Application of an ELISA Milk Pregnancy Test in Beef Cows

Pregnancy‐associated glycoproteins (PAG) are secreted by the binucleate giant cells of the ruminant placenta and enter maternal circulation at the time of placental attachment. The IDEXX Milk Pregnancy Test (IDEXX, Westbrook, ME) detects a subset of PAG in milk. Although designed as a management tool for dairy cows, there is potential for using the milk PAG test in beef cows. Our objective was to compare the performance of the milk PAG ELISA with a gold standard method for pregnancy diagnosis and determine the agreement between milk and serum PAG analysis in lactating beef cows. Angus and Angus‐crossed cows (n = 332) from two Michigan beef herds were enrolled in this study. Cows were subjected either to timed artificial insemination followed by exposure to a bull or exclusively exposed to a bull. The bulls and cows were separated 30 days prior to examination. Serum and milk samples were collected and submitted within 24 h of collection to a commercial laboratory for PAG analysis using the IDEXX Milk Pregnancy Assay (milk) and the IDEXX Bovine Pregnancy Assay (serum). Concurrently with milk and serum collection, each cow was examined transrectally by palpation or ultrasonography. When compared to transrectal examination, the performance (and 95% confidence intervals) of the milk PAG ELISA was sensitivity of 99.7% (99.0–100.0%) and specificity of 80.8% (65.6–95.9%). The lower specificity is likely due to the low prevalence (9.9%) of open cows (n = 30) in the herds examined. Of the 332 cows examined, 1.8% (n = 6) were classified as rechecks using the milk PAG ELISA. Results of the milk and serum PAG ELISA were in high agreement (kappa coefficient = 0.91). The milk PAG ELISA was accurate in predicting pregnancy status using milk collected from beef cattle between days 37 and 125 post‐insemination and may be useful for aiding management decisions in beef herds.     

Results of a survey of attitudes of dairy veterinarians in New Zealand regarding painful procedures and conditions in cattle

AIMS: To quantify the range of attitudes and perceptions of cattle practitioners to painful procedures and conditions in cattle, to identify some of the demographic factors affecting those attitudes and perceptions, and to compare results from veterinarians based in New Zealand with those from the United Kingdom (UK) and Europe.

METHODS: A questionnaire, based on one used for similar surveys in Europe, was sent to all 455 members of the Society of Dairy Cattle Veterinarians (DCV) of the New Zealand Veterinary Association. This questionnaire included a section on demographic data, e.g. gender, year of graduation, and preveterinary school background, and a section which asked the respondents to rate on a scale of 1 to 10 how painful they thought 24 procedures and conditions would be without any analgesia.

RESULTS: A total of 166 questionnaires were returned, a response rate of 37%. From the range of procedures and conditions outlined in the questionnaire, those perceived as most painful were claw amputation, then Caesarean section, followed by surgery for left-displaced abomasum (LDA). The two least painful were mastitis with milk clots only, and the effect on a calf of dystocia.

There were significant differences between the pain scores assigned by men and women and by respondents who had graduated in different decades. Female respondents and more recent graduates tended to give a higher pain score for most conditions. These effects remained, even after the potential interaction between age and gender had been assessed. The effect on pain score of either background or time spent treating cattle was much less marked than the effect of age and gender.

Overall, the results were very similar to results from similar surveys undertaken in the UK and Europe.

CONCLUSIONS: The responses to this survey indicate that, as in the UK and Europe, dairy cattle practitioners in New Zealand have a wide range of attitudes to pain in cattle. The estimates of the severity of pain were subjective, but such a survey allows the majority opinion of a considerable number of informed assessors to be quantified.

CLINCAL RELEVANCE: The wide range of results suggests that more needs to be done to disseminate up-to-date knowl- edge of pain in cattle to veterinarians to ensure they provide appropriate levels of analgesia. In particular, the baseline data from this study can be used by practitioners to identify whether they are underestimating pain in cattle and, if they are, to assess whether they are using analgesia appropriately. Additionally, this dataset provides an informed and independent assessment of the pain associated with husbandry procedures, and could be used to better guide legislation concerning pain control of such procedures.     

Trials with Marek's disease vaccines prepared from a turkey herpes virus and an attenuated Marek's disease virus.

In field trials involving over 224,000 fowls in 11 different commercial flocks, three vaccines were used, namely a freeze-dried vaccine prepared from a turkey herpes virus, a cell-associated virus vaccine prepared from the same isolate and a cell-associated vaccine prepared from a strain of Marek's disease virus isolated from a fowl. The mortality from Marek's disease was reduced by 80 per cent to 95 per cent in birds vaccinated with the freeze-dried vaccine. Cell associated vaccines gave slightly less protection.     

Vitrification of Bovine Blastocysts Produced In Vitro Inflicts Selective Damage to the Inner Cell Mass

In contrast to the embryos derived from live animals, the embryos produced in vitro undergo increased damage and reduced survival after cryopreservation, particularly when produced with serum. In medium containing serum, retinoic acid increases cell numbers in the inner cell mass and the trophectoderm without altering their relative proportions in the bovine blastocyst. In this work, in medium without serum, we analyzed the contribution of retinoic acid to the development of blastocyst and survival to vitrification, and found a strong cell reduction in the inner mass when compared to the trophectoderm. Day-6 in vitro -produced morulae were treated for 24 h with retinoic acid (0.7 and 1.4 μ m ) and subsequently cultured without additives for a further 24 h period. Day-8 blastocyst production and cell counts in hatched blastocysts were unaffected by retinoic acid. However, Day-7 expanded, vitrified embryos produced with retinoic acid 1.4 μ m survived at lower rates than controls when cultured after warming. Vitrification greatly reduced cell numbers in the inner mass (p < 0.0001), while cells in the trophectoderm remained unaltered. Differential cell counts analysis in blastocysts should be taken up to replace unspecific determination of total cells to appreciate substantial modifications in their exact terms. The strong reduction we found in the inner cell mass could explain why in vitro survival to cryopreservation is sometimes scarcely informative on the viability of the embryo after transfer to recipients.     

Conservation of transnational species: The tensions between legal requirements and best scientific evidence

1. This paper describes the tensions between the legal requirements for conservation and the most beneficial biological practice for mobile transnational marine species, using the harbour porpoise (Phocoena phocoena) in European Atlantic waters as a case study.
2. Harbour porpoise are the smallest and one of the most abundant cetaceans occurring throughout the European continental shelf waters, and are affected by human activities occurring in the same waters, especially certain fishing activities.
3. The Convention on the Conservation of European Wildlife and Natural Habitats (the Bern Convention) and its implementing legislation the Council Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora 92/43/EEC (i.e. the Habitats Directive) are the main legal drivers for species conservation throughout the European Union. They aim for the long-term achievement of favourable conservation status and make provision for the use of two conservation measures: protected areas and strict protection measures. The strict protection measures aim to ensure that all forms of deliberate killing are prevented, and that where incidental killing and capture occurs, it does not have a negative effect on conservation status.
4. The conservation of harbour porpoise is currently dependent upon tackling the key issue of bycatch in fisheries. However, in challenges to Member States on their application of the Habitats Directive, the European Commission has chosen to focus on site designation rather than the implementation of the strict protection measures required to monitor and, where necessary, reduce bycatch.
5. This tension between a legal focus on the designation of protected areas instead of tackling threats such as bycatch has potentially led to negative conservation consequences for harbour porpoise and, in part, may explain why wider marine biodiversity has continued to deteriorate in Europe.

     

Cryptococcosis in seven horses

The clinical, radiographic and post-mortem findings in 6 horses with cryptococcal pneumonia and one horse with an abdominal cryptococcal granuloma are described. In pulmonary cryptococcosis, the lesions were either diffuse and multiple, with bilateral lung involvement, or localised mainly to the dorsocaudal region of one lung. The cases of diffuse multiple cryptococcosis were thought to be associated with haematogenous spread of the fungus after gastrointestinal infection and dissemination from regional lymph nodes. The localised form of the disease was thought to have been associated with inhalation of cryptococci. In all cases of pulmonary cryptococcosis, encapsulated yeast-like organisms were demonstrated in Wright's-stained sediment of tracheal washes. In the horse with the abdominal granuloma, cryptococci were present in a fine needle aspirate sample. Isolates of Cryptococcus neoformans var gattii were recovered from 2 of the 5 horses in which cultures were attempted. In addition to a history of previous illness that may have predisposed to infection, most horses in this report had been in areas in which Eucalyptus camaldulensis, or the closely related E rudis, were growing. In humans, an epidemiological relationship between E camaldulensis and infection with C neoformans var gattii has been suggested. Cases of equine cryptococcosis carry a poor prognosis and treatment was not attempted in any of these cases.     

Cirgadian variation in the metabolic rate of growing chickens and laying hens of a broiler strain

1. Circadian variation in the heat production rate of young broiler chickens and laying broiler hens was studied by indirect calorimetry.

2. Variation in heat production rate was synchronised by the light cycle both in the 23‐h light : 1‐h dark regime of the growing chickens and the 14‐h light : 10‐h dark regime of the laying hens.

3. The relative amplitude of the decrease during the dark phase was about twice as great during the 10 h of darkness afforded the adult hens as it was during the 1‐h period of darkness experienced by the growing birds.