Review of surrogacy program for endangered victorian brush-tailed rock wallaby (Petrogale penicillata) with special reference to animal husbandry and veterinary considerations.

A surrogacy program to increase the reproductive rate of the critically endangered Victorian brush-tailed rock wallaby (Petrogale penicillata), initially developed in semicaptive conditions, was established in close captivity at Adelaide Zoological Gardens in 1998. Pouch young were removed from their mothers on days 8-20 or 40-45 after parturition and placed onto the teat of a tammar wallaby (Macropus eugenii) or yellow-footed rock wallaby (Petrogale xanthopus xanthopus) surrogate mother. During the early years of the program, mortality of brush-tail pouch young was high (12/16, 75%), both before transfer while still on their mother (5/16) and after transfer to a surrogate mother (7/11). Changing pouch young transfer methodology and improving the health status of the surrogate animals during the later years of the program significantly reduced the mortality of brush-tail pouch young (8/29). Under the new methodology, no mortality of brush-tail pouch young was observed between birth and the time of transfer, (0/29), and after transfer, pouch young mortality rate was eight of 29 (28%). Factors implicated in the improved success of the program included 1) the early transfer (between days 8 and 20) of brush-tail pouch young from mother to surrogate mother, 2) review of the veterinary history and health of the animals selected to act as surrogate mothers, and 3) increased access to grazing pasture for foster mothers. The reproductive rate of the brush-tail females in the later years of the breeding program was sixfold above natural birthing rates. These and other factors important in establishing a breeding program of this nature are discussed.     

Plasma biochemistry and hematologic values for wild-caught flying foxes (Pteropus giganteus) in India.

Although bats of the genus Pteropus are important ecologically as pollinators and natural hosts for zoonotic pathogens, little is known about their basic physiology. Hematology and plasma biochemistries were determined from wild-caught flying foxes (Pteropus giganteus) in northern India (n=41). Mean lymphocyte differential count was higher for juveniles than adults. Mean platelet count was lower than previously reported. No hemoparasites were observed. No differences were observed between plasma biochemistry values of male and female bats, juveniles and adults, or lactating and nonlactating females. Variation in aspartate aminotransferase (AST) was seen based on body condition score. Blood urea nitrogen and cholesterol concentrations were lower in P. giganteus than other mammalian groups, but were consistent with those reported from other Pteropus species. Alanine aminotransferase and AST concentrations were higher than those reported for Pteropus vampyrus, a closely related species. This study provides basic physiologic information that can be used in future health and disease studies of Indian flying foxes.     

Plasma atrial natriuretic peptide concentration in warmblood horses with heart valve regurgitations

ObjectivesThis study measured plasma atrial natriuretic peptide (ANP) concentration in horses with heart valve regurgitations (HVR) with and without atrial and ventricular dilatation.BackgroundIn humans and small animals, plasma ANP concentration is increased in heart disease and correlates with the severity of clinical signs and heart enlargement.Animals, materials and methodsTen healthy horses (control) and 36 horses with HVR were evaluated by auscultation, electrocardiography, echocardiography, and determination of plasma ANP.ResultsControl horses demonstrated mean plasma ANP concentration of 21 ± 5.4 pg/mL. Of the 36 horses with HVR, 17 horses possessed normal echocardiographic heart size (group 1), 10 horses had a left atrial dilatation (group 2) and 9 horses had both left atrial and ventricular dilatation (group 3). Mean plasma ANP concentration of groups 1, 2 and 3 was 20.1 ± 5.6 pg/mL, 22.9 ± 11.0 pg/mL and 27.6 ± 17.4 pg/mL, respectively. The plasma ANP concentrations of HVR and control horses were not significantly different. The highest ANP concentrations were observed in horses with atrial and ventricular dilatation. No correlation between left atrial or ventricular size, weight, or sex and the plasma ANP concentration was found.ConclusionsNo significant differences in plasma ANP concentration was observed between groups. Further study, especially in horses with clinical signs of heart failure is needed.     

Comparative responses to sodium selenite and organic selenium supplements in Belgian Blue cows and calves

Belgian Blue (BB) beef cattle is particularly prone to selenium (Se) deficiency due to the poor Se content of soil and roughages on rearing farms and the higher requirements of this hypermuscled breed. The goal of this trial was to compare the effects of different forms and concentrations of Se supplementation on Se status, health and performance in 60 pregnant Se-deficient BB cows. Cows were allocated to 3 experimental groups receiving selenized-yeast at 0.5 ppm Se on total ration (Y–Se 0.5), Na–selenite at 0.5 ppm Se on total ration (Na–Se 0.5) and Na–selenite at 0.1 ppm Se on total ration (Na–Se 0.1), respectively. Cows were supplemented from 2 months before calving until 2 months after calving. Data on performance, health and Se status of the dams and their calves were analyzed using a linear model, least squares means and logistic regression. At the end of the study, plasmatic Se (pSe) was significantly higher (P < 0.01) in cows receiving Y–Se than in cows from other groups. Glutathion-peroxidase in erythrocytes (GSH-pxe) was higher in Y–Se and Na–Se 0.5 than Na–Se 0.1 group (P < 0.01). Se content in colostrum and milk was significantly higher (P < 0.01) in Y–Se than other groups. At birth, Se status of calves from group Y–Se was significantly higher than those of other groups (P < 0.01). Plasmatic Se in calves remained higher for 75 days after birth in Y–Se compared to other groups (P < 0.01). Diarrhoea was the most commonly observed disease in the calves and, during the first 15 days of life, diarrhoea occurred in 6%, 21% and 35% of calves from groups Y–Se, Na–Se 0.5 and Na–Se 0.1, respectively. Over the whole 75 days trial period, incidence of diarrhoea was 19, 29 and 65%, respectively. Average daily gain (ADG) in calves born from Y–Se group of cows tended to be higher than in Na–Se 0.5 (P = 0.06) and Na–Se 0.1 (P < 0.05) but there was no difference between Na–Se 0.5 and Na–Se 0.1 (P > 0.1). At the same dosage, Y–Se conferred better Se status in both dams and their calves than did Na–Se. Requirement of 0.1 ppm Se seems to be insufficient in BB to optimise health and performance. Regarding health status and ADG in calves, Y–Se seems also to result in better performance.     

Interactions between dietary fatty acids and hepatic gene expression in livers of pigs during the weaning period

The aim of the present study was to evaluate the impact of dietary fatty acids (FA) during the weaning period on expression of genes involved in the oxidation and metabolism of FA (peroxisome proliferator-activated receptor (PPAR-), stearoyl-CoA-desaturase (SCD), Δ6-desaturase (D6D), acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS)). Liver samples were obtained from littermates, either on day 28 of age just before weaning, or at day 56 after the 4 weeks ad lib. provision of 5% of either animal fat, fish oil or sunflower oil. In conclusion, genes involved in the regulation of FA conversion (SCD, D6D) were influenced by the n-6 to n-3 ratio, whereas the FA oxidation, as indicated by the expression of PPAR-, was highly likely regulated by the hepatic ratio between mono- and poly-unsaturated FA. Furthermore, weaning and/or age affected the hepatic expression of genes involved in FA synthesis and conversion, but not the expression of PPAR-.     

Structural Characterisation of the Interaction between Triticum aestivum and the Dothideomycete Pathogen Stagonospora nodorum

The interaction between Stagonospora nodorum and a susceptible wheat cultivar was investigated using a range of microscopic techniques. Germination of pycnidiospores occurred approximately 3 h after making contact with the leaf surface and was followed by attempted penetration 8–12 h later. Penetration was observed through stomata and also directly through periclinal and anticlinal epidermal cell walls. Penetration down the anticlinal cell walls appeared to occur without a differentiated penetrating structure whilst structures identified as either lateral appressoria or hyphopodia were typically present when penetrating over a periclinal cell wall. Once inside the leaf, the fungus continued to grow for the next 4–5 days colonising all parts of the leaf except the vascular bundles. Only in the later phase of the infection was total host cell collapse apparent. Evidence of polyphenolic compounds was observed. The infection cycle was completed within 7 days as indicated by sporulation on the leaf surface. These results have allowed us to understand how the fungus physically interacts with the leaf and will help the overall understanding of the infection process.     

Assessment of Partial Resistance to Powdery Mildew (Podosphaera pannosa) in a Tetraploid Rose Population Using a Spore-suspension Inoculation Method

Powdery mildew (Podosphaera pannosa) is the most important fungal disease in greenhouse roses and is in practice controlled by fungicides. The creation of novel cultivars with durable resistance to powdery mildew is highly desirable. To understand the inheritance of mildew resistance, a tetraploid rose population with a size of 181 seedlings was obtained by crossing two tetraploid genotypes each having partial resistance. The population and its parents were tested under greenhouse conditions with two well-defined monospore isolates (2 and F1) using artificial inoculation with spore suspensions. Disease score at 11 days post-inoculation, latent period and rate of symptom development were used to describe seedling resistance. The tests for both isolates exhibited a wide and significant variation among genotypes for resistance. The distribution of the genotypic means of the disease scores was continuous and showed a considerable transgression. Statistical analysis, scatter plot of disease scores for the isolates, and correlation analyses indicated that the two isolates differed in pathogenicity. The outcome of the tests showed that the inoculation assay with spore suspensions was a reliable and effective way to screen large numbers of genotypes under greenhouse conditions for genetic and breeding studies. This is the first report on spore-suspension inoculation to be used successfully in rose.     

Farmers' attitudes towards techniques for improving oestrus detection in dairy herds in South West England

Unidentified heats contribute to declining fertility rates in English dairy herds. Several techniques have been advocated to improve heat detection rates. Despite demonstrable technical efficacy and cost-effectiveness, uptake is low. A study in South West England used the Theory of Reasoned Action (TORA) to explore dairy farmers' attitudes and beliefs towards heat detection techniques. Few farmers were convinced that following prescribed observation times, milk progesterone testing and using pedometers would fit their system or improve on their current heat detection practices. Perceived difficulty of using a technique was not a constraint on adoption. Without promotion that addresses identified barriers and drivers to adoption, little change in current practice can be expected.     

直播方式与田间有害生物的关系

在北美高地草原地区,直播正在成为1种重要的播种方式。在加拿大阿尔贝塔州,少耕和免耕田的比率已经占年播种面积的63%(加拿大农业统计资料,2001)。直播是指不处理前作残茬,只进行适当翻耕、少量翻耕或不翻耕,然后直接播种的种植方式,当前的主要做法是少量翻耕的直播方式。直播不仅仅是播种方式,而是种植制度的变化,对作物生长环境有显著的影响。“在田间,保留残茬将使土壤温度发生变化,从而影响后茬作物的萌发、出土和生长发育、影响植物营养的吸收和循环、土壤微生物的活动”(Wierenga et al.,1992)。同样,还会影响田间杂草、病害和虫害的…