Farm factors associated with the presence of Mycobacterium paratuberculosis infection in dairy herds on the New York State Paratuberculosis Control Program

An extensive questionnaire was developed and used to collect data from 33 herds that were on the New York State Paratuberculosis Control Program, to study farm factors associated with the presence of Mycobacterium paratuberculosis infection in dairy herds. The results of the last whole herd paratuberculosis fecal culture were used to indicate presence of infection in a herd, with herds having one or more animals positive classified as ‘infected’. The average prevalence within herds was 5.2%. Fourteen herds were uninfected and 19 herds had prevalences ranging from 0.7%–28.2%. Data on 31 continuous and 67 categorical risk factors were collected by questionnaire. Ten factors were significantly associated with prevalence risk of infection in the univariable logistic regression. These factors were: the type of farm operation (commercial/registered or both); earlier diagnosis of the disease before entering the control program; number of clinical cases in the previous year; whether clinical cases were raised or purchased animals; typical signs in clinical cases; exposure of calves 0–6 weeks of age to feces of adult cows; contact of young stock with adult animal feces from using the same equipment to clean the housing for both groups of animals; spreading feces on fields from which forage is later harvested and fed to animals of any age group; what is done with animals that are suspected of having paratuberculosis or test positive on culture; and frequency of cleaning the cow barn. Stepwise logistic regression was used to determine the significance of each risk factor while controlling simultaneously for the effect of other factors. The significant factors were the type of farm operation, clinical signs, and exposure of calves to feces of adult cows. Commercial herds, presence of clinical signs typical of paratuberculosis in animals, and exposure of calves 0–6 weeks old to feces of adult cows all indicate a higher likelihood that a herd is infected with M. paratuberculosis.     

干旱区城市化对城市内河水质的影响研究——以吐曼河为例

随着城市社会经济的迅速发展，工业主导的城市化过程带来了许多城市生态环境问题，引起了城市内河水质的恶化。采用1996～2000年喀什市吐曼河水质观测数据、1990年与1999年卫星遥感图像和城市发展中有关的社会经济统计数据与土地利用资料，在3S技术的支持下，运用地表水污染综合指数法，对吐曼河水质进行评价，定量与定性相结合分析了干旱区城市化对城市内河水质的影响。结果表明：大气中的总悬浮颗粒是导致吐曼河水质严重污染的主要原因。此外，城市化所带来得人口增加、工业化与土地利用方式的改变也一定程度的影响了吐曼河的水质。     

Effects of water deficit on growth,nodulation and physiological and biochemical processes in Medicago sativa-rhizobia symbiotic association

The effects of water deficit on growth, nodulation, and several physiological and biochemical processes in six symbiotic combinations involving three Moroccan alfalfa (Medicago sativa L.) populations (Tafilalet1, Adis-Tata and Demnate2), an American Moapa variety and two rhizobial strains (RhL9 and RhL10) were studied. The experiment was conducted under greenhouse conditions. Seedlings were separately inoculated with the suspension of two rhizobial strains and grown under two irrigation regimes: 80% of field capacity (optimal irrigation) and 40% of field capacity (water deficit). The water stress was applied for five weeks and the agro-physiological and biochemical parameters related to water deficit tolerance were assessed. The results showed that the water deficit had significantly reduced the height of the plants, the dry biomass and nodulation. This constraint also negatively affected the relative water content of leaves, the membrane permeability, the stomatal conductance, the maximum quantum yield of photosystem II, the time to reach maximum fluorescence, the total chlorophyll content and the total nitrogen content. Comparison among the tested symbiotic combinations showed that their behaviors were significantly different. Under drought, oasis populations Ad and Ta maintained high PS II efficiency, membrane stability, relative water content, chlorophyll and nitrogen content in comparison to the mountain one Dm2 and the American Moapa variety. These parameters were maintained at adequate levels in the plants inoculated with the rhizobial strain RhL9 that showed a tolerance to water deficit conditions.     

Color,Yield, and Texture of Heat and High Pressure Processed Mussels During Ice Storage

High pressure processing (HPP) can shuck (open) shellfish, saving labor while conferring food safety and yield benefits. Mostly male New Zealand Greenshell? mussels (Perna canaliculus) were HPP-shucked (3 min at 500 MPa, 30°C) and assessed during 6-days’ ice storage (0°C) for cooked yield, color, and texture compared with heat processed (1 min at 70°C) and untreated samples. HPP-treated mussels had improved yields but lost more weight during ice storage. Male mussels from all treatments became darker with ice storage. HPP-treated mussels had firmer adductor muscles, while their guts required higher maximum force but less energy to puncture them.     

Quantifying stem discoloration and decay following pruning and thinning an Acacia hybrid plantation

Acacia hybrid (Acacia mangium × A. auriculiformis) is widely planted in Vietnam, and part of the estate is managed for solid timber products. This requires pruning and thinning – practices that through mechanical wounding can facilitate the entry of fungal organisms, leading to stem defects. The extent to which this happens in Acacia hybrid has not been previously studied in Vietnam. A destructive survey was conducted in a 3‐year‐old Acacia hybrid plantation at Nghia Trung in Binh Phuoc province, 18 months after the imposition of pruning and thinning treatments. Pruned trees had a higher incidence and severity of discoloration and decay in the stem than unpruned trees; thinning increased the incidence of stem decay and the severity of discoloration but not the severity of decay. An interaction between pruning and thinning did not influence the incidence of stem decay but did increase the severity of discoloration in thinning treatments. Across treatments, levels of discoloration and decay were <30% and <5%, respectively. Modification of current pruning practices may be necessary to ensure that decay levels are kept within acceptable limits at an anticipated harvest age of 7–8 years.     

Kisspeptin injection improved the semen characteristics and sperm rheotaxis in Ossimi ram

The aim of the present study was to investigate the effect of kisspeptin-10 (Kp10) injection on semen characteristics, testosterone (T) production and sperm rheotaxis using microfluidic devices in immature ram. Computer-assisted sperm analysis (CASA) with controlled flow velocity was used to explore the kinetic parameters of sperm and positive rheotaxis (PR %). PR % was defined as the number of PR sperms over the number of motile sperms. Healthy Ossimi rams were randomly divided into two groups; a saline-treated control group and Kp10-treated one (5 µg/kg body weight). Treatments were given by intramuscular injection once a week for 1 month. After 1 month, the semen was collected and evaluated weekly for 6 weeks, while the blood samples were collected every 2 weeks for the next 8 weeks. Semen properties were significantly affected by Kp10 injection (p < .01). The Kp10 increased the volume, sperm concentration and percentages of live sperm compared with those of control. Additionally, sperm trajectories and rheotaxis get improved by the injection of Kp10 with time. Furthermore, kisspeptin improved the secretion of testosterone levels throughout the period of study. In conclusion, injections of the Kp10 had a positive impact on semen characteristics as well as improved sperm rheotaxis of Ossimi rams in subtropics.     

Relationship between age of flock seroconversion to hemorrhagic enteritis virus and appearance of adenoviral inclusions in the spleen and renal tubule epithelia of turkeys.

A retrospective study was conducted to evaluate the temporal relationship between flock seroconversion to hemorrhagic enteritis virus (HEV) and the appearance of adenoviral inclusions in the spleen and renal tubular epithelium. The study was conducted on samples of turkey poults submitted to the Fresno Branch of the California Veterinary Diagnostic Laboratory System during May to December 1988. The study included 78 submissions (four to eight poults per submission) of ages ranging from 6 to 15 weeks. Sera were tested for antibodies to HEV using the agar gel immunodiffusion test. Spleen and kidney samples were examined by light microscopy for the presence of inclusions in the mononuclear phagocytes of the spleen or in the renal tubular epithelium of the kidney. Logistic regression statistical analysis was used to evaluate the association between the age of the bird and the likelihood of the presence of inclusions in the spleen and kidney, as well as the likelihood of seroconversion to HEV. A significant association (P less than 0.05) was found between the presence of splenic inclusion bodies and the age of the bird. The probability of splenic inclusions was higher in younger birds (6 weeks of age), and decreased as the birds became older, approaching zero at 11 weeks of age. The kidney inclusions were significantly associated with age. The probability of detecting the inclusions increased with age, reached a maximum at 10 weeks, and then declined, approaching zero by 14 weeks. However, the probability of seroconversion to HEV increased significantly with age up to 10 weeks and then remained positive throughout the remainder of the study period.     

Bovine rotavirus diagnosis: comparison of various antigens and serological tests

Agar gel immunodiffusion (AGID) and counter-immunoelectrophoresis (CIEP), complement fixation (CF), radio-immunoassay (RIA), haemagglutination (HA) and haemagglutination inhibition (HI) tests were compared in their efficiency for the detection of bovine rotavirus antigens and antibodies. As a test for antigen using hyperimmune serum, CIEP was found to have advantages over AGID by being more rapid as well as approximately four times more sensitive regardless of whether the antigen was of faecal or tissue culture origin. The CF test was more sensitive than either of the immunodiffusion procedures studied for antigen detection, but was more tedious to perform and of limited use as some faecal samples exhibited anti-complementary activity. For measurement of rotavirus antibody the radio-immunoassay (RIA) was the most sensitive technique and the CIEP least sensitive. Using the RIA a limited survey of cattle demonstrated that approximately 75% of the animals tested possessed specific antibody to rotavirus.     

Factors associated with the risk of developing sarcoid tumours in horses.

A retrospective case-control study was conducted to identify risk factors in horses associated with the development of the common skin tumours known as sarcoids. The study involved 503 sarcoid cases diagnosed (January 1980-December 1989) at New York State College of Veterinary Medicine and a similar number of controls (non-sarcoid cases). Data on age, breed and sex of cases and controls were obtained from computerised records. Multiple logistic regression analysis was used to identify risk factors. Separate data were obtained for the same 10-year period from the Veterinary Medical Data Program to determine the proportional morbidity rate at different veterinary colleges in North America. Appaloosa, Arabian and Quarter horses were at a higher risk of developing sarcoid tumours than were Thoroughbred horses. Standardbred horses had a lower risk of developing sarcoids. Geldings were at a higher risk of developing sarcoids in comparison with stallions. There was no significant difference in the risk of developing sarcoids between stallions and mares. The risk of developing sarcoid increased with age up to 15 years and then declined. The proportional morbidity rate of sarcoids among the veterinary colleges ranged between 0 and 14 per 1,000 cases, with an average of 6 per 1,000.