Expression and location of IGF binding proteins-2, -4, and -5 in developing fetal tissues.

Insulin-like growth factors are associated with myogenesis in vivo, and their actions are mediated by IGF binding proteins (IGFBP). Sites of IGFBP production and their location during early development are not clear. The objective of this research was to examine the developmental expression and location of IGFBP-2, -4, and -5 mRNA and peptides in developing porcine skeletal muscle and liver. Pregnant pigs were euthanatized at various times postconception (pc). Developmental expression of IGFBP was evaluated using total RNA extracted from skeletal muscle and liver of 30-, 44-, 59-, 68-, 75-, 89-, and 109-d pc fetuses and from adult and neonatal pigs. Localization of IGFBP-2, -4, and -5 mRNA and peptides was examined by in situ hybridization and immunocytochemistry of muscle samples from contralateral pelvic limbs of each pig. Overall muscle IGFBP gene expression decreased (P < .05) with increasing age. Moreover, expression of liver IGFBP-2 and -5, but not of IGFBP-4, was greater (P < .05) during prenatal than during postnatal periods. The majority of immunoreactive IGFBP was located in developing muscle cells, with little localized to connective tissue, except at later stages of development. These data show that IGFBP-2, -4, and -5 expression is time- and tissue-dependent in fetal liver and muscle.     

Feather folliculoma in a captive-bred barn owl (Tyto alba).

Proliferative cutaneous lesions are frequently encountered in examination of avian species. Tumors of the skin have been reported in many bird species, although comparatively less is known about the incidence of integumentary neoplasia in nondomesticated species than in production or companion species. An adult male, 9-yr-old, captive-bred barn owl (Tyto alba) was presented for examination of a proliferative skin mass of several months' duration on the left wing. An excisional biopsy was performed, and the owl recovered uneventfully. Light microscopic examination of tissue sections of the mass revealed a focal, unencapsulated, well-demarcated, multiloculated mass that consisted of variably sized cystic spaces lined by stratified squamous epithelium and containing concentric laminations of keratin and foci of feather differentiation. A histopathologic diagnosis of feather folliculoma was made. This neoplasm has not previously been described in owls. Its incidence and documentation are significant in that this neoplasm should be considered as a differential diagnosis of proliferative skin lesions in this raptorial species.     

Presence of cervical vertebral malformation in Dobermann puppies and the effects of diet and growth rate

OBJECTIVE: To investigate the relationship between diet, growth rate and the presence of caudal cervical malformation in Doberman puppies. DESIGN: A prospective study of 15 Dobermann puppies from three unrelated litters, aged from 0 to 16 weeks. PROCEDURE: The growth rate in terms of body weight gain and increase in ulna length were measured weekly for all puppies. In addition the nutritional quality of the diets was assessed. Radiographs of the cervical spine were taken at 6 and between 12 and 16 weeks of age and examined for the presence of caudal cervical vertebral malformation. A mixed model for repeated measures data was used to investigate the relationship between the growth rate of the puppies and the fixed effects age, dam, diet, gender and presence of caudal cervical malformation. RESULTS: Five of the puppies had changes consistent with caudal cervical malformation. The diets fed were either balanced or transiently deficient in protein, calcium, phosphorus and/or magnesium. There was no significant association between growth rate and the variables dam, gender and the presence of caudal cervical vertebral malformation. There was no significant association between diet and increase in ulna length, but a trend existed between body weight gain and the feeding of a balanced diet (P = 0.0672). CONCLUSION: Caudal cervical vertebral changes can be detected radiographically as early as 6 weeks of age in some Dobermann puppies. A balanced diet and growth rate are not significant factors in its initial development.     

Microsatellite variation between an African and five European taurine breeds results in a geographical phylogenetic tree with a bison outgroup

Genetic variation is being used extensively for individual identification and linkage analysis, and may be useful for interpopulation studies. Previously, blood groups and biochemical variants in blood cell and serum proteins have been used to study (evolutionary) relationships in mammals. But genetic divergence and gene flow among closely related populations are difficult to measure with these classical markers because their mutation rate is so low that new mutations have not had sufficient time to appear and become fixed. So they have a small number of alleles and a relatively low level of heterozygosity. These markers are now replaced by DNA markers, mostly microsatellites. These microsatellite loci are useful genetic markers at which alleles differ in length due to differences in the number of short sequence motifs arranged adjacent to one another. They are abundantly distributed throughout the mammalian genome. They have a large number of alleles, a high level of heterozygosity and are inherited in true Mendelian fashion. These characteristics make them valuable for parentage control, linkage analysis, genome mapping and phylogenetic studies. In terrestrial vertebrates with limited mobility, genetic differentiation often increases with the distance between populations or corresponds to the extent of geographic and habitat barriers (R oy et al. 1994). Investigations of short tandem repeats yield a considerable volume of genetic data regarding the similarities and divergence times of different cattle populations. Microsatellite markers are suitable for the estimation of these parameters as they are not generally subject to direct selection and environmental influences. Computation of genetic distances based on data from several loci can be used to evaluate the taxonomic relationship between populations. The aim of this study was to estimate the relative genetic variability between Belgian cattle breeds and to reconstruct the evolutionary relationship among them, also using two small genetically isolated cattle-like populations.     

Clinical assessment of left ventricular relaxation

Ventricular relaxation is altered in a number of cardiac disorders affecting domestic animals. Clinical determination of the ventricular relaxation rate can provide useful information regarding disease severity and response to therapy. We believe that the current gold standard for assessing left ventricular relaxation requires measurement of ventricular luminal pressure at end-expiration using a high-fidelity catheter. Ventricular pressure should be digitized at ≥200 Hz for the period of pressure fall between the minimum rate of change of ventricular pressure and 10 mm Hg above left ventricular end-diastolic pressure of the preceding beat. The rate of relaxation then should be determined from the digitized data by Marquardt nonlinear least squares parameter estimation using an exponential decay model with nonzero asymptote. The major disadvantage in using an invasive method for evaluating left ventricular relaxation is that it requires general anesthesia in animals that frequently are categorized as high-risk anesthetic patients. Noninvasive estimates of ventricular relaxation using echocardiographic parameters such as isovolumic relaxation time, peak early filling rate, and time from end-systole to peak filling rate provide a crude and nonspecific assessment of ventricular relaxation that can be obtained from conscious animals. Determinations of these echocardiographic indices are of limited usefulness in assessing changes in ventricular relaxation associated with disease progression or therapeutic intervention, unless concurrent estimates of left atrial pressure, mitral valve characteristics, and left ventricular compliance are available.     

Bacterial meningitis and diseases caused by bacterial toxins

Bacterial meningitis most commonly occurs in young calves secondary to septicemia. Clinical signs of hyperirritability are usually seen. Meningitis can be confirmed by cerebrospinal fluid analysis and culture or by necropsy. Intoxications by the exotoxins of Clostridium perfringens types C and D, C. botulinum, and C. tetani are difficult to confirm. The clinical signs of these intoxications vary from flaccid paralysis (botulism) to muscular rigidity (tetanus). Treatment of affected cattle has been unrewarding in botulism and enterotoxemia, whereas early aggressive treatment of tetanus cases can often be successfully resolved. Botulism and enterotoxemia can be proved using mouse inoculation tests, whereas tetanus is diagnosed largely by ruling out other diseases.     

Sequential study of lesion development in experimental haemophilus pleuropneumonia

Recently weaned pigs were infected aerogenically with Haemophilus (Actinobacillus) pleuropneumoniae, serotype 5. At three, six, 12, and 18 hours and one, two, four and seven days after exposure to haemophili a pair of animals were killed and necropsied. Pulmonary oedema with multifocal petechial haemorrhages and a diffuse neutrophilic bronchiolitis and alveolitis were observed at three and six hours after infection. Focal areas of coagulative necrosis developed in areas of intense suppuration at 12 and 18 hours after infection. At one and two days after infection, necrotic areas were surrounded by dense bands of degenerating leucocytes and contained unidentifiable round and elongated cells characteristic of this disease. In subacute lesions a thick layer of granulation tissue formed around the outer margin of developing abscesses. Most of the round and elongated cells in alveolar exudates could not be identified by enzyme histochemistry or electron microscopic examination. Neutrophils in various stages of degeneration and deterioration provided strong evidence that some of the cells were of this type. These findings suggest that neutrophils may play an early and significant role in development of lesions.     

Suckling behavior of calves with dams varying in milk production

Two experiments were performed to test the hypothesis that suckling behavior of calves with similar growth potential varies depending on cows' level of estimated milk production and stage of lactation. Eleven mature cows, which varied in estimated 205-d milk production (996 to 2354 kg/205 d), nursing heifer calves of similar growth potential were used in Exp. 1. Suckling behavior of calves was observed for two 24-h periods at three stages of lactation (average of 52, 104 and 167 d postpartum). Suckling frequency (suckling bouts/24 h) declined as milk production increased at 52 d of lactation (-.00382 bouts/kg milk) but was unrelated to milk production at later stages. Duration of suckling (minutes/suckling bout) increased with estimated level of milk production at all stages of lactation (means = .001556 min/kg milk). Total time suckling tended to increase as estimated level of milk production decreased at 52 d of lactation, but this component of suckling behavior was unaffected by milk level at later stages. Suckling frequency declined from 8.6 bouts/24 h at 52 d of lactation to 4.5 bouts/24 h at 167 d of lactation when averaged across all cows. Total minutes nursed/24 h declined in a similar manner (64 min/24 h to 44 min/24 h) between 52 and 167 d of lactation. Duration of each suckling bout did not change with stage. In the second experiment the relationship of suckling behavior to estimated milk production was evaluated at four early stages (average of 17, 38, 59 and 80 d postpartum) of lactation using 20 mature cows.(ABSTRACT TRUNCATED AT 250 WORDS)