Detection and effects on platelet function of anti-platelet antibody in mule foals with experimentally induced neonatal alloimmune thrombocytopenia

Horse mares carrying mule foals were immunized during the last trimester of pregnancy with whole acid-citrate-dextrose-anticoagulated donkey blood to experimentally induce neonatal alloimmune thrombocytopenia. Thrombocytopenia occurred in the neonatal mule foals born to immunized horse mares within 24 hours after ingestion of their dams' colostrum. Mule foals born to mares not immunized with donkey blood did not develop thrombocytopenia. These findings suggest that antibodies may have been directed against a donkey platelet antigen present in the mule foals but not present in their dams. The objectives of this study were to determine whether anti-platelet antibody could be detected in mule foals with experimentally induced neonatal alloimmune thrombocytopenia, to identify any platelet proteins recognized by serum antibody in these foals, and to determine if platelet function was altered by sera from these mule foals. An indirect enzyme-linked immunosorbent assay demonstrated significantly higher absorption at 1:200 of platelet-bindable immunoglobulin G in serum from thrombocytopenic mule foals, compared with nonthrombocytopenic mule foals. Sera from thrombocytopenic and nonthrombocytopenic mule foals produced similar binding patterns in western immunoblots with donkey platelet proteins separated on sodium dodecyl sulfate polyacrylamide gels. Maximal platelet aggregation and relative slope of aggregation in response to collagen were significantly inhibited after incubation with sera from thrombocytopenic mule foals. These results suggest that mule foals with induced alloimmune thrombocytopenia have serum antibodies that bind to platelets and may compete with collagen binding sites to impair platelet aggregation.     

Trypanosoma vivax in Colombia: Interpretation of field results

The use of the indirect fluorescent antibody test and complementary blood smear examinations in Colombia has shown that Trypanosoma vivax infections of cattle may be considered to be distributed throughout the tropical and subtropical areas of the country. However within this distribution the prevalence showed wide variations between herds and localised epidemic situations could occur at the herd and village level. the examination of sequential serum samples from 2 localities has given additional information on incidence and on transmission patterns.     

Equine neonatal thoracic and abdominal ultrasonography.

Pathologic disorders of the equine neonate often develop shortly after foaling as a result of prematurity, dystocia, trauma, or septicemia. Recognition of these disorders requires routine patient assessment along with diagnostic aids, including abdominal and thoracic ultrasonography. Fortunately, modern technology affords today's equine practitioners the opportunity to use ultrasonography to advance their practice, and it is the authors' hope that this article might help in those efforts.     

Interaction of protein nutrition and laidlomycin on feedlot growth performance and digestive function in Holstein steers

Two isonitrogenous diets (12.5% CP) containing 20 (20% NPN) or 40% (40% NPN) of the N as nonprotein N were evaluated with 0 or 10 mg laidlomycin propionate (LP)/kg in a 2 x 2 factorial arrangement. Changes in dietary NPN:N ratio were developed by partial substitution of urea N for fish meal N. In Trial 1, four Holstein steers (349 kg) with cannulas in the rumen and proximal duodenum were used to evaluate treatment effects on digestive function. Total tract OM digestion was slightly greater (1.2%, P < .10) for diets containing 20% of N as NPN, due to greater (3.4%, P < .05) postruminal OM digestion. Supplemental LP decreased passage of microbial N to the small intestine (7.4%, P < .10) and ruminal degradation of dietary CP (DIP, 8.1%, P < .10). Decreasing the NPN:N ratio decreased microbial N flow to the small intestine (7.5%, P < .10) and DIP (15%, P < .01) and increased (6%; P < .05) the flow of indispensable amino acids to the small intestine. Supplemental LP increased (P < .10) ruminal pH. There were no treatment effects (P > .10) on ruminal molar proportions of acetate or propionate. In Trial 2, 120 Holstein steers (122 kg) were used to evaluate treatment effects on growth performance. Decreasing the NPN:N ratio increased ADG (P < .01) by 36, 40, and 16%, respectively, for the initial three 56-d periods of the trial. Overall, ADG was 17% greater (P < .01) for cattle consuming diets containing 20 vs 40% NPN. Decreasing the NPN:N ratio increased (P < .01) gain efficiency by 17 and 14%, respectively, for the initial two 56-d periods. Overall, gain efficiency was 6% greater (P < .01) for diets containing 20% NPN. Dietary NPN:N ratio did not influence (P > .10) the NE value of diets. Supplemental LP did not affect DMI (P > .10) but increased ADG (6%, P < .01) and gain efficiency (5%, P < .05) and decreased (11%, P < .05) the maintenance energy requirements. Protein nutrition limited growth performance of calves receiving the 20% NPN diets during the initial 112 d of the trial. With the 40% NPN diets, protein nutrition limited growth performance throughout most of the trial (d 1 to d 224). We conclude that LP will enhance daily weight gain and gain efficiency of calf-fed Holstein steers. Conventional urea-based diets will not diminish response to LP, although they may not meet the metabolizable amino acid requirements of calf-fed Holsteins during the first three-quarters of the feeding period.     

Thermal tolerance and compatibility zones as a tool to establish the optimum culture condition of the halibut Paralichthys californicus (Ayres, 1859)

California halibut, Paralichthys californicus (Ayres, 1859) juveniles were studied to ascertain the thermal tolerance and the compatibility zone where these species can be cultivated. Juvenile halibut acclimated at 15, 18, 21 and 24 °C preferred temperatures of 15.1, 18.2, 18.5 and 24.7 °C respectively. The final preferendum (FP) was 18.4 °C, equivalent to the temperature where the physiological processes are more efficient and the optimum growth temperature of 18.02 °C was calculated using the Jobling (1981) equation. The maximum average weekly temperature that must not be exceeded in a juvenile cultivation system is 22.6 °C. Juveniles avoided temperatures of 10.8 and 29.1 °C if they were acclimated between 15 and 24 °C. The thermal tolerance range of the juvenile halibut, having low and high lethal temperatures of 5.0 and 31 °C, characterizes it as a eurythermic organism. The tolerance of the halibut did not increase with the acclimation temperature corresponding to the ultimate upper incipient lethal temperature of 31 °C that differed by only 0.83 °C to the value calculated using the Jobling (1981) equation. The thermal tolerance and compatibility zone for the California halibut were 242.8 and 121.5 (°C)², respectively; they characterize the thermal niche that includes the FP supporting an optimal growth of juveniles.     

Hematology of natural bovine trypanosomosis in the Brazilian Pantanal and Bolivian wetlands.

We report hematological changes observed in natural cases of bovine trypanosomosis due to Trypanosoma vivax in beef and dairy cattle from Bolivian wetlands and Pantanal, Brazil. The main hematologic changes produced by T. vivax infections were anemia and severe leucopenia. The cattle presented macrocytic hypochromic anemia. The leukocyte changes were characterized by relative lymphocytosis and monocytosis and decrease in the neutrophil counts. The clinical signs were lachrymation, progressive weakness, marked weight loss, inappetence, diarrhea and abortions during the third trimester of pregnancy.     

Reversible and washing resistant textile-based optical pH sensors by dyeing fabrics with curcuma

Curcuma powder was used to dye cotton and polyamide 6,6 fabrics in order to produce textile-based optical pH sensors. Both fabrics showed a bright yellow color after dyeing and demonstrated color changes (towards red) when contacted with basic solutions. Color change and sensitivity differ for cotton and for polyamide. Curcuma-dyed cotton shows color changes in particular in the range of pH between 6.5 and 8.5, whilst curcuma-dyed polyamide shows a wider pH range: from 8.5 to 13.0. The stability of pH sensing to washing was evaluated. Three different kinds of washing agents were used in order to simulate the real life conditions of a garment or a cloth. Standard test methods were used when available for washing tests. The pH sensing of the curcuma-dyed fabrics demonstrated an excellent fastness to all kinds of washing. Ionic strength of the solution does not affect the color changes. Moreover, color reversibility of the fabrics was proven, too. Color change and reversibility of the fabrics was assessed by an UV-visible spectrophotometer. Spectral changes were observed at 540 nm for curcuma-dyed cotton, and at 487 and 574 nm for polyamide.     

Progesterone administration in vivo stimulates release of luteinizing hormone-releasing hormone in vitro

The release of luteinizing hormone-releasing hormone (LHRH) from tissue from the mediobasal hypothalamic-anterior hypothalamic-preoptic area of prepuberal female rats was measured in a perfusion system. Measurements were also made of the concentrations of LHRH in these tissue fragments and of luteinizing hormone in serum obtained when the rats were killed. Four groups of immature rats were studied: intact, ovariectomized, ovariectomized and implanted with estradiol-containing capsules, and ovariectomized rats primed with estradiol and injected with progesterone. The release of LHRH from the tissue of ovariectomized animals was significantly less than that of intact females and was not modified when the ovariectomized rats received estradiol. However, there was a four- to fivefold increase in LHRH release from tissue of ovariectomized rats primed with estradiol when they were killed 6 hours after they received an injection of progesterone. The concentrations of LHRH in tissue and of luteinizing hormone in serum varied among groups and with the time of day that the animals were killed. The interactions among luteinizing hormone, gonadal steroids, and the photoperiod seem to set the appropriate conditions for neural processes triggering a complete and normal release of luteinizing hormone.     

Impact of housing environment and management on pre-/post-weaning piglet productivity

The complex environment surrounding young pigs reared in intensive housing systems directly influences their productivity and livelihood. Much of the seminal literature utilized housing and husbandry practices that have since drastically evolved through advances in genetic potential, nutrition, health, and technology. This review focuses on the environmental interaction and responses of pigs during the first 8 wk of life, separated into pre-weaning (creep areas) and post-weaning (nursery or wean-finish) phases. Further, a perspective on instrumentation and precision technologies for animal-based (physiological and behavioral) and environmental measures documents current approaches and future possibilities. A warm microclimate for piglets during the early days of life, especially the first 12 h, is critical. While caretaker interventions can mitigate the extent of hypothermia, low birth weight remains a dominant risk factor for mortality. Post-weaning, the thermoregulation capabilities have improved, but subsequent transportation, nutritional, and social stressors enhance the requisite need for a warm, low draft environment with the proper flooring. A better understanding of the individual environmental factors that affect young pigs as well as the creation of comprehensive environment indices or improved, non-contact sensing technology is needed to better evaluate and manage piglet environments. Such enhanced understanding and evaluation of pig–environment interaction could lead to innovative environmental control and husbandry interventions to foster healthy and productive pigs.