5.7, +7.7, and +8.5%, respectively). Corresponding figures for heterosis effects in DH × DJ and DR × DJ were favorable as well: +2.3, +4.1, +5.6, and +6.2% in DH × DJ and +3.1, +7.3, +6.9, and +7.2% in DR × DJ. The favorable heterosis effects show that crossbreeding is an efficient tool for improving longevity in Danish dairy cattle.