Goat medicine and surgery

Comparative Analysis of Tat-Dependent and Tat-Deficient Natural Lentiviruses

The emergence of human immunodeficiency virus (HIV) causing acquired immunodeficiency syndrome (AIDS) in infected humans has resulted in a global pandemic that has killed millions. HIV-1 and HIV-2 belong to the lentivirus genus of the Retroviridae family. This genus also includes viruses that infect other vertebrate animals, among them caprine arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), the prototypes of a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting both goat and sheep worldwide. Despite their long host-SRLV natural history, SRLVs were never found to be responsible for immunodeficiency in contrast to primate lentiviruses. SRLVs only replicate productively in monocytes/macrophages in infected animals but not in CD4+ T cells. The focus of this review is to examine and compare the biological and pathological properties of SRLVs as prototypic Tat-independent lentiviruses with HIV-1 as prototypic Tat-dependent lentiviruses. Results from this analysis will help to improve the understanding of why and how these two prototypic lentiviruses evolved in opposite directions in term of virulence and pathogenicity. Results may also help develop new strategies based on the attenuation of SRLVs to control the highly pathogenic HIV-1 in humans.

Effects of dietary crude glycerin supplementation on nutrient digestibility, ruminal fermentation, blood metabolites, and nitrogen balance of goats

This experiment was conducted to evaluate the effects of increasing concentrations of crude glycerin (CGLY) in diets on nutrient utilization, ruminal fermentation characteristics, and nitrogen utilization of goats. Four male crossbred (Thai Native×Anglo Nubian) goats, with an average initial weight of 26±3.0 kg, were randomly assigned according to a 4×4 Latin square design with four 21 days consecutive periods. Treatments diets contained 0%, 5%, 10%, and 20% of dietary DM of CGLY. Based on this experiment, there were no significant differences (p>0.05) among treatment groups regarding DM intake and digestion coefficients of nutrients (DM, OM, CP, EE, NDF, and ADF). Likewise, mean serum glucose, BHBA, and PCV concentrations were not affected (p>0.05) by dietary treatments, whereas serum insulin concentration linearly increased (L, p = 0.002) with increasing the amount of CGLY supplementation. Ruminal pH, NH₃-N, and BUN concentration were unchanged by dietary treatments, except for 20% of CGLY, NH₃-N, and BUN were lower (p<0.05) than for the diets 10% of CGLY, while the difference between the diets 0%, 5%, and 20% of CGLY were not significant. The amount of N absorption and retention were similar among treatments. Based on this study, CGLY levels up to 20% in total mixed ration could be efficiently utilized for goats and this study elucidates a good approach to exploiting the use of biodiesel production for goat production.

Levels of protein fractions in blood serum of periparturient goats

The aim of the study was to compare contents of individual protein fractions determined by electrophoresis in blood serum of healthy periparturient goats. Eight clinically healthy white shorthaired goats were examined. Blood samples of these goats were taken from v. jugularis three weeks and two weeks before the anticipated parturition, on the parturition day, 7 days after the parturition, and 28 days after the parturition. Individual protein fractions, albumins, α1-, α2-, β1-, β2- and γ-globulins were identified by electrophoretic analysis of blood serum. Percentage shares of individual protein fractions were converted from total protein values to g·l-1 values. The results indicated that individual serum protein fractions in periparturient goats showed significant dynamics of change. There were no significant differences between samples taken before the parturition and on the parturition day (except for the increase of β2 from 2.5 ± 0.3 g·l-1 observed 3 weeks before the parturition to 3.2 ± 0.4 g·l-1 measured 2 weeks before the parturition, and the decrease of γG levels from 9.5 ± 2.6 g·l-1 observed three weeks before the parturition to 8.1 ± 1.7 g·l-1 found on the parturition day), yet most indicators measured after the parturition were significantly higher (p < 0.05) than on the parturition day (values in g·l-1 observed on the parturition day versus values measured 28 days after the parturition: total protein 60.6 ± 4.3 vs. 71.3 ± 2.4, albumins 37.4 ± 2.9 vs. 42.7 ± 1.0, α2 3.4 ± 0.5 vs. 4.1 ± 0.8, β1 5.6 ± 0.5 vs. 6.3 ± 0.9, γG 8.1 ± 1.7 vs. 12.3 ± 1.9). The results bring new knowledge on the values of individual fractions of serum proteins in healthy goats, which is necessary for diagnostic interpretation of pathological findings in animals and also for experimental studies.

The immunology of animal papillomaviruses

Papillomaviruses are species- and tissue-specific double-stranded DNA viruses. These viruses cause epithelial tumours in many animals, including man. Typically, the benign warts undergo spontaneous, immune-mediated regression, most likely effected by T-cells (especially CD4, but also CD8 subsets), whereas humoral immunity can prevent new infections. Some papillomavirus infections fail to regress spontaneously and others progress to malignant epithelial tumours. Additionally, the impact of these lesions is greater in immunosuppressed individuals. Many therapies are ineffective, and there is much interest in the potential for immunological intervention in papillomavirus infections of man and animals. Vaccination can be achieved with 'live' virus, formalin-inactivated virus, synthetic virus-like particles, and DNA vaccination. There has been much recent progress in the development of such vaccines for papillomavirus infections in the rabbit, ox and dog. Success in these animal models suggests that similar approaches may prove useful for prophylactic or therapeutic vaccination against the important human papillomaviruses involved in the development of cutaneous and anogenital warts, laryngeal papillomatosis, and cervical cancer.

Profiles of some clinical chemical parameters in growing dwarf and landrace kids

Plasma creatinine, urea, bilirubin, glucose, cholesterol, calcium, magnesium, sodium, potassium, inorganic phosphorus and total serum proteins were analyzed in kids of Dwarf and Danish Landrace breeds from birth to 12 months of age. The purpose was to determine the reference ranges, age profiles and the influence of other factors. Comparisons between parametric (mean +/- standard deviation) and the corresponding nonparametric (5th and 95th percentile, median) values were calculated for each parameter, the results of which indicated no apparent differences. The levels were very much dependent on age. Creatinine, urea and total serum protein levels increased gradually with age. Glucose and cholesterol levels were high at birth and then decreased with age. The electrolyte concentrations were maintained within narrow limits. Significant differences were observed between kids of different ages (within the breeds), breeds (within similar age) and herds (within the same age and breed). Differences between female and male Landrace kids of the same ages were observed in plasma urea, creatinine, glucose and total serum proteins. It is concluded that age has a major influence on the clinical chemical reference values in young goats, followed by herd and breed, but the influence of sex was small and is negligible in most parameters.

Haematological profile in neonatal dwarf and landrace kids

The haematological profile in neonatal dwarf and Danish landrace kids was investigated in 62 healthy Danish landrace and 34 dwarf kids from birth to 12 months of age in 7 herds. The objective was to determine the reference values in the breeds, and evaluate the influence of age and environment on haematological parameters. Parametric (means and standard deviations) and non-parametric (5th, 95th percentile, median) values were calculated for each analysis. Results of the two statistical methods were close to each other. The number of erythrocytes in both breeds increased with age from neonatal minimum values. Haemoglobin concentration and haematocrit decreased from the neonatal values in the following two weeks of life, whereafter they increased. Haemoglobin concentration and mean corpuscular volumes were significantly higher in neonatal dwarf than in landrace kids. Differences in erythrocyte counts and haematocrit were observed with subsequent growth. There were significant differences in erythrocyte counts, haemoglobin concentration, haematocrit, mean corpuscular volume and mean corpuscular haemoglobin, between breeds (in kids of similar age), age groups (within the breeds) and herds (in kids of similar age within the breeds). Statistically significant differences in haematological values between female and male kids of similar young ages within the same breed were not observed. Age, breed and environment influenced the level of haematological parameters in kids.

Experimental pestivirus infections in newborn goat kids

Two experiments were carried out in which 37 healthy newborn goat kids were inoculated with a non-cytopathic ovine (BDV) or a cytopathic bovine pestivirus (BVDV) by intramuscular or intracerebral injection. No kids showed signs of disease or gross lesions which could be attributed to these viruses, but inoculated kids had lower mean growth rates than the controls. Significant histological changes in the CNS of 14 kids were restricted largely to the white matter and consisted mainly of hypercellular foci comprising microglial/histiocytic cells and mild perivascular infiltration by mononuclear cells. Varying degrees of infiltration of the myocardium by lymphocytes and plasma cells were observed. All kids remained negative for neutralizing antibodies against pestivirus until 2 to 3 weeks after infection. Titres increased during the following weeks. Pestiviruses were recovered from kids necropsied 10 days after inoculation, but not from any kids killed 20 days after inoculation or later. Non-cytopathic virus was isolated from various tissues of four kids that had received BDV and three kids that had been given BVDV. Cytopathic viruses were not recovered from any kids. Mean white blood cell counts in all kids were within the normal range at 4 and 8 weeks after inoculation. The lymphocyte response to stimulation by phytohaemagglutinin was significantly increased on both sampling occasions in the BDV-inoculated kids, while in the BVDV-inoculated animals, a similar increase was seen only at 8 weeks.

Caprine arthritis-encephalitis syndrome (CAE): a review

Caprine arthritis-encephalitis syndrome (CAE) is a viral disease of domestic goats characterized by chronic proliferative synovitis and periarthritis of adult goats while acute afebrile leukoencephalomyelitis is characteristic in goat kids. The causative agent, a Lentivirus, is transmitted from adult goats to kids via the colostrum or lateral transmission also occurs. The CAE virus is worldwide in distribution. All breeds and ages of goats are susceptible to infection, and once established it persists throughout the animal's life. A diagnosis can be based on the clinical signs, pathological changes, and demonstration of serum antibody levels. A vaccine is not available. Control or eradication of the disease is based on periodic serological testing, culling of all CAE antibody-positive animals, and separation of kids from adults following birth.