Objective To investigate the distribution and prevalence of mucormycosis in platypus (Ornithorhynchus anatinus) from the Inglis, Emu and Black-Detention catchment areas in north-west Tasmania. Procedure A field study was performed and resulted in the examination of 44 wild platypuses; in addition, one dead platypus and two live platypuses were examined after they were independently submitted to a local veterinary clinic. Results No cases of mucormycosis were conclusively diagnosed. One platypus with signs consistent with those previously described in cases of mucormycosis was captured in the Emu River catchment. However, laboratory tests did not provide a definitive diagnosis for the lesion. Two platypuses from the Inglis catchment area had signs very similar to those previously described in cases of mucormycosis, but laboratory tests found Corynebacterium ulcerans to be the likely cause of the cutaneous ulcers on one of these platypuses and an unidentified fungal agent to be the cause of a cutaneous nodule in the other. Conclusions These findings do not prove that mucormycosis is absent from the populations studied. However, they may indicate that the prevalence of disease is low. The possibility that Mucor amphibiorum is present in a subclinical form in platypuses, or infecting another reservoir, is not excluded. The findings also suggest that caution should be exercised when diagnosing mucormycosis based on clinical findings alone and raise the possibility that some cases may have been incorrectly diagnosed. 相似文献
The variation in milk acetone concentration between cows and the resumption of ovarian activity was determined in 68 Holstein–Friesian cows grazing pasture. Cows calved in two groups approximately three weeks apart and were assessed over the first 60 d of lactation.
The largest coefficient of variation (152%) for milk acetone concentration between cows was found in the first week of lactation. This variability in milk acetone concentration was largely explained by a consistent cyclic pattern, in relation to the day of the study, with regular peaks at 21–26 d intervals. These peaks were synchronised between cows, and cows in the second group synchronised with cows in the first group.
Milk acetone peaks greater than 0.4 mmol/L were associated with a significant drop in milk yield, possibly due to energy deprivation around this time. In this respect, liveweight change over the first 60 d of lactation was significantly negatively correlated (r = − 0.29, p < 0.05) with the mean milk acetone concentration taken over the same period. However, there was no significant relationship (p > 0.05) between mean or maximal milk acetone concentration and the resumption of ovarian activity for the cows that resumed ovarian activity in the first 9-weeks post-partum.
The results of this study suggest that the use of milk acetone as a practical indicator of energy balance is limited due to its variability over time. Milk acetone concentration may be useful in experimental situations or when regular milk samples can be obtained in the field, such as in-line analysis. There is a need to undertake more research to elucidate the implications of the cyclic pattern of acetone concentration in milk on reproductive performance. 相似文献
The objective of this study was to quantify the differences in the nutritive value over 4 seasons, of 7 C3 temperate grasses, 2 C4 tropical grasses and 11 clover species used as forages for dairy cows. The nutritive value was assessed in terms of nutrient content and the availability of effective rumen degradable protein, rumen by pass protein, metabolisable protein (MP) and fermentable metabolisable energy.
All species were grown in plots as monocultures under conditions of non limiting nutrients and moisture and harvested by mechanical means. All species had a high crude protein content and this resulted in a high effective rumen degradable protein: fermentable metabolisable energy ratio varying from 15, for cowpeas (Vigna unguiculata) to 29 for birdsfoot clover (Lotus corniculatus), and all were above the ratio of 11 required for optimal microbial protein synthesis in the rumen of dairy cows. The calculated availability of MP varied from 105 g/kg dry matter (DM) for cowpeas to 173 g/kg DM for berseem clover (Trifolium alexandrinum) indicating that all forages would be able to meet the requirements of dairy cows producing up to 30 L/milk/day, provided they were able to consume over 19 kg DM of forage/cow/day.
Grasses had much higher hemicellulose (neutral detergent fibre minus acid detergent fibre) content than legumes. Kikuyu (Pennisetum clandestinum), a C4 grass, had a higher proportion of hemicellulose content than the C3 temperate grasses. Perennial ryegrass (Lolium perenne) and kikuyu had a similar metabolisable energy (ME) density (9.9 MJ/kg DM) in summer. The mean ME density of perennial ryegrass, prairie grass (Bromus wildinowii) and short rotation ryegrass (Lolium multiflorum) winter was similar at 10.6 MJ/kg DM and slightly higher than cocksfoot (Dactylus glomeratus), phalaris (Phalaris tuberosa) and fescue (Fescue arundunicea) which had a mean ME density of 10 MJ/kg DM.
All forages grown were able to satisfy MP and ME requirements of dairy cows producing up to 30 L milk/cow/day, provided they were able to consume sufficient forage to achieve this level of production. 相似文献
AIMS: To examine associations between various cow-level factors and quality of first-milking colostrum (measured as Brix), and to evaluate herd-level associations between vaccination against calf diarrhoea and colostrum quality, in cows from dairy herds in the Waikato region of New Zealand.METHODS: A single colostrum sample was collected, by complete udder evacuation, from each of 20 cows from 29 dairy herds in the Waikato region of New Zealand during the 2016 spring calving period. Vaccination pre-partum with a calf diarrhoea vaccine was used in 15 herds. Each colostrum sample was tested using a digital Brix refractometer. The body condition score of each cow was recorded at the time of sample collection and farmers provided records of clinical mastitis and facial eczema from the previous 12 months, as well as the age and breed of cows. Associations between cow-level variables in non-vaccinated herds and Brix were examined using a multivariable linear mixed model and estimated marginal means obtained for different categories.RESULTS: Mean Brix of 281 samples from cows in non-vaccinated herds was 18.7 (SD 0.26)%; 63/281 (22.4%) samples had Brix ≥22% and 152/281 (54.1%) had Brix ≥18%. Mean Brix of colostrum samples from cows aged ≥6 years (20.2 (95% CI=19.1–21.2)%) was higher than for samples from 2-year-old cows (18.6 (95% CI=17.3–19.9)%) (p=0.005). Colostrum that was collected at the first milking on the day of calving had higher Brix (20.0 (95% CI=19.1–20.9)%) than colostrum collected from cows that calved the previous day (17.5 (95% CI=16.5–18.4)%) (p<0.001). Mean Brix of colostrum samples from cows which produced ≥8?L (18.2 (95% CI=17.1–19.2)%) tended to be lower than from cows which produced <8?L first-milking colostrum (19.1 (95% CI=18.3–20.0)%) (p=0.08). Among vaccinating herds, 9/15 (60%) had ≥60% colostrum samples with Brix ≥18% compared with 4/14 (29%) of non-vaccinating herds (p=0.04).CONCLUSIONS AND CLINICAL RELEVANCE: Colostrum quality, as measured by Brix, was associated with the total volume of first-milking colostrum, interval from calving to colostrum collection and cow age. Vaccination against calf diarrhoea was associated with a higher proportion of colostrum samples with adequate Brix. Careful selection of colostrum donor cows should ensure newborn calves are fed adequate quality colostrum which should be beneficial in preventing failure of passive transfer of IgG. Testing of colostrum from individual cows with a Brix refractometer is advocated for the selection of colostrum for feeding newborn calves. 相似文献
In India, cotton crop residues available after cotton picking are considered as waste materials and disposed off the field. For developing better residue management practices, knowledge of the decomposition kinetics is needed. Short-term laboratory incubations were conducted to determine the pattern of C mineralization from cotton leaves and stems [stem pieces (ca. 2 cm) vs. ground stem (0.25 mm)] in the two major soil groups (vertisols and inceptisols) on which cotton is grown to a large extent. The amount of C mineralized was significantly greater from leaf- (18.3% of added C) and ground stem-C (19% of added C) when compared to stem pieces-C (13.2% of added C). Differences between the residues were not seen in the inceptisols. The cumulative amount of C mineralized ranged from 9.6-11.5% of the added C. Narrowing the C:N ratio of stem did not enhance C mineralization. 相似文献
An ovarian enlargement (diameter, 8 cm) was identified and surgically excised from a 5-year-old female dog. Microscopic examination of the multinodular neoplasm revealed sheets of polygonal neoplastic cells with large nuclei, frequent mitosis, necrosis and haemorrhage. Immunohistochemically, the neoplastic cells were positive for vimentin and alkaline phosphatase but were negative for CD3, CD79a, cytokeratin, alpha-fetoprotein, inhibin-α and S-100. The histopathological diagnosis of the mass was unilateral ovarian dysgerminoma. 相似文献
In this study, the effect of increasing the proportion of concentrate in the diet, on efficiency of feed utilisation, was determined when Holstein–Friesian cows grazed short-rotation ryegrass (Lolium multiflorum) or kikuyu (Pennisetum clandestinum) pastures. The concentrates were energy-dense dairy pellets fed twice-a-day at milking and the roughage component was lucerne hay and the pasture.When cows grazed ryegrass, there was no effect on animal performance as the proportion of concentrate in the diet increased from 0.23 to 0.35 (4.75 to 7.50 kg concentrate/cow/day). The substitution rate of concentrates for pasture for the first 1.57 kg concentrate/cow/day fed was 0.58 but rose to 1.18 for the next 1.28 kg concentrate/cow/day.When cows grazed kikuyu, there was also no effect of increasing the proportion of concentrate in the diet on total dry matter intake (DMI) or milk production. However, there was a substantial increase in the in vivo digestibility of whole diet, pasture and acid detergent fibre (ADF) was observed when the proportion of concentrate in the diet increased from 0.08 to 0.25. However, there was a marked decline in pasture digestibility (72% to 64%), and more so in ADF digestibility (61.3% to 48.4%), as the proportion of concentrate in the diet increased further to 0.29 (5.52 kg/cow/day). The intake of kikuyu, when determined by difference between pre- and post-grazing pasture mass, was substantially underestimated compared to the use of the n-alkane technique, and this discrepancy increased as the pasture on offer increased.On both pasture types, the neutral detergent fibre intake, as a % of bodyweight varying from 1.6% to 2.2% for kikuyu and 1.5% to 1.6% for ryegrass was far above the values claimed of 1.2% to restrict intake.The results of this study highlight the limits to the amount of concentrate that can be fed on a typical Australian dairy farm where concentrates can only be fed twice-a-day at milking. The results also provide a more appropriate benchmark for fibre limitation in the ration when cows graze pasture, particularly poorer quality tropical grasses, and this value is well above that found in more intense feeding situations. 相似文献
Twenty calves were orally infected with Mycobacterium paratuberculosis before weaning. Ten of these plus 4 non-infected controls were maintained on elevated dietary iron intake from 6 to 33 months of age. During this time, in which the majority of animals were bred, the influence of increased dietary iron upon tests of cellular and humoral immune responsiveness to antigens of the organism were monitored. Results were examined in relation to the organism's capacity to multiply and infect up to 7 portions of the intestinal tract. No significant differences were detected in the degree of intestinal disease or pattern of faecal excretion of M. paratuberculosis in iron supplemented and non-supplemented cattle. Cutaneous delayed-type hypersensitivity (DTH) to johnin PPD developed at 1 month and in-vitro lymphocyte and immunostimulatory activity (LS) to this antigen at 2 months after infection. LS indices were significantly reduced in magnitude in iron-supplemented cattle (p less than 0.01). Most ELISA antibody responses were positive 10 to 17 months after infection and preceded the fewer number of CF responses by several months. Neither of the antibody tests was affected by elevated iron intake. Generally, complete or partial resistance to paratuberculosis was associated with sustained positive monthly LS tests (index greater than or equal to 2.0), whereas antibody levels tended to be sustained only in the more severely affected cattle. Although neither test system was affected by pregnancy the ELISA failed to detect a significant proportion of cattle chronically shedding M. paratuberculosis in faeces. 相似文献
SUMMARY Lice were collected from 71 flocks detected as Infested at market Inspection in 1990 and 1991, from 16 flocks where resistance was suspected and from 31 flocks from Kangaroo Island. Susceptibility to cypermethrin was measured by a treated surface technique and survival of lice at 5 ppm or greater was taken as an indication of resistance. The prevalence of resistance was 34% in louse populations from the market inspection sample, 50% in flocks in which resistance was suspected and 68% in flocks from Kangaroo Island. Most resistance factors were in the range 1 to 20 although one louse population with a resistance factor of 91 was found on Kangaroo Island. 相似文献
