Effect of environmental design on the growth and behaviour of weaned pigsInfluence de milieux expérimentaux sur la croissance et le comportement des porcs sevrésEffect der umweltgestaltung auf das wachstum und verhalten abgesetzter ferkel

Large White × Landrace pigs weaned at 24–29 days were placed in a structured environment planned as a 2 × 2 factoral design. The two variables were the presence or absence of a box (1.2 m × 0.92 m × 0.86 m) and the presence or absence of an extended floor which increased the solid area in the control pen from 60% of the total area to 80%. The box with no extended floor exceeded all other environments in stimulating the relative growth rates of the piglets. On removal of the temperature covariance the box still accounted for most of the variance in relative growth rate. Elements of the box (element 1, corner, back and side wall; element 2, corner, front and side wall; element 3, side wall only; element 4, back wall only) were tested for effect on relative growth rate and it was found that element 3, side wall only, promoted the most regular growth rates. The rates of agonistic behaviour over each 10 min were not significantly different for pigs in any of the tested environments.     

Size factors in apple fruit

Eight ‘Golden Delicious’ apple trees on an experimental plot were systematically thinned to give different numbers of fruit per spur, per branch, and per tree. At harvest, fruits were weighed individually and their positions on spurs and branches noted. Trunk and branch girths were measured.Mean fruit weights were not significantly affected by the presence of several fruits on a spur, or by the degree of local crowding on branches, compared with the general mean for the whole tree. However, mean fruit weight varied between trees, depending on the number of fruits carried per unit of trunk girth of cross-sectional area.μ (mean fruit weight) = a — bN (number of fruit per unit trunk dimension)The distribution of fruit weights on each tree can be regarded as normal and on the 8 trees examined, standard deviations did not differ significantly. An equation was derived relating total crop per tree and fruit-size distribution to trunk dimensions and fruit number, both of which were variable from tree to tree, involving 2 coefficients of the mean size equation and the standard deviation of the weight distribution, which seem to be constant for the 8 trees under the prevailing conditions.Using the equations, it could be shown that although fruit thinning would increase the proportion of larger fruit in the crop, in only one case would careful thinning have increased the total weight of larger fruit.     

Cytokine and chemokine gene expression of IL-1beta stimulated equine articular chondrocytes

OBJECTIVE: To evaluate mRNA expression of several proinflammatory and anti-inflammatory cytokines and chemokines in equine unstimulated and interleukin-1beta (IL-1beta)-stimulated chondrocytes. STUDY DESIGN: In vitro experiment using equine chondrocyte cultures. SAMPLE POPULATION: Whole articular cartilage from metacarpophalangeal joints (n=5 horses; 10 fetlocks). METHODS: Chondrocyte monolayer cultures were established from digested adult equine articular cartilage and stimulated with 5 ng/mL of recombinant human IL-1beta. RNA was extracted from the cells 24 hours after stimulation. IL-1beta, IL-4, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and ubiquitin (house keeping gene) mRNA expression were investigated by real-time RT-PCR. RESULTS: IL-1beta, IL-6, and IL-8 mRNA were expressed in unstimulated chondrocytes from macroscopically normal joints and were significantly up-regulated after stimulation (5/5 horses). IL-4 mRNA was not detected in any samples (0/5 horses). TNF-alpha mRNA, by comparison, was expressed in 2/5 unstimulated samples and in all stimulated samples but a considerable sample variation in response to IL-1beta stimulation was observed. CONCLUSIONS: Equine chondrocytes express mRNA for several proinflammatory cytokines and chemokines and IL-1beta modulates their expression. CLINICAL RELEVANCE: Chondrocytes express proinflammatory cytokines and chemokines capable of modulating a local inflammatory cascade in articular cartilage, which could potentially lead to focal degradation and osteoarthritis.     

Blue eye disease porcine rubulavirus (PoRv) infects pig neurons and glial cells using sialo-glycoprotein as receptor

Pig neural cells express glycoproteins with sialylated N-linked oligosaccharide chains (SNOC) which are used by the porcine rubulavirus (PoRv) as receptors. Pig neuronal or glial cell cultures were employed to investigate (a) whether PoRv infects such cells using a molecule expressing SNOC, and (b) the role of viral envelope glycoproteins in establishing the infection. Enriched neuronal or glial cell cultures were exposed to PoRv and infection was detected immunocytochemically. Neuronal cultures prepared from neonatal pigs were treated enzymatically to eliminate sialic acid or N-linked oligosaccharide chains. Primary neural cultures were exposed to anti-HN or anti-F preincubated with PoRv to study the role of the viral glycoproteins. In enriched cultures, PoRv infected neurons and glial cells, and sialic acid expressed in N-linked oligosaccharide chains appeared to play a central role in infection. It was concluded that HN and F viral glycoproteins are required to infect neurons and glial cells.     

Multiple meningiomas: clinical, radiological, surgical, and pathological findings with outcome in four cats

The present report describes the clinical signs, magnetic resonance imaging (MRI) findings, surgical procedure, pathological findings and follow-up in four cats with multiple meningiomas; three castrated male and one spayed female domestic shorthair indoor cats, ranging in age from 11 to 14 years. In three of four cats, clinical signs at presentation were suggestive of a focal lesion. Three cats had two meningiomas and one had four meningiomas. Most of the tumours were supratentorial, one arose from the tentorium and one was infratentorial. The duration of presenting signs before surgery ranged from 10 days to 11 months. Postoperative MRI revealed complete gross tumour removal in three cases. In one cat with two cranial fossa meningiomas, subtotal excision with a small basal remnant (2 x 2 mm) of the ventral part of one meningioma lying on the floor of the skull, was observed. Based on histopathological architecture, six tumours revealed features of a transitional subtype meningioma, and four of a meningotheliomatous meningioma. In each cat, the multiple meningiomas were all assigned to the same histopathological group. The preoperative presenting signs had resolved by the follow-up examinations 4 weeks after surgery in two cats. Long-term follow-up evaluation revealed that surgically-induced or exacerbated neurological deficits in two cats had completely or almost completely resolved within 8 weeks of surgery. All patients are still alive 12 to 21 months after surgery and no clinical signs of recurrence could be detected at that time.     

Experimental challenge models for Johne's disease: a review and proposed international guidelines

An international committee of Johne's disease (JD) researchers was convened to develop guidelines for JD challenge studies in multiple animal species. The intent was to develop and propose international standard guidelines for models based on animal species that would gain acceptance worldwide. Parameters essential for the development of long-term and short-term infection models were outlined and harmonized to provide a "best fit" JD challenge model for cattle, goats, sheep, cervids, and mice. These models will be useful to study host-pathogen interactions, host immunity at the local and systemic level, and for evaluating vaccine candidates and therapeutics. The consensus guidelines herein list by animal species strains of Mycobacterium avium subsp. paratuberculosis used, challenge dose, dose frequency, age of challenge, route of challenge, preparation of inoculum, experimental animal selection, quality control, minimal experimental endpoints and other parameters.     

Cloning and expression of Rift Valley fever virus nucleocapsid (N) protein and evaluation of a N-protein based indirect ELISA for the detection of specific IgG and IgM antibodies in domestic ruminants

Serodiagnosis of Rift Valley fever (RVF) currently relies on the use of live or inactivated whole virus as antigens. The recombinant nucleocapsid (N) protein of RVF virus was tested for diagnostic applicability in an indirect enzyme-linked immunosorbent assay (I-ELISA), using sera from experimentally infected sheep (n=128), vaccinated sheep (n=240), and field-collected sera from sheep (n=251), goats (n=362) and cattle (n=100). The N-protein based I-ELISA performed at least as good as VN and HI tests. In goat the diagnostic sensitivity (D-Sn) and specificity (D-Sp) of the I-ELISA was 100% when using the anti-species IgG conjugate. Using protein G as a detection system, the D-Sn and D-Sp in goats were 99.4% and 99.5%, in sheep field sera both 100%, in cattle 100% and 98.3%, respectively. The I-ELISA based on recombinant N-protein has the potential to complement the traditional assays for serodiagnosis of RVF. Advantages of the N-protein are its safety, stability and cost-effectiveness in use and production.     

Analysis of the mode of inheritance for distichiasis in the Elo dog breed using complex segregation analyses

The inheritance of distichiasis was analyzed in the dog breed Elo using complex segregation analyses.The different hypotheses of monogenic, mixed-monogenic-polygenic and polygenic inheritance as well as a pure environmental model were tested. In further analyses the number of examined Elo dogs per ophthalmologist and the proportion of genes of Eurasian and Old English Sheepdogs were included in the models as covariates. Seven families were randomly collected for the analyses.The seven families comprised a total of 296 animals with 218 examined and 65 affected dogs. A genetic component was verified for the prevalence of distichiasis. Mixed models with a recessive, dominant or arbitrary major gene effect and the polygenic model represented likely hypotheses of inheritance. The prevalence of distichiasis observed was insufficiently explained by non-genetic factors and the breed composition. Therefore, a model only including non-genetic factors and the breed composition could be excluded.     

Influence of extracellular matrix on bovine mammary gland progenitor cell growth and differentiation

OBJECTIVE: To examine the impact of simple versus complex extracellular matrices (ECMs) on morphologic development and differentiation of bovine mammary gland progenitor cells (BMGPCs). SAMPLE POPULATION: Cultures of BMGPCs. PROCEDURES: BMGPCs were grown on the following extracellular matrices: collagen I, collagen IV, laminin, and a commercially available gelatinous protein mixture. Cells were examined with light microscopy and transmission electron microscopy. RESULTS: Formation of organoids and production of the gap junction protein, connexin 43, were the criteria for BMGPC differentiation. The BMGPCs formed a 2-dimensional monolayer when grown on plastic, laminin, collagen I, or collagen IV. These cells did not have a network of cells forming epithelial organoids resembling a honeycomb. However, they did produce gap junction proteins. When BMGPCs were cultured on the commercially available gelatinous protein mixture, 3-dimensional epithelial organoids resembling a honeycomb formed and connexin 43 was produced. The thickness of the commercially available gelatinous protein mixture also regulated cell shape reorganization. Cell density affected the formation organoid networks and the rate at which monolayers reached confluency. CONCLUSIONS AND CLINICAL RELEVANCE: When plated on a commercially available gelatinous protein mixture, the BMGPC culture system allowed us to simulate, in vitro, the interaction between epithelial cells in varying stages of differentiation and the microenvironment. Thus, a heterogeneous ECM, such as the commercially available gelatinous protein mixture, is more physiologically relevant in providing a microenvironment for BMGPC lineage pathway differentiation to mimic an in vivo environment. In contrast, BMGPCs grown on homogenous ECM, although able to produce connexin 43, are unable to form organoids.