Sex estimation research trends in forensic anthropology between 2000 and 2022 in five prominent journals.

In forensic anthropology, osteological sex estimation methods are continuously reevaluated and updated to improve classification accuracies. Therefore, to gain a comprehensive understanding of recent trends in sex estimation research in forensic anthropology, a content analysis of articles published between 2000 and 2022 in Forensic Science International, the Journal of Forensic Sciences, the International Journal of Legal Medicine, the American Journal of Biological Anthropology, and Forensic Anthropology, was performed. The main goals of this content analysis were to (1) examine trends in metric versus morphological research, (2) examine which areas of the skeleton have been explored, (3) examine which skeletal collections and population affinities have been most frequently utilized, and (4) determine which statistical methods were commonly implemented. A total of 440 articles were coded utilizing MAXQDA and the resulting codes were exported for analysis. Statistical analyses were conducted utilizing the Cochran-Armitage and Jonckheere-Terpstra tests for trends, as well as Fisher-Freeman-Halton tests. The results demonstrate that sex estimation research published in these journals has prioritized metric over morphological methods. Further, the most utilized skeletal regions continue to be the skull and pelvis, while the most popular classification statistics continue to be discriminant function analysis and logistic regression. This study also demonstrates that a substantial portion of research has been conducted utilizing U.S. and Europe-based collections and limited populations. Based on these results, future sex estimation research must continue exploring the use of long bones and other postcranial elements, testing newer methods of analysis, as well as developing population-inclusive methods.

Inhibitory medial zona incerta pathway drives exploratory behavior by inhibiting glutamatergic cuneiform neurons.

The cuneiform nucleus (CnF) regulates locomotor activity, which is canonically viewed as being primarily involved in initiating locomotion and regulating speed. Recent research shows greater context dependency in the locomotor functions of this nucleus. Glutamatergic neurons, which contain vesicular glutamate transporter 2 (vGLUT2), regulate context-dependent locomotor speed in the CnF and play a role in defensive behavior. Here, we identify projections from the medial zona incerta (mZI) to CnF vGLUT2 neurons that promote exploratory behavior. Using fiber photometry recordings in male mice, we find that mZI gamma-aminobutyric acid (GABA) neurons increase activity during periods of exploration. Activation of mZI GABAergic neurons is associated with reduced spiking of CnF neurons. Additionally, activating both retrogradely labeled mZI-CnF GABAergic projection neurons and their terminals in the CnF increase exploratory behavior. Inhibiting CnF vGLUT2 neuronal activity also increases exploratory behavior. These findings provide evidence for the context-dependent dynamic regulation of CnF vGLUT2 neurons, with the mZI-CnF circuit shaping exploratory behavior.

Genetic covariance components for measures of nitrogen utilization in grazing dairy cows.

Improved nitrogen utilization of dairy production systems should improve not only the economic output of the systems but also the environmental metrics. One strategy to improve efficiency is through breeding programs. Improving a trait through breeding is conditional on the presence of exploitable genetic variability. Using a database of 1,291 deeply phenotyped grazing dairy cows, the genetic variability for 2 definitions of nitrogen utilization was studied: nitrogen use efficiency (i.e., nitrogen output in milk and meat divided by nitrogen available) and nitrogen balance (i.e., nitrogen available less nitrogen output in milk and meat). Variance components for both variables were estimated using animal repeatability linear mixed models. Genetic variability was detected for both nitrogen utilization metrics, even though their heritability estimates were low (<0.10). Validation of genetic evaluations revealed that animals divergent for nitrogen use efficiency or nitrogen balance indeed differed phenotypically, further demonstrating that breeding for improved nitrogen efficiency should result in a shift in the population mean toward better efficiency. Nitrogen use efficiency and nitrogen balance were not genetically correlated with each other (<|0.28|), and neither metric was correlated with milk urea nitrogen (<|0.12|). Nitrogen balance was unfavorably correlated with milk yield, showing the importance of including the nitrogen utilization metrics in a breeding index to improve nitrogen utilization without negatively impacting milk yield. In conclusion, improvement of nitrogen utilization through breeding is possible, even if more nitrogen utilization phenotypic data need to be collected to improve the selection accuracy considering the low heritability estimates.

Cow-level factors associated with nitrogen utilization in grazing dairy cows using a cross-sectional analysis of a large database.

Reducing nitrogen pollution while maintaining milk production is a major challenge of dairy production. One of the keys to delivering on this challenge is to improve the efficiency of how dairy cows use nitrogen. Thus, estimating the nitrogen utilization of lactating grazing dairy cows and exploring the association between animal factors and productivity with nitrogen utilization are the first steps to understanding the nitrogen utilization complex in dairy cows. Nitrogen utilization metrics were derived from milk and body weight records from 1,291 grazing dairy cows of multiple breeds and crossbreeds; all cows had sporadic information on nitrogen intake concurrent with information on nitrogen sinks (and other nitrogen sources, such as body tissue mobilization). Several nitrogen utilization metrics were investigated, including nitrogen use efficiency (nitrogen output as products such as milk and meat divided by nitrogen intake) and nitrogen excreted (nitrogen intake less the nitrogen output as products such as milk and meat). In the present study, a primiparous Holstein-Friesian used, on average, 20.6% of the nitrogen it ate, excreting the surplus as feces and urine, representing 402 g of nitrogen per day. Intercow variability existed, with a between-cow standard deviation of 0.0094 for nitrogen use efficiency and 24 g of nitrogen per day for nitrogen excretion. As lactation progressed, nitrogen use efficiency declined and nitrogen excretion increased. Nevertheless, nitrogen use efficiency improved (i.e., decreased) from first to second parity, even though it did not improve from second to third parity or greater. Furthermore, nitrogen excretion continued to increase from first to third parity or greater. Nitrogen use efficiency and nitrogen excretion were negatively correlated (-0.56 to -0.40), signifying that dairy cows who partition more of the ingested nitrogen into products such as milk and meat, on average, also excrete less nitrogen. Milk urea nitrogen was, at best, weakly correlated with nitrogen use efficiency and nitrogen excretion; the correlations were between -0.01 and 0.06. In conclusion, several cow-level factors such as parity, stage of lactation, and breed were associated with the range of different nitrogen efficiency metrics investigated; moreover, even after accounting for such effects, 4.8% to 6.3% of the remaining variation in the nitrogen use efficiency and nitrogen balance metrics were attributable to intercow differences.

Examining the long-term effects of traumatic brain injury on fear extinction in male rats.

There is a strong association between traumatic brain injuries (TBIs) and the development of psychiatric disorders, including post-traumatic stress disorder (PTSD). Exposure-based therapy is a first-line intervention for individuals who suffer from PTSD and other anxiety-related disorders; however, up to 50% of individuals with PTSD do not respond well to this approach. Fear extinction, a core mechanism underlying exposure-based therapy, is a procedure in which a repeated presentation of a conditioned stimulus in the absence of an unconditioned stimulus leads to a decrease in fear expression, and is a useful tool to better understand exposure-based therapy. Identifying predictors of extinction would be useful in developing alternative treatments for the non-responders. We recently found that CO2 reactivity predicts extinction phenotypes in rats, likely through the activation of orexin receptors in the lateral hypothalamus. While studies have reported mixed results in extinction of fear after TBI, none have examined the long-term durability of this phenotype in the more chronically injured brain. Here we tested the hypothesis that TBI results in a long-term deficit in fear extinction, and that CO2 reactivity would be predictive of this extinction phenotype. Isoflurane-anesthetized adult male rats received TBI (n = 59) (produced by a controlled cortical impactor) or sham surgery (n = 29). One month post-injury or sham surgery, rats underwent a CO2 or air challenge, followed by fear conditioning, extinction, and fear expression testing. TBI rats exposed to CO2 (TBI-CO2) showed no difference during extinction or fear expression relative to shams exposed to CO2 (sham-CO2). However, TBI-CO2 rats, showed significantly better fear expression than TBI rats exposed to air (TBI-air). In contrast to previous findings, we observed no relationship between CO2 reactivity and post-extinction fear expression in either the sham or TBI rats. However, compared to the previously observed naïve sample, we observed more variability in post-extinction fear expression but a very similar distribution of CO2 reactivity in the current sample. Isoflurane anesthesia may lead to interoceptive threat habituation, possibly via action on orexin receptors in the lateral hypothalamus, and may interact with CO2 exposure, resulting in enhanced extinction. Future work will directly test this possibility.

Real-world implementation of non-endoscopic triage testing for Barrett's oesophagus during COVID-19.

BACKGROUND: The Coronavirus pandemic (COVID-19) curtailed endoscopy services, adding to diagnostic backlogs. Building on trial evidence for a non-endoscopic oesophageal cell collection device coupled with biomarkers (Cytosponge), an implementation pilot was launched for patients on waiting lists for reflux and Barrett's oesophagus surveillance. AIMS: (i) To review reflux referral patterns and Barrett's surveillance practices. (ii) To evaluate the range of Cytosponge findings and impact on endoscopy services. DESIGN AND METHODS: Cytosponge data from centralized laboratory processing (trefoil factor 3 (TFF3) for intestinal metaplasia (IM), haematoxylin & eosin for cellular atypia and p53 for dysplasia) over a 2-year period were included. RESULTS: A total of 10 577 procedures were performed in 61 hospitals in England and Scotland, of which 92.5% (N = 9784/10 577) were sufficient for analysis. In the reflux cohort (N = 4074 with gastro-oesophageal junction sampling), 14.7% had one or more positive biomarkers (TFF3: 13.6% (N = 550/4056), p53: 0.5% (21/3974), atypia: 1.5% (N = 63/4071)), requiring endoscopy. Among samples from individuals undergoing Barrett's surveillance (N = 5710 with sufficient gland groups), TFF3-positivity increased with segment length (odds ratio = 1.37 per cm (95% confidence interval: 1.33-1.41, P < 0.001)). Some surveillance referrals (21.5%, N = 1175/5471) had ≤1 cm segment length, of which 65.9% (707/1073) were TFF3 negative. Of all surveillance procedures, 8.3% had dysplastic biomarkers (4.0% (N = 225/5630) for p53 and 7.6% (N = 430/5694) for atypia), increasing to 11.8% (N = 420/3552) in TFF3+ cases with confirmed IM and 19.7% (N = 58/294) in ultra-long segments. CONCLUSIONS: Cytosponge-biomarker tests enabled targeting of endoscopy services to higher-risk individuals, whereas those with TFF3 negative ultra-short segments could be reconsidered regarding their Barrett's oesophagus status and surveillance requirements. Long-term follow-up will be important in these cohorts.

The dynamic interplay between sleep and mood: an intensive longitudinal study of individuals with bipolar disorder.

BACKGROUND: Sleep disturbances are important symptoms to monitor in people with bipolar disorder (BD) but the precise longitudinal relationships between sleep and mood remain unclear. We aimed to examine associations between stable and dynamic aspects of sleep and mood in people with BD, and assess individual differences in the strength of these associations. METHODS: Participants (N = 649) with BD-I (N = 400) and BD-II (N = 249) provided weekly self-reports of insomnia, depression and (hypo)mania symptoms using the True Colours online monitoring tool for 21 months. Dynamic structural equation models were used to examine the interplay between weekly reports of insomnia and mood. The effects of clinical and demographic characteristics on associations were also assessed. RESULTS: Increased variability in insomnia symptoms was associated with increased mood variability. In the sample as a whole, we found strong evidence of bidirectional relationships between insomnia and depressive symptoms but only weak support for bidirectional relationships between insomnia and (hypo)manic symptoms. We found substantial variability between participants in the strength of prospective associations between insomnia and mood, which depended on age, gender, bipolar subtype, and a history of rapid cycling. CONCLUSIONS: Our results highlight the importance of monitoring sleep in people with BD. However, researchers and clinicians investigating the association between sleep and mood should consider subgroup differences in this relationship. Advances in digital technology mean that intensive longitudinal data on sleep and mood are becoming increasingly available. Novel methods to analyse these data present an exciting opportunity for furthering our understanding of BD.

Genetic risk for schizophrenia is associated with increased proportion of indirect connections in brain networks revealed by a semi-metric analysis: evidence from population sample stratified for polygenic risk.

Research studies based on tractography have revealed a prominent reduction of asymmetry in some key white-matter tracts in schizophrenia (SCZ). However, we know little about the influence of common genetic risk factors for SCZ on the efficiency of routing on structural brain networks (SBNs). Here, we use a novel recall-by-genotype approach, where we sample young adults from a population-based cohort (ALSPAC:N genotyped = 8,365) based on their burden of common SCZ risk alleles as defined by polygenic risk score (PRS). We compared 181 individuals at extremes of low (N = 91) or high (N = 90) SCZ-PRS under a robust diffusion MRI-based graph theoretical SBN framework. We applied a semi-metric analysis revealing higher SMR values for the high SCZ-PRS group compared with the low SCZ-PRS group in the left hemisphere. Furthermore, a hemispheric asymmetry index showed a higher leftward preponderance of indirect connections for the high SCZ-PRS group compared with the low SCZ-PRS group (PFDR < 0.05). These findings might indicate less efficient structural connectivity in the higher genetic risk group. This is the first study in a population-based sample that reveals differences in the efficiency of SBNs associated with common genetic risk variants for SCZ.

Selective effects of acute and chronic stress on slow and alpha-theta cortical functional connectivity and reversal with subanesthetic ketamine.

Anxious, depressive, traumatic, and other stress-related disorders are associated with large scale brain network functional connectivity changes, yet the relationship between acute stress effects and the emergence of persistent large scale network reorganization is unclear. Using male Thy 1-jRGECO1a transgenic mice, we repeatedly sampled mesoscale cortical calcium activity across dorsal neocortex. First, mice were imaged in a homecage control condition, followed by an acute foot-shock stress, a chronic variable stress protocol, an acute on chronic foot-shock stress, and finally treatment with the prototype rapid acting antidepressant ketamine or vehicle. We derived functional connectivity metrics and network efficiency in two activity bands, namely slow cortical activity (0.3-4 Hz) and theta-alpha cortical activity (4-15 Hz). Compared to homecage control, an acute foot-shock stress induced widespread increases in cortical functional connectivity and network efficiency in the 4-15 Hz temporal band before normalizing after 24 h. Conversely, chronic stress produced a selective increase in between-module functional connectivity and network efficiency in the 0.3-4 Hz band, which was reversed after treatment with the rapid acting antidepressant ketamine. The functional connectivity changes induced by acute stress in the 4-15 Hz band were strongly related to those in the slow band after chronic stress, as well as the selective effects of subanesthetic ketamine. Together, this data indicates that stress induces functional connectivity changes with spatiotemporal features that link acute stress, persistent network reorganization after chronic stress, and treatment effects.

Culturally adapted digital mental health interventions for ethnic/racial minorities: A systematic review and meta-analysis.

OBJECTIVE: Digital mental health interventions (DMHIs) are typically designed as "one-size fits all" which may perpetuate health disparities for racialized minorities. This systematic review identified culturally adapted DMHIs and examined their efficacy and acceptability among racial and ethnic minorities. METHOD: PsycINFO, Web of Science, and Pubmed databases were searched between 2000 and 2021. Studies that examined the development or impact of a culturally adapted DMHI for racial or ethnic minority populations using quantitative and/or qualitative methodologies were included. Meta-analyses explored the efficacy of DMHIs, and moderator analyses were used to identify differences in effect sizes due to study quality, clinical outcomes, therapist support, and attrition. RESULTS: Thirty-two studies met inclusion criteria and were reviewed. DMHIs were deemed acceptable and feasible in most studies (n = 24). Among eligible randomized controlled studies (n = 12) comprising 653 participants, results indicated that culturally adapted DMHIs produced a large, positive, significant effect (g = 0.90) across a range of outcomes when compared to wait-list and treatment as usual control conditions. The average attrition rate per study was 42%, and most participants did not complete all modules despite reporting high satisfaction. CONCLUSIONS: Culturally adapted DMHIs are efficacious and acceptable. Such interventions represent a powerful opportunity to circumvent barriers to mental health treatment and improve mental health equity among racially and ethnically minoritized communities. However, the prevalence of feasibility studies, lack of active comparison treatments-and limited research for Black and Indigenous populations-indicate that more research is needed to achieve this purpose. Recommendations are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Fabrication of asymmetrical morpholine phthalocyanines conjugated chitosan-polyacrylonitrile nanofibers for improved photodynamic antimicrobial chemotherapy activity.

The work is based on the synthesis and photodynamic antimicrobial chemotherapy (PACT) activities of neutral (1 and 2) and cationic (1Q and 2Q) morpholine substituted phthalocyanines. For applicability, these complexes were covalently linked to modified polyacrylonitrile (PAN) to form 1-PAN, 2-PAN, 1Q-PAN, and 2Q-PAN, respectively. Chitosan was conjugated to PAN (to form PAN-CS) which was then linked to the Pcs to form PAN-CS-1, PAN-CS-2, PAN-CS-1Q, and PAN-CS-2Q, respectively. Singlet oxygen quantum yields improved following the inclusion of chitosan. The PACT activities of the complexes alone and when anchored to both PAN and PAN-CS was evaluated against bacteria: S. aureus, E. coli and fungi C. albicans. Cationic phthalocyanine showed high efficacy values of >7 log reduction value for all microorganisms. These results translated into excellent bacterial colony reduction of >90% against both S. aureus and C. albicans after 1 h of photoirradiation on PAN-CS support.

Multi-omic cross-sectional cohort study of pre-malignant Barrett's esophagus reveals early structural variation and retrotransposon activity.

Barrett's esophagus is a pre-malignant lesion that can progress to esophageal adenocarcinoma. We perform a multi-omic analysis of pre-cancer samples from 146 patients with a range of outcomes, comprising 642 person years of follow-up. Whole genome sequencing reveals complex structural variants and LINE-1 retrotransposons, as well as known copy number changes, occurring even prior to dysplasia. The structural variant burden captures the most variance across the cohort and genomic profiles do not always match consensus clinical pathology dysplasia grades. Increasing structural variant burden is associated with: high levels of chromothripsis and breakage-fusion-bridge events; increased expression of genes related to cell cycle checkpoint, DNA repair and chromosomal instability; and epigenetic silencing of Wnt signalling and cell cycle genes. Timing analysis reveals molecular events triggering genomic instability with more clonal expansion in dysplastic samples. Overall genomic complexity occurs early in the Barrett's natural history and may inform the potential for cancer beyond the clinically discernible phenotype.

An ethical analysis of divergent clinical approaches to the application of genetic testing for autism and schizophrenia.

Genetic testing to identify genetic syndromes and copy number variants (CNVs) via whole genome platforms such as chromosome microarray (CMA) or exome sequencing (ES) is routinely performed clinically, and is considered by a variety of organizations and societies to be a "first-tier" test for individuals with developmental delay (DD), intellectual disability (ID), or autism spectrum disorder (ASD). However, in the context of schizophrenia, though CNVs can have a large effect on risk, genetic testing is not typically a part of routine clinical care, and no clinical practice guidelines recommend testing. This raises the question of whether CNV testing should be similarly performed for individuals with schizophrenia. Here we consider this proposition in light of the history of genetic testing for ID/DD and ASD, and through the application of an ethical analysis designed to enable robust, accountable and justifiable decision-making. Using a systematic framework and application of relevant bioethical principles (beneficence, non-maleficence, autonomy, and justice), our examination highlights that while CNV testing for the indication of ID has considerable benefits, there is currently insufficient evidence to suggest that overall, the potential harms are outweighed by the potential benefits of CNV testing for the sole indications of schizophrenia or ASD. However, although the application of CNV tests for children with ASD or schizophrenia without ID/DD is, strictly speaking, off-label use, there may be clinical utility and benefits substantive enough to outweigh the harms. Research is needed to clarify the harms and benefits of testing in pediatric and adult contexts. Given that genetic counseling has demonstrated benefits for schizophrenia, and has the potential to mitigate many of the potential harms from genetic testing, any decisions to implement genetic testing for schizophrenia should involve high-quality evidence-based genetic counseling.

Genetic risk for schizophrenia is associated with altered visually-induced gamma band activity: evidence from a population sample stratified polygenic risk.

Gamma oscillations (30-90 Hz) have been proposed as a signature of cortical visual information processing, particularly the balance between excitation and inhibition, and as a biomarker of neuropsychiatric diseases. Magnetoencephalography (MEG) provides highly reliable visual-induced gamma oscillation estimates, both at sensor and source level. Recent studies have reported a deficit of visual gamma activity in schizophrenia patients, in medication naive subjects, and high-risk clinical participants, but the genetic contribution to such a deficit has remained unresolved. Here, for the first time, we use a genetic risk score approach to assess the relationship between genetic risk for schizophrenia and visual gamma activity in a population-based sample drawn from a birth cohort. We compared visual gamma activity in a group (N = 104) with a high genetic risk profile score for schizophrenia (SCZ-PRS) to a group with low SCZ-PRS (N = 99). Source-reconstructed V1 activity was extracted using beamformer analysis applied to MEG recordings using individual MRI scans. No group differences were found in the induced gamma peak amplitude or peak frequency. However, a non-parametric statistical contrast of the response spectrum revealed more robust group differences in the amplitude of high-beta/gamma power across the frequency range, suggesting that overall spectral shape carries important biological information beyond the individual frequency peak. Our findings show that changes in gamma band activity correlate with liability to schizophrenia and suggest that the index changes to synaptic function and neuronal firing patterns that are of pathophysiological relevance rather than consequences of the disorder.

Improving Acceptability and Uptake Behavior for Internet-Based Cognitive-Behavioral Therapy.

Internet-based cognitive behavioral therapy (iCBT) programs have the potential to improve access to mental healthcare, but they are not viewed as acceptable nor widely utilized by the general public. This study tested whether two acceptance-facilitating interventions improved acceptability and uptake-related behavior for therapist assisted and self-guided iCBT. Participants were randomly assigned to read a treatment rationale for iCBT (vs. a brief definition) and to receive a small financial incentive (or not) for seeking more information about evidence-based iCBT programs. Participants (N = 662) were a diverse group recruited from a University participant pool and the surrounding community. Participants completed standardized measures of attitudes toward and outcome expectancy for iCBT and a single question about willingness to use it and were given the opportunity to get information about accessing evidence-based iCBT programs. A series of MANCOVAs showed small, positive effects of the treatment rationale on attitudes and outcome expectancy for both self-guided and therapist-assisted iCBT, but not for willingness to use it. A hierarchical logistic regression model found no effect of the treatment rationale or financial incentive on whether participants sought additional information about how to access iCBT, although psychopathology symptoms and identifying as White or multiracial were positively associated with information-seeking. Inconsistent with past research, participants rated therapist-assisted and self-guided iCBT as equally acceptable. Participants recruited from the community reported greater willingness to use iCBT than University students. These results underscore the urgent need for further research toward improving the acceptability and uptake of iCBT so that it may better fulfill its potential to fill the gap in unmet mental health need.

The correlation between full moon and admission volume for penetrating injuries at a major trauma centre in South Africa.

BACKGROUND: The possible effect of full moon on admission volume of trauma centres is a well-mentioned phenomenon that has been perpetuated worldwide. We aimed to review the correlation between full moon and admission volume and to interrogate any possible relationship on admission for penetrating trauma. METHODS: A retrospective study from 2012 to 2018 at Pietermaritzburg Metropolitan Trauma Service (PMTS), South Africa. RESULTS: A total of 8 722 patients were admitted. Eighty-three per cent (7 242/8 722) were male and the mean age was 29 years. The total number of days during the study period was 1 953, 66 of which were 'full moon' (FM) days and 1 887 were 'non-full moon' (NFM) days. There was no significant difference between gender or age distribution. The mean number of admissions per day on FM days compared with NFM days was not significant (4.1 vs 4.5, p = 0.583). A total of 3 332 patients with penetrating trauma were admitted. This constituted 42% (113/271) of admission on FM days and 38% (3 219) on NFM days, which is not statistically significant (p = 0.229). Subgroup analysis did not demonstrate any significant difference between the number of stab wounds - 28% (77/113) vs 25% (2 124/3 219) - or gunshot wounds - 13% (16/113) vs 12% (990/3 219) - between FM and NFM days. CONCLUSION: The correlation between full moon and trauma admission is unfound in our setting. The perpetuating notion that 'it must be full moon tonight' is likely to be an urban myth with no scientific evidence for such a claim.

Restricting dairy cow access time to pasture in autumn: The effects on milk production, grazing behaviour and DM intake of late lactation dairy cows.

Extending the grazing season in pasture based systems of dairy production can increase farm profitability; poor weather and soil conditions can reduce the number of grazing days. The study objectives were to (i) examine the effect of restricted access to pasture in the autumn on the milk production, grazing behaviour and DM intake (DMI) of late lactation spring-calving dairy cows and (ii) establish the effect of alternating restricted and continuous access to pasture on dairy cow production, DMI and grazing behaviour. Cows were randomly assigned to one of four grazing treatments: (i) 22 h (full-time) access to pasture (22H; control); (ii) Two 5-h periods of access to pasture (2×5H); (iii) Two 3-h periods of access to pasture (2×3H); and (iv) alternating between full-time and 3-h access to pasture with no more than three continuous days on any one regime, e.g. Monday - full-time access, Tuesday - 2x3H access, Wednesday - 2x3H access; Thursday - full-time access, etc. (2×3HV). Restricted access to pasture was offered after a.m. and p.m. milking. Swards of similar quality and pregrazing herbage mass were offered. Treatment had no effect on milk yield (13.2 kg/day), milk fat (48.2 g/kg), protein (39.0 g/kg) or lactose content (42.6 g/kg) and milk solid yield (1.15 kg/day). Similarly, there was no effect of treatment on final BW (483 kg) or final BCS (2.66). There was no significant difference in DMI (15.1 kg DM/cow/day) between treatments. There was an effect on daily grazing time, 22H cows (565 min/cow/day) grazed for longest time, however, when the 2x3HV treatment had full-time access to pasture, they had a similar grazing time (543 min/cow/day) to the 22H cows and were similar to the 2x3H treatment on days with restricted access to pasture (357 min/cow/day). The 22H and 2x5H animals had similar grass DMI/min (29.2 g/min), the 2x3HV were higher (33.9 g/min) but were similar to the comparable treatment when offered 2x3H access time (41.6 g/min) and when offered 22H access time (27.7 g/min). The results from this study show how when offered a grass only diet of autumn pasture grazing behaviour can be modified by restricting pasture access time without reducing dairy cow production in late lactation at low production levels. There was also no effect of alternating access time between 22H and 2x3H on milk production and DMI in the 2x3HV treatment. Restricted access time to pasture in autumn may be a strategy which farmers can use to extend the grazing season.

Incorporation of the grazing utilization subindex and new updates to the Pasture Profit Index.

Grazing efficiency has been shown to differ between perennial ryegrass varieties. Such differences affect the utilization of grass within grazing systems, influencing the profitability of grass-based ruminant production systems. The Pasture Profit Index (PPI) is an economic merit grass variety selection tool developed to identify varieties with the greatest economic potential for grass-based dairy production systems. A new grass utilization subindex was developed and incorporated into the PPI to identify varieties with superior grazing efficiency. The subindex rewards varieties with superior grazing efficiency, measured as Residual grazed height, as these varieties allow increased amounts of herbage dry matter to be used by grazing animals. The economic values of all other traits within the PPI were reviewed and updated to ensure that the index was reflective of the current economic scenarios with appropriate assumptions included in the models, thus ensuring that varieties excelling in the agronomic traits with the greatest effect on profitability were recognized. The difference between the highest and lowest performing varieties for the grass utilization trait ranged from €23 to -€24. A range of €211 to €43 was recorded between the highest and lowest ranked varieties within the updated PPI. Spearman's rank correlation between the updated and original PPI lists was 0.96. The introduction of the utilization subindex will allow farmers to make informed variety selection decisions when reseeding pasture, particularly on their grazing platforms and it will allow a demand-based communication process between the farmer and the grass merchant or breeder, ultimately affecting trait selection for future breeding strategies.