Young Stock Research Articles

Development of an objective and uniform scoring method to evaluate the quality of rearing in Dutch dairy herds

Young stock rearing is an essential part of dairy management, and it is important that the quality of rearing can be monitored and altered if necessary. In this study, a young stock rearing quality system (KalfOK) was developed with the aim to provide an objective and standardized means to evaluate and monitor the quality of young stock rearing in Dutch dairy herds. In the project, 201 dairy farmers participated. Twelve key indicators were defined that were related to calving and successful rearing, antimicrobial use, and herd health. For each of the key indicators, the value was calculated per herd and quarter of the year between January 2014 and April 2017. Benchmark values were determined to compare herd-specific results and for selection of threshold values. Each of the key indicators was graded when the value scored above the threshold. Combining the grades resulted in the herd-specific KalfOK score, which could vary between 0 and 100. Subsequently, 100 of the participating dairy herds were visited and the quality of young stock rearing was scored by a trained veterinarian. Using principal component analysis, the results of the herd health checks were combined into a factor score that represented the observed quality of young stock rearing during the visit. The amount of variance in observed quality of rearing during the herd health check that was explained by the key indicators in KalfOK was evaluated. Additionally, the validity of KalfOK to distinguish herds with an excellent or insufficient quality of young stock rearing was assessed by comparing the top and bottom 10% herds in the herd health check with the proportion of herds with a KalfOK score above or below a prespecified cutoff value. The results of the linear regression model showed that the key indicators included in KalfOK accounted for 56% of the variation in the score of the herd visits by a veterinarian. The moving average of the annual KalfOK score, which was the sum of the grades of all key indicators, was 77 points (25th percentile = 71, 75th percentile = 85 points). The combination of the sensitivity (88%, 95% confidence interval = 47-100%) and specificity (67%, 95% confidence interval = 54-78%) of KalfOK to correctly classify herds with an excellent quality of young stock rearing was highest when a cutoff value of 80 points was applied. Detection of dairy herds with an insufficient quality of young stock rearing was best at a cutoff value of 70 points (sensitivity 86%, 95% confidence interval = 42-100%; specificity 77%, 95% confidence interval = 66-86%). The KalfOK score that was based on routinely collected herd data provided an indication of the quality of young stock rearing in individual Dutch dairy farms. The KalfOK score illustrates how such data can be transferred into herd-specific information in support of animal health and welfare. Given the increasing availability of automatically assembled data, the development of similar monitoring tools seems a feasible option to enhance herd-specific management.

Current situation and future trends for beef production in the United States of America - A review.

USA beef production is characterized by a diversity of climates, environmental conditions, animal phenotypes, management systems, and a multiplicity of nutritional inputs. The USA beef herd consists of more than 80 breeds of cattle and crosses thereof, and the industry is divided into distinct, but ofttimes overlapping sectors, including seedstock production, cow-calf production, stocker/backgrounding, and feedlot. Exception for male dairy calves, production is predominantly pastoral-based, with young stock spending relatively brief portions of their life in feedlots. The beef industry is very technology driven, utilizing reproductive management strategies, genetic improvement technologies, exogenous growth promoting compounds, vaccines, antibiotics, and feed processing strategies, focusing on improvements in efficiency and cost of production. Young steers and heifers are grain-based diets fed for an average of 5 months, mostly in feedlots of 1,000 head capacity or more, and typically are slaughtered at 15 to 28 months of age to produce tender, well-marbled beef. Per capita beef consumption is nearly 26 kg annually, over half of which is consumed in the form of ground products. Beef exports, which are increasingly important, consist primarily of high value cuts and variety meats, depending on destination. In recent years, adverse climatic conditions (i.e., draught), a shrinking agricultural workforce, emergence of food-borne pathogens, concerns over development of antimicrobial resistance, animal welfare/well-being, environmental impact, consumer perceptions of healthfulness of beef, consumer perceptions of food animal production practices, and alternative uses of traditional feed grains have become increasingly important with respect to their impact on both beef production and demand for beef products. Similarly, changing consumer demographics and globalization of beef markets have dictated changes in the types of products demanded by consumers of USA beef, both domestically and abroad. The industry is highly adaptive, however, and responds quickly to evolving economic signals.

Decision support beyond total savings—Eligibility and potential savings for individual participants from changes in the national surveillance strategy for bovine viral diarrhoea (BVD) in Ireland

Surveillance and management of livestock diseases is often evaluated with reference to expected sector-wide costs. In contrast, we calculate losses or savings for individual herd owners of a change in monitoring strategy during a national cattle disease eradication programme: bovine viral diarrhoea (BVD) in Ireland. The alternative strategy differs in how the disease is identified; by its sample- rather than census-based approach; and by its greater cost per test. We examined the costs faced by each breeding herd if testing were conducted using serology on a sample of young stock, in contrast to the current method of tissue-tag testing of all newborn calves. Following best knowledge of the likely costs, the following input values were used: i) €2.50 per test for tissue-tag testing and €7.66 for serology, ii) serology conducted on a sample of 10 young stock per management group from either the 6–12 month or 9–18 month cohorts; iii) 3 scenarios for the number of management groups: one per herd (M∞), one per 100 cows (M100) and one per 50 cows (M50). We found that many herds would often not be able to supply a suitable sample of young stock for serology or would face higher testing costs than when using tissue tag testing. The largest number (25%) of herds would benefit from participating in the change if sampling were done in October. These could annually save between €2.1 million under M∞ and €0.8 million under M50 (€108 - €49 per herd). However, analysing herd-level data we found that 90% of all Irish breeding herds would save less than €1.42 per cow or €99 in total per annum under M∞, and €0.59 per cow or €36 in total under M50. In a sensitivity analysis, we allowed serology costs to vary between €2 and €10 per animal. Herds at the 10 t h percentile of most savings made from switching would save at most €155 (M∞ at €2 per serology test) but would not save anything under M50 at costs ≥ €10. We conclude that, under these assumptions, the expected reduction in testing costs for the majority of beneficiaries would barely outweigh the practical implications of the strategy switch or the risks to the eradication programme associated with sample based surveillance. This study does not assess the cost-effectiveness of alternatives post-eradication.

Farm level risk factors for bovine digital dermatitis in Taranaki, New Zealand: An analysis using a Bayesian hurdle model

As part of a cross-sectional study of bovine digital dermatitis (BDD) in 60,455 cows across 224 herds, in Taranaki, a region of the North Island of New Zealand, from September 2014 to February 2015, questionnaires from 114 farms were analysed to identify the key management practices which affect the probability of a farm being affected by BDD and the prevalence of an individual cow being affected on affected farms. The data from the questionnaires were analysed using a Bayesian hurdle model. Two factors were identified as being associated with farm level infection status: (1) milking parlour type; farms which had rotary platforms were more likely to be recorded as having BDD than those which had herringbone parlours (odds ratio, OR, 3.19; 95% probability interval, PI, 1.31–8.51); and (2) young stock movement; farms whose young stock were reared on farms alongside heifers from other farms had a higher odds of being BDD positive than farms where heifers were kept separate (OR 4.15; 95% PI 1.39–15.27). Two factors were associated with an increase in the prevalence of BDD within affected farms: (1) farms which used outside staff to trim feet had a higher prevalence of BDD (prevalence ratio, PR, 3.13; 95% PI 1.25–7.29) than farms which did not use outside staff; and (2) farms examined in spring (September to November) had a higher prevalence of BDD (PR 2.16; 95% PI 1.05–4.43) than farms examined in summer (December to February).

The effect of sub-clinical infection with Mycobacterium avium subsp. paratuberculosis on milk production in a New Zealand dairy herd

BackgroundJohne’s disease is a major production limiting disease of dairy cows. The disease is chronic, progressive, contagious and widespread; there is no treatment and there is no cure. Economic losses arise from decreased productivity through reduced growth, milk yield and fertility and capital losses due to premature culling or death. This study attempts to address the effect of subclinical JD on milk production under New Zealand pastoral dairy farming conditions using a new testing approach. Blood samples were taken from all lactating animals from a single seasonally calving New Zealand dairy herd in the autumn of 2013 and 2014. Samples were subject to serological assay for antibodies to Mycobacterium avium subsp. paratuberculosis using a combination of four ELISA tests in parallel followed by selective quantitative fecal PCR to confirm the fecal shedding characteristics of ELISA positive cows. ELISA status was classified as Not-Detected, Low, Moderate or High and fecal PCR status as Not-Detected, Moderate or High.ResultsA mixed generalized regression model indicated that, compared to cows where MAP was not detected, daily milk solids production was 4% less for high ELISA positive cows (p = 0.004), 6% less for moderate fPCR cows (p = 0.036) and 12% less for high fPCR cows (p < 0.001).ConclusionsThis study confirms that sub-clinical JD can have a significant impact on milk production and that the testing methodology used stratified the animals in this herd on their likely impact on production and disease spread. This allowed the farmer to prioritize removal of heavily shedding, less-productive animals and so reduce the risk of infection of young stock. This is the first longitudinal study based in New Zealand looking at the effect of Johne’s infection status on daily milk production allowing for intermediary and confounding factors.

Corporate CAPEX and market capitalization of firms on Malawi stock exchange: an empirical study

PurposeMarket capitalization of firms reflects the current value of a firm and provides a reasonable basis on mergers and acquisition bargains. Determinants of a firm’s increasing or decreasing market capitalization are multi-faceted, hence the study. The paper is about a historical study of the responsiveness of common share prices of some listed industrial companies to the firms’ investments in capital expenditure. This study aims to discuss the impact of capital expenditure on a firm’s market capitalization, with a focus on companies listed on the Malawi stock exchange (MSE).Design/methodology/approachThe study reviews data collected from published annual reports for the years from 2007 to 2015. The variations in capital expenditure (CAPEX) which are termed “increase” or “decrease” were studied to establish their association with variations in stock prices before the increase or decrease, and after the increase or decrease. As stock price changes are caused by other determinants, the variables of return on capital employed (ROCE), net profit margin (NPM), asset turnover (ATO) and earnings retention ratio (ERT) were analyzed, and a respective correlation test was done against CAPEX movement over the years through panel data analysis and regression analysis to establish the correlation between the variables using XLSTAT.FindingsAt 95 per cent confidence level, CAPEX correlates with ROCE and NPM at 0.373 and 0.249 coefficients, respectively, and negatively with ERT at 6.45e-2. With tests favoring a positive relationship between elements of profitability and stock price, the study finds that there is a positive relationship between a firm’s CAPEXs and its future stock prices.Research limitations/implicationsThe firm’s commitment to CAPEX has a positive impact on its stock price on the stock exchange. These findings, however, need to be interpreted with caution as the data reviewed excluded that from financial institutions, the inclusion of which may affect the outcome, and that the data are derived from a small and young stock market which may be lacking in its efficiency compared to the old and big ones the world over.Originality/valueThe study was undertaken based on the study of listed companies on the Malawi Stock Exchange, and the results may or may not reflect the reality on the ground in other stock exchanges.

Control of Staphylococcus aureus in dairy herds in a region with raw milk cheese production: farmers\u2019 attitudes, knowledge, behaviour and belief in self-efficacy

BackgroundContagious mastitis is an important disease in dairy cattle, and the causative agent S. aureus can also impair raw milk cheese quality. In a confined region in eastern Switzerland attitude, knowledge and behaviour towards S. aureus und S. aureus control was assessed in 90 dairy farmers with communal alpine pasturing including raw milk cheese production with the aid of a questionnaire.ResultsForty-three out of 90 questionnaires were returned (48% return rate). Farmers perceived reproductive problems as most important in their dairy herds followed by respiratory disease and diarrhoea in young stock. Most frequently stated as important motivating factors to participate in S. aureus control were “avoiding negative news about cheese quality in the press” followed by “I want to be proud of my somatic cell counts again”. Most frequently chosen and identified as important constraining factors were “I fear that the authorities dictate and the farmers are not heard” followed by “costs to control S. aureus are too high because of premature culling” and “I am afraid to be forced to cull genetically valuable cows”. Farmers with an experience of a S. aureus problem in their dairy herds had a significantly better knowledge about contagiosity and clinical manifestation of different S. aureus genotypes than farmers with no self-reported experience of a S. aureus problem. Veterinarians were indicated as the most important experts, farmers seek advice in case of mastitis and most farmers suggested subsidising bacteriological milk analysis as an incentive to motivate farmers towards S. aureus control.ConclusionAccording to the results an improved knowledge transfer on S. aureus to dairy producers and an integrative approach to a S. aureus control program with subsidising milk analysis will be most promising to improve the S. aureus situation in this confinded region of eastern Switzerland. Veterinarians should cover a key role in consulting farmers during the control program.

Bipolar versus total hip arthroplasty in the treatment of avascular necrosis of the femoral head in young patients.

The authors evaluate medium-term results of bipolar and total hip arthroplasty as a treatment for avascular necrosis of the femoral head. Between 1990 and 2000, 57 hips (45 patients) were treated with a bipolar (BHA: 37 hips) or total hip arthroplasty (THA: 20 hips) depending on the radiographic and macroscopic aspect of the acetabulum. At surgery, all patients were under 65 years of age (average: 45.09 years). All had the same cementless hydroxylapatite coated femoral stem inserted through an anterolateral approach. The BHA were followed during a mean of 4.49 years. One BHA was lost to follow-up. Seven out of 36 hips (19.44%) were considered failures: three due to a poor functional result (Harris Hip Score (HHS) <70) and four which needed conversion to THA for groin pain. Two hips were revised for periprosthetic fracture. Twenty BHA (55.56%) had a good or excellent result (HHSY80). The THA were followed for a mean of 4.32 years. One THA was lost to follow-up. Four out of 19 hips (21.05%) were considered as failures. Three due to a poor functional result (HHS<70) and one which needed cup revision for recurrent dislocation. Fifteen THA (78.95%) had a good or excellent functional result (HHSY80). BHA as a treatment of avascular necrosis of the femoral head in young patients preserves bone stock for later revisions and can lead to excellent results. But the outcome seems less predictable than after THA. Groin pain associated to BHA can be treated successfully with conversion to THA if necessary. (Hip International 2002; 2: 142-9).

Pre-main sequence variables in young cluster Stock 18

We have carried out multi-epoch deep I band photometry of the open cluster Stock 18 to search for variable stars in star forming regions. In the present study, we identified 65 periodic and 217 non-periodic variable stars. The periods of most of the periodic variables are between 2 hours to 15 days and their magnitude varies between 0.05 to 0.6 mag. We have derived spectral energy distributions for 48 probable pre-main sequence variables. Their average age and mass are 2.7 ± 0.3 Myrs and 2.7 ± 0.2 Mo, respectively.

Three years of ULTRASPEC at the Thai 2.4-m telescope: Capabilities and scientific highlights

High temporal resolution observations enable the study of rapid phenomena such as the flux varia¬tions in binary system objects, e.g. cataclysmic variables, compact binary systems, the flux variations in young star clusters, stellar occultations and more. The 2.4-m Thai National Telescope (TNT) is ideally suited for this niche research, being the largest facility in Southeast Asia and being equipped with ULTRASPEC, a high-speed imager based on a low-noise frame transfer electron-multiplying CCD. In the sub-window mode, ULTRASPEC can record uninterrupted sequences with frame rates as fast as few milliseconds. We present some of the key results obtained in the area of high time resolution with ULTRASPEC. We also present the results of a recent worldwide campaign to observe the current series of lunar occultations of Aldebaran (α Tauri) carried out in close collaboration with the Devasthal facilities, the out-of-eclipse variations on the post common-envelope system J1021+1744, and pre-main-sequence variables in young open cluster Stock 8.

Management of the dry and transition periods of dairy cattle in free stall housing systems in Lower Saxony. - Part 2: Risk factores for subclinical ketosis, hypocalcaemia and increased lipomobilisation

Determination of the frequency of subclinical hypocalcaemia, increased lipomobilisation and subclinical ketosis as problems in dairy herds and identification of possible risk factors. Information was obtained from 51 dairy farms on husbandry, feeding, management of the cows and heifers, animal health and prophylactic treatments using a questionnaire. Blood samples from 20% of the cows and 30% of the heifers of each farm (= herd sample) were collected in the week ante partum (a. p.) for determination of serum calcium (Ca), magnesium (Mg), phosphorus (P) and non-esterified fatty acids (NEFA) concentrations and in the week post partum (p. p.) for measurement of serum β-hydroxybutyrate (BHB) concentration. For evaluation of the herd sample results, the percentage of animals with a laboratory value above a determined threshold value for the various parameters was calculated. When the percentage exceeded a certain threshold (alert) level, a herd problem was assumed. Alert levels from the literature and adapted levels were used. For minerals, an adapted alert level of 10% was taken as a basis. In cows, the alert level for Ca, Mg, P (too low) and P (too high) was exceeded in 13.7%, 13.7%, 25.7% and 7.8% of the herd samples, respectively. NEFA (a. p.) and BHB (p. p.) had an adapted alert level of 30%. For NEFA, the alert level was exceeded by cows and heifers on 47.1 % and 51.0% of the farms, respectively. For BHB, the alert level was exceeded by cows and heifers on 33.3% and 13.7% of the farms, respectively. As risk factors, a too large group size for the transition cows (Ca, Mg), pasturing (Ca, BHB), one phasic feeding of dry cows (Mg, BHB) and a lack of a separated dry cow area (BHB) were identi fied. Risk factors for the heifers were no pasturing of the young stock (NEFA) and a low frequency of pushing up the diet in the feed bunk (BHB). Subclinical ketosis in cows and an increased lipomobilisation in heifers were frequent herd problems in the dairy herds studied and were asso ciated with husbandry, feeding and management. Therefore, these herd problems should be handled intensively in veterinary herd health programs with the aim to establish effective preventive measures.

ИЗУЧЕНИЕ ЭФФЕКТИВНОСТИ РЕЖИМОВ И ТЕХНОЛОГИИ АЭРОЗОЛЬНОЙ ДЕЗИНФЕКЦИИ ОБЪЕКТОВ ВЕТЕРИНАРНОГО НАДЗОРА ПРЕПАРАТОМ АБАЛДЕЗ

Effective modes and technology of aerosol disinfection of objects of veterinary supervision by preparation Abaldez were developed as the results of the tests. It was established that in poultry houses for growing young stock hens and keeping laying hens during the application the aerosols of 8% solution of the preparation Abaldez in the dose of 30 ml/m3 and exposure 6 hours all surfaces (wall, floor, cage, feeding bowl, drinking bowl), contaminated with intestinal sticks and staphylococci, completely disinfected, which indicates the high efficiency of the Based on the results of the researches was developed and approved «Technology of aerosol disinfection of objects of veterinary supervision by preparation «Abaldez» (approved by RAS 15.11.2016) for veterinary practice.

The heavy metals (Pb and Cd) accumulation in beef meat when using triticale and lupin in a diet

The recipes of grain mixtures for young stock fattening in the third zone of radioactive contamination with different dosages of triticale have been developed. It has been determined that the Pb concentration in the produce was considerably less than the MPL hereby the content of Pb in the longest muscle of animals back in testing groups decreased by 0.004–0.055mg/kg or by 2.8–32% as compared to check analogies. When 29–40% (in mass) of grain chop is substituted by 20–40% (in mass) of triticale chop, the Pb concentration in liver also decreases by 11.8–13.1%. The level of beef meat and liver contamination by Cd was 9.8–14.6 and 2.3–3.1 times more than in the normative requirements. The concentration of Cd in meat and liver occurred to be the least in the second group of animals — 0.488 and 0.689 mg/kg correspondingly. In the bull-calves of this group the content of Cd in the longest muscle of animals back and in the liver was less by 24.3–33.2% and 21.4–25.4% correspondingly as compared to the analogies in other testing groups. The coefficients of Cd transition into beef-meat and liver were high — 18.8–29.9% and 26.6–40.7% correspondingly. The substitution of 20% (in mass) of grain chop for the same amount of triticale chop in a grain-mixture content when fattening the calves contributed to a considerably lesser transition of Cd into the production (18.8 and 26.6% that is lower than the analogical indexes in other groups by 9.6–11.1%, 9.3–14.1% correspondingly.

Transition of Akabane virus genogroups and its association with changes in the nature of disease in Japan.

Akabane virus (AKAV) is teratogenic to the foetus of domestic ruminants and causes a significant reproduction loss in cattle in Japan. In several past epizootics in cattle, AKAV was also associated with post-natal encephalomyelitis, mainly in calves and young stock. Previously analysed AKAV isolates in East Asia form two major clusters, genogroups I and II, with isolates involved in encephalomyelitis belonging mainly to the former. Between 2007 and 2013, AKAV epizootics were regularly observed in Japan during the summer/autumn season, and abnormal deliveries and post-natal encephalomyelitis caused by the virus in cattle were reported. During this period, 30 AKAV isolates were obtained from diseased and sentinel cattle, a piglet and Culicoides biting midges throughout Japan and were subjected to genetic comparison and phylogenetic analysis with previous isolates. In 2007, 2011 and 2013, AKAV belonging to genogroup I was identified in the central nervous systems of calves showing neurological disorders. Notably, a total of 165 cases of bovine encephalomyelitis were reported in 2011 and the isolated viruses from affected animals shared high genetic identities with a South Korean isolate that was associated with a large outbreak in 2010, suggesting some epidemiological linkage between these epizootics. Epizootics of genogroup II were observed in 2008 and 2010, but bovine post-natal encephalomyelitis cases rarely occurred. Our findings suggest that the frequent incursion of genogroup I isolates has increased the frequency of post-natal encephalomyelitis cases in Japan in recent years. Infection by genogroup I virus was also identified in piglets with neurological disorders or congenital malformations in 2011 and 2013. The aetiological role of AKAV in pigs should be elucidated in the future.

Sea lice (Ceratothoa oestroides), (Rissa, 1826), infestation in Mediterranean aquaculture: new information

Arthropoda parasites of fish are: Copepoda, Branchiura and Isopoda. The Branchiura are exclusively parasitic, while most of the Copepoda and Isopoda are free-living. About 450 species of isopods are parasites of marine and freshwater fish. Isopods are Malacostraca. In the isopod families Cymothoidae and Anilocridae, which number about 200 species, are parasitic species that remain on the fish body throughout their life. The main genus/species of interest to the Greek marine fish farmers is Ceratothoa oestroides. Other isopod species (Flabellifera-Cymothoidae, Anilocridae) have been reported to infest net-pen reared sea bass and/or sea bream, such as: Anilocra physodes, Nerocila orbignyi, Emetha audouini, Ceratothoa parallela. The name "Anilocra" is widely used by farmers for any type of isopods infesting their fish. A mature gravid female isopod releases about 400-550 larvae at a time. Ceratothoa sp are constantly fertile, remaining in reproductive condition throughout the year. Fecundity and hatching rate increase in warmer temperatures, July being the period of optimum isopod proliferation in the Mediterranean.Members of these families (Cymothoidae, Anilocridae) are protandrus hermaphrodites, i.e. an individual develops and functions first as a male and then may become a female. Sexual differentiation takes place after the pulii II larvae have left the marsupium. Regarding the most sensitive age of the fish hosts when the parasites attach in their buccal cavity, empirical observations agree with research results that there is a significant correlation between the level of infection and the length of the host. Fish fry are the evident target for isopod attachment. Ceratothoa oestroides pulii II larvae remain free swimming and capable of infecting a host for about 7 days at 22°C. During this period, in case the host dies, after successful settlement of the parasite, the isopod larvae immediately abandon the dead fish and are still capable of actively seeking another. Parasitic isopods are fairly common crustacean infestations of wild tropical marine fish.They are less common in cold marine waters and not often found on freshwater fish. The distribution of parasitic isopods, as that of all other parasites, is closely related to the occurrence and ecology of their hosts. Demersal fish in coastal waters are mainly infected, the parasites being rarer in benthic- and pelagic fish. Intensive fish farming in coastal waters in the Mediterranean provides an almost ideal environment for isopod parasites, hence, farmed sea bream (Sparus auratus), but mostly sea bass (Dicentrarchus labrax) infestations by isopods comprise a frequent problem in the Mediterranean. Ceratothoa oestroides is the most common among the isopod parasites and inflicts major damage to farmed fish. Among the wild fish, the usual hosts of parasitic isopods are mullets (Mugil sp., Liza sp.), bogues (Boops boops), goldlines (Boops salpa), striped breams (Lithognathus mormyrus) and white breams (Diplodus sargus). These fish species abound in the vicinity of sea bream (Sparus auratus) and sea bass (Dicentrarchus labrax) net pens feeding on waste feed and comprise the vectors for the transmission of the parasites to the farmed species. Heavy infestations of parasitic larvae may kill smaller fish when they first infect them, while seeking permanent attachment. Injured tissues are frequently invaded by secondary bacterial pathogens, such as Aeromonas sp., Flexibacter sp., Vibrio sp. and this may lead to severe escalation of mortality. In young stocks, the cumulative mortality due to parasitism by the pulii II larvae may run as high as 15% even without any bacterial implications. Isopod infestation is confirmed by gross observation of the parasites on the skin, mouth or in the gill chamber of the fish. Recommended prevention would be mainly by means of stock management measures. Excessive fish densities in the fry holding pens must be avoided. Often, in cases of heavy parasitism and mortality, reducing the fish density is enough by itself to remedy the situation. It is worth noting that on farms, where injection vaccination of sea bass is routinely performed, manual delousing of the anaesthetised fish, by means of small blunt forceps, prior to injecting results in a sharp drop of fish retaining adult isopods. Treatment of isopod larvae infestations has been attempted with considerable success by means of hourly formalin baths, at concentrations of about 150ppm, subsequent to enclosing the fish in a tarpaulin and providing ample water oxygenation. Laboratory and field experiments with deltamethrin (pyrethroid), in live fish and in isolated parasites, have indicated that the minimum effective in vitro dose, that kills Ceratothoa oestroides adults in 30 minutes, is 0.05mg/litre.

A longitudinal study of gastrointestinal parasites in English dairy farms. Practices and factors associated with first lactation heifer exposure to Ostertagia ostertagi on pasture

The gastrointestinal nematode Ostertagia ostertagi is an important cause of lost production, health, and welfare in cattle. Detailed records were obtained over a 5-yr period (2010-2015) by questionnaires and qualitative interviews to investigate the practices adopted by dairy farmers to control cattle helminth infections and the factors associated with heifer exposure to O. ostertagi on pasture. In total, 1,454 heifers' individual milk samples were collected over a 1-yr period (2014-2015) in 43 dairy farms in England and tested for O. ostertagi antibody by ELISA. Multilevel linear regression models were used to investigate the association between individual milk optical density ratio (ODR) against O. ostertagi and heifer management from birth to time of sampling. Farm and heifer median ODR against O. ostertagi were 0.98 (interquartile range = 0.76-1.02) and 0.64 (interquartile range = 0.42-0.84), respectively. The majority of heifers (88%) received an anthelmintic treatment before sampling in this study. After controlling for the effect of anthelmintic treatments, heifer individual milk ODR against O. ostertagi significantly increased with high stocking rate at first grazing and co-grazing with adult cows before calving. Conversely, heifer individual milk ODR against O. ostertagi significantly decreased when heifers had co-grazed with sheep and pasture grass had frequently been mowed. Overall, these results provide evidence to support targeting grazing management toward limiting the use of anthelmintics in dairy young stock to enable sustainable control of cattle helminth infections in England. However, to be accepted and adopted by farmers, these best practices would need to take into account farmers' perspectives and contextual challenges.

Prevalence of digital dermatitis in young stock in Alberta, Canada, using pen walks

Digital dermatitis (DD), an infectious bacterial foot lesion prevalent in dairy cattle worldwide, reduces both animal welfare and production. This disease was recently identified in replacement dairy heifers, with implications including increased risk of DD and decreased milk production in first lactation, poor reproductive performance, and altered hoof conformation. Therefore, a simple and effective method is needed to identify DD in young stock and to determine risk factors for DD in this group so that effective control strategies can be implemented. The objectives of this study were to (1) determine prevalence of DD in young stock (based on pen walks); and (2) identify potential risk factors for DD in young stock. A cross-sectional study was conducted on 28 dairy farms in Alberta, Canada; pen walks were used to identify DD (present/absent) on the hind feet of group-housed, young dairy stock. A subset of 583 young stock on 5 farms were selected for chute inspection of feet to determine the accuracy of pen walks for DD detection. Pen walks as a means of identifying DD lesions on the hind feet in young stock had sensitivity and specificity at the animal level of 65 and 98%, with positive and negative predictive values of 94 and 83%, respectively, at a prevalence of 37%. At the foot level, pen walks had sensitivity and specificity of 62 and 98%, respectively, with positive and negative predictive values of 92 and 88%, respectively, at a prevalence of 26%. Pen walks identified DD in 79 [2.9%; 95% confidence interval (95% CI): 2.3-3.6%] of 2,815 young stock on 11 (39%; 95% CI: 22-59%) of 28 farms, with all 79 DD-positive young stock ≥309 d of age. Apparent within-herd prevalence estimates ranged from 0 to 9.3%, with a mean of 1.4%. True within-herd prevalence of DD in young stock, calculated using the sensitivity and specificity of the pen walks, ranged from 0 to 12.6%, with a mean of 1.4%. On the 11 DD-positive farms, the proportion of young stock >12 mo of age with DD lesions was 9.9% (95% CI: 7.8-12.0%). Multilevel logistic regression was used to assess associations with potential risk factors for DD lesions, including age, leg cleanliness, and lactating herd DD prevalence. Presence of DD in young stock increased as their age increased and was associated with increased prevalence of DD in the lactating herd. Pen walks can be used to identify specific young stock with DD or groups where management practices can be implemented to prevent disease proliferation and transmission.

A quantitative risk-analysis for introduction of Bovine Viral Diarrhoea Virus in the Netherlands through cattle imports

Many countries have implemented control programmes aiming to eradicate Bovine Viral Diarrhoea Virus (BVDV). After obtaining the free status, a risk of re-introduction of the virus through import may remain. Therefore the risk of introduction of BVDV through cattle imports in the Netherlands was quantified and the effectiveness of subsequent intervention measures was assessed.Data, literature and expert opinion were used to estimate values for input parameters to feed a stochastic simulation model. The probability that BVDV was imported was differentiated into persistently infected (PI) cattle, trojan cows that transmitted the virus vertically resulting in a PI foetus (TR) and transient infected cattle (TI). The import risk was stratified to beef, dairy, small scale, suckler, trade, veal and young stock herds. The intervention scenarios that were evaluated consisted of virus testing, a combination of virus testing and antibody testing in pregnant cows, abolishment of imports from high risk countries (i.e. countries with a BVDV prevalence >15%) and a combination of import restrictions and testing prior to import.Each year, 334 (5th and 95th percentile: 65–902) Dutch cattle herds were estimated to be infected with BVDV through import. Veal herds account for most infections associated with import (87%), whereas in the other herd types, only 9 beef, 6 dairy, 2 small scale, 16 suckler, 10 trade and 2 young stock herds are infected through imports per year. Import of PI cattle is the most important risk for introduction in veal herds, while import of TR cows is the main source of BVDV introduction in dairy, small scale and suckler herds. With the intervention scenarios, the number of BVDV infected herds in the Netherlands could be reduced to 81 and 58 herds per year when respectively virus testing or a combination of virus and antibody testing was applied or to 108 herds when import from high risk countries was abolished. With the scenario in which both import from high risk countries was abolished combined with virus and antibody testing, the number of BVDV infected herds could be reduced to 17 herds per year. The risk assessment showed that BVDV is regularly imported in the Netherlands. The import risk can effectively be reduced by implementing diagnostic testing prior to import and only import cattle with a favourable result, eventually combined with certain trade restrictions.

Commercial equine production in New Zealand. 2. Growth and development of the equine athlete

During the past 20 years, there has been a contraction in the New Zealand Thoroughbred industry and, to a lesser extent, within the Standardbred industry. These changes have seen an increasing proportion of the market being associated with fewer larger commercial farms. Many of these farms manage their own mares, and the mares and foals of several clients. This, in turn, has increased the similarity of the management of breeding and young stock within New Zealand. The temperate climate allows the majority of the management of breeding and young stock to be pasture based. The predominant pasture is ryegrass–clover mix that has been demonstrated to provide adequate nutrition for growth and development. The temperate climate also permits management of horses at pasture year round, which is proposed to stimulate development of the musculoskeletal system. Apart from a brief period during weaning, most young stock remain at pasture from birth until the start of yearling preparation. Free access to pasture exercise provides the opportunity to stimulate the musculoskeletal system for the future challenges as a racehorse. The export focus of many of the equine industries heavily influences the management decisions. Despite the availability of good-quality pasture post-weaning, many foals receive up to 50% of the daily dietary energy requirement as concentrates, possibly reflecting the emphasis on early sales as yearlings and the drive to optimise growth. The observations of drench resistance of common internal parasites presents an emerging problem for pasture-based production systems. A large proportion of the Thoroughbred foal crop is exported as yearlings or ready to run 2-year-olds. There is an increasing trend for Standardbreds to be sold as yearlings and this has resulted in changes in the management of Standardbred young stock.

Livestock mortality and offtake in sheep and goat flocks of livestock owners making use of services offered by paravets in West Afghanistan

In the present study, we quantified the effect of livestock services provided through paravets (intermediate-level training in veterinary medicine) on mortality and offtake of small ruminants in Western Afghanistan for the years 2010, 2011 and 2013. We compared mortality in adult and in young stock, and offtake of young stock of 120 livestock owners that made use of the paravet services (Users) with 120 livestock owners who did not make use of these services (Non-users). Security issues in the districts under study influenced the choice of villages. Within villages, livestock owners were purposively selected based on their known use of the services, including the provision of biologicals such as anthelmintics and vaccines. In addition, we subdivided both categories into ‘partial’ and ‘full’ based on the intensity of use of biologicals. Paravets were not only trained on preventive and curative veterinary medicine, they were also trained in extension and trained on adhering to a cold-chain and applying quality biologicals. For Non-users there was the possibility to buy biologicals through a local market or bazaar. In Afghanistan, local markets have an extensive supply of vaccines, anthelmintics, and medicines from a variety of sources, often not handled appropriately and therefore of varying quality.The results indicated that livestock owners making partial or full use of the paravet services had statistically significant better animal health and production results. The mortalities in adult stock, expressed as Incidence Rate Ratios (IRRs), for the partial-Users and full-Users categories were estimated to be respectively 0.80 and 0.73 times the mortality observed in the partial Non-users’, the reference category. A similar result was observed for young stock mortality with estimated IRRs of 0.81 and 0.77 for partial and full-Users category respectively. The offtake for partial- and full-Users category livestock owners were 1.24 and 1.21 times higher compared with the reference category.In conclusion, we demonstrated significant improvement of health and production parameters in small ruminants’ flocks of owners making use of the services of the DCA-trained paravets, emphasizing the importance of this sustainable and effective system of private veterinary service delivery in Afghanistan.