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1.
AIMS: To determine if abdominal insufflation with medical air will improve oxygenation and ventilation parameters when compared to insufflation with CO2 in xylazine-sedated sheep undergoing laparoscopic artificial insemination (AI).

METHODS: Forty-seven sheep underwent oestrus synchronisation and were fasted for 24 hours prior to laparoscopic AI. Each animal was randomised to receive either CO2 or medical air for abdominal insufflation. An auricular arterial catheter was placed and utilised for serial blood sampling. Respiratory rates (RR) and arterial blood samples were collected at baseline, after xylazine (0.1?mg/kg I/V) sedation, 2 minutes after Trendelenburg positioning, 5 minutes after abdominal insufflation, and 10 minutes after being returned to a standing position. Blood samples were collected in heparinised syringes, stored on ice, and analysed for arterial pH, partial pressure of arterial O2 (PaO2), and CO2 (PaCO2). The number of ewes conceiving to AI was also determined.

RESULTS: Repeated measures ANOVA demonstrated temporal effects on RR, PaO2, PaCO2 and arterial pH during the laparoscopic AI procedure (p<0.001), but no difference between insufflation groups (p>0.01). No sheep experienced hypercapnia (PaCO2>50?mmHg) or acidaemia (pH<7.35). Hypoxaemia (PaO2<70?mmHg) was diagnosed during the procedure in 14/22 (64%) ewes in the CO2 group compared with 8/23 (35%) ewes in the medical air group (p=0.053). Overall, 15/20 (75%) ewes in the CO2 group conceived to AI compared with 16/22 (72.7%) in the medical air group (p=0.867).

CONCLUSIONS AND CLINICAL RELEVANCE: There were no statistical or clinical differences in RR, PaO2, PaCO2, pH, or conception to AI when comparing the effects of CO2 and medical air as abdominal insufflation gases. None of the sheep experienced hypercapnia or acidaemic, yet 42% (19/45) of sheep developed clinical hypoxaemia, with a higher percentage of ewes in the CO2 group developing hypoxaemia than in the medical air group. Based on the overall analysis, medical air could be utilised as a comparable alternative for abdominal insufflation during laparoscopic AI procedures.  相似文献   
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1. The significance of fat accumulation during physiological development of layers was studied using White Leghorn x Australorp pullets from 12 weeks of age.

2. Liver fat, carcass fat, liver weight and body weight increased markedly at the onset of sexual maturity.

3. Within the liver, the protein to DNA ratio did not alter significantly during development; glycogen was not consistently depleted by egg production.

4. Liver fat content was significantly correlated with carcass fat, liver weight and DNA concentration, and plasma total lipid and cholesterol, independent of stage of development; with body weight, liver protein, moisture, and protein to DNA ratio, excluding the period prior to commencement of sexual maturation; and with plasma phospholipid during lay.

5. Obesity was a feature of faster growing fowls which matured earlier, consumed more, utilised food less efficiently for egg production and produced fewer saleable eggs.  相似文献   

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The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty‐six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination.  相似文献   
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The continued use of purified protein derivative (PPD) tuberculin is considered to be the main factor which limits the specificity of diagnostic tests for bovine tuberculosis (TB). This study evaluated a whole blood interferon-gamma (IFN-gamma) assay and compared the diagnostic potential of PPD with two tuberculosis-specific antigens, ESAT-6 and MPB70. To provide estimates of sensitivity and specificity, responses were measured in 180 skin test-reacting cattle, of which 131 were confirmed as tuberculous, and in 128 cattle from TB-free herds. For the skin test reactors, there was a positive correlation between the IFN-gamma responses to PPD from Mycobacterium bovis (PPDB) and PPD from Mycobacterium avium (PPDA), indicating cross-reactivity between these complex antigens which are the basis of the skin test. In comparisons of the ESAT-6 IFN-gamma test with a PPD IFN-gamma test (using PPDB compared with PPDA), there was a decrease in sensitivity (76.3 per cent vs 89.3 per cent), but a clear increase in specificity (99.2 per cent vs 92.2 per cent). The provision of high specificity, even with lower sensitivity, offers major benefits for testing in areas with a low incidence of TB.  相似文献   
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Bovine viral diarrhea virus (BVDV) infection continues to have a significant impact upon US cattle producers despite the availability of more than 140 federally licensed vaccines. Detection and control is hampered by viral heterogeneity that results in differences in neutralizing epitopes, cytopathology and virulence. Recently it was found that there are two different genotypes, BVDV1 and BVDV2, among BVDV. BVDV2 isolates make up a significant proportion of the BVDV isolated in North America. Serologically BVDV2 viruses can be distinguished from BVDV1 and border disease viruses. Mab binding also distinguishes between BVDV1, BVDV2 and BDV. Like the BVDV1 viruses, BVDV2 viruses may exist as one of two biotypes, cytopathic or noncytopathic, based on their activity in cultured cells. Cytopathogenic effects on cultured cells does not correlate with virulence in vivo, as BVDV2 associated with hemorrhagic syndrome (HS) are noncytopathic. Variation among BVDV1 and BVDV2 in the 5' UTR is similar. Phylogenetic analysis and differences in virulence suggest that BVDV2 are heterogeneous. Symptoms resulting from BVDV2 infections may range from clinically inapparent to clinically severe. Recently, disease outbreaks associated with acute uncomplicated BVDV infection have been reported in the US and Canada. These outbreaks of clinically severe disease, termed HS, were all associated with viruses from the BVDV2 genotype. Not all BVDV2 isolates cause clinically severe disease. Avirulent BVDV2 isolates do exist and may predominate over virulent BVDV2 in nature. When virulent BVDV2 viruses are inoculated into calves they induce a disease characterized by fever, diarrhea, leukopenia, lymphopenia, neutropenia, thrombocytopenia, and death. Infection with avirulent BVDV2 results in a reduction of luekocytes that may be accompanied by a low-grade fever. These viruses do not cause clinical disease or a clinical leukopenia.  相似文献   
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Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterised, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower than companion field experiments for the competition of cowpea and purslane. The validated simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habit on final biomass production of cowpea and sunflower. The model suggested that erect growth habit was more competitive than semi‐erect and prostrate growth habit, when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass. Our simulation approach is suggested as a method for crop breeders to gauge the likely success of selection for competitive crops before undertaking expensive long‐term breeding experiments.  相似文献   
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Leptospira interrogans serovar hardjo was demonstrated in the vaginal discharges of 12 experimentally infected heifers for up to eight days after abortion or calving. Organisms were recovered from the oviducts of heifers examined at slaughter eight to 22 days after calving or 32 to 91 days after infection. They were also recovered from the uteri of four heifers eight to 22 days after calving.  相似文献   
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