Comparative study of epidural xylazine or clonidine in horses

OBJECTIVE: To evaluate the cardiorespiratory and behavioural effects of epidural xylazine (XYL) or clonidine (CLO) in horses. STUDY DESIGN: Blinded, randomized experimental study. ANIMALS: Twelve healthy Arabian yearling horses weighing 117-204 kg were randomly allocated into two groups: XYL (n = 6) and CLO (n = 6). METHODS: An epidural catheter was inserted and a facial arterial catheter was placed and the next day the horses were restrained in stocks. Baseline values for heart (HR) and respiratory (RR) rates, arterial pressure and behavioural responses were evaluated before (T0) and 10, 20, 30, 45, 60, 90 and 120 minutes after epidural injection (T10-T120). The horses received 0.2 mg kg(-1) of XYL or 5 microg kg(-1) CLO; adjusted to (3.4 + (body weight in kg x 0.013) mL with saline. Data were analysed by the Kolmogorov-Smirnov test, one-way anova with repeated measures, and one-way anova followed by a Student-Newman-Keuls test or Fisher's exact test, as necessary. Significance was set at p < or = 0.05. RESULTS: Sedation and ataxia were seen at T10, persisting until T120 in four and three horses, respectively, in XYL and all horses in CLO respectively. Two XYL and one CLO horses became recumbent at T45 and T25 respectively. Penile prolapse occurred in four of five males at T30 and T45, in the XYL and CLO groups, respectively, resolving by T120. Tail relaxation was present from T10 to T120 in all horses in XYL and in four horses in CLO. Head drop was observed from T20 to T60 and from T10 to T120 in XYL and CLO respectively. Respiratory rate decreased significantly only at T45 in the CLO group. Heart rate and arterial blood pressure remained stable. CONCLUSIONS AND CLINICAL RELEVANCE: Epidural CLO and XYL produce similar cardiorespiratory and behavioural changes but neither would be safe to use clinically at the doses used in this study.     

Population dynamics of horn fly, Haematobia irritans irritans (L.) (Diptera: Muscidae), on Hereford cattle in Uruguay

Abundance of adult horn flies, Haematobia irritans irritans (L.), was monitored on 25 untreated Hereford cows in Tacuarembó Department, Uruguay, during three consecutive grazing seasons, from October 1999 to May 2002. The population showed a variable pattern of abundance during three years, with peaks in late summer-early fall of each year. Adult flies were continuously present, although in very low numbers in intervening winters. Numbers of flies per cow rarely exceeded a reference level of 200 flies per animal during the grazing season. Degree-day calculations indicated that approximately 12 generations were possible each year. Time series analysis of mean densities among consecutive generations indicated that population growth was governed by simple, direct density-dependence, with additional effects of seasonally varying weather. Response surface regressions confirmed that intergenerational growth was inversely related to mean density, and directly related to temperature. Stochastic simulations with the response surface model suggested that within the range of temperatures observed in our study, horn fly populations on Hereford cattle will tend toward densities of approximately 150 flies per animal in summer, and exceed a nominal level of 200 flies per cow one or more times in about 65 of every 100 grazing seasons.     

A panel of protein candidates for comprehensive study of Caprine Arthritis Encephalitis (CAE) infection

The caprine arthrite encephalite (CAE) is a disease that affects especially dairy goat. The virus shows compartmentalization features, that allows it to hide at certain times during the course of the disease, making it difficult to control. The present study was conducted to identify the major seminal plasma protein profile of goats infected by CAE and its associations with seroconversion using Western blotting. Two groups containing five males each, were used in this experiment. The first group was composed by seropositive animals and the control by seronegative confirmed by Western blotting and PCR. The semen was collected through artificial vagina and after that, two-dimensional electrophoresis and MALDI-TOF MS were used. Seventy-five spots were identified in the goat seminal plasma gels, equivalent to 13 different proteins with more expression. The similar proteins found in both groups and related to reproduction were spermadhesin Z13-like, bodhesin and bodhesin-2, Lipocalin, protein PDC-109-like, and albumin. In infected goats, proteases such as arisulfatase A have been identified, whose function probably is related to metabolism control of sulfatides, involved to virus control. The other ones were bifunctional ATP-dependent dihydroxyacetone kinase/FAD-AMP lyase, cathepsin F isoform X1, disintegrin and metalloproteinase domain-containing protein 2-like isoform X1, clusterin, carbonic anhydrase 2, electron transfer flavoprotein subunit beta, and epididymal secretory glutathione peroxidase. The results of this study show the reaction of the innate immune system against chronic infection of goats by CAE.     

Performance and ingestive behavior of steers on integrated system using legume and/or energy supplementation

Tropical Animal Health and Production - This study aimed to evaluate the effect of a mixture of temperate and legume grasses with or without energy supplementation on the performance and feeding...     

Sperm Morphology Assessment in Captive Neotropical Primates

The main objective of this study was to evaluate sperm morphology in four neotropical primate species to compare the sperm morphological traits and the sperm morphometric parameters as a basis for establishing normative sperm standards for each species. Data from 80 ejaculates collected from four primate species, Callithrix jacchus, Callimico goeldii, Alouatta caraya and Ateles geoffroyi, were analysed for detection of sperm morphological alterations using subjective World Health Organization (WHO‐2010) standards and Sperm Deformity Index (SDI) criteria, objective computer‐assisted sperm morphometry analysis (CASMA) and subpopulation sperm determination (SSD) methods. There were multiple differences (p < 0.01) observed among primate species in values obtained from WHO‐2010, SDI, CASMA and SSD sperm analysis methods. In addition, multiple significant positive and negative correlations were observed between the sperm morphological traits (SDI, Sperm Deformity Index Head Defects, Sperm Deformity Index Midpiece Defects, Sperm Deformity Index Tail Defects, Normal Sperm, Head Defects, Midpiece Defects and Tail Defects) and the sperm morphometric parameters (SSD, Area (A), Perimeter (P), Length (L), Width (W), Ellipticity, Elongation and Rugosity) (p ≤ 0.046). In conclusion, our findings using different evaluation methods indicate that pronounced sperm morphological variation exists among these four neotropical primate species. Because of the strong relationship observed among morphological and morphometric parameters, these results suggest that application of objective analysis methods could substantially improve the reliability of comparative studies and help to establish valid normative sperm values for neotropical primates.     

Genomic Imprinting in Canis familiaris

For the vast majority of mammalian genes, maternally- and paternally-derived alleles behave identically and are either expressed or repressed, regardless of whether they were inherited from egg or sperm. For imprinted genes, however, this is not the case. The alleles of imprinted genes are epigenetically modified in a parent-of-origin-specific manner and, as a consequence, maternally- and paternally-derived alleles behave differently. Typically one allele is expressed while the other is silent. Although relatively few in number, imprinted genes are the focus of intensive study, as they have important roles in embryonic development. Abnormal expression of imprinted genes results in growth disorders and is implicated in several clinical conditions. Most studies of imprinted genes have been performed in rodents or primates, with limited studies in other mammals such as bovine and opossum. We have recently demonstrated the existence of imprinted genes in the canine, by showing that the canine insulin-like growth factor 2 receptor gene ( IGF2R ) is monoallelically expressed, with predominant expression of the maternally-derived allele and repression of the paternally-inherited allele. Our ultimate goal is to characterize all imprinted genes in the canine, and to understand how they contribute to canine reproduction, development and disease. Such knowledge will be vital for optimizing the success of most reproductive strategies in the canine.     

Concentrations of Prolactin, LH, Testosterone, TSH and Thyroxine in Normospermic Dogs of Different Breeds

Concentrations of prolactin (PRL), LH, testosterone (T), TSH and thyroxine (T₄) were determined before and at 20, 120 and 180 min after a single iv injection of thyrotropin-releasing hormone (TRH) in eight Beagles, eight Fox Terriers, six Labrador Retrievers and five Great Danes that were normospermic. Mean basal PRL concentrations were lower in the Fox Terriers compared with the Great Danes (p < 0.05). Mean LH concentrations were higher in the Fox Terriers than in the Beagles, and T was lower in the Fox Terriers at some times but not others (p < 0.05). Thyroid Stimulating Hormone (TSH) concentrations did not differ among breeds, while mean basal T₄ values were lower in Fox Terriers compared with Labrador Retrievers and Great Danes (p < 0.05). Stimulation of T₄ secretion 120 and 180 min after iv TRH injection was most pronounced in the Beagles and less in the Fox Terriers (p < 0.05). The results of the present study indicate that potential breed differences in circulating concentrations of PRL, LH, T, TSH and T₄ in male dogs with apparently normal fertility can be encountered, but further studies are needed to determine whether the observed differences are typical features of these breeds, reflect subsets of dogs within breeds, or are in part because of possible uncontrolled parameters such as sample timing, ambient photoperiod, housing conditions or diet.     

Identification of an alpha-amylase inhibitor from Pterodon pubescens with ability to inhibit cowpea weevil digestive enzymes

Cowpea seeds (Vigna ungiculata) are widely cultivated by poor farmers in Latin America and Africa and are often severely damaged by the cowpea weevil Callosobruchus maculatus. A proteinaceous inhibitor of cowpea weevil digestive enzymes, PpAI, was purified from white sucupira seeds (Pterodon pubescens) and biochemically characterized in this study. Proteins were extracted from seeds and precipitated with ammonium sulfate at 100% saturation. This fraction was applied onto a Red-sepharose CL-6B column, and the retained peak showed 70% inhibitory activity toward larval C. maculatus digestive alpha-amylases. The retained peak was then purified using an analytical reversed-phase HPLC column. Purified PpAI showed 65% inhibitory activity against larval C. maculatus enzymes. Enzymatic assays also showed that the purified P. pubescens inhibitor was unable to reduce the activity of mammalian alpha-amylases, suggesting specificity toward insect enzymes. Moreover, artificial seeds containing PpAI were able to reduce larval weight by 36% and cause 55% mortality. Mass spectrometry and SDS-PAGE analyses indicated that PpAI showed a molecular mass of approximately 5.0 kDa. This alpha-amylase inhibitor, coming from a native Cerrado plant, could be used to construct a genetically engineered cowpea with enhanced resistance against weevil pests.     

Sacral osteochondrosis in two German Shepherd Dogs

Two young adult male castrated German Shepherd Dogs were referred for evaluation of intermittent episodes of hindlimb pain. Physical examination suggested lumbosacral stenosis, and plain radiographs and computed tomography revealed lesions consistent with sacral osteochondrosis. One dog had osteochondral fragments removed surgically; the other was managed conservatively. The surgically treated dog had complete resolution of clinical signs whereas the dog managed conservatively had repeated episodes of mild pain and received one short course of non-steroidal anti-inflammatory medication in 18 months. Sacral osteochondrosis has not been previously reported in Australia.