Isolated volar dislocation of the distal radioulnar joint: a case series and systematic review

INTRODUCTION

Isolated volar dislocations of the distal radioulnar joint are reported as rare. We observed three such cases over a 12-month period. Literature to date consists of multiple case reports and case series with no structured reviews. There is debate as to incidence, mechanism, investigation, treatment and prognosis.

METHODS

A case series and formal systematic review was performed. This included an analysis of the demographics, mechanism, presentation, investigation, treatment and outcome of the cases identified from the wider published series.

FINDINGS

In total 99 cases of this injury were identified from 59 papers, with a further 9 cases having an associated ulna styloid fracture.

CONCLUSIONS

This is a rare injury, representing up to 0.02% of all bony injuries, which is diagnosed late in 36% of cases. Inability to obtain a true lateral radiograph may contribute to the diagnosis being missed. Computed tomography scans are useful in suspected cases without radiographic confirmation. Acute cases are successfully treated with closed reduction in 78% of cases; however associated soft tissue injuries may need to be surgically addressed. Delayed presentation is more likely to require open surgery and preoperative MRI scans are indicated to aid surgical planning. Chronic instability rarely occurs and may need treatment with reconstruction or salvage. A good, subjective, result is reported in the majority of patients.

Development of breeding values for susceptibility to virulent footrot in sheep: A strategy to accommodate variable disease progression at time of scoring

Genetic evaluations utilising footrot scores from industry flocks in their essence, incorporate data from a wide range of challenge environments, resulting in potentially large differences in means, variances and distribution of scores across challenges. The date that commencement of infection occurs is generally unknown, and progression of the infection varies with the prevailing environmental and management conditions, virulence of the bacterium Dichelobacter nodosus, as well as the genetic potential and (permanent) environmental ability of animals to resist footrot. In practice, animals are unlikely to be repeatedly scored to identify the best time for comparison, or monitor development of disease progression. Furthermore, field challenges are limited by the need to treat animals before their welfare is compromised. Therefore, the duration and intensity of infection varies and this affects comparisons between animals for their susceptibility. Diseases such as footrot are characterised by multiple categorical scores reflecting clinical stages that describe the progression and relative impact of the disease. This provides the opportunity for the transformation of the data to a standardised prevalence. Scoring events from multiple footrot field challenges under a standardised protocol were used to establish a series of transition matrices to describe disease progression between scores over time. These transition matrices were used to standardise challenge events to the more severe scoring events, observed later in the challenge. The accuracy of the transition technique was tested by comparing the ranking of animals and sires against the observed scores. Transitioning the data from low disease prevalence to the higher prevalence at the subsequent scoring event improved the correlations between the scoring events, at the animal level, by upwards of 0.10 across challenges. The utilisation of a transition matrix to transform low prevalence disease challenges by taking into account the natural biological rate of progression through the clinical stages of the disease provides a more accurate technique to account for variation in disease prevalence. The transition technique increases the acceptable range of disease expression targeted by producers when scoring virulent footrot challenges reducing the need for repeat scoring and allowing earlier treatment and reducing the impact of the disease on the host animal.

Capturing lean distribution in lamb carcases is of more value to the processor than the breeder

With an increased implementation of chain speed measures of lean weight in lamb processing plants there is the potential for increased feedback of measures for carcase composition to the breeder. The following studies used computed tomography scans of 3167 Merino and Merino cross lamb carcases to determine the importance of capturing variation in carcase, fore, saddle and hind section lean to the processor and the breeder. Sectional measures of lean weight will provide processors with improved precision around the decision making associated with carcase processing and endpoint usage. Genetic correlations between lean (adjusted for carcase weight) within carcase sections ranged from 0.47 to 0.63. Whilst the correlations are moderate, current differences in the value of lean across the carcase does not make it viable for sheep breeders to target disproportional gains in lean across carcase sections. Instead, sheep breeders should continue to target overall carcase lean as part of their breeding objective.

Single-step genomic evaluation of lambing ease in Australian terminal sire breed sheep

Context Australian sheep breeding values (ASBVs) for the categorical trait of lambing ease are routinely estimated by Sheep Genetics via a threshold model. This has been pedigree-only, and has not utilised genomic information. Aim The present study aimed to update the genetic evaluation model and parameters for lambing ease for terminal sire sheep (dominated by White Suffolk and Poll Dorset breeds). The model includes correlations with birthweight and gestation length. Cross-validation was used to determine the value of the improved models and the inclusion of genomic information. Methods New data-preparation pipelines were developed to accommodate improved data-filtering methods and contemporary group construction. Genetic parameters, including correlations among traits, were estimated using continuous and threshold models, with various combinations of effects in mixed animal models. Cross-validation of breeding values was performed against progeny performance, by using forward prediction. Key results The increased volume of data, improved data preparation steps and enhanced evaluation software now allow a more complex model to be fitted, including maternal, sire by flock-year and genetic group effects, which were significant for all traits, along with the inclusion of multiple sire groups in the pedigree. However, the inclusion of the direct-maternal covariance and sire by flock-year terms resulted in unrealistically inflated estimates of some components, and thus the final covariance matrices required some adjustments. Cross-validation of breeding values was performed against progeny performance using forward prediction. For all traits, the phenotype accuracies and estimated breeding value correlations were higher from the new model without genomics than were those from the current routine evaluation. The benefit from including genomic information based on cross-validation is minimal currently but is expected to improve as the size of the reference population grows. Further work is required to define acceptable data-quality thresholds for the construction of datasets for routine breeding value estimation. Conclusions The new model and parameters resulted in ASBVs with an improved predictive ability, with increased accuracy and reduced bias compared with the current analysis. Furthermore, a small increase in accuracy was observed for all traits from utilising genomic information in the model. Implications The new genetic evaluation procedures and models will be used to update those being applied in the routine Sheep Genetics evaluation system and also support further index development for the terminal sire breeds in Australia.

New genomically enhanced reproduction breeding values for Merino sheep allow targeted selection for conception rate, litter size and ewe rearing ability

Context Net reproduction rate defined as number of lambs weaned for joined ewes reflects conception, litter size and the ability of ewes to rear lambs to weaning age. These three attributes can be treated as separate traits for genetic evaluation, allowing breeders to focus selection for each appropriately. Aims The aim of the present paper was to present characteristics of the data, models and genetic parameters estimated from Merino data, along with results demonstrating the predictive capacity of breeding values, for conception, litter size, rearing ability, maternal behaviour and body condition score. Methods Industry data from MERINOSELECT were used to derive phenotypes for conception, litter size and rearing ability traits separately for yearling and adult ewes, along with maternal behaviour and body condition score. Indirect traits provided correlated information, including scrotal circumference, weight, scanned fat and eye muscle depths at up to three ages (post-weaning, yearling and hogget), along with pre-joining weight and condition score for ewes. Co-variances were estimated among the 19 traits included in the analysis. Breeding values were estimated using single step genomic methodology using consensus estimates of genetic parameters, with the predictive capacity of breeding values being estimated using forward-validation. Key results Heritabilities ranged from 0.04 to 0.06 for conception, litter size and rearing ability, and were moderate for maternal behaviour (0.13) and condition score (0.20). Component traits were genetically controlled by some common genes, but with genetic correlations less than 0.5, each component can be selected for independently. Weight, fat depth and muscle depth measures were moderately to highly correlated with body condition score. These body development traits generally had low, favourable genetic correlations with ewe reproductive traits. Conclusions These procedures provide better use of data recorded by breeders subject to both data limitations and opportunities, and provide separate breeding values for conception, litter size, rearing ability, maternal behaviour and body condition score. Implications New breeding values with good predictive ability are now available for the component traits of reproduction. Direct recording data of the traits is required to achieve accuracy of breeding values. Australian Merino breeders are now able to select directly for components of reproduction and specific maternal characteristics.

The performance of the Border Leicester in Australia

Aims We examine the average performance of Border Leicester (BL) flocks that are part of LAMBPLAN, Australia’s sheep performance recording and genetic evaluation system. We also summarise outcomes from the New South Wales Department of Primary Industry’s research on BL improvement, and discuss the performance required for the BL to continue to be a pivotal part of the Australian prime lamb industry. Key results Modest gains have been recorded in the BL in growth since 2000 and faecal egg counts have reduced, suggesting improved worm resistance. The net reproductive rate has slightly improved, while inbreeding continues to increase. In work conducted by the New South Wales Department of Primary Industries, an improved BL flock, encompassing selection for multiple births and a broadening of the breed’s genetic base, had advantages over purebred BLs in many aspects of performance, including a 19.3% advantage in the net reproductive rate. Advantages in fertility were ~5%, litter size ~7% and lamb rearing ability ~5%. BL improved × Merino and (BL improved × BL) × Merino crossbred ewes also had advantages over traditional BL × Merino ewes in their joining performance when joined to Dorset rams. Conclusions Selection in the BL needs to emphasise traits in a manner consistent with their importance to commercial lamb production. Implications Embracing this selection and broadening the BL’s genetic base will assist the BL to maintain its place in the Australian lamb industry.

Substantial genetic gains in reducing breech flystrike and in improving productivity traits are achievable in Merino sheep by using index selection

Context The availability of effective indirect rather than direct selection criteria for genetically reducing breech flystrike is crucial for the Australian wool industry, as expression of breech flystrike is routinely suppressed by management interventions to minimise the risks to sheep health, welfare and productivity. Understanding how much genetic gain can be made in reducing breech strike, while also selecting for other key traits is important in choosing breeding objectives, particularly for Merino genetic improvement programs. Aims We predicted genetic gains from within-flock selection to reduce breech flystrike incidence (FS) and improve productivity under a range of scenarios that all used indirect selection criteria in the genetic evaluation of FS. Methods Three breeding objectives were modelled, by adding FS as a trait to the breeding objective for the Dual Purpose Plus (DP+), Fibre Production Plus (FP+) and Merino Production Plus (MP+) indexes available from MERINOSELECT. A large range of economic values were examined for FS, from 0 to –$240/strike.sheep per year in $20 increments. For all scenarios, full records of productivity traits and pedigree information were assumed to be available for use as selection criteria, as well as records of breech wrinkle, dag and breech cover scores. Predictions were conducted for scenarios assuming (a) moderate heritability for FS (b) low heritability for FS, and (c) low heritability for FS, but higher heritability for dag score than assumed for scenarios (a) and (b). Key results After 10 years of selection, under assumption (a) predicted genetic gains in FS ranged from 0, up to maximum reductions of 0.19, 0.21, and 0.20/strike.sheep per year from use of the FP+FS, MP+FS and DP+FS indexes, respectively. Under assumption (b) predictions of genetic gain for FS were considerably lower and ranged from 0 to maximum reductions of 0.04, 0.06 and 0.06/strike.sheep per year based on use of FP+FS, MP+FS and DP+FS indexes, respectively. Under assumption (c), predicted genetic gains in FS were very similar to those under assumption (b). When 70% of the maximum gains in FS studied were targeted, from 70% to 93% of genetic gains in the overall index (excluding FS) were predicted to be retained when FS had moderate heritability, and from 85% to 95% when FS had low heritability. Conclusions and implications There is a practical range of economic values for FS (from –$60 to –$80/strike.sheep per year for MP+FS and DP+FS indexes and –$60 to –$140/strike.sheep per year for a FP+FS index when the heritability of FS is moderate and –$100 to –$200/strike.sheep per year for a MP+FS index and –$140 to –$240/strike.sheep per year for FP+FS and DP+FS indexes when the heritability of FS is low), that could be used in breeding programs to genetically reduce FS, while retaining competitive levels of genetic gains for other important traits. Reduction of FS is achievable to low levels, after 10–20 years of index selection, similar to levels achieved by mulesing (0.01/strike.sheep per year in average seasonal conditions).

Genetic parameters for faecal worm egg count at different ages in Australian sheep under natural challenge

The data used in the present study consisted of 24535 worm egg count records on sheep observed from 63 to 560 days of age under conditions of the natural challenge of trichostrongylid species. Records were extracted from the Information Nucleus Flock database of the Australia Sheep Cooperative Research Centre program from 2007 to 2011. Records were observed at various ages and subdivided into weaning (W, ~3 months), post-weaning (P, ~4 months), yearling (Y, ~12 months) and hogget (H, ~18 months) age stages and were used to investigate genetic variation at different age stages in univariate analyses and estimate genetic correlations between age stages in multi-trait analyses. The full data were also analysed by random regression models to study how heritability and genetic correlations varied with age. Heritability estimates from univariate analyses were 0.20 ± 0.05, 0.15 ± 0.02, 0.36 ± 0.09, 0.22 ± 0.06 for W, P, Y and H age stages respectively. A similar trend of heritability over ages was found from random regression analyses, which decreased from 0.16 at 90 days to 0.09 at 120 days, following a steady increase to 0.32 at ~410 days, and then decreased afterwards to 0.24 at 520 days. Strong genetic correlations (>0.8) were found between W and P age stages, along with Y and H age stages. Sire by flock interaction effects were significant, and accounted for the reduced estimates of heritability and increased genetic correlations between age stages. The results indicated that a multiple-trait approach is required for genetic evaluation of worm egg count when measurements are at different ages, and the accuracy of evaluations would benefit from recording at least two separate age stages.

Weaner survival is heritable in Australian Merinos and current breeding objectives are potentially leading to a decline in survival

There is little evidence to show that mortality rates during the period after weaning are improving over time in Australian sheep. The average mortality rate of Merino lambs during the post-weaning period has been estimated to be 5.2%. The present study explored the potential for producers to breed for improved survival rates during the post-weaning period and the potential impact this would have on key production traits. A total of 122526 weaner survival (mortality) records were obtained from 18 Merino flocks, between 1989 and 2014, encompassing a wide variety of Australian Merino sheep types and production systems. The heritability of weaner survival from a sire model was estimated to be 0.07 ± 0.01 and was significantly greater than zero. The survival of lambs post-weaning was significantly influenced by weaning weight, with higher survival rates observed in the heavier lambs. The phenotypic relationship with weight indicates that selection for heavier weaning and post-weaning weights, and in turn larger growth rates, will improve survival rates. There is genetic variation in weaner survival not explained by the relationship with weaning weight. Weight-corrected weaner survival was antagonistically genetically correlated with fleece weight. Due to these antagonistic genetic relationships selection based on popular MERINOSELECT indexes is leading to a very small reduction in the survival rate of lambs after weaning through to the post-weaning stage. To prevent a decline in weaner survival, producers are advised to record weaner survival and include it in their breeding objective.

Genetic correlations between wool traits and meat quality traits in Merino sheep

Genetic correlations between 29 wool production and quality traits and 25 meat quality and nutritional value traits were estimated for Merino sheep from an Information Nucleus (IN). Genetic correlations among the meat quality and nutritional value traits are also reported. The IN comprised 8 flocks linked genetically and managed across a range of sheep production environments in Australia. The wool traits included over 5,000 yearling and 3,700 adult records for fleece weight, fiber diameter, staple length, staple strength, fiber diameter variation, scoured wool color, and visual scores for breech and body wrinkle. The meat quality traits were measured on samples from the and included over 1,200 records from progeny of over 170 sires for intramuscular fat (IMF), shear force of meat aged for 5 d (SF5), 24 h postmortem pH (pHLL; also measured in the , pHST), fresh and retail meat color and meat nutritional value traits such as iron and zinc levels, and long-chain omega-3 and omega-6 polyunsaturated fatty acid levels. Estimated heritabilities for IMF, SF5, pHLL, pHST, retail meat color lightness (), myoglobin, iron, zinc and across the range of long-chain fatty acids were 0.58 ± 0.11, 0.10 ± 0.09, 0.15 ± 0.07, 0.20 ± 0.10, 0.59 ± 0.15, 0.31 ± 0.09, 0.20 ± 0.09, 0.11 ± 0.09, and range of 0.00 (eicosapentaenoic, docosapentaenoic, and arachidonic acids) to 0.14 ± 0.07 (linoleic acid), respectively. The genetic correlations between the wool production and meat quality traits were low to negligible and indicate that wool breeding programs will have little or no effect on meat quality. There were moderately favorable genetic correlations between important yearling wool production traits and the omega-3 fatty acids that were reduced for corresponding adult wool production traits, but these correlations are unlikely to be important in wool/meat breeding programs because they have high SE, and the omega-3 traits have little or no genetic variance. Significant genetic correlations among the meat quality traits included IMF with SF5 (-0.76 ± 0.24), fresh meat color * (0.50 ± 0.18), and zinc (0.41 ± 0.19). Selection to increase IMF will improve meat tenderness and color which may address some of the issues with Merino meat quality. These estimated parameters allow Merino breeders to combine wool and meat objectives without compromising meat quality.

More feed efficient sheep produce less methane and carbon dioxide when eating high-quality pellets

The Australian sheep industry aims to increase the efficiency of sheep production by decreasing the amount of feed eaten by sheep. Also, feed intake is related to methane production, and more efficient (low residual feed intake) animals eat less than expected. So we tested the hypothesis that more efficient sheep produce less methane by investigating the genetic correlations between feed intake, residual feed intake, methane, carbon dioxide, and oxygen. Feed intake, methane, oxygen, and carbon dioxide were measured on Merino ewes at postweaning (1,866 at 223 d old), hogget (1,010 sheep at 607 d old), and adult ages (444 sheep at 1,080 d old). Sheep were fed a high-energy grower pellet ad libitum for 35 d. Individual feed intake was measured using automated feeders. Methane was measured using portable accumulation chambers up to 3 times during this feed intake period. Heritabilities and phenotypic and genotypic correlations between traits were estimated using ASReml. Oxygen (range 0.10 to 0.20) and carbon dioxide (range 0.08 to 0.28) were generally more heritable than methane (range 0.11 to 0.14). Selecting to decrease feed intake or residual feed intake will decrease methane (genetic correlation [] range 0.76 to 0.90) and carbon dioxide ( range 0.65 to 0.96). Selecting to decrease intake ( range 0.64 to 0.78) and methane ( range 0.81 to 0.86) in sheep at postweaning age would also decrease intake and methane in hoggets and adults. Furthermore, selecting for lower residual feed intake ( = 0.75) and carbon dioxide ( = 0.90) in hoggets would also decrease these traits in adults. Similarly, selecting for higher oxygen ( = 0.69) in hoggets would also increase this trait in adults. Given these results, the hypothesis that making sheep more feed efficient will decrease their methane production can be accepted. In addition, carbon dioxide is a good indicator trait for feed intake because it has the highest heritability of the gas traits measured; is cheaper, faster, and easier to measure than feed intake and has strong phenotypic and genetic correlations with feed intake. Furthermore, selection for feed intake, feed efficiency, methane, and carbon dioxide can be done early in sheep at postweaning age or hoggets. This early selection reduces the generation interval for breeding, thereby increasing response to selection.

Genetic parameters for wool traits, live weight, and ultrasound carcass traits in Merino sheep

Genetic correlations between 29 wool production and quality traits and live weight and ultrasound fat depth (FAT) and eye muscle depth (EMD) traits were estimated from the Information Nucleus (IN). The IN comprised 8 genetically linked flocks managed across a range of Australian sheep production environments. The data were from a maximum of 9,135 progeny born over 5 yr from 184 Merino sires and 4,614 Merino dams. The wool traits included records for yearling and adult fleece weight, fiber diameter (FD), staple length (SL), fiber diameter CV (FDCV), scoured color, and visual scores for breech and body wrinkle. We found high heritability for the major yearling wool production traits and some wool quality traits, whereas other wool quality traits, wool color, and visual traits were moderately heritable. The estimates of heritability for live weight generally increased with age as maternal effects declined. Estimates of heritability for the ultrasound traits were also higher when measured at yearling age rather than at postweaning age. The genetic correlations for fleece weight with live weights were positive (favorable) and moderate (approximately 0.5 ± 0.1), whereas those with FD were approximately 0.3 (unfavorable). The other wool traits had lower genetic correlations with the live weights. The genetic correlations for FAT and EMD with FD and SL were positive and low, with FDCV low to moderate negative, but variable with wool weight and negligible for the other wool traits. The genetic correlations for FAT and EMD with postweaning weight were positive and high (0.61 ± 0.18 to 0.75 ± 0.14) but were generally moderate with weights at other ages. Selection for increased live weight will result in a moderate correlated increase in wool weight as well as favorable reductions in breech cover and wrinkle, along with some unfavorable increases in FD and wool yellowness but little impact on other wool traits. The ultrasound meat traits, FAT and EMD, were highly positively genetically correlated (0.8), and selection to increase them would result in a small unfavorable correlated increase in FD, moderately favorable reductions in breech cover and wrinkle, but equivocal or negligible changes in other wool traits. The estimated parameters provide the basis for calculation of more accurate Australian Sheep Breeding Values and selection indexes that combine wool and meat objectives in Merino breeding programs.

Data capture through Australian beef cattle and meat sheep value chains: opportunities for enhanced feedback to commercial producers

Technologies for capturing and transmitting data from different points in livestock value chains are developing very rapidly, and interest is growing in how best to use such technologies. While new data-capture technology comes with the promise of producers and others being more informed about a system, what usually results is large and complex datasets. A key challenge is to make use of the data or information. The present paper initially outlines the data-capture points and flow of information that occurs throughout the Australian beef cattle and meat sheep value chain. The avenues through which feedback can be delivered to commercial producers are briefly summarised, along with the value of this feedback and the factors that affect its value. Finally, practical principles for effective feedback systems are provided. While data capture is occurring throughout the value chain, the main focus of the paper is on carcass- and eating-quality feedback from processors to commercial producers. There is significant variation in the volume, nature and quality of data collected, and also the flow of information among members of the chain. Further, there appears to be an inconsistency in the levels of demand or desire for the feedback. The value of feedback ultimately depends on the producer’s ability to make better business decisions as a result of having that data or information. Increasing market specifications and compliance will result in greater profitability for the producer, as well as processor. The value of feedback also depends on several other factors, including its accuracy, its granularity, whether or not it can be connected to other data, and what options the producer has to use that information in the future. Feedback must be interpretable and enable better business decisions. The value of feedback will also increase if extended further upstream along the supply chain for genetic evaluation, provided there is enough information on genetically informed animals and their identifications can be tracked across the supply chain. For efficient feedback systems, every member in the chain needs to see value in the feedback, and there needs to be a mutual commitment and shared vision between all value-chain partners. Further, feedback must be provided in an efficient and practical manner, so as to increase the willingness of the information providers to deliver the feedback. Producers should be involved in any attempts to enhance feedback systems. Since there is variability in the needs, wants and capabilities of processors and producers, multiple dynamic and flexible feedback systems are required. An incentive to enhance feedback systems is to provide a value proposition by calculating the monetary value of the feedback to all members of the chain. Better objective measurements and Meat Standards Australia for lamb is likely to also contribute to better feedback value propositions. Communication and fostering of relationships among supply-chain members will always remain critical. While data permissions add a complication to information sharing across the chain, benefits can be gained by not only the commercial producer, but the entire industry.

A versatile apparatus for two-dimensional atomtronic quantum simulation

We report on the implementation of a novel optical setup for generating high-resolution customizable potentials to address ultracold bosonic atoms in two dimensions. Two key features are developed for this purpose. The customizable potential is produced with a direct image of a spatial light modulator, conducted with an in-vacuum imaging system of high numerical aperture. Custom potentials are drawn over an area of 600×400 μm with a resolution of 0.9 μm. The second development is a two-dimensional planar trap for atoms with an aspect ratio of 900 and spatial extent of Rayleigh range 1.6 × 1.6 mm, providing near-ballistic in-planar movement. We characterize the setup and present a brief catalog of experiments to highlight the versatility of the system.

In vivo recording of the vestibular microphonic in mammals

BACKGROUND

The Vestibular Microphonic (VM) has only featured in a handful of publications, mostly involving non-mammalian and ex vivo models. The VM is the extracellular analogue of the vestibular hair cell receptor current, and offers a tool to monitor vestibular hair cell activity in vivo.

OBJECTIVE

To characterise features of the VM measured in vivo in guinea pigs, using a relatively simple experimental setup.

METHODS

The VM, evoked by bone-conducted vibration (BCV), was recorded from the basal surface of either the utricular or saccular macula after surgical removal of the cochlea, in 27 guinea pigs.

RESULTS

The VM remained after vestibular nerve blockade, but was abolished following end-organ destruction or death. The VM reversed polarity as the recording electrode tracked across the utricular or saccular macula surface, or through the utricular macula. The VM could be evoked by BCV stimuli of frequencies between 100 Hz and 5 kHz, and was largest to vibrations between 600 Hz and 800 Hz. Experimental manipulations demonstrated a reduction in the VM amplitude with maculae displacement, or rupture of the utricular membrane.

CONCLUSIONS

Results mirror those obtained in previous ex vivo studies, and further demonstrate that vestibular hair cells are sensitive to vibrations of several kilohertz. Changes in the VM with maculae displacement or rupture suggest utricular hydrops may alter vestibular hair cell sensitivity due to either mechanical or ionic changes.

Genetic correlations between wool traits and carcass traits in Merino sheep

Genetic correlations between 29 wool production and quality traits and 14 whole carcass measures and carcass component traits were estimated from the Information Nucleus of 8 flocks managed across a range of Australian sheep production environments and genetically linked. Wool data were from over 5,000 Merino progeny born over 5 yr, whereas carcass data were from over 1,200 wether progeny of over 176 sires, slaughtered at about 21 kg carcass weight, on average. Wool traits included yearling and adult records for wool weight, fiber diameter, fiber diameter variation, staple strength, scoured color, and visual scores for breech and body wrinkle. Whole carcass measures included HCW, dressing percentage (DP), and various measures of fat depth and eye muscle dimensions. Carcass components were obtained by dissection, and lean meat yield (LMY) was predicted. Heritability estimates for whole carcass measures ranged from 0.12 ± 0.08 to 0.35 ± 0.10 and ranged from 0.17 ± 0.10 to 0.46 ± 0.10 for carcass dissection traits, with no evidence of important genotype × environment interactions. Genetic correlations indicated that selection for increased clean wool weight will result in reduced carcass fat (-0.17 to -0.34) and DP (-0.48 ± 0.15), with little effect on carcass muscle. Selection for lower fiber diameter will reduce HCW (-0.48 ± 0.15) as well as carcass fat (0.14 to 0.27) and muscle (0.21 to 0.50). There were high genetic correlations between live animal measures of fat and muscle depth and the carcass traits (generally greater than 0.5 in size). Selection to increase HCW (and DP) will result in sheep with fewer wrinkles on the body (-0.57 ± 0.10) and barer breeches (-0.74 ± 0.12, favorable), with minor deterioration in scoured wool color (reduced brightness and increased yellowness). Selection for reduced fat will also result in sheep with fewer body wrinkles (-0.42 to -0.79). Increasing LMY in Merinos through selection would result in a large reduction in carcass fat and DP (-0.66 to -0.84), with a smaller increase in carcass muscle and some increase in wool weight and wrinkles. Although no major antagonisms are apparent between the wool and carcass traits, developing selection indexes for dual-purpose wool and meat breeding objectives will require accurate estimates of genetic parameters to ensure that unfavorable relationships are suitably considered. The findings will aid development of dual-purpose wool and meat breeding objectives.

Differences in the Contribution of CD4+ T Cells to Proislet and Islet Allograft Rejection Correlate with Constitutive Class II MHC Alloantigen Expression

Allografts of BALB/c (H-2d) fetal proislets facilitated long-term (>100 days) reversal of streptozotocin-induced diabetes in CBA/H (H-2k) mice treated with a combination of anti-CD4 and anti-CD8 mAbs. Anti-CD8 monotherapy was partially effective in restoring normoglycemia but anti-CD4 mAb treatment of host animals failed to promote allograft function. In contrast, allografts of BALB/c adult islets demonstrated indefinite reversal of diabetes in recipient mice treated only with anti-CD8 mAb. Anti-CD4 monotherapy resulted in only transient restoration of normoglycemia. These findings clearly demonstrate (1) a critical role for CD8 T cells in the acute rejection of pancreatic islet tissue allografts and (2) tissue-specific differences in the participation of CD4 T cells as primary effectors in the rejection reaction. Immunohistochemical studies showed that the capacity for CD4 T cells to initiate the rejection of proislet but not adult islet allografts correlates with the presence/absence, respectively, of graft parenchymal cells that constitutively express Class II MHC alloantigens. Proislet grafts, unlike transplants of purified adult islets, contain heterogeneous tissue components including Class II MHC+ve duct epithelium. Thus, the participation of CD8 and CD4 T cells as primary effectors of graft rejection depends on which class or classes of MHC antigens are constitutively expressed on graft parenchymal cells and are available for recognition. Islet tissue in both rejecting proislet and islet allografts showed de novo induction of Class II MHC alloantigens only after severe disruption to islet architecture had been achieved by infiltrating mononuclear cells. Thus, at this stage of advanced allograft injury, CD4 T cells have the potential to act as secondary effectors, possibly by amplifying the inflammatory reaction and thus accelerating graft destruction. The capacity for antirejection mAb therapy to establish transplant tolerance was facilitated in the islet allograft model where it was necessary to target only the CD8 T cell subpopulation.

Genomic prediction of reproduction traits for Merino sheep

Economically important reproduction traits in sheep, such as number of lambs weaned and litter size, are expressed only in females and later in life after most selection decisions are made, which makes them ideal candidates for genomic selection. Accurate genomic predictions would lead to greater genetic gain for these traits by enabling accurate selection of young rams with high genetic merit. The aim of this study was to design and evaluate the accuracy of a genomic prediction method for female reproduction in sheep using daughter trait deviations (DTD) for sires and ewe phenotypes (when individual ewes were genotyped) for three reproduction traits: number of lambs born (NLB), litter size (LSIZE) and number of lambs weaned. Genomic best linear unbiased prediction (GBLUP), BayesR and pedigree BLUP analyses of the three reproduction traits measured on 5340 sheep (4503 ewes and 837 sires) with real and imputed genotypes for 510 174 SNPs were performed. The prediction of breeding values using both sire and ewe trait records was validated in Merino sheep. Prediction accuracy was evaluated by across sire family and random cross-validations. Accuracies of genomic estimated breeding values (GEBVs) were assessed as the mean Pearson correlation adjusted by the accuracy of the input phenotypes. The addition of sire DTD into the prediction analysis resulted in higher accuracies compared with using only ewe records in genomic predictions or pedigree BLUP. Using GBLUP, the average accuracy based on the combined records (ewes and sire DTD) was 0.43 across traits, but the accuracies varied by trait and type of cross-validations. The accuracies of GEBVs from random cross-validations (range 0.17-0.61) were higher than were those from sire family cross-validations (range 0.00-0.51). The GEBV accuracies of 0.41-0.54 for NLB and LSIZE based on the combined records were amongst the highest in the study. Although BayesR was not significantly different from GBLUP in prediction accuracy, it identified several candidate genes which are known to be associated with NLB and LSIZE. The approach provides a way to make use of all data available in genomic prediction for traits that have limited recording.

Genetic relationships between internal parasite resistance and production traits in Merino sheep

Breeding Merino sheep that are resistant to internal parasites alleviates the high costs associated with treatment of worm infestation and loss of production, as well as mitigating the development of anthelmintic resistance among the major worm species. Faecal worm egg count ((cube root transformation), wec) can be used in sheep as a measure of internal parasite resistance. Accurate estimates of genetic parameters for wec are required for calculation of Australian Sheep Breeding Values and inclusion of worm resistance in sheep breeding programs. This study provides updated estimates of heritability for wec and its genetic correlations with production traits. Data were analysed from a wide range of Australian and New Zealand Merino sheep in the MERINOSELECT database, which included 141 flocks with 801 flock years and up to 217 137 animals with wec recorded in at least one of four ages (W = weaning, P = post weaning, Y = yearling, H = hogget). The heritability estimates ranged from 0.16 ± 0.01 for Ywec to 0.29 ± 0.01 for Wwec, with generally high genetic correlations between the ages. Bivariate analyses estimated genetic correlations between wec at the various ages and growth, carcass quality, reproduction and wool production traits at various ages. These genetic correlations were generally small or close to zero, albeit with some significantly different from zero. The moderate heritability for wec (0.2–0.3) and its high phenotypic variation (coefficient of variation >30%) shows that relatively rapid selection response for worm resistance could be achieved. Inclusion of wec in sheep breeding programs to increase worm resistance would be expected to have little if any impact on other important production traits. These genetic parameters have been incorporated into MERINOSELECT by Sheep Genetics to provide Australian Sheep Breeding Values for wec and appropriate indices for wool and meat production. There is evidence that genotype × environment interactions may be important in some environments by reducing the accuracy of Australian Sheep Breeding Values for wec. Hence it may be prudent for breeders to implement strategies that manage the risk of any impact of genotype × environment on their breeding program.

Genetic evaluation of adult ewe bodyweight and condition: relationship with lamb growth, reproduction, carcass and wool production

This paper reports on genetic variation in the growth, wool production, carcass, reproduction and the bodyweight and body condition of ewes managed in the Information Nucleus Flock (INF), with a focus on evaluating the potential value of including adult ewe bodyweight and condition change traits in the Australian national sheep genetic evaluations provided by Sheep Genetics. Data were collected over a 7-year period (2007–2013) at eight research sites across southern Australia. Approximately 13 700 ewes were weighed and condition scored with ewes on average mated four times during the study. Adult ewe weight and body condition were recorded across the production cycle and the impact of the physiological status and change in status of the ewe on the genetic relationships with lamb growth, carcass and wool production traits was evaluated. Strong genetic correlations between measurements across the production cycle for adult ewe bodyweight and condition, low heritability of change traits, along with weak genetic relationships between change traits and key production traits suggest that in production systems where nutritional challenges can be managed, change traits provide no improvement to the current practice of using static bodyweight and condition records. The genetic variation in weight and body condition and their genetic relationships with production traits were highly consistent across ages and the production cycle. As a result, the current practice by Sheep Genetics to treat adult weight as a single trait with repeat records is most likely sufficient. However, the inclusion of body condition within the Sheep Genetics evaluation has potential to assist in improving maternal performance, and the feed costs associated with maintaining ewe body condition.

Impact of liveweight, fat and muscle sire breeding values on ewe reproduction is minimal but variable across Australian grazing systems

Australian sheep producers have the potential to improve reproductive rates through optimising ewe body condition across the production cycle. Managing ewe body condition can become costly when supplementary feeding is required due to poor pasture growth or rainfall and by using appropriate genetics, producers can theoretically reduce the flock’s dependency on supplementary feed and improve reproductive rates. Reproductive records from the Information Nucleus Flock and Sheep Genetics Merino and maternal breed datasets were analysed to examine the influence of sire breeding values for liveweight (post-weaning, yearling and adult assessments), fat and eye muscle depths (post-weaning and yearling assessments) and number of lambs weaned on reproductive performance (fertility, litter size and number of lambs born) across a variety of production environments. To determine the impact of environmental conditions on the relationship between weight, ultrasound body composition, and reproduction traits the daughters’ adjusted reproductive performances were regressed on the sire’s breeding value across flocks, within flocks and within flock × year. Irrespective of age at assessment, sire breeding values for liveweight, fat and eye muscle depths had very little association with the reproductive performance of their daughters, on average. The regressions of reproduction on weight, and fat and eye muscle depth traits varied across flocks from unfavourable to favourable estimates. The very small overall impact of weight, and fat and eye muscle depth traits, on average suggests that using sire breeding values for number of lambs weaned, which had a large impact on reproduction, will provide the most viable method to genetically improve reproductive performance within the production system in question.

Impact of young ewe fertility rate on risk and genetic gain in sheep-breeding programs using genomic selection

Genomic selection could be useful in sheep-breeding programs, especially if rams and ewes are first mated at an earlier age than is the current industry practice. However, young-ewe (1 year old) fertility rates are known to be lower and more variable than those of mature ewes. The aim of the present study was to evaluate how young-ewe fertility rate affects risk and expected genetic gain in Australian sheep-breeding programs that use genomic information and select ewes and rams at different ages. The study used stochastic simulation to model different flock age structures and young-ewe fertility levels with and without genomic information for Merino and maternal sheep-breeding programs. The results from 10 years of selection were used to compare breeding programs on the basis of the mean and variation in genetic gain. Ram and ewe age, availability of genomic information on males and young-ewe fertility level all significantly (P < 0.05) affected expected genetic gain. Higher young-ewe fertility rates significantly increased expected genetic gain. Low fertility rate of young ewes (10%) resulted in net genetic gain similar to not selecting ewes until they were 19 months old and did not increase breeding-program risk, as the likelihood of genetic gain being lower than the range of possible solutions from a breeding program with late selection of both sexes was zero. Genomic information was of significantly (P < 0.05) more value for 1-year-old rams than for 2-year-old rams. Unless genomic information was available, early mating of rams offered no greater gain in Merino breeding programs and increased breeding-program risk. It is concluded that genomic information decreases the risk associated with selecting replacements at 7 months of age. Genetic progress is unlikely to be adversely affected if fertility levels above 10% can be achieved. Whether the joining of young ewes is a viable management decision for a breeder will depend on the fertility level that can be achieved in their young ewes and on other costs associated with the early mating of ewes.

A low cost virtual reality system for home based rehabilitation of the arm following stroke: a randomised controlled feasibility trial

Objective:

To assess the feasibility of conducting a randomised controlled trial of a home-based virtual reality system for rehabilitation of the arm following stroke.

Design:

Two group feasibility randomised controlled trial of intervention versus usual care.

Setting:

Patients’ homes.

Participants:

Patients aged 18 or over, with residual arm dysfunction following stroke and no longer receiving any other intensive rehabilitation.

Interventions:

Eight weeks’ use of a low cost home-based virtual reality system employing infra-red capture to translate the position of the hand into game play or usual care.

Main measures:

The primary objective was to collect information on the feasibility of a trial, including recruitment, collection of outcome measures and staff support required. Patients were assessed at three time points using the Wolf Motor Function Test, Nine-Hole Peg Test, Motor Activity Log and Nottingham Extended Activities of Daily Living.

Results:

Over 15 months only 47 people were referred to the team. Twenty seven were randomised and 18 (67%) of those completed final outcome measures. Sample size calculation based on data from the Wolf Motor Function Test indicated a requirement for 38 per group. There was a significantly greater change from baseline in the intervention group on midpoint Wolf Grip strength and two subscales of the final Motor Activity Log. Training in the use of the equipment took a median of 230 minutes per patient.

Conclusions:

To achieve the required sample size, a definitive home-based trial would require additional strategies to boost recruitment rates and adequate resources for patient support.

Sensitivity of the cochlear nerve to acoustic and electrical stimulation months after a vestibular labyrinthectomy in guinea pigs

Single-sided deafness patients are now being considered candidates to receive a cochlear implant. With this, many people who have undergone a unilateral vestibular labyrinthectomy for the treatment of chronic vertigo are now being considered for cochlear implantation. There is still some concern regarding the potential efficacy of cochlear implants in these patients, where factors such as cochlear fibrosis or nerve degeneration following unilateral vestibular labyrinthectomy may preclude their use. Here, we have performed a unilateral vestibular labyrinthectomy in normally hearing guinea pigs, and allowed them to recover for either 6 weeks, or 10 months, before assessing morphological and functional changes related to cochlear implantation. Light sheet fluorescence microscopy was used to assess gross morphology throughout the entire ear. Whole nerve responses to acoustic, vibrational, or electrical stimuli were used as functional measures. Mild cellular infiltration was observed at 6 weeks, and to a lesser extent at 10 months after labyrinthectomy. Following labyrinthectomy, cochlear sensitivity to high-frequency acoustic tone-bursts was reduced by 16 ± 4 dB, vestibular sensitivity was almost entirely abolished, and electrical sensitivity was only mildly reduced. These results support recent clinical findings that patients who have received a vestibular labyrinthectomy may still benefit from a cochlear implant.

Ability of sire breeding values to predict progeny bodyweight, fat and muscle using various transformations across environments in terminal sire sheep breeds

Data used for the genetic evaluation of the terminal sire sheep breeds in Australia originate from a large range of genotypes and environments. This means there are large differences in the level of production and therefore contemporary group means and variances within the data. This study examined four transformations to account for the heterogeneity of variance in the observed data and their effect on the ability of estimated breeding values of sires (sire EBV) to predict progeny performance. This predictive ability was described by regressing offspring performance on sire EBV. The expected value of this regression is 0.5, which indicates that half of the sire EBV differences can be expected in the progeny. The transformations of observed data were investigated in low, medium and high production environments for weight and ultrasound scan traits (fat and muscle) in terminal sire sheep breeds. There were records from over 300 000 sheep in the LAMBPLAN terminal sire dataset, predominately from Poll Dorset, Texel, Suffolk and White Suffolk breeds. The transformation methods applied to the observed data were: traits expressed as a percentage of the contemporary group mean; traits re-scaled to a common contemporary group mean in units of measurement; a logarithmic transformation; and a square root transformation. The heritabilities and other variance ratios estimated from the transformed traits were not significantly different from those using the observed data. Phenotypes transformed to a proportion of the contemporary group mean, either as a percentage or in units of measurement, resulted in the most consistent EBV across all production environments for weight and fat traits, with little effect of transformations for muscle traits. The transformation of data to the contemporary mean in units of measurement for weight and fat traits has been implemented in the Sheep Genetics evaluation system. The consistency of the progeny–sire EBV regressions around 0.5 in the data from these purebred industry flocks is heartening for terminal sire evaluation.

Estimation of genetic parameters for lambing ease, birthweight and gestation length in Australian sheep

This study presents estimates of genetic parameters for lambing ease (LE), birthweight (BW) and gestation length (GL) in Australian terminal sire sheep breeds using data from the Sheep Genetics LAMBPLAN database. LE was scored on lambs on a 1–5 scale, with 1 being no assistance and 5 being other such as special veterinary assistance. The full dataset consisted of 43 448 records on LE and its two subsets (the single and twin subsets) based on the birth type of the litter were analysed. Four models with different combinations of random effects consisting of direct genetic, maternal genetic and maternal permanent environmental effects were compared. All traits were analysed using linear animal models and linear sire models with LE further analysed by threshold sire models for all datasets to evaluate the influence of datasets and models on the estimation of genetic parameters. The results showed that multiple-born lambs had shorter GL, less BW and less lambing difficulty than single-born lambs. Lambing difficulty decreased with the increase of dam age from 1.5 to 4.5 years, and then increased afterwards. Genetic parameters using linear animal models were similar to those using linear sire models for all traits. Phenotypic variance and direct heritability were higher for single-born lambs compared with twin-born lambs. No significant maternal permanent environmental effect was detected for LE. Based on results using linear animal models with the full dataset, the direct heritabilities were 0.06 ± 0.01, 0.15 ± 0.01 and 0.52 ± 0.02, the maternal heritabilities were 0.03 ± 0.01, 0.15 ± 0.01 and 0.13 ± 0.02 for LE, BW and GL, respectively. The proportions of maternal permanent environmental effects to the total variances were 0.13 ± 0.01 for BW. Low to moderate direct genetic correlations of 0.31 ± 0.09 (LE and BW), 0.24 ± 0.11 (LE and GL) and 0.08 ± 0.08 (BW and GL) were estimated using tri-variate analysis from the full dataset, indicating the trend that lambs with greater BW and longer GL would result in more lambing difficulty.

Genetic importance of fat and eye muscle depth in Merino breeding programs

Australian Merino breeders have traditionally selected animals for breeding predominately on the basis of wool characteristics. Over recent decades, an increasing proportion of Merino breeders are interested in producing a ewe that can be used for prime-lamb production, but that also performs well for wool characteristics. Correlations between ultrasound carcass traits and other traits such as wool, internal parasite resistance and reproduction traits, are not very well known. The aims of this study were three-fold: (1) to estimate the genetic relationships between ultrasound carcass traits and wool, internal parasite resistance and reproduction traits, (2) to determine the value of recording ultrasound carcass traits in Merino breeding programs, and (3) to evaluate the impact of improving ewe genetic merit for fatness on their reproduction performance. Ultrasound fat and eye muscle depth had small to moderate genetic correlations with most traits, with positive correlations observed for bodyweight, fibre diameter, fibre curvature and reproduction, and negative correlations observed for fleece weight, fibre diameter coefficient of variation, worm egg count and breech wrinkle. As expected on the basis of these genetic correlations, estimated breeding values for fat depth of ewes had a positive association with their observed reproduction performance, but the effect explained only minimal variation in reproductive performance, and was extremely variable among flocks and years. A range of measurement scenarios was investigated for three standard MERINOSELECT indexes. Measuring fat and eye muscle depth resulted in 3%, 4% and 21% additional economic index gain for the fine, medium and dual purpose indexes, respectively, whereas measuring reproduction traits directly resulted in 17%, 27% and 45% additional gain in the economic index. Dual purpose index gains benefited more from measuring ultrasound carcass traits as it is the only index with a direct economic value placed on carcass traits. Measuring fat and eye muscle depth also resulted in a greater reduction in worm egg count. The results indicated that desirable genetic progress can be made in wool, ultrasound carcass, internal parasite resistance and number of lambs born and weaned simultaneously using multiple trait selection to account for the mix of favourable and unfavourable correlations between these traits. These results also demonstrated that the best method to maximise economic gain is to measure as many traits (or closely correlated traits) in the breeding objective as possible.

Genetic parameters for liveweight, wool and worm resistance traits in multi-breed Australian meat sheep. 1. Description of traits, fixed effects, variance components and their ratios

Sheep breeders in Australia that focus on lamb production simultaneously breed sheep that have higher growth rate, improved carcass quality and are resistant to internal parasites. The objective of this study was to estimate genetic parameters for 11 traits recorded in Australian meat sheep, covering liveweight, carcass and internal parasite resistance traits. As the population of meat sheep in this database have become increasingly crossbred this study also investigates the genetic variation within and between breeds. The data comprised 1 046 298 animals from 149 Poll Dorset, 17 Suffolk, 24 Texel and 118 White Suffolk flocks. The results are averages of analyses of 10 datasets constructed by randomly sampling 25% of these flocks. There was considerable genetic variation in all traits analysed: the lowest heritabilities (0.12) were found for weaning weight and the highest heritabilities (0.31–0.32) for eye muscle depth. There were also significant differences between breeds for most traits, which breeders appear to be utilising through crossbreeding. Direct heterosis effects were small and only significant for the liveweight traits ranging from 2% to 3.4% of the phenotypic means. Maternal heterosis was not significant for any trait studied. The inclusion of heterosis effects in the model did not significantly influence the estimated genetic parameters. The results from this study have been used to review the genetic parameters used in the LAMBPLAN routine genetic evaluations conducted by Sheep Genetics.

Genetic parameters for liveweight, wool and worm resistance traits in multi-breed Australian meat sheep. 2. Genetic relationships between traits

Australian sheep breeders aim to simultaneously breed sheep that have high growth rate, superior carcass quality and are resistant to internal parasites. The objective of this study was to estimate genetic and phenotypic relationships between 11 traits recorded in Australian meat sheep, covering liveweight, carcass and internal parasite resistance traits. The data comprised 1 046 298 animals from 149 Poll Dorset, 17 Suffolk, 24 Texel and 118 White Suffolk flocks. Within all trait groups, the different age expressions were moderately to highly correlated. The genetic correlations between liveweight with both fat and eye muscle depth were generally negative ranging between –0.10 and –0.42. Fat and eye muscle depth were moderately correlated (0.27–0.59). Results indicate that selection for an increase in liveweight will have a negative effect on fat and eye muscle depth. The negative correlations of ultrasound scan traits and worm egg count indicates that animals with high genetic merit for fat and eye muscle depth are less prone to infection from internal parasites. The results from this study have been used to review the genetic correlations used in the LAMBPLAN routine genetic evaluations conducted by Sheep Genetics.

Genetic evaluation of maternal behaviour and temperament in Australian sheep

The temperament of ewes and maternal behaviour at lambing has been implicated as contributing factors to lamb survival. Some 14 054 records of maternal behaviour score (MBS, 1 = good, 5 = poor) were collected at lamb tagging from 32 breeds of sheep over several years in a variety of environments. Records for two objectively scored temperament traits, flight time from a weighing crate (FT) and agitation score in an isolation box test (IBT) were available on 19 151 and 17 159 animals, respectively. These data were pooled from three sources, which included research and commercial ram breeding flocks. The combined data were also split into three subsets based on breed groups (Merino, Maternal and Terminal) for analyses. Records of weights and number of lambs weaned (NLW), as well as pedigree information was available from the national genetic evaluation database. The heritability estimates from the combined analyses were 0.20 ± 0.02 for MBS, 0.18 ± 0.02 for FT and 0.26 ± 0.02 for IBT, with a repeatability of 0.24 ± 0.01 for MBS. There were some small differences between the breed groups in the heritability estimates. The genetic correlations between FT and MBS were negative (favourable) and consistent across the datasets (–0.47 ± 0.12, combined analysis). The genetic correlations between IBT and MBS were positive (favourable) but not significant (0.12 ± 0.11, combined analysis). The genetic correlations between IBT and FT were also favourable, but small and generally not significant. There were small favourable genetic correlations between MBS and various bodyweights (–0.17 ± 0.07, yearling) and NLW (–0.25 ± 0.07). However, there were no significant genetic relationships between the temperament and production traits. The moderate heritability and repeatability of MBS indicate maternal behaviour could be improved by selection, and that it could be a useful additional trait in breeding programs for improved reproduction.

Treatment of fracture subluxations of the proximal interphalangeal joint using a ligamentotaxis device: a multidisciplinary approach

Complex fracture subluxations of the proximal interphalangeal joint are often difficult to treat and their outcome variable. A number of methods for treatment of these injuries have been described. We have used a ligamentotaxis device (Ligamentotaxor, Arex, Palaiseau Cedex, France) since 2008. We performed 28 operations in 28 patients with complex proximal interphalangeal joint injuries over a 3-year period. Patients followed a standardized postoperative rehabilitation regime, including fixator adjustment as necessary. The mean age was 33 years (range 18-67). The mean time to surgery was 7 days. At final follow-up (mean 22 months, range 6-52) the mean proximal interphalangeal joint range of motion was 85° (range 60°-110°). The mean QuickDASH functional outcome score was 4.8 (range 0-36.4). Our results compare favourably with other devices reported in the literature.

Monitoring liveweight in sheep is a valuable management strategy: a review of available technologies

Liveweight is a widely accepted proxy for the energy status of sheep at a particular point in time. Fleece- and conceptus-free ewe liveweight and liveweight change influence the productivity of the ewe and optimisation may increase whole-farm profitability. Despite this, it is uncommon for producers to monitor ewe liveweight regularly and objectively. The current review discusses why ewe liveweight is important, identifies and assesses available technologies for monitoring sheep liveweight, and highlights future research priorities. The common theme in the literature is that while there are options that could possibly be used to monitor the liveweight of sheep in extensive grazing systems, few of them offer realistic solutions, especially in regard to timeliness of data collection. Thermal and stereo imaging, body measurements and plasma hormonal assays are unlikely to be commercially viable, while visual assessment, although widely practised, offers a surprisingly poor indication of sheep liveweight. Alternatively, assessment of body condition (condition scoring) or fat (fat scoring) offers viable methods of assessing sheep energy status; however, like conventional static weighing, they are performed infrequently and therefore contribute little to the day-to-day tactical management of sheep flocks. Walk-over weighing systems offer a feasible alternative for regular monitoring of sheep liveweight. Such systems are fully automated, and may be operated remotely. Currently, there are challenges associated with monitoring the liveweight of individual animals using such systems and hence there is little commercial opportunity for individual animal management. Mob-based walk-over weighing, which generates flock average liveweight estimates, offers greater potential in the short term, although the technology would benefit from further research and development, primarily to increase the frequency and repeatability of liveweight capture.

The role of post-operative radiographs in predicting risk of flexor pollicis longus tendon rupture after volar plate fixation of distal radius fractures - a case control study

BACKGROUND AND AIM

Volar plating of distal radius fractures is one of the common procedures performed in trauma surgery. Flexor pollicis longus (FPL) rupture has been described as complication following volar plating of distal radius fractures. The aim of our study was to investigate the possible relation between parameters measured on post-operative radiographs and the occurrence of FPL ruptures.

MATERIALS AND METHODS

This was a case control study. The post-operative radiographs of 11 FPL rupture, and 22 non-FPL rupture patients were reviewed with respect to fracture reduction and plate position and the various parameters were calculated by five independent people. Logistic regression was used to examine the importance of the variables.

RESULTS

We identified two significant factors to predict FPL rupture after volar plating of distal radial fractures. These were radial tilt and plate distance from the joint line. The odds ratio of ruptures was 0.74 (95% CI 0.57-0.95) for every degree of radial tilt <25° and 0.50 (95% CI 0.28-0.88) for every millimetre that the distal end of the plate was away from the volar lip of the distal radius at the wrist joint.

CONCLUSION

Post-operative radiographs could help us predict FPL rupture after distal radius volar plating. The findings also highlight the need for good fracture reduction and thoughtful placement of the volar plate intraoperatively to minimise the risk of FPL tendon rupture.

Short to medium results using the remotion total wrist replacement for rheumatoid arthritis

We present the clinical outcome of patients who underwent RE-MOTION Total Wrist Replacement (TWR) for the treatment of Rheumatoid arthritis involving the wrist. Ten patients were available for follow-up, ranging from one to five years after index surgery. Two patients required surgical intervention for wound breakdown, including one patient who required a radial forearm flap for skin coverage. No patients required revision surgery or conversion to fusion. Patients who did not have complications gained statistically significant pain relief and improvement in mean overall flexion. In this small case series with short to medium results patients reported an improvement in terms of flexion and pain. Despite this, the question of efficacy of TWR compared to fusion in the long term remains unanswered due to the high rate of complications.