Validating the female fertility estimated breeding value in Australian commercial dairy herds.

We conducted a retrospective cohort study to validate the efficacy of the Australian multitrait fertility estimated breeding value (EBV). We did this by determining its associations with phenotypic measures of reproductive performance (i.e., submission rate, first service conception rate, and early calving). Our secondary aim was to report the associations between these reproductive outcomes and management and climate-related factors hypothesized to affect fertility. Our study population included 38 pasture-based dairy herds from the northern Victorian irrigation region in Australia. We collected records for 86,974 cows with 219,156 lactations and 438,578 mating events from the date on which managers started herd recording until December 2016, comprising both fertility-related data such as insemination records, calving dates, and pregnancy test results, and systems-related data such as production, herd size, and calving pattern. We also collected hourly data from 2004 to 2017 from the closest available weather station to account for climate-related factors (i.e., temperature humidity index; THI). Multilevel Cox proportional hazard models were used to analyze time-to-event outcomes (days to first service, days to cow calving following the planned herd calving start date), and multilevel logistic regression models for binomial outcomes (conception to first service) in the Holstein-Friesian and Jersey breeds. A 1-unit increase in daughter fertility EBV was associated with a 5.4 and 8.2% increase in the daily hazard of calving in the Holstein-Friesian and Jersey breeds respectively. These are relative increases (i.e., a Holstein-Friesian herd with a 60% 6-wk in-calf rate would see an improvement to 63.2% with a 1-unit increase in herd fertility EBV). Similar results were obtained for submission and conception rate. Associations between 120-d milk yield and reproductive outcome were complicated by interactions with 120-d protein percentage and calving age, depending on the breed and outcome. In general, we found that the reproductive performance of high milk-yielding animals deteriorated faster with age than low milk-yielding animals, and high protein percentage exacerbated the differences between low and high milk-yielding animals. Climate-related factors were also associated with fertility, with a 1-unit increase in maximum THI decreasing first service conception rate by 1.2% for Holstein-Friesians but having no statistically significant association in the Jersey breed. However, THI had a negative association in both breeds on the daily hazard of calving. Our study validates the efficacy of the daughter fertility EBV for improving herd reproductive performance and identifies significant associations between 120-d milk and protein yields and THI on the fertility of Australian dairy cows.

Herd manager attitudes and intentions regarding the selection of high-fertility EBV sires in Australia.

Reproductive performance in dairy cattle has declined over the last 50 years as an unintended consequence of selection for high milk yield. Since the early 2000s, dairy geneticists have released successive versions of fertility estimated breeding values (EBV) to assist in reversing this trend. At the herd level, fertility EBV can help managers accelerate improvements in reproductive performance by acting as a second selection criteria when used in tandem with a breeding index. However, use of the fertility EBV in sire selection currently varies between herd managers. The aim of this study was to better understand the reasons why herd managers choose or do not choose to select high-fertility EBV sires, using the Theory of Planned Behavior (TPB) as a social research framework. Thirty-five Victorian dairy herd managers were recruited as part of a larger study investigating the daughter fertility Australian Breeding Value and interviewed using a series of questions examining TPB constructs. The interviews were recorded and transcribed using template analysis. A wide range of herd manager types were enrolled into the study, with representation from diverse systems. Out of the 35 herd managers, 27 included fertility in their list of high-priority breeding objectives. A wide variation in results was consistent with previous studies that have demonstrated marked heterogeneity in herd manager attitudes toward bull selection. Herd manager-perceived barriers to selection of sires with high daughter fertility EBV included a lack of high daughter fertility bulls with other desirable traits, a lack of trust in the fertility EBV or in the Australian EBV system, difficulty in interpreting international proofs, information overload, semen prices, low bull reliability, and difficulty in understanding bull catalogs. Not all herd managers found the process problematic, however, particularly if a breeding consultant was employed to select all or most of the sires. Herd manager-perceived barriers for choosing to select daughter fertility as a breeding objective include a lack of awareness of the EBV, a lack of interest in genetics in general, low confidence in the impact of genetic selection for fertility, and a feeling that fertility was not important for their production system. The results of this study suggest that animal geneticists and on-farm service providers need to work together to allow the opportunities arising from appropriate use of fertility EBV to be realized more broadly across the dairy industry.

Associations between immune competence, stress responsiveness, and production in Holstein-Friesian and Holstein-Friesian × Jersey heifers reared in a pasture-based production system in Australia.

The objectives of this study were to assess antibody and cellular immune responses in first-lactation dairy heifers reared under a pasture-based production system and to investigate associations between immune competence and stress responsiveness, health, and productivity. A commercial vaccine was used to induce antibody and cellular immune responses and, based on measured responses, animals were classified as above average, average, and below average for each trait independently and in combination (overall immune competence). Overall immune competence phenotypic rankings were generated by combining standardized residual values for antibody and cellular responses measured in individual heifers. Cortisol responses to handling and yarding were used to assess stress responsiveness, worm egg counts were used to assess internal parasite burden, somatic cell counts to assess udder health and estimates of total daily milk volume, and milk fat and milk protein contents to assess productivity. A total of 393 Holstein-Friesian and Holstein-Friesian × Jersey crossbred heifers from 2 herds practicing seasonal calving in a pasture-fed production system were enrolled in the study. The immune competence phenotypes of individual heifers were assessed before their first mating and their subsequent performance during their first lactation was monitored. Animals with below-average antibody and cellular immune competence had higher serum cortisol concentrations compared with their counterparts following handling, suggesting they had a reduced ability to cope with management-induced stress. Furthermore, a significant negative (favorable) correlation was observed between antibody responses and stress responsiveness. Similarly, correlations between antibody responses and internal parasite burden were significant and negative (favorable). No correlations were observed between overall immune competence and milk yield, milk fat, and milk protein content.

Clinical findings from 104 cases of calving paralysis in dairy cows from Gippsland, Australia.

Case History: Dairy cows recumbent following calving on farms in South Gippsland, Australia were examined during two 3-month seasonal calving periods in 2011 and 2012 as part of a larger study of 218 recumbent cows. A cohort of 104 cows diagnosed with calving paralysis following dystocia was derived from the larger group, which were examined with 3 days of becoming recumbent. A thorough medical and musculoskeletal clinical examination was performed on each cow including flexor-withdrawal and patellar reflex tests, and postural assessment in the lifted position, unless the facilities were not available. Cows were diagnosed with one or more neurological syndromes: sciatic, tibial paresis, obturator or femoral, based on clinical findings consistent with damage to these peripheral nerves or their nerve roots. Clinical Findings: Evidence of sciatic syndrome was found in 100/104 (96.2%) cows and 146/172 (84.9%) affected hind limbs either as the sole neuropathy or in combination with tibial paresis, obturator or femoral syndromes. Pelvic damage was also present in 3/104 (2.8%) cows. Obturator syndrome was diagnosed in 30/104 (29%) cows and 45/172 (26.2%) affected hind limbs but not apparently as the sole reason for the recumbency. Femoral syndrome occurred in 16/104 (15.4%) cows and 21/172 (12.2%) affected hind limbs and was the only syndrome recorded in one cow. Clinical Relevance: Sciatic syndrome was the most common neurological syndrome observed in cows with calving paralysis. The other major nerves arising from the lumbo-sacral plexus were also affected and the various syndromes associated with damage to these nerves or their ventral nerve roots occurred in many combinations. Calving paralysis should be thought of as a paresis or paralysis resulting from damage to the ventral nerve roots of the lumbo-sacral plexus as any of the nerves originating from this plexus can be damaged during dystocia either individually or in combination with other nerves from the plexus.

Scrotal circumference, bodyweight and semen characteristics in growing dairy-breed natural-service bulls in Tasmania, Australia.

AIMS: To provide herd managers with a set of decision rules allowing them to predict the likelihood that a juvenile bull is ready for Bull Breeding Soundness Evaluation (BBSE), or breeding, if bodyweight and scrotal circumference are known. METHODS: This was a longitudinal study following two groups of young pasture-fed Holstein and Jersey bulls from northwest Tasmania, Australia. Individual scrotal circumference, bodyweight and semen characteristics were recorded at 6-8 weekly intervals, from 6-18 months of age. Classification and regression tree analyses were used to predict the probability that a bull had ≥70% normal sperm morphology based on scrotal circumference and bodyweight measurements. RESULTS: Overall 1,661 scrotal circumference and bodyweight measurements were obtained, and 518 semen samples from 356 bulls were assessed for sperm morphology, from 16 examination sessions that took place between 29 May 2015 and 17 August 2016. Classification and regression tree analyses generated a decision tree for Holstein bulls with four node endpoints, and for Jersey bulls with three node endpoints. Diagnostic test performance showed that for Holstein bulls, using the node endpoints of scrotal circumference ≥27 cm and bodyweight ≥349 kg, 98% had ≥70% normal sperm (positive likelihood ratio 10.4; 95% CI = 2.7-41), and using the node endpoints of scrotal circumference ≥27 cm and bodyweight between 282-349 kg, 89% had ≥70% normal sperm (positive likelihood ratio 1.6; 95% CI = 0.9-2.6). For Jersey bulls, using the node endpoints of bodyweight ≥259 kg and scrotal circumference ≥29 cm, 88% had ≥70% normal sperm (positive likelihood ratio 3.4; 95% CI = 1.6-7.0). CONCLUSIONS: This study provides a set of relatively simple decision rules based on bodyweight and scrotal circumference measurements that allows herd managers to assess the likelihood that juvenile bulls are ready for BBSE or breeding. ABBREVIATIONS: BBSE: Bull breeding soundness evaluation; BRT: Boosted regression tree.

Early-life events associated with first-lactation performance in pasture-based dairy herds.

This was a prospective cohort study to determine how events from birth until first calving affect performance during the first lactation in pasture-based dairy herds in Victoria, Australia. Events during the preweaning (0-84 d), prepubertal (85-473 d), and postpubertal (474-804 d) periods were recorded in 6 herds, and their association with first-lactation 100-d and 250-d total milk, fat, and protein yields was quantified. Predictors of first-lactation performance included passive transfer status as a calf; season of birth; age of dam; the presence or absence of dystocia at the time of the heifer's birth; the presence or absence of preweaning diarrhea; preweaning, prepubertal, and postpubertal average daily weight gain; age at first calving; the presence or absence of periparturient disease at first calving; sex of the first-born calf; the presence or absence of a stillborn calf at the first calving; and requirement of assistance at the first calving. Lactation performance was quantified using cumulative 100-d and 250-d milk, fat, and protein yields estimated from herd recording. A multivariable linear regression model was developed for each outcome: cumulative 100-d milk, fat, and protein yield and cumulative 250-d milk, fat, and protein yield. Heifers that experienced dystocia at the time of their birth produced 7.6 kg [95% confidence interval (CI): 1.8-13.3] less fat and 4.8 kg (95% CI: 0.6-8.9) less protein at 100 d in milk in the first lactation compared with heifers that were delivered without dystocia. Heifers born in the summer and autumn produced 20 L (95% CI: 0.8-40) more milk and 20 kg (95% CI: 5.9-33) more protein at 250 d in milk in the first lactation compared with heifers born in the spring. For 100 g/d increases in prepubertal average daily gain, heifers produced an additional 182 L (95% CI: 149-216) of milk, 4.1 kg (95% CI: 2.8-5.5) of fat, and 4.0 kg (95% CI 3.1-5.0) of protein at 100 d in milk and an additional 345 L (95% CI 264-425) of milk, 6.1 kg (95% CI 3.2-9.0) of fat, and 7.5 kg (95% CI 5.3-9.7) of protein at 250 d in milk. Postpubertal average daily gain was positively associated with 100-d milk yield and 250-d milk yield and protein production. We conclude that of all the growth periods assessed in this study, events that occurred during the prepubertal period (85-473 d of age) had the greatest effect on first-lactation performance.

An assessment of dairy herd bulls in southern Australia: 2. Analysis of bull- and herd-level risk factors and their associations with pre- and postmating breeding soundness results.

In pasture-based, seasonally calving dairy herds of southern Australia, the mating period usually consists of an initial artificial insemination period followed by a period of natural service using herd bulls. The primary objective of this study was to identify associations between individual bull- and herd-level management factors and bull fertility as measured by a pre- and postmating bull breeding soundness evaluation (BBSE). Multivariable mixed effects logistic regression models were used to identify factors associated with bulls being classified as high risk of reduced fertility at the premating and postmating BBSE. Bulls older than 4 yr of age at the premating BBSE were more likely to be classified high risk compared with bulls less than 4 yr of age. Bulls that were in herds in which concentrates were fed before mating were more likely to be classified as high risk at the postmating BBSE compared with bulls that were in herds where concentrates were not fed. Univariable analyses also identified areas in need of further research, including breed differences between dairy bulls, leg conformation and joint abnormalities, preventative hoof blocking for bulls, and mating ratios.

An assessment of dairy herd bulls in southern Australia: 1. Management practices and bull breeding soundness evaluations.

In the pasture-based, seasonally calving dairy herds of southern Australia, the mating period usually consists of an initial artificial insemination period followed by a period of natural service using herd bulls. Bull breeding soundness evaluations (BBSE) were performed on 256 bulls from 32 dairy herds in southwest Victoria, using guidelines produced by the Australian Cattle Veterinarians, before and immediately after a single natural mating period. At the same time, herd managers were questioned regarding the management of the bulls. The objectives of this study were to describe the management practices of dairy herd bulls; to describe the causes of increased risk of reduced fertility in dairy herd bulls, as measured by a standard BBSE; and to describe the reasons for bull removal by herd managers during mating. At the premating BBSE, 19.5% of bulls were classified as high risk of reduced fertility, mostly due to physical abnormalities and reduced semen quality. At the postmating BBSE, 36.5% of bulls were classified as high risk of reduced fertility, mostly due to physical abnormalities, primarily lameness. Of the bulls used, 15.9% were removed from normal mating use by the herd manager, predominantly due to lameness and injuries. A premating BBSE is recommended in dairy herd bulls to identify bulls at risk of reduced fertility. Lameness is the most common problem in dairy herd bulls during the natural mating period, and risk factors associated with lameness in these bulls should be identified to better manage herd bulls.

Survey of bovine colostrum quality and hygiene on northern Victorian dairy farms.

One of the major challenges for dairy producers is to produce, harvest, and store high-quality colostrum and feed it to their replacement heifer calves. Limited published data are available in Australia regarding the relationship between colostrum management, hygiene, and quality. The objectives of this study were to investigate (1) the colostrum storage and handling practices carried out on farm; (2) the immunoglobulin concentration and bacterial composition of colostrum being fed to replacement dairy heifer calves; (3) the percentage of colostrum being fed to replacement dairy heifer calves that meet industry recommendations; and (4) risk factors for bacterial contamination of colostrum. The study was carried out on 24 dairy farms located near Rochester, Victoria, Australia. Two hundred forty colostrum samples were collected (10 samples per farm). Each farm harvested and stored first-milking colostrum under normal farm conditions. A 10-mL sample of the colostrum was collected in a sterile container immediately before feeding, and a Brix refractometer reading was taken. The samples were then frozen at -4°C and submitted for bacterial concentration analysis. Fifty-eight percent of colostrum samples met the recommended industry standard of a total plate count (TPC) of <100,000cfu/mL, and 94% of colostrum samples met the recommended industry standard of total coliform count (TCC) of 10,000cfu/mL. However, when all the current industry recommendations for TPC, TCC, and Brix refractometer percentage for colostrum quality were considered, only 23% of the samples met all standards. These findings demonstrate that a large number of calves were at risk of receiving colostrum of poor quality, with high bacterial loads that may have interfered with the acquisition of transfer of passive immunity and affected calf health. Further investigation is required to identify the farm-specific factors that may influence the level of bacterial contamination of colostrum. Recommendations as a result of this study include refrigeration of excess colostrum shortly (within 1h) after collection and thorough disinfection of the calf feeding apparatus before use.

Twice- rather than once-daily basal insulin is associated with better glycaemic control in Type 1 diabetes mellitus 12 months after skills-based structured education in insulin self-management.

AIM: This study investigates the relationship between basal insulin regimen and glycaemic outcomes 12 months after skills-based structured education in the UK Dose Adjustment for Normal Eating (DAFNE) programme for Type 1 diabetes mellitus. METHOD: Retrospective analysis of data from 892 DAFNE participants from 11 UK centres. RESULTS: Mean HbA1c 12 months after DAFNE was lower in those using twice- rather than once-daily basal insulin after correcting for differences in baseline HbA1c , age and duration of diabetes; difference -2 (95% CI -3 to -1) mmol/mol [-0.2 (-0.3 to -0.1)%], P = 0.009. The greatest fall in HbA1c of -5 (-7 to -3) mmol/mol [-0.4 (-0.6 to -0.3)%], P < 0.001 occurred in those with less good baseline control, HbA1c  ≥ 58 mmol/mol, who switched from once- to twice-daily basal insulin. There was no difference in the 12-month HbA1c between users of glargine, detemir and NPH insulin after correcting for other variables. Relative risk of severe hypoglycaemia fell by 76% and ketoacidosis by 63% 12 months after DAFNE. The rate of severe hypoglycaemia fell from 0.82 to 0.23 events/patient year in twice-daily basal insulin users. In the group with greatest fall in HbA1c , the estimated relative risk for severe hypoglycaemia in twice-daily basal insulin users versus once daily at 12 months was 1.72 (0.88-3.36, P = 0.110). CONCLUSION: After structured education in adults with Type 1 diabetes mellitus, use of basal insulin twice rather than once daily was associated with lower HbA1c , independent of insulin type, with significant reductions in severe hypoglycaemia and ketoacidosis in all groups.

Substantial reductions in the number of diabetic ketoacidosis and severe hypoglycaemia episodes requiring emergency treatment lead to reduced costs after structured education in adults with Type 1 diabetes.

AIMS: To determine the impact of structured education promoting flexible intensive insulin therapy on rates of diabetic ketoacidosis, and the costs associated with emergency treatment for severe hypoglycaemia and ketoacidosis in adults with Type 1 diabetes. METHODS: Using the Dose Adjustment For Normal Eating research database we compared the rates of ketoacidosis and severe hypoglycaemia during the 12 months preceding Dose Adjustment For Normal Eating training with the rates during the 12-month follow-up after this training. Emergency treatment costs were calculated for associated paramedic assistance, Accident and Emergency department attendance and hospital admissions. RESULTS: Complete baseline and 1-year data were available for 939/1651 participants (57%). The risk of ketoacidosis in the 12 months after Dose Adjustment For Normal Eating training, compared with that before training, was 0.39 (95% CI: 0.23 to 0.65, P < 0.001), reduced from 0.07 to 0.03 episodes/patient/year. For every 1 mmol/mol unit increase in HbA1c concentration, the risk of a ketoacidosis episode increased by 6% (95% CI: 5 to 7%; 88% for a 1% increase), and for each 5-year increase in diabetes duration, the relative risk reduced by 20% (95% CI: 19 to 22%). The number of emergency treatments decreased for ketoacidosis (P < 0.001), and also for severe hypoglycaemia, including paramedic assistance (P < 0.001), Accident and Emergency department attendance (P = 0.029) and hospital admission (P = 0.001). In the study cohort, the combined cost of emergency treatment for ketoacidosis and severe hypoglycaemia fell by 64%, from £119,470 to £42,948. CONCLUSIONS: Structured training in flexible intensive insulin therapy is associated with a 61% reduction in the risk of ketoacidosis and with 64% lower emergency treatment costs for ketoacidosis and severe hypoglycaemia.

Faecal egg counts in Australian pasture-based dairy herds.

In Australian pastoral dairy systems, a variety of 'routine' anthelmintic programs are used in lactating cows varying from nil anthelmintic use to bi-annual application. Anthelmintic resistance has been repeatedly diagnosed on dairy farms and studies have indicated variable milk production benefits from anthelmintics internationally. We aimed to identify the predominant gastrointestinal parasites in recently calved dairy cows in south-west Victoria and examined the relationship between individual faecal egg counts (FEC) and other cow and management factors such as body condition score, age, and historical anthelmintic use. This study included 18 pasture-based dairy farms in south-west Victoria. FECs were measured in recently calved primiparous and multiparous cows. Individual FEC tests with a minimum detectable FEC of 2.5 eggs per gram of faeces (epg) and group larval cultures were completed. Farm management data and cow information was recorded for data analysis with the Jamovi statistical package. Overall, 35% of all cows had FEC ≥ 2.5 epg (26% of multiparous and 45% of primiparous). Ostertagi ostertagi was the predominant gastrointestinal nematode in all cohorts. Cooperia pectinata or C. punctata were also present in mixed infestations alongside C. oncophora. Multiparous cows in low body condition score post calving (<4) were more likely to have a FEC of >5 epg. Faecal egg counts at a minimum detectable FEC of 2.5 epg are effective indicators of parasitism in recently calved primiparous and poorly conditioned multiparous dairy cows. Increasing the test sensitivity (minimum detectable count) of FECs from 10 epg to 2.5 epg resulted in increasing the overall positive FEC rate from 15% to 35%. Further investigation of sensitive FECs and their relevance to production along with the timing and value of anthelmintic use in dairy cattle is warranted.

Early life events associated with first lactation reproductive performance in southwest Victorian pasture-based dairy herds.

This was a prospective cohort study to determine how events from birth until first calving affect reproductive performance in the first lactation in pasture-based dairy herds in Victoria, Australia. Events during the preweaning (0 to 84 days), weaning to first breeding (85 to 473 days) and first breeding to first calving periods (474 to 804 days) were recorded and their association with reproductive performance during the first lactation was quantified. Reproductive performance outcomes included the number of days from first mating start date to first service (MSD-S1) and the number of days from first mating start date to first conception (MSD-CON). Predictors for reproductive performance included: passive transfer status as a calf; season of birth; age and breed of the dam; breed; the presence or absence of dystocia at the time of the heifer's birth; active feeding of colostrum versus being left on the dam for colostrum intake; presence of twinning; the presence or absence of preweaning diarrhoea; preweaning, prepubertal and postpubertal average daily gain; the presence or absence of periparturient disease at first calving; age at first calving; body condition score at first calving; sex of the first-born calf; the presence or absence of a stillborn calf at the first calving and requirement of assistance at first calving. Two Cox proportional hazards regression models were developed: the first for early life event variables associated with MSD-S1 and the second for early life events associated with MSD-CON. Heifers born in autumn and winter had 2.89 (95% CI 1.50 to 5.59, P = 0.002) times and 1.97 (95% CI 1.12 to 3.44, P = 0.018) times the daily hazard of being inseminated compared with heifers born in spring, respectively. For the MSD-S1 analyses heifers that gave birth to a live calf had 1.64 (95% CI 1.14 to 2.36, P = 0.008) times the daily hazard of being inseminated compared with heifers that had a stillborn calf. Increases in weight gain during the first breeding to first calving period by 0.1 kg/day increments increased the daily hazard of first insemination by a factor of 1.10 (95% CI 1.00 to 1.22, P = 0.043). Heifers that experienced periparturient disease had a significantly lower hazard of conception per day compared with heifers that did not experience periparturient disease at the first calving (HR 0.67, 95% CI 0.50 to 0.91, P = 0.009). Increases in weight gain during the first breeding to first calving period by 0.1 kg/day increased the daily hazard of conception by a factor of 1.10 (95% CI 1.01 to 1.21, P = 0.038). We conclude that of all the growth periods assessed in this study, events that occurred during the first breeding to first calving period (474 to 804 days) had the greatest association with reproductive performance in the first lactation. There should be a focus on increasing growth rates during this period and reducing the risk of stillbirth and periparturient disease to improve reproductive performance in the subsequent mating period after calving.

Variability in fasting lipid and glycogen contents in hepatic and skeletal muscle tissue in subjects with and without type 2 diabetes: a 1H and 13C MRS study.

The measurement of tissue lipid and glycogen contents and the establishment of normal levels of variability are important when assessing changes caused by pathology or treatment. We measured hepatic and skeletal muscle lipid and glycogen levels using (1)H and (13)C MRS at 3 T in groups of subjects with and without type 2 diabetes. Within-visit reproducibility, due to repositioning and instrument errors was determined from repeat measurements made over 1 h. Natural variability was assessed from separate measurements made on three occasions over 1 month. Hepatic lipid content was greater in subjects with diabetes relative to healthy subjects (p = 0.03), whereas levels of hepatic and skeletal muscle glycogen, and of intra- and extra-myocellular lipid, were similar. The single-session reproducibility values (coefficient of variation, CV) for hepatic lipid content were 12% and 7% in groups of subjects with and without diabetes, respectively. The variability of hepatic lipid content over 1 month was greater than the reproducibility, with CV = 22% (p = 0.08) and CV = 44% (p = 0.004) in subjects with and without diabetes, respectively. Similarly, levels of variation in basal hepatic glycogen concentrations (subjects with diabetes, CV = 38%; healthy volunteers, CV = 35%) were significantly larger than single-session reproducibility values (CV = 17%, p = 0.02 and CV = 13%, p = 0.05, respectively), indicating substantial biological changes in basal concentrations over 1 month. There was a decreasing correlation in measurements of both hepatic lipid and glycogen content with increasing time between scans. Levels of variability in intra- and extra-myocellular lipid in the soleus muscle, and glycogen concentrations in the gastrocnemius muscle, tended to be larger than expected from single-session reproducibility, although these did not reach significance.

Differences in post-mortem findings after stillbirth in women with and without diabetes.

AIMS: The reason for the fivefold increased risk of stillbirth in women with diabetes is not known. Further understanding of the underlying mechanisms may facilitate identification of pregnancies at increased risk. We have compared post-mortem reports in matched pairs of stillbirths in women with and without diabetes. METHODS: Post-mortem reports were provided by the Centre for Maternal and Child Enquiries. Stillbirths as a result of lethal congenital and genetic abnormalities were excluded. Whole body, placenta and organ weights and histo-pathological findings in cases and controls were compared and also related to published reference values. RESULTS: We analysed post-mortem reports on 23 matched pairs of stillbirths from 2009 to 2010. Mean placental weight in women with diabetes was 75 g less than in control subjects (95% CI -143 to -7 g; P = 0.032). In maternal diabetes, the thymus was often small and showed a 'starry sky' pattern on histology in 11 of 20 cases compared with four of 22 controls (P = 0.03). This histological finding was associated with a particularly low mean placental weight z-score -2.1 (1.1) standard deviations below a reference population corrected for gestational age. CONCLUSIONS: In over half of the stillbirths occurring in women with diabetes, there was a 'starry sky' appearance in the fetal thymus on histology, this being associated with a small placenta. These findings are consistent with a critical subacute metabolic disturbance being a prominent cause of the increased risk of stillbirth in pregnancies complicated by maternal diabetes.

Measurement of fetal fat in utero in normal and diabetic pregnancies using magnetic resonance imaging.

OBJECTIVES: To assess the reliability of magnetic resonance imaging (MRI) to measure fetal fat volume in utero, and to study fetal growth in women with and without diabetes in view of the increased prevalence of macrosomia in the former. METHODS: We studied 26 pregnant women, 14 with pre-gestational diabetes and 12 non-diabetic controls. Fetal assessment took place at 24 weeks' gestation and again at 34 weeks by standard ultrasound biometry followed by MRI at 1.5 T. Fetal fat volume was determined from T1-weighted water-suppressed images using a semi-automated approach based on pixel intensity and taking into account partial volume effects. Fetal volume was also determined from the MRI images. Fetal weight was calculated using published fat and lean tissue densities. RESULTS: There was little fetal fat at 24 weeks' gestation, but at 34 weeks the fetal fat content was considerably higher in the women with diabetes, with a mean fat content of 1090 ± 417 cm(3) compared with 541 ± 348 cm(3) in the controls (P = 0.006). Measurements of fetal fat volume showed low intra- and interobserver variability at 34 weeks, with intraclass correlation coefficients consistently above 0.99. Birth-weight centile correlated with fetal fat volume (R(2) = 0.496, P < 0.001), percentage of fetal fat (R(2) = 0.362, P = 0.008) and calculated fetal weight (R(2) = 0.492, P < 0.001) at 34 weeks. CONCLUSIONS: MRI appears to be a promising tool for the determination of fetal fat, body composition and weight in utero during the third trimester of pregnancy.

An automated walk-over weighing system as a tool for measuring liveweight change in lactating dairy cows.

Automated walk-over weighing systems can be used to monitor liveweights of cattle. Minimal literature exists to describe agreement between automated and static scales, and no known studies describe repeatability when used for daily measurements of dairy cows. This study establishes the repeatability of an automated walk-over cattle-weighing system, and agreement with static electronic scales, when used in a commercial dairy herd to weigh lactating cows. Forty-six lactating dairy cows from a seasonal calving, pasture-based dairy herd in southwest Victoria, Australia, were weighed once using a set of static scales and repeatedly using an automated walk-over weighing system at the exit of a rotary dairy. Substantial agreement was observed between the automated and static scales when assessed using Lin's concordance correlation coefficient. Weights measured by the automated walkover scales were within 5% of those measured by the static scales in 96% of weighings. Bland and Altman's 95% limits of agreement were -23.3 to 43.6 kg, a range of 66.9 kg. The 95% repeatability coefficient for automated weighings was 46.3 kg. Removal of a single outlier from the data set increased Lin's concordance coefficient, narrowed Bland and Altman's 95% limits of agreement to a range of 32.5 kg, and reduced the 95% repeatability coefficient to 18.7 kg. Cow misbehavior during walk-over weighing accounted for many of the larger weight discrepancies. The automated walk-over weighing system showed substantial agreement with the static scales when assessed using Lin's concordance correlation coefficient. This contrasted with limited agreement when assessed using Bland and Altman's method, largely due to poor repeatability. This suggests the automated weighing system is inadequate for detecting small liveweight differences in individual cows based on comparisons of single weights. Misbehaviors and other factors can result in the recording of spurious values on walk-over scales. Excluding outlier weights and comparing means of 7 consecutive daily weights may improve agreement sufficiently to allow meaningful assessment of small short-term changes in automated weights in individuals and groups of cows.

Glycaemic control and weight 7 years after Dose Adjustment For Normal Eating (DAFNE) structured education in Type 1 diabetes.

AIMS: The provision of structured education is increasingly prevalent in the management of Type 1 diabetes. There are little long-term follow-up data from such programmes. We have assessed HbA(1c) and weight over a 7-year period following the Dose Adjustment For Normal Eating (DAFNE) structured education course. METHODS: We obtained annual HbA(1c) and weight data in 111 patients who attended the initial series of DAFNE courses in our centre from June 2002 to end 2003 and in a matched group of 111 patients with Type 1 diabetes of similar age and duration of diabetes seen over the same period who had not undergone structured education. RESULTS: With DAFNE structured education, the mean (± sd) HbA(1c) fell from 71 ± 12 mmol/mol (8.6 ± 1.1%) at baseline to 65 ± 12 mmol/mol (8.1 ± 1.1%) at year 1, with a subsequent rise to 67 ± 13 mmol/mol (8.3 ± 1.2%) at year 7 (P = 0.0048 vs. baseline). In the comparator group, the baseline HbA(1c) level was 70 ± 14 mmol/mol (8.5 ± 1.3%) and remained approximately constant during 7 years of follow-up. Weight increased by 2.4 ± 6.0 and 2.8 ± 6.6 kg in the DAFNE and comparator group, respectively, during follow-up (not significant). CONCLUSIONS: DAFNE structured education is associated with an improvement in glycaemic control at 1 year, and there remains a persistent and clinically relevant reduction in HbA(1c) of 3 mmol/mol (0.3%) after 7 years. The improvement in glycaemic control after DAFNE is achieved without excess weight gain.

Elevation of alanine transaminase and markers of liver fibrosis after a mixed meal challenge in individuals with type 2 diabetes.

BACKGROUND: Hyperalimentation for 4 weeks is associated with raised liver enzymes and liver fat content (LFC), which are two common features found in individuals with diabetes. AIM: We evaluated the effect of two mixed meal challenges on LFC, liver enzymes and serum bio-markers of liver injury and fibrosis in 16 healthy volunteers (HV) and subjects with type 2 diabetes (T2DM). METHODS: Subjects (HV: 9 male, 7 female, aged 57.9 ± 1.7 years, body mass index (BMI) 27.1 kg/m(2); and T2DM: 11 male, 5 female, aged 62.1 ± 1.3 years, BMI 28.0 ± 0.4 kg/m(2)) consumed two meals at 1 h (884 kcal) and at 6 h (1,096 kcal). LFC determined by (1)H magnetic resonance spectroscopy, serum levels of liver enzymes, hyaluronic acid (HA), procollagen III N-terminal peptide (P3NP) and tissue inhibitor metalloproteinase-1 (TIMP-1) were estimated at time 0 (fasting) and 9 h (postprandial). RESULTS: Fasting LFC was higher in the T2DM group 7.6 % (4.9, 15.4) [median (inter-quartile range)] than in the HV group 2.3 % (0.8, 5.1) (p < 0.05) while levels of HA, P3NP and TIMP-1 were similar. Following the meal challenge there was no significant change in LFC. Subjects with T2DM had higher post-prandial rise in alanine transaminase (ALT) (p = 0.014), serum HA (p = 0.007) and P3NP (p = 0.015) compared with HV. Fasting LFC correlated with a greater post-prandial increase in P3NP levels in all subjects (Pearson correlation r = 0.53, p = 0.001). CONCLUSIONS: In subjects with T2DM, a mixed meal challenge is associated with a significant elevation in the serum levels of ALT, HA and P3NP without significant changes in LFC. These markers should be performed in the fasted state.

Prevalence of failure of passive immunity transfer in Australian non-replacement dairy calves.

Failure of passive immunity transfer (FPIT) increases the risk of morbidity and mortality in dairy calves. The prevalence of FPIT in dairy calves has generally been reported to be high, with FPIT estimated to occur in 38%-42% of Australian dairy calves. However, the focus of previous studies has been on replacement heifer calves. Our aim was to assess the prevalence of FPIT in Victorian bobby calves (non-replacement dairy calves). We collected blood samples from 3608 bobby calves at three abattoirs at exsanguination, and measured serum total protein as an indicator of passive transfer. We found that 36% of bobby calves showed evidence of FPIT (serum total protein ≤52 g/L), and 50% of calves had poor or fair passive transfer (<58 g/L). When a subset of calves (from farms with more than five calves in the dataset) was analysed using a linear mixed model, Jersey calves and crossbred/other calves had an estimated 5.3 g/L and 5.1 g/L higher serum total protein concentration, respectively, than Holstein-Friesian calves (P < 0.001). Our results suggest that the prevalence of FPIT in bobby calves at abattoirs is similar to that reported in dairy heifer calves sampled on farms. A high prevalence of FPIT has implications for bobby calf morbidity and mortality, as well as calf viability and profitability for dairy-beef production.