Regulation of ovarian folliculogenesis by IGF and BMP system in domestic animals

Involvement of insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) in ovarian folliculogenesis has been extensively studied during the last decade. In all mammalian species, IGF-I stimulates granulosa cell proliferation and steroidogenesis. The concentrations of IGF-I and -II do not vary during terminal follicular growth and atresia. In contrast, the levels of IGFBP-2 and -4, as well as IGFBP-5 in ruminants, dramatically decrease and increase during terminal follicular growth and atresia, respectively. These changes are responsible for an increase and a decrease in IGF bioavailability during follicular growth and atresia, respectively. They are partly explained by changes in ovarian expression. In particular, expression of IGFBP-2 mRNA decreases during follicular growth in ovine, bovine and porcine ovaries, and expression of IGFBP-5 mRNA dramatically increases in granulosa cells of bovine and ovine atretic follicles. Changes in IGFBP-2 and -4 levels are also due to changes in intrafollicular levels of specific proteases. Recently, we have shown that the pregnancy-associated plasma protein-A (PAPP-A) is responsible for the degradation of IGFBP-4 in preovulatory follicles of domestic animals. Expression of PAPP-A mRNA is restricted to the granulosa cell compartment, and is positively correlated to expression of aromatase and LH receptor. From recent evidence, the bone morphogenetic protein (BMP) family would also play a key role in ovarian physiology of domestic animals. In particular, we and others have recently shown that a non-conservative substitution (Q249R) in the bone morphogenetic protein-receptor type IB (BMPR-IB) coding sequence is fully associated with the hyperprolific phenotype of FecB(B)/FecB(B) Booroola ewes. BMP-4 and GDF-5, natural ligands of BMPR-IB, strongly inhibit secretion of progesterone by ovine granulosa cells in vitro, but granulosa cells from FecB(B)/FecB(B) ewes are less responsive than those from FecB(+)/FecB(+) to the action of these peptides. It is suggested that in FecB(B)/FecB(B) ewes, Q249R substitution would impair the function of BMPR-IB, leading to a precocious differentiation of granulosa cells and of follicular maturation. Interestingly, recent findings have described mutations in BMP-15 gene associated with hyperprolific phenotypes in Inverdale and Hanna ewes, suggesting that the BMP pathway plays a crucial role in the control of ovulation rate.     

Managing helminths of ruminants in organic farming

The use of anthelmintics is strongly limited in organic farming. This may induce a change in the intensity (no of worms) and diversity (proportions of species) of helminth infection. Helminths remain a major preoccupation in organic sheep farming: high levels of infection have been recorded on several farms and helminth diversity is always higher. The helminth infection in milk cattle of northern Europe is controlled and diversity is higher in organic farms, as recorded in sheep. The role of helminth diversity on intensity is still unclear. Grazing management is one of the means to controlling helminths. The use of safe pastures for calves and sheep after weaning is one of the major components of control. The use of alternate or mixed grazing is common for cattle in northern countries but is uncommon for sheep in France. Grazing management is not sufficient to controlling infection in sheep and conventional anthelmintic treatments are performed. Additionally, alternative treatments are used. The alternative therapies based on phytotherapy or homeopathy are largely recommended in organic farming but do not have any demonstrated efficacy. More research is needed to evaluate such therapies.     

Placement of a low-profile duodenostomy and jejunostomy device in five dogs

Five male crossbred dogs successfully underwent surgical placement of button enterostomy tubes to evaluate the placement technique, maintenance and complications of these tubes. Surgical placement was quick, technically straightforward and similar to techniques used for other feeding tubes. None of the dogs experienced life-threatening complications during the 10 month follow-up period. One device required replacement as it was removed by the dog before a permanent fistula had formed. Open tubes due to loose safety plugs and focal cellulitis surrounding the exit sites of these tubes were noted in all dogs. The button tube may be a feasible option for long-term nutritional support in patients with pancreatic, hepatobiliary or gastrointestinal conditions.     

Control of parturition in swine. 2. Study results of parturition synchronization in swine with the prostaglandin analog cloprostenol (I.C.I. 80.996: Estrumate)

Premature parturition was induced in 115 of 121 sows (95%) that had been given injections of 150 microgram or 200 microgram of "Estrumate", a prostaglandin analogues, on the 112th and 113th days of gestation. The average time that elapsed between injection and parturition of those 115 animals was 27.2 +/- 7.7 hours, with no difference being observed between gilts, on the one hand, and old sows, on the other. The time of gestation of the treated animals was shortened with significance from 114.6 +/- 1.6 days for the controls to 113.2 +/- 0.4 days. The average duration of parturition proper was 3.7 +/- 2.2 hours, the average litter being 11.2 +/- 3.3 piglets. The total number of piglets born was 1,320, with stillbirths accounting for 4.17%. The average weight at birth, 1,330 +/- 210 g, and the weight at weaning did not differ from weight figures recorded from the controls. The courses of parturition and puerperium were in agreement with normal biological standards. The sows treated were tested for their blood counts close to full term and for their endometrial histomorphology after weaning, with no side effects of "Estrumate" treatment being established. The behaviours of progesterone, 17-beta oestradiol, and cortisol in serum of "Estrumate"-treated sows were investigated, and congruence was established between spontaneous and prostaglandin-induced parturitions, which was in agreement with international literature. The conclusion is that 150 micrograms of 'Estrumate", administered to swine, after the 11th day of gestation has very good labour-inducing effects and ensures normal physiological parturition and piglet development.     

Rapid and Homogenous Detection of Apple stem pitting Virus by RT-PCR and a Fluorogenic 3' Minor Groove Binder-DNA Probe

Real-time PCR with fluorogenic hydrolysis probes (5' nuclease assay) is increasingly used for the detection of pathogens for diagnostic purposes. Nevertheless, the size of the probes, usually 25–40 nucleotides, might limit their use to detect pathogens with high genome variability between isolates, where an identical sequence cannot be found without multiple mismatches. In this report, we describe a 5' nuclease assay, to detect Apple stem pitting virus, based on the use of a shorter probe which is chemically modified with a minor groove binder in order to increase duplex stability and raise the melting temperature to a value suitable for real-time analysis. The short size of the probe, which is critical to target a conserved cluster sequence of 14 nucleotides in the RNA polymerase gene, circumvents the genome variability of the virus. The assay correlates at 96 percent with gel analysis and is more reliable than biological indexing to detect Apple stem pitting virus field isolates. It is fast and fully compatible with automation, and therefore particularly suitable for plant certification.     

Fracture configurations of the equine radius and tibia after a simulated kick.

The objective of this postmortem study was to determine the fracture configurations of the equine radius and tibia after a simulated kick. Fracture configurations of 35 radii and 36 tibiae from 19 adult horses were evaluated after a simulated kick in an experimental ex-vivo study. The bones were dissected, the proximal and distal ends were embedded in resin, fixed horizontally and preloaded in compression, and a steel impactor, designed to simulate a shod equine hoof, was dropped from a height of three to six metres onto the diaphysis. The experiments were filmed with a high-speed camera (30,000 pictures/second). The bones were then photographed and radiographed using a C-arm based 3D imaging device. A software programme (Osirix) was used to reconstruct the fissured and fractured bones three-dimensionally on a computer screen for assessment of the fracture configuration and fissure lines. Incomplete fractures occurred in 26 bones and complete fractures in 42. The complete fractures included 22 butterfly and 20 simple fractures; the latter included 17 oblique, two transverse and one longitudinal fracture. Additional longitudinal fissures occurred in 98% of the fractures. The butterfly fragment was always located on the side opposite the impact. There was a significant correlation between the type of bone and the fracture configuration: butterfly and oblique fractures occurred more frequently in the tibia, and incomplete fractures occurred more frequently in the radius. The data collected can be used to optimize evaluation of fractures and fissures caused by a kick and thereby improve surgical stabilization.     

Field observations during the bluetongue serotype 8 epidemic in 2006. I. Detection of first outbreaks and clinical signs in sheep and cattle in Belgium, France and the Netherlands

Starting August 2006, a major epidemic of bluetongue (BT) was identified in North-West Europe, affecting The Netherlands, Belgium, Germany, Luxemburg and the North of France. It was caused by BT virus serotype 8 (BTV-8), a serotype previously unknown to the European Union (EU). In this outbreak, the virus caused clinical disease in a few individual animals within cattle herds, whereas overt clinical disease was usually restricted to sheep. Investigations in Belgium suggested that the first clinical signs of BTV-8 appeared mid July 2006 in a cattle herd, while the first suspicion of a BT-outbreak in Belgium was reported on 17 August 2006. In the first 10 BTV-8 outbreaks in the Netherlands, the owners indicated that the first clinical signs started approximately 12-17 days before a suspicion was reported to the veterinary authorities via a veterinary practitioner. In BTV-8 affected sheep flocks, erosions of the oral mucosa, fever, salivation, facial and mandibular oedema, apathy and tiredness, mortality, oedema of the lips, lameness, and dysphagia were among the most frequent clinical signs recorded. The most prominent clinical signs in BTV-8 affected cattle herds were: crusts/lesions of the nasal mucosa, erosions of lips/crusts in or around the nostrils, erosions of the oral mucosa, salivation, fever, conjunctivitis, coronitis, muscle necrosis, and stiffness of the limbs. Crusts/lesions of nasal mucosa, conjunctivitis, hyperaemic/purple coloration and lesions of the teats, and redness/hypersensitivity of the skin were relatively more seen on outbreak farms with cattle compared to sheep. Mortality, oedema of the head and ears, coronitis, redness of the oral mucosa, erosions/ulceration of tongue mucosa, purple coloration of the tongue and tongue protrusion and dyspneu were relatively more seen on outbreak farms with sheep compared to cattle.     

Field observations during the Bluetongue serotype 8 epidemic in 2006. II. Morbidity and mortality rate, case fatality and clinical recovery in sheep and cattle in the Netherlands

Data collected in the Netherlands during the Bluetongue serotype 8 (BTV-8) epidemic indicated that in outbreak cattle herds, predominantly dairy and nursing cows were clinically affected and not young stock, beef cattle, beef calves, or breeding animals. In outbreak sheep flocks, mainly ewes and - if present - rams, were clinically affected and not the lambs. Median morbidity rate in outbreak herds was 1.85 per 100 sheep-month at risk and 0.32 per 100 cattle-month at risk for sheep and cattle, respectively. The mean proportion of BT-affected animals in outbreak herds that recovered from clinical disease was approximately eight times higher for cattle compared to sheep in the Netherlands. Median mortality rate in outbreak herds was 0.5 per 100 sheep-month at risk of dying and 0 per 100 cattle-month at risk of dying for sheep and cattle, respectively. Median recovery time of both sheep and cattle that recovered from clinical disease in outbreak herds was 14 days. Median case fatality was 50% in sheep outbreak flocks and 0% in outbreak cattle herds. It is concluded that morbidity and mortality in outbreak cattle herds was very limited during the BTV-8 epidemic in the Netherlands in 2006. In outbreak sheep flocks, morbidity was limited, with exceptions for a few flocks. However, almost 50% of the clinically sick sheep died in outbreak sheep herds.     

Breed differences in the pharmacokinetics of ivermectin administered subcutaneously to Holstein and Belgian Blue calves

Belgian Blue (BB) cattle are very sensitive to mange caused by Psoroptes ovis and, in contrast to the case in Holstein cattle, single treatments with ivermectin do not result in complete elimination of the parasite. The objective of the present study was to determine the concentration of ivermectin in plasma, skin and hair following subcutaneous administration to Holstein and BB calves and to assess the influence of breed on drug pharmacokinetics and availability. Two groups of six healthy female Holstein and BB calves were treated with ivermectin (SC formulation) at a dose of 0.2 mg/kg. Blood, skin and hair were collected before treatment and up to 21 days after treatment. Ivermectin was analyzed in plasma and tissue by high-performance liquid chromatography (HPLC). The peak concentrations (Cmax), time-peak concentrations (Tmax), the area under the plasma concentration-time curves (AUC) and the mean residence time (MRT) were determined. The patterns of plasma and tissue ivermectin concentrations were similar in the two breeds of animals, however, the AUC and Cmax levels for plasma and skin were significantly higher in the BB calves. In hair, ivermectin was detected later than in plasma and skin, with the Tmax ranging between 4 days (Holstein group) and 6 days (BB group). The possible reasons for the significantly higher levels in plasma and skin in BB calves compared to Holstein calves are discussed.