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Genomic selection and doubled haploids hold significant potential to enhance genetic gains and shorten breeding cycles across various crops. Here, we utilized stochastic simulations to investigate the best strategies for optimize a sweet corn breeding program. We assessed the effects of incorporating varying proportions of old and new parents into the crossing block (3:1, 1:1, 1:3, and 0:1 ratio, representing different degrees of parental substitution), as well as the implementation of genomic selection in two distinct pipelines: one calibrated using the phenotypes of testcross parents (GSTC scenario) and another using F1 individuals (GSF1). Additionally, we examined scenarios with doubled haploids, both with (DH) and without (DHGS) genomic selection. Across 20 years of simulated breeding, we evaluated scenarios considering traits with varying heritabilities, the presence or absence of genotype-by-environment effects, and two program sizes (50 vs 200 crosses per generation). We also assessed parameters such as parental genetic mean, average genetic variance, hybrid mean, and implementation costs for each scenario. Results indicated that within a conventional selection program, a 1:3 parental substitution ratio (replacing 75% of parents each generation with new lines) yielded the highest performance. Furthermore, the GSTC model outperformed the GSF1 model in enhancing genetic gain. The DHGS model emerged as the most effective, reducing cycle time from 5 to 4 years and enhancing hybrid gains despite increased costs. In conclusion, our findings strongly advocate for the integration of genomic selection and doubled haploids into sweet corn breeding programs, offering accelerated genetic gains and efficiency improvements., Competing Interests: Conflicts of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Genetics Society of America.)

Sweet corn breeding programs, like field corn, focus on the development of elite inbred lines to produce commercial hybrids. For this reason, genomic selection models can help the in silico prediction of hybrid crosses from the elite lines, which is hypothesized to improve the test cross scheme, leading to higher genetic gain in a breeding program. This study aimed to explore the potential of implementing genomic selection in a sweet corn breeding program through hybrid prediction in a within-site across-year and across-site framework. A total of 506 hybrids were evaluated in six environments (California, Florida, and Wisconsin, in the years 2020 and 2021). A total of 20 traits from three different groups were measured (plant-, ear-, and flavor-related traits) across the six environments. Eight statistical models were considered for prediction, as the combination of two genomic prediction models (GBLUP and RKHS) with two different kernels (additive and additive + dominance), and in a single- and multi-trait framework. Also, three different cross-validation schemes were tested (CV1, CV0, and CV00). The different models were then compared based on the correlation between the estimated breeding values/total genetic values and phenotypic measurements. Overall, heritabilities and correlations varied among the traits. The models implemented showed good accuracies for trait prediction. The GBLUP implementation outperformed RKHS in all cross-validation schemes and models. Models with additive plus dominance kernels presented a slight improvement over the models with only additive kernels for some of the models examined. In addition, models for within-site across-year and across-site performed better in the CV0 than the CV00 scheme, on average. Hence, GBLUP should be considered as a standard model for sweet corn hybrid prediction. In addition, we found that the implementation of genomic prediction in a sweet corn breeding program presented reliable results, which can improve the testcross stage by identifying the top candidates that will reach advanced field-testing stages., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Peixoto, Leach, Jarquin, Flannery, Zystro, Tracy, Bhering and Resende.)

Background: Achieving a reduction in mastitis in dairy cows is a common industry goal, but there is no recent peer-reviewed record of progress in the UK., Methods: A convenience sample of 125 herds in England and Scotland was recruited based on the quality of records in 2016, willingness to participate and representative geographical distribution. Individual cow somatic cell counts and clinical mastitis data from 2012 to 2021 were summarised annually, and temporal changes were analysed. Eighty-one herds had sufficient data for comparison between 2012 and 2021, for one or more parameters., Results: Over this period, the median incidence rate of clinical mastitis decreased from 40.0 to 21.0 cases per 100 cows per year (p < 0.001), with improvement in both lactation and dry period indicators. Lactation new infection rate calculated from individual cow somatic cell counts fell from 8.75% to 5.95% (p < 0.001), dry period new infection rate fell from 16.8% to 14.1% (p < 0.05) and proportion of cows over 200,000 cells/mL fell from 20.0% to 14.3% (p < 0.001)., Limitations: Data were necessarily from herds with good records and do not provide absolute values for the industry., Conclusion: The findings reflect good progress over a 10-year period in a cohort of well-recorded herds and align with other national datasets., (© 2023 British Veterinary Association.)

Considerable efforts have been made to characterize active enhancer elements, which can be annotated by accessible chromatin and H3 lysine 27 acetylation (H3K27ac). However, apart from poised enhancers that are observed in early stages of development and putative silencers, the functional significance of cis-regulatory elements lacking H3K27ac is poorly understood. Here we show that macroH2A histone variants mark a subset of enhancers in normal and cancer cells, which we coined 'macro-Bound Enhancers', that modulate enhancer activity. We find macroH2A variants localized at enhancer elements that are devoid of H3K27ac in a cell type-specific manner, indicating a role for macroH2A at inactive enhancers to maintain cell identity. In following, reactivation of macro-bound enhancers is associated with oncogenic programs in breast cancer and their repressive role is correlated with the activity of macroH2A2 as a negative regulator of BRD4 chromatin occupancy. Finally, through single cell epigenomic profiling of normal mammary stem cells derived from mice, we show that macroH2A deficiency facilitates increased activity of transcription factors associated with stem cell activity., (© 2023. The Author(s).)

Background: The nature and depth of bedding material have an important influence on cow lying behaviour and comfort. Increasing use of recycled manure solids (RMS) as bedding led to an investigation of the influence of this material on cow lying behaviour., Methods: Leg mounted accelerometers were used to estimate daily lying time and number and duration of lying bouts in four groups of 40 cows. Each group spent two 2-week periods on each of four bedding systems: deep sand, deep RMS, sawdust on mattresses and RMS on mattresses., Results: Total daily lying times were significantly shorter on both RMS treatments than on sawdust. Number of lying bouts per day was greater on sawdust than any other treatment, while lying bouts were 2.6 min longer on deep RMS and 9.3 min longer on sand, than on sawdust., Conclusions: Greater depth and apparent softness of bedding material does not necessarily result in longer total daily lying times. RMS may have some characteristics that reduce its attraction as a bedding material for cows. The influence of bedding system on number and duration of lying bouts and the resulting total lying time appear complex., (© 2021 British Veterinary Association.)

In maize, starch mutants have facilitated characterization of key genes involved in endosperm starch biosynthesis such as large subunit of AGPase Shrunken2 ( Sh2 ) and isoamylase type DBE Sugary1 ( Su1 ). While many starch biosynthesis enzymes have been characterized, the mechanisms of certain genes (including Sugary enhancer1 ) are yet undefined, and very little is understood about the regulation of starch biosynthesis. As a model, we utilize commercially important sweet corn mutations, sh2 and su1 , to genetically perturb starch production in the endosperm. To characterize the transcriptomic response to starch mutations and identify potential regulators of this pathway, differential expression and coexpression network analysis was performed on near-isogenic lines (NILs) (wildtype, sh2 , and su1 ) in six genetic backgrounds. Lines were grown in field conditions and kernels were sampled in consecutive developmental stages (blister stage at 14 days after pollination (DAP), milk stage at 21 DAP, and dent stage at 28 DAP). Kernels were dissected to separate embryo and pericarp from the endosperm tissue and 3' RNA-seq libraries were prepared. Mutation of the Su1 gene led to minimal changes in the endosperm transcriptome. Responses to loss of sh2 function include increased expression of sugar (SWEET) transporters and of genes for ABA signaling. Key regulators of starch biosynthesis and grain filling were identified. Notably, this includes Class II trehalose 6-phosphate synthases, Hexokinase1 , and Apetala2 transcription factor-like (AP2/ERF) transcription factors. Additionally, our results provide insight into the mechanism of Sugary enhancer1 , suggesting a potential role in regulating GA signaling via GRAS transcription factor Scarecrow-like1 ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Finegan, Boehlein, Leach, Madrid, Hannah, Koch, Tracy and Resende.)

Selective use of antibiotic dry cow treatment can be implemented at the cow or quarter level, with the latter having the potential to further reduce antibiotic use. Our objective was to compare these 2 approaches in 6 herds in the United Kingdom in which environmental mastitis predominated. Eight hundred seven cows were enrolled and categorized as having a high cell count (n = 401) or low cell count (n = 406) in the last 3 mo of lactation and clinical mastitis history. All quarters of all enrolled cows received an internal teat sealant. Within each category, cows were randomly allocated to 1 of 3 groups; in one group antibiotic treatment was allocated at cow level (i.e., all 4 quarters received antibiotic), whereas in the 2 remaining groups antibiotic treatment was allocated at quarter level, based on California Mastitis Test (CMT) findings. Two different thresholds, score 1 and 2, were used to determine likely infection status. Quarter milk samples were collected at dry off and postcalving for bacteriological culture and somatic cell count (SCC). Cows were monitored for clinical mastitis from dry off until 100 d in milk. Cow level SCC and milk yield data were collated from farm records. Within each category, the 2 quarter level treatment groups were compared with cow level treatment at dry off. Leaving quarters untreated with intramammary antibiotic in cows in the high cell count group, with a CMT <2 or <1, reduced antibiotic use by 55% and 31%, respectively, and resulted in no difference in the odds of being infected with any pathogen postcalving, but was associated with a higher SCC at the first test day. Intramammary antibiotic treatment of quarters with a CMT ≥1 in cows in the low cell count category at dry off was not associated with any reduction in the odds of being infected with a major pathogen postcalving but was associated with a decrease in the odds of being infected with a minor mastitis pathogen postcalving. The use of antibiotics in quarters of cows categorized as low cell count at dry off, increased the proportion of quarters treated with antibiotic from 0% at cow level to 31% (CMT ≥ 1) and 12% (CMT ≥ 2) at quarter level, only resulting in a reduction in SCC of around 20,000 cells/mL at the first test day, if all quarters with CMT score ≥1 were treated with antibiotic. No differences in clinical mastitis incidence and milk yield in the first 100 d in milk were detected between any of the treatment groups. These study findings support selective quarter level dry off treatment only in cows with cow level SCC >200,000 cells/mL at dry off., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Sweet corn is one of the most important vegetables in the United States and Canada. Here, we present a de novo assembly of a sweet corn inbred line Ia453 with the mutated shrunken2-reference allele (Ia453-sh2). This mutation accumulates more sugar and is present in most commercial hybrids developed for the processing and fresh markets. The ten pseudochromosomes cover 92% of the total assembly and 99% of the estimated genome size, with a scaffold N50 of 222.2 Mb. This reference genome completely assembles the large structural variation that created the mutant sh2-R allele. Furthermore, comparative genomics analysis with six field corn genomes highlights differences in single-nucleotide polymorphisms, structural variations, and transposon composition. Phylogenetic analysis of 5,381 diverse maize and teosinte accessions reveals genetic relationships between sweet corn and other types of maize. Our results show evidence for a common origin in northern Mexico for modern sweet corn in the U.S. Finally, population genomic analysis identifies regions of the genome under selection and candidate genes associated with sweet corn traits, such as early flowering, endosperm composition, plant and tassel architecture, and kernel row number. Our study provides a high-quality reference-genome sequence to facilitate comparative genomics, functional studies, and genomic-assisted breeding for sweet corn.

Mastitis in dairy cattle is extremely costly both in economic and welfare terms and is one of the most significant drivers of antimicrobial usage in dairy cattle. A critical step in the prevention of mastitis is the diagnosis of the predominant route of transmission of pathogens into either contagious (CONT) or environmental (ENV), with environmental being further subdivided as transmission during either the nonlactating "dry" period (EDP) or lactating period (EL). Using data from 1000 farms, random forest algorithms were able to replicate the complex herd level diagnoses made by specialist veterinary clinicians with a high degree of accuracy. An accuracy of 98%, positive predictive value (PPV) of 86% and negative predictive value (NPV) of 99% was achieved for the diagnosis of CONT vs ENV (with CONT as a "positive" diagnosis), and an accuracy of 78%, PPV of 76% and NPV of 81% for the diagnosis of EDP vs EL (with EDP as a "positive" diagnosis). An accurate, automated mastitis diagnosis tool has great potential to aid non-specialist veterinary clinicians to make a rapid herd level diagnosis and promptly implement appropriate control measures for an extremely damaging disease in terms of animal health, productivity, welfare and antimicrobial use.

The introduction of bedding dairy cows on recycled manure solids (RMS) in the UK led to concern by competent authorities that there could be an increased, unacceptable risk to animal and human health. A cross-sectional study was designed to evaluate the microbial content of different bedding materials, when used by dairy cows, and its impact on the microbial content of milk. Data were collected from farms bedding lactating cows on sand (n=41), sawdust (n=44) and RMS (n=40). The mean duration of RMS use prior to sampling was 13months. Total bacterial count, and counts of Streptococcus/Enterococcus spp., Staphylococcus spp., Bacillus cereus, thermophilic, thermoduric and psychrotrophic bacteria were determined in used bedding and milk. Samples were evaluated for the presence/absence of Listeria monocytogenes, Salmonella spp. and Yersinia enterocolitica. Data on milking practices were collected to investigate their potential to reduce microbial transfer from bedding to milk. There were substantial differences in bacterial counts both within and between bedding materials. However, there were no significant differences between bedding groups in counts in milk for any of the organisms studied, and no significant correlations between bacterial load in used bedding and milk. Fore-milking was associated with a reduced total bacterial count in milk. Dipping teats with disinfectant and drying, prior to milking, was associated with lower numbers of Streptococcus/Enterococcus spp. in milk. Disinfecting clusters between milking different cows was associated with a reduction in thermophilic and psychrotrophic counts in milk. This study did not provide evidence that use of RMS bedding increased the risk of presence of Y. enterocolitica, Salmonella spp. or L. monocytogenes in milk. However, the strength of this conclusion should be tempered by the relatively small number of farms on which Y. enterocolitica and Salmonella spp. were isolated. It is concluded that, despite the higher bacterial load of RMS, its use as bedding for lactating dairy cows need not be associated with a higher bacterial load in milk than the use of sand or sawdust. However, this finding must be interpreted in the light of the relatively recent introduction of RMS as a bedding material on the farms studied. Teat preparation provides a control point for the potential transfer of microorganisms from bedding to milk. The detection of zoonotic pathogens in a small proportion of milk samples, independent of bedding type, indicates that pasteurisation of milk prior to human consumption remains an important control measure., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The selection and field application of animal-based welfare measures for pigs, sheep, dairy cows and broilers was the first step towards the future development of welfare improvement schemes for Serbia - a country that is applying for EU accession. The aim of this pilot study was to: (1) test the feasibility of a protocol for monitoring farm animal welfare in Serbia, (2) ascertain preliminary data on animal-based outcomes of farm welfare and (3) gain insight into Serbian farmers' understanding of animal welfare as part of a wider project working towards inclusion of animal-based assessments in a 'higher welfare' voluntary assurance scheme. This study encompasses the first national survey of farm animal welfare in which animal-based outcomes were tested on 105 farms by a total of ten trained assessors. Data on the views and aspirations of the farmers from these 105 farms were also systematically gathered during face-to-face interviews. Existing animal-based measures for pigs, sheep, dairy cows and broilers that have been successfully applied and identified as valid, reliable and feasible measures in other countries, were found to be largely transferable. However, some on-farm protocols, previously used in other countries, had to be shortened for logistical reasons when used in Serbia. Our findings suggest that further refinement may be needed in order to allow local application of all measures. While the term 'animal welfare' has only recently been introduced into the Serbian language, seventy-three percent of farmers had heard of it. Overall, few positive associations were found between farmer satisfaction with animals' living conditions and animal-based data. Many farmers had aspirations to develop and expand their farms, which may potentially enhance animal welfare, but these farmers identified that financial and technical advice and support would be needed in order to achieve these goals.

Carbohydrate partitioning is the process of carbon assimilation and distribution from source tissues, such as leaves, to sink tissues, such as stems, roots and seeds. Sucrose, the primary carbohydrate transported long distance in many plant species, is loaded into the phloem and unloaded into distal sink tissues. However, many factors, both genetic and environmental, influence sucrose metabolism and transport. Therefore, understanding the function and regulation of sugar transporters and sucrose metabolic enzymes is key to improving agriculture. In this review, we highlight recent findings that (i) address the path of phloem loading of sucrose in rice and maize leaves; (ii) discuss the phloem unloading pathways in stems and roots and the sugar transporters putatively involved; (iii) describe how heat and drought stress impact carbohydrate partitioning and phloem transport; (iv) shed light on how plant pathogens hijack sugar transporters to obtain carbohydrates for pathogen survival, and how the plant employs sugar transporters to defend against pathogens; and (v) discuss novel roles for sugar transporters in plant biology. These exciting discoveries and insights provide valuable knowledge that will ultimately help mitigate the impending societal challenges due to global climate change and a growing population by improving crop yield and enhancing renewable energy production., (© The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

During daylight, plants produce excess photosynthates, including sucrose, which is temporarily stored in the vacuole. At night, plants remobilize sucrose to sustain metabolism and growth. Based on homology to other sucrose transporter (SUT) proteins, we hypothesized the maize (Zea mays) SUCROSE TRANSPORTER2 (ZmSUT2) protein functions as a sucrose/H + symporter on the vacuolar membrane to export transiently stored sucrose. To understand the biological role of ZmSut2, we examined its spatial and temporal gene expression, determined the protein subcellular localization, and characterized loss-of-function mutations. ZmSut2 mRNA was ubiquitously expressed and exhibited diurnal cycling in transcript abundance. Expressing a translational fusion of ZmSUT2 fused to a red fluorescent protein in maize mesophyll cell protoplasts revealed that the protein localized to the tonoplast. Under field conditions, zmsut2 mutant plants grew slower, possessed smaller tassels and ears, and produced fewer kernels when compared to wild-type siblings. zmsut2 mutants also accumulated two-fold more sucrose, glucose, and fructose as well as starch in source leaves compared to wild type. These findings suggest (i) ZmSUT2 functions to remobilize sucrose out of the vacuole for subsequent use in growing tissues; and (ii) its function provides an important contribution to maize development and agronomic yield., (© 2017 Institute of Botany, Chinese Academy of Sciences.)

Sucrose transporters (SUTs) translocate sucrose (Suc) across cellular membranes, and in eudicots, multiple SUTs are known to function in Suc phloem loading in leaves. In maize (Zea mays), the Sucrose Transporter1 (ZmSut1) gene has been implicated in Suc phloem loading based upon RNA expression in leaves, electrophysiological experiments, and phenotypic analysis of zmsut1 mutant plants. However, no previous studies have examined the cellular expression of ZmSut1 RNA or the subcellular localization of the ZmSUT1 protein to assess the gene's hypothesized function in Suc phloem loading or to evaluate its potential roles, such as phloem unloading, in nonphotosynthetic tissues. To this end, we performed RNA in situ hybridization experiments, promoter-reporter gene analyses, and ZmSUT1 localization studies to elucidate the cellular expression pattern of the ZmSut1 transcript and protein. These data showed that ZmSut1 was expressed in multiple cell types throughout the plant and indicated that it functions in phloem companion cells to load Suc and also in other cell types to retrieve Suc from the apoplasm to prevent its accumulation and loss to the transpiration stream. Additionally, by comparing a phloem-mobile tracer with ZmSut1 expression, we determined that developing maize leaves dynamically switch from symplasmic to apoplasmic phloem unloading, reconciling previously conflicting reports, and suggest that ZmSut1 does not have an apparent function in either unloading process. A model for the dual roles for ZmSut1 function (phloem loading and apoplasmic recycling), Sut1 evolution, and its possible use to enhance Suc export from leaves in engineering C 3 grasses for C 4 photosynthesis is discussed., (© 2016 American Society of Plant Biologists. All Rights Reserved.)

An easy-to-perform protocol for isolating and quantifying soluble sugars (sucrose, glucose, and fructose) and starch from maize (Zea mays) leaf tissue is described. The method has been optimized to extract non-structural carbohydrates (NSC) from frozen, finely ground tissue in a methanol:chloroform:water solution. Three rounds of tissue extraction for 30 min each at 50°C provide quantitative recovery of soluble sugars. The use of alternative extraction solvents is discussed, as well as the advantages and disadvantages of these solvents. Additionally, we provide two support protocols. The first quantifies the isolated NSC via commercially available enzymatic kits that couple the amount of each specific sugar to the production of NADPH, which is detected using equipment readily available to most laboratories. The second describes the preparation of a purification column to remove strongly charged or hydrophobic molecules from the extracted sugar solution, which is required prior to quantification with high-pressure liquid chromatography or high-performance anion-exchange chromatography. The protocols are robust and easily adapted for use in measuring NSC extracted from other plant species or tissues, making them ideal for new users. © 2016 by John Wiley & Sons, Inc., (Copyright © 2016 John Wiley & Sons, Inc.)

A simple, robust, inexpensive, high-throughput method for isolating genomic DNA from maize (Zea mays) leaf tissues is described. The DNA obtained using this extraction protocol is suitable for polymerase chain reaction (PCR) genotyping, which can be employed for the identification of alleles in diverse genetic and breeding approaches, such as marker-assisted selection, genetic fine mapping, and mutant introgression. This method utilizes 96-well plates for the collection of leaf tissue and the subsequent isolation of genomic DNA. The DNA isolation step is performed inexpensively within 3 hr and uses a urea-based extraction buffer that does not require an organic extraction step. Yields of genomic DNA are sufficient to perform ∼25 PCR-genotyping reactions per sample. These qualities, coupled with the protocol being robust and easy for inexperienced users to master, make this method ideal for new researchers. © 2016 by John Wiley & Sons, Inc., (Copyright © 2016 John Wiley & Sons, Inc.)

Material obtained from physical separation of slurry (recycled manure solids; RMS) has been used as bedding for dairy cows in dry climates in the US since the 1970s. Relatively recently, the technical ability to produce drier material has led to adoption of the practice in Europe under different climatic conditions. This review collates the evidence available on benefits and risks of using RMS bedding on dairy farms, with a European context in mind. There was less evidence than expected for anecdotal claims of improved cow comfort. Among animal health risks, only udder health has received appreciable attention. There are some circumstantial reports of difficulties of maintaining udder health on RMS, but no large scale or long term studies of effects on clinical and subclinical mastitis have been published. Existing reports do not give consistent evidence of inevitable problems, nor is there any information on clinical implications for other diseases. The scientific basis for guidelines on management of RMS bedding is limited. Decisions on optimum treatment and management may present conflicts between controls of different groups of organisms. There is no information on the influence that such 'recycling' of manure may have on pathogen virulence. The possibility of influence on genetic material conveying antimicrobial resistance is a concern, but little understood. Should UK or other non-US farmers adopt RMS, they are advised to do so with caution, apply the required strategies for risk mitigation, maintain strict hygiene of bed management and milking practices and closely monitor the effects on herd health., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A survey was conducted to elicit dairy farmers' willingness to pay (WTP) to reduce the prevalence of lameness in their herds. A choice experiment questionnaire was administered using face-to-face interviews of 163 farmers in England and Wales. Whole herd lameness assessments by trained researchers recorded a mean lameness prevalence of nearly 24% which was substantially higher than that estimated by farmers. Farmers' responses to a series of attitudinal questions showed that they strongly agreed that cows can suffer a lot of pain from lameness and believed that they could reduce lameness in their herds. Farmers' mean WTP to avoid lameness amounted to UK£411 per lame cow but with considerable variation across the sample. Median WTP of UK£249 per lame cow was considered a better measure of central tendency for the sample. In addition, the survey found that farmers had a substantial WTP to avoid the inconvenience associated with lameness control (a median value of UK£97 per lame cow) but that they were generally prepared to incur greater inconvenience if it reduced lameness. The study findings suggest that farmers need a better understanding of the scale and costs of lameness in their herds and the benefits of control. To encourage action, farmers need to be convinced that lameness control measures perceived as inconvenient will be cost effective., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Incomplete detection, high tolerance of lameness, and shortage of time and labour have been identified as barriers to reducing lameness in dairy herds. The effects of farmer participation in a project aimed at reducing lameness in dairy cattle on these factors were investigated. Over the course of the project farmers' detection of lameness improved and tolerance decreased. On farms entering the study with lameness prevalence below the median of 35%, improved detection was correlated with a reduction in lameness prevalence, but this was not the case for farms entering above the median prevalence. Lowered tolerance of lameness was correlated with reduced lameness regardless of initial prevalence. A greater importance given to lack of time as an initial barrier to progress was correlated with a greater reduction in lameness over the course of the project, suggesting that farmers who recognised limited time as a barrier were able to overcome this to some extent., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Insect endosymbionts influence many important metabolic and developmental processes of their host. It has been speculated that they may also help to manipulate and suppress plant defenses to the benefit of herbivores. Recently, endosymbionts of the root herbivore Diabrotica virgifera virgifera have been reported to suppress the induction of defensive transcripts in maize roots, which may explain the finding of another study that once attacked plants become more susceptible to subsequent D. v. virgifera attack. To test this hypothesis, we cured D. v. virgifera from its major endosymbiont Wolbachia and tested whether endosymbiont-free individuals elicit different defense responses in maize roots. The presence of Wolbachia did not alter the induction of defense marker genes and resistance in a susceptible maize hybrid and a resistant line. Furthermore, attacked maize plants emitted the same amount of (E)-β-caryophyllene, a volatile signal that serves as foraging cue for both entomopathogenic nematodes and D. v. virgifera. Finally, the effectiveness of the entomopathogenic nematode Heterorhabditis bacteriophora to infest D. v. virgifera was not changed by curing the larvae from their endosymbionts. These results show that the defense mechanisms of maize are not affected by Wolbachia. Consequently, D. v. virgifera does not seem to derive any plant-defense mediated benefits from its major endosymbiont.

Previous research has suggested that temperature at the coronary band increases in the presence of claw horn lesions in dairy cattle. However the reliability of using infrared thermography (IRT) as a method of distinguishing between lesions has not been investigated. The objective of this study was to examine the potential of IRT as a non-invasive tool for rapidly screening for the presence of digital dermatitis (DD). Eighty-two cows which either had no skin lesions on the hind feet (controls, n=41 feet) or a DD lesion on one or both feet were selected during milking. Following selection, each cow was moved into the farm crush where thermal images were taken from the plantar aspect of each foot at the pastern when the foot was dirty, cleaned and raised for visual inspection. Following recording of thermal images each hind foot was trimmed and the presence of any lesion recorded. It was found that the temperature did not differ significantly between feet with DD lesions and other skin or claw horn lesions, regardless of whether the feet were dirty, clean or raised for inspection. As IRT was not sensitive enough for lesion specific detection, the reliability of setting a temperature threshold above which any type of lesion causing lameness could be detected was investigated. The optimal trade off between sensitivity and specificity could be reached without having to either clean or lift the feet. Setting the threshold for disease at 27°C for dirty feet identified 80% of feet with lesions and 73% of feet without lesions correctly. In conclusion, IRT was reliable in detecting elevated temperature associated with foot lesions. Future research investigating the development of lesions may identify a temperature threshold for early treatment intervention. This technique may also be useful to quantify the effectiveness of early treatment by tracking recovery and recurrence of cases., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Many 'influencers' allied to the agricultural industry support farmers to implement management changes that affect animal welfare. Developing approaches to working with farmers that achieve both engagement and subsequently management changes is critical. As an example, the generation of action points and implementation of change to control dairy cattle lameness is reported and discussed here. Action plans were generated on farms receiving both lameness monitoring and intervention support (MS group; n=117) as part of a 3 year intervention project. At the start of year 1, MS farmers received action planning advice from a veterinary surgeon, and then at the start of years 2 and 3, farmers generated their own lameness control action plans with facilitator support. Engagement was achieved with 114 MS farmers who generated 692 action points in total. Two hundred and sixteen of these resulted from veterinary advice and 476 were generated by the farmers with facilitator support. In terms of activity, MS farms implemented a mean of 8.22 changes per farm as compared to 6.77 on farms which only received annual lameness monitoring (MO group; n=72). While these levels of change were similar, fewer changes implemented on the MS farms (8.5%) were judged 'likely to increase the risk of lameness' compared to the MO farms (16.5%). Farmers generated substantial numbers of lameness control action points for their own farms aided by a facilitator and, crucially, veterinary or facilitator involvement reduced changes that were likely to compromise lameness control., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Digital dermatitis (DD) is currently the most problematic infectious skin disease in dairy cattle associated with lameness. Reducing the disease prevalence through early detection and treatment is an essential management tool. The traditional detection method involves lifting and inspecting the feet in a cattle crush, but this is a time intensive and costly practice and impractical for regular detection of individual cases or monitoring herd prevalence. This study aimed to establish the accuracy of detecting and classifying DD lesions in traditional (pit) milking parlours compared with a borescope, and a gold standard lifted foot inspection. With the exception of one lesion, parlour screening was as accurate as the lifted foot inspection in determining the presence of 86 DD lesions on 160 hind feet (99% agreement; κ 0.99; sensitivity 1.00; specificity 0.99). Describing lesions by colour, depth or stage of lesion in the parlour or using the borescope reached substantial agreement with the gold standard. The stage of lesion was closely linked to colour and depth descriptors. There was greater agreement when categorising more advanced stages of disease progression. Borescope and parlour inspections led to both over and under recording of actual size, particularly in smaller lesions. Screening cows in traditional milking parlours for the presence of DD was found to be an accurate and practical means of detecting lesions. This method should be considered for on farm use to evaluate DD prevention and treatment strategies., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

An 'early threshold' protocol for treating cows within 48 h of being detected lame in one or more hind limbs at fortnightly mobility scoring was tested on a randomly selected group of cattle on four commercial dairy farms. The outcomes of the early threshold treatment for first cases of lameness were compared with those of the farmers' conventional approach to treatment. The early threshold schedule resulted in a much shorter time to treatment than the conventional approach, for which the median time from the cow first being scored lame to treatment was 65 days. The early threshold group presented with less severe foot lesions and cattle were less likely to be selected for further treatments by the farmer than conventionally treated cows. Early threshold treatment reduced the prevalence of lameness 4 weeks after treatment, compared with controls. A clear effect of the early treatment on milk yield was not detected., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Lameness in dairy cattle remains a significant welfare concern for the UK dairy industry. Farms were recruited into a 3-yr study evaluating novel intervention approaches designed to encourage farmers to implement husbandry changes targeted toward reducing lameness. All farms completing the study were visited at least annually and received either monitoring only (MO, n=72) or monitoring and additional support (MS, n = 117) from the research team. The additional support included traditional technical advice on farm-specific solutions, facilitation techniques to encourage farmer participation, and application of social marketing principles to promote implementation of change. Lameness prevalence was lower in the MO (27.0 ± 1.94 SEM) and MS (21.4 ± 1.28) farms at the final visit compared with the same MO (38.9 ± 2.06) and MS (33.3 ± 1.76) farms on the initial visit. After accounting for initial lameness, intervention group status, and year of visit within a multilevel model, we observed an interaction between year and provision of support, with the reduction in lameness over time being greater in the MS group compared with the MO group. Farms in the MS group made a greater number of changes to their husbandry practices over the duration of the project (8.2 ± 0.39) compared with those farms in the MO group (6.5 ± 0.54). Because the lameness prevalence was lower in the MS group than the MO group at the start of the study, the contribution of the additional support was difficult to define. Lameness can be reduced on UK dairy farms although further work is needed to identify the optimum approaches., (Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Reducing lameness in dairy herds requires farmers to adapt or change existing practices or resources. Those who seek to improve animal welfare by influencing the actions of farmers need to understand farmers' motivations. To investigate why farmers see lameness as a problem and what motivates their efforts to reduce lameness, a questionnaire was carried out with 222 UK dairy farmers. Farmers considered pain and suffering for the cows to be an important outcome of lameness, but reduced performance by lame cows was also seen as a considerable problem. The motivator most commonly given high importance was pride in a healthy herd. Factors incorporating accreditation issues, public image and costs of treatment were generally seen to be of some, but lesser importance. Advisors need to take all these areas into consideration when working to encourage farmers to act to reduce lameness and thereby improve animal welfare., (2010 Elsevier Ltd. All rights reserved.)

On 222 dairy farms, the farmer's perception of the scale of the herd lameness problem was compared with the prevalence detected by observation of the milking herd, and a questionnaire explored the barriers to lameness reduction. Ninety percent of farmers did not perceive lameness to be a major problem on their farm, although the average prevalence of lameness was 36%. For 62% of the sample, lameness was not the top priority for efforts made to improve herd health. Time and labour were important limiting factors for lameness control activities and financial constraints prevented farmers taking action on advice in 30% of cases. Farmers' understanding the implications of lameness for the farm business was limited. Lameness reduction is restricted by farmers' perception of lameness, but also by time, labour and finance; these issues need to be addressed at the industry level to support animal welfare improvement., (2010 Elsevier Ltd. All rights reserved.)

Evaluating the prevalence of lameness within herds of dairy cattle is important for management and certification purposes; however, sampling strategies that could reduce the time taken for an assessment would be valuable. The prevalence of lame and severely lame cows on 224 United Kingdom dairy farms was available for analysis. Presence of more than 1 severely lame cow on a farm was a useful indication of a lameness problem. The vast majority (80%) of the 182 farms that had > or = 1 severely lame cow present had an overall lameness prevalence >25%, whereas only 24% of the 42 farms that had no severely lame cows had an overall prevalence >25%. Information was available on individual milking order through the parlor on the day of the lameness assessment. On 37 farms where cows were housed in a group, lameness prevalence was 11.9% greater in the last third compared with the first third of the milking order. For 36 herds that were larger than 100 cows, sampling a maximum of 100 cows from the middle of the milking order produced an estimate of prevalence within 5% of the true prevalence on 83% of farms. A reasonable sampling strategy may, therefore, be to observe up to 100 cows from the middle of the milking order. Also, presence of severely lame cows at the end of milking may be useful for identifying those farms likely to benefit from further support., (Copyright 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Visits were made to 205 dairy farms in England and Wales between October 2006 and May 2007 by 1 or more of 4 researchers. At each visit, all milking cows were locomotion scored (lameness scored) using a 4-point scale (0=sound locomotion, 1=imperfect locomotion, 2=lame, 3=severely lame). The mean prevalence of lameness (scores 2 and 3) across the study farms was 36.8% (range=0-79.2%). On each farm, the presence within the housing and grazing environments of commonly reported risks for increased lameness was recorded. Each farmer was interviewed to gauge the ability of the farm staff to detect and treat lameness. A multivariable linear regression model was fitted. Risk factors for increased lameness were the presence of damaged concrete in yards, cows pushing each other or turning sharply near the parlor entrance or exit, cattle grazing pasture also grazed by sheep, the use of automatic scrapers, not treating lame cows within 48h of detection, and cows being housed for 61 d or longer at the time they were locomotion scored by the visiting researcher. Having a herd consisting entirely of a breed or breeds other than Holstein-Friesian was associated with a reduction in lameness prevalence compared with having a herd consisting entirely of Holstein-Friesians.

The fundamental objective for health research is to determine whether changes should be made to clinical decisions. Decisions made by veterinary surgeons in the light of new research evidence are known to be influenced by their prior beliefs, especially their initial opinions about the plausibility of possible results. In this paper, clinical trial results for a bovine mastitis control plan were evaluated within a Bayesian context, to incorporate a community of prior distributions that represented a spectrum of clinical prior beliefs. The aim was to quantify the effect of veterinary surgeons' initial viewpoints on the interpretation of the trial results. A Bayesian analysis was conducted using Markov chain Monte Carlo procedures. Stochastic models included a financial cost attributed to a change in clinical mastitis following implementation of the control plan. Prior distributions were incorporated that covered a realistic range of possible clinical viewpoints, including scepticism, enthusiasm and uncertainty. Posterior distributions revealed important differences in the financial gain that clinicians with different starting viewpoints would anticipate from the mastitis control plan, given the actual research results. For example, a severe skeptic would ascribe a probability of 0.50 for a return of < 5 UK pounds per cow in an average herd that implemented the plan, whereas an enthusiast would ascribe this probability for a return of > 20 UK pounds per cow. Simulations using increased trial sizes indicated that if the original study was four times as large, an initial skeptic would be more convinced about the efficacy of the control plan but would still anticipate less financial return than an initial enthusiast would anticipate after the original study. In conclusion, it is possible to estimate how clinicians' prior beliefs influence their interpretation of research evidence. Further research on the extent to which different interpretations of evidence result in changes to clinical practice would be worthwhile.

Identifying lame cows and quantifying the prevalence of lameness are important elements of cattle welfare assessment that are generally achieved by methods involving observations of each animal walking. There is no published method for assessing lameness in cows confined in tie-stalls. The objective of this study (carried out within the European Commission's Welfare Quality(R) project) was to develop a suitable method and validate it for lameness detection against a published locomotion score. A series of indicators of lameness visible in tied cows was formalized into a stall assessment protocol. This was validated against a traditional locomotion score and tested for repeatability between 2 observers. A total of 98 cows on 4 farms were assessed. Overall interobserver agreement was 91%. Sensitivity compared with locomotion scoring was 0.54 to 0.77, dependent on observer and threshold definition. Assessment in the stall underestimated the herd prevalence of lameness revealed by locomotion scoring by 11 to 37% (mean 27%). The discrepancy between herd lameness prevalence assessed in the stall and by locomotion scoring was not affected significantly by farm or observer. The cases of lameness that were not detected in the stall tended to be the least severe. The proposed method for lameness detection in tie-stalls could be used for herd-level assessment of lameness and detection of individual lame animals by farmers and their advisors, but it is important to remember that it is less sensitive than locomotion scoring.

The California mastitis test (CMT) is used on farms to identify subclinical mastitis by an indirect estimation of the somatic cell count (SCC) in milk. Four commercially available detergents were compared with a bespoke cmt fluid for their ability to detect milk samples with a scc above 200,000 cells/ml; differences between the interpretation of the results of the tests by eight operators were also investigated. The sensitivity and specificity of the test were affected by the type of detergent, and by the operators' interpretations. When used by the most sensitive operator, suitably diluted Fairy Liquid performed almost identically to cmt fluid in identifying milk samples with more than 200,000 cells/ml. The average sensitivities achieved by the eight operators for detecting this threshold were 82 per cent for Fairy Liquid and 84 per cent for cmt fluid, and the specificities were 93 and 91 per cent respectively. The other detergents contained less anionic surfactants and were less sensitive but similarly specific.

Pelvic osteomyelitis is unusual in children. We retrospectively reviewed charts of patients with this infection seen at our institution. From 1998 to 2005, 31 patients with pelvic osteomyelitis were identified: 19 males and 12 females with an age range of 1.5 months to 17 years 9 months. Duration of illness prior to admission ranged from 1 day to 2.5 months. Chief complaints included nonspecific pain, fever, limp, and decreased weight bearing. Microorganisms isolated included Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella, Enterobacter cloacae, and Kingella kingae. Bones involved were acetabulum/ilium (22 patients), ischium (7 patients), and pubis (4 patients); 2 patients had several bones involved. Imaging studies performed included magnetic resonance imaging (21 patients), computed tomography (14 patients), and nuclear bone scan (25 patients). Our study, the largest contemporary series of pediatric pelvic osteomyelitis from one institution, highlights the consequences of prolonged duration of illness and delayed diagnosis.

An intervention study was carried out on 52 dairy farms in England and Wales to determine whether the implementation of a well-specified mastitis control plan in herds with an incidence of clinical mastitis of more than 35 cases per 100 cows per year would reduce the incidence of clinical mastitis, and also reduce the incidence of increases in the somatic cell counts of individual cows. A clearly defined plan for the diagnosis and control of mastitis was developed by two veterinary specialists from the research literature. The herds were randomly allocated to receive the plan either at the start of the study (intervention herds) or after one year (control herds). Data on mastitis management and the farm environment were collected during farm visits. After one year there was a significant 22 per cent reduction in the proportion of cows affected with clinical mastitis on the intervention farms compared with the control farms. There were also significant reductions of approximately 20 per cent in the incidence of clinical mastitis and in the occurrence of increases in the somatic cell counts of individual cows from below, to above 200,000 cells/ml.

A survey of clinical and subclinical mastitis was carried out on 97 dairy farms in England and Wales, selected at random from members of a national milk recording scheme. The farmers were asked to collect aseptic milk samples from five consecutive cases of clinical mastitis and from five quarters with high somatic cell counts using a defined protocol, and they completed a questionnaire that included information on the cows sampled, the herd and the history of mastitis in the herd. The samples were collected throughout the year. The mean incidence of clinical mastitis was 47 cases per 100 cows per year (estimated from historic farm records) and 71 cases per 100 cows per year (estimated from the samples collected). Streptococcus uberis and Escherichia coli were isolated in pure culture from 23.5 per cent and 19.8 per cent, respectively, of the clinical samples; 26.5 per cent of the clinical samples produced no growth. The most common isolates from the samples with high cell counts were coagulase-negative staphylococci (15 per cent), S uberis (14 per cent) and Corynebacterium species (10 per cent). Staphylococcus aureus and coagulase-positive staphylococci together accounted for 10 per cent of the samples with high somatic cell counts; 39 per cent produced no bacterial growth.

A route to produce novel three-dimensional structures in thin films is demonstrated. Such structures are most difficult to produce in a simple manner without the use of multiple fabrication steps. Here, we show the generation of 3-D cage-type structures using a combination of electrohydrodynamic instabilities and dewetting in a polymer/polymer/air trilayer. Removal of one of the components by use of a selective solvent or by degradation of one of the components reveals the formation of a three-dimensional structure, where one polymer is encased in the other. Thus, by coupling an external field with a surface field inherent to the polymers, a novel fabrication strategy is shown that has clear applications in microfluidics and microelectromechanical systems with extensions to patterned surfaces and structured fluids, like block copolymers.

Electrohydrodynamics were studied in a trilayer thin film system consisting of two different polymeric layers and air. A polymer with a higher dielectric constant, poly(methyl methacrylate), was sandwiched between air and a lower dielectric constant polymer, polystyrene. An electric field was applied normal to the interfaces. Along with electrostatic forces, dewetting forces were significant at two of the interfaces, namely, the polystyrene/silicon wafer and the polystyrene/poly(methyl methacrylate) interfaces. These two combined forces produce novel closed-cell structures that are difficult to produce by other existing techniques.

Heifers were reared separately on wet fermented (WF) (grass silage based) or dry unfermented (DU) (straw based) diets. Clinical lameness was recorded and physical claw attributes were measured regularly, up to six months after calving at approximately two years of age. Two months before calving, some aspects of animal behaviour and the properties of slurry were studied. The incidence of lameness due to claw horn lesions was significantly higher (P < 0.01) in WF than in DU. WF suffered more serious heel erosion prior to calving (P < 0.05) and had softer claw horn at two (heel and axial sole) out of five sites throughout (P < 0.01 and P < 0.05). The slurry produced by WF had lower total solids content (P < 0.05) and viscosity (P < 0.001). WF spent longer standing and feeding (P < 0.001). It is proposed that standing for longer in less viscous slurry contributed to softer claw horn and more severe heel erosion, predisposing WF to claw horn lesions causing lameness. Reducing contact with low dry matter slurry is recommended for improving claw health.

In pines, self-pollination rates can be as high as 34% yet only 5% of viable seed is a product of self-fertilization. This decline in selfed seed viability is the consequence of post-fertilization exclusion mechanisms operating via the embryo lethal system. Recent molecular marker dissection studies suggest that the embryo lethal system is composed of semilethal factors dispersed across the genome, but it is not clear whether overdominant lethal factors are rare or representative. The study objective was to determine if overdominance was rare for the embryo lethal system in conifers. Three cohorts of selfed offspring from a single Pinus taeda parent were genotyped for nuclear microsatellites. Maximum likelihood tests based on distorted segregation ratios for single markers and for interval mapping were used to infer the degree of dominance. Four hypotheses about overdominance lethal factors were tested: (1) overdominant lethal factors rarely occur within the embryo lethal system, (2) overdominant lethal factors are rarely detected because they are transient and display stage-specific expression, (3) overdominant lethal factors are rarely detected due to tight linkage with rare marker alleles and (4) dominance estimation is unbiased by gametic selection. Four out of the seven chromosomal segments were linked to an overdominant lethal factor. One of these four segments had symmetric overdominance, an effect which persisted from embryo maturity through germination. Four overdominant lethal factors were linked to common and rare marker alleles. Gametic selection was not a source of bias in dominance estimation. Overdominant or pseudo-overdominant lethal factors are a common component of the conifer embryo lethal system.

In a continuous design study the claw health of 54 Holstein-Friesian heifer calves was recorded from three months of age until six months after first calving (30 months of age). Pre-calving heifers were either fed a wet, fermented grass silage-based diet (WF) or a dry, unfermented straw and concentrate based diet (DU), apart from grazing during their first summer. Approximately one month before calving both groups were fed a silage-based diet and afterwards all received a silage and concentrate lactation ration. Claws were examined four times during rearing, once pre-calving, and four times during lactation. Both white line and sole lesions were significantly worse for WF than DU both during rearing and throughout first lactation although the effect was not as consistent over time for white line lesions. It is concluded that for optimal claw health youngstock diets should not be heavily based on wet grass silage (less than 25% DM).

We have investigated the responses of cow teats to machine milking in a study of relatively newly installed commercial milking parlours fitted with one of two types of milking cluster. The first was a common type with a large claw volume (> 200 ml), 15-16 mm i.d. long milk tube, 10 mm short pulse tube, cluster weight < 3-2 kg and used alternate pulsation. The second was a more traditional type with a 150 ml claw bowl volume, 13.5 mm i.d. long milk tube, 8 mm short pulse tube, cluster weight approximately 3.5 kg and used simultaneous pulsation. We scored approximately 50 cows in each of 20 herds, all within 60 s of cluster removal, for changes from the premilking teat condition: teat colour (creation of reddening or blueness), firmness, thickening at the base of the teat associated with the position of the liner mouthpiece, and whether the teat duct orifice was open. There were statistically significant differences in the proportion of cows displaying these four alterations in teat condition between herds using the two types of cluster. The more common type of cluster was always associated with better teat condition. The cause and effect of poorer teat condition have not been fully established and are likely to be multifactorial. The principal risk factors may be cluster weight, overmilking, vacuum applied during the overmilking phase and the design of the liner mouthpiece.

Experimental techniques used to measure structural parameters of thin films such as thickness, density, and coverage provide important insights into the physical properties of these films. Structural parameters are also often used to predict the eventual performance of thin films. In this study, we use three different measurement techniques-X-ray reflectivity (XRR), electron spectroscopy for chemical analysis (ESCA), and optical ellipsometry-to measure the thickness of molecularly thin perfluoropolyether (PFPE) polymer films on silicon substrates and carbon overcoats. PFPE films are commonly used to lubricate surfaces in magnetic recording devices. Here, we use XRR to measure the absolute thickness of the films, which, in turn, is used to test the validity of ESCA and ellipsometry thickness measurements. Excellent agreement is found among the three methods, provided that a 25-Å electron mean-free path (MFP) is used for the PFPE film and the substrate in ESCA (single MFP model), that the bulk PFPE refractive index is used in ellipsometry, and that adventitiously adsorbed hydrocarbons are properly taken into account. Copyright 2000 Academic Press.

Claw lesions are a major cause of lameness in dairy cattle. Analysis of the development of lesions is aided by numerical representation of their significance. Using data from observations on 31 heifers at 9 weeks post-calving, 5 lesion scoring method were compared. These were: (1) number of lesions; (2) severity; (3) adjusted severity; (4) size (measured by a novel technique involving image analysis of distal view photographs) and (5) size multiplied by adjusted severity (combined score). Relationships between scores for sole and white line lesions and between different claws within a cow were investigated. The small size but high clinical significance of severe lesions means that severity must be weighted if combined with size in a score. Sole and white line lesions showed a moderate but significant correlation in terms of severity but none in terms of size. The highest correlation between scores for a single claw (the right hind outer) and the remaining claws was found for adjusted severity of sole lesions.

The development of claw haemorrhages was monitored in first-calving dairy heifers from 4 weeks before calving to 32 weeks after calving. Before calving, lesions were few but the number, extent and severity of claw haemorrhages increased following simultaneous calving and housing. Lesions were most severe in the white line at 9 weeks, and in the sole at 14 weeks, but recovery began while the animals were still housed. That the increase in white line lesions after calving, and the subsequent recovery preceded that of the sole, suggests that the pathogenesis of the lesions may differ in these two anatomical regions. It is proposed that an initial insult to the corium primarily affects the laminar region and that corium damage increases with the resulting alteration in the physical forces on the sole.