Resident forum abstractsEVALUATION OF THROMBOELASTOGRAPHY (TEG) IN NORMAL CATS

Objective: To establish normal parameters of thromboelastography (TEG) in healthy adult cats. Background: Thromboelastography (TEG) is an in vitro test of coagulation that has been shown to be useful in humans, dogs and select species to identify and quantify alterations of hemostasis (e.g., hypercoagulable and hypocoagulable states). It has also been demonstrated to be useful in monitoring effects of anticoagulant therapies. This test has not been evaluated in cats. Methods: Blood was collected from 25 clinically normal cats by venipuncture using a 21 gauge×3 1/2 inch butterfly catheter and syringe for medial saphenous or jugular venipuncture. A single 1.8 mL sample in 3.8% Sodium Citrate (9:1) was collected from each cat. Recalcified whole blood was analyzed 30 minutes following collection with the TEG® 5000 analyzer (Haemoscope, Niles, IL). Analysis temperature was 37.6°C. TEG parameters recorded included: R‐value (represents initial fibrin formation), K (time from R to standard fixed measure of clot firmness which represents contributions of platelets and fibrinogen), maximum amplitude (MA; represents absolute clot strength), and alpha angle (α; the slope of TEG tracing which represents rate of clot formation). The coagulation index (CI) was derived from the formula generated for humans to provide an overall assessment of whether the sample was hyper‐ or hypocoagulable. Results: Values for the 25 normal cat samples are reported as mean ±2 standard deviations. R=2.97; 1.23–4.72; K=1.54, 0.38–2.71; α=70.70, 57.76–83.65; MA=58.50, 45.26–71.74 and CI=2.27, 0.07–4.46. Compared to historical information obtained on normal dogs, cats have significantly shorter R and K and larger α, MA and CI. Conclusions: TEG does have reproducible performance when used to evaluate coagulation status in normal cats. Compared to dogs, normal cats favor a hypercoagulable state. Species‐specific normal values are necessary for interpretation of TEG results. This test bears potential value for use in future experimental and clinical work to investigate hemostasis in cats receiving anticoagulant therapies or in cats suffering from diseases such as cardiomyopathy which are thought to be associated with altered coagulation status.     

Cell Subpopulation‐related Volumetric Parameters: a Complementary Tool of the Modified Hypo‐osmotic Swelling Test on Model of Boar Spermatozoa

It is a general property of the intact animal cell to swell rapidly in response to hypo‐osmotic conditions. The modified hypo‐osmotic swelling test (HOS‐test) is an indicative test to evaluate the integrity of the plasma membrane by means of an electronic cell counter, based on the relative increase of the cell volume in response to hypo‐osmotic conditions. In this study the relationships between the osmotically induced changes of the cell volume of boar spermatozoa as determined by cell counter and the integrity of the membrane as determined by propidium iodide staining (PI) were studied. Boar sperm cell volume distributions were measured under iso‐osmotic (300 mosmolar) conditions and after a hypo‐osmotic stress (150 mosmolar). The relative volume shift of mean and modal volume were calculated as a proportion coefficient of modal and mean values of the cell volume distributions by transition from iso‐osmotic to hypo‐osmotic conditions. The volumetric parameters related to the different cell subpopulations were derived from the different peaks of cell volume distributions. PI‐staining techniques were used for comparison. The values of the volume shift and of derived percentages of the osmotically inactive cells were correlated negatively and positively, respectively (p < 0.05) with the percentage of the PI‐stained cells. This correlation indicates that a relationship exists between membrane functions of the different cell compartments (sperm head and tail) due to the circumstance that the increase of the cell volume in the HOS‐test is associated with the morphological changes in the tail and the PI‐staining is associated with the membrane integrity and permeability of the head region. The advantage of computer‐assisted volume measurement is that a large number of cells (5000–50 000 spermatozoa) can be measured and evaluated during one procedure and in a very short time. The relative volume shift is a quantitative continuous parameter characterizing the osmotic reactivity and membrane functional competence of a cell population and of subpopulations within one ejaculate. This parameter could be useful to evaluate membrane functional competence rapidly and sensitively.     

Digestibility of amino acids in corn, corn coproducts, and bakery meal fed to growing pigs

The objectives of this experiment were to determine the apparent ileal digestibility and the standardized ileal digestibility (SID) of CP and AA in bakery meal, corn gluten meal, corn gluten feed, corn germ meal, and hominy feed and to compare these values with the apparent ileal digestibility and SID of CP and AA in corn and distillers dried grains with solubles (DDGS). Eight growing barrows (initial BW: 82.5 ± 5.5 kg) were randomly allotted to an 8 × 8 Latin square design with 8 diets and 8 periods. Diets contained corn, DDGS, bakery meal, corn gluten meal, corn gluten feed, corn germ meal, or hominy feed as the sole source of protein and AA. An N-free diet was used to measure basal endogenous losses of AA and protein. Pigs were fed experimental diets for eight 7-d periods, with ileal digesta being collected on d 6 and 7 of each period. Results indicated that the SID of Lys in corn gluten meal (78.7%) was greater (P < 0.01) than in DDGS, bakery meal, corn germ meal, and hominy feed (46.0, 48.4, 68.4, and 58.8%, respectively). The SID of all indispensable AA except Arg, Leu, and Met in bakery meal were not different from those in DDGS. The SID of Arg, His, Leu, and Met in corn gluten feed were less (P < 0.01) than in corn, but the SID of all other indispensable AA in corn gluten feed were not different from those in corn. However, for most indispensable AA, the SID in corn gluten feed was not different from the SID in DDGS. The SID of all indispensable AA in corn germ meal, except Arg, His, Leu, and Met, were not different from the SID in corn. Likewise, the SID of all indispensable AA in corn germ meal, except Arg and Leu, were not different from those in DDGS. The SID of Ile, Met, Phe, and Val in hominy feed were less (P < 0.01) than in corn, but the SID of the remaining indispensable AA in hominy feed were not different from the SID of indispensable AA in corn. All indispensable AA in hominy feed also had SID values that were not different from the SID values of AA in DDGS, except for Arg and Lys, which had greater (P < 0.01) SID than in DDGS. In conclusion, bakery meal had SID values of most AA that were less than in corn, but corn gluten meal had SID values for most AA that were greater than the SID of AA in corn, bakery meal, and corn coproducts.     

A comprehensive approach to soil‐atmosphere trace‐gas flux estimation with static chambers

A new procedure (HMR) for soil‐atmosphere trace‐gas flux estimation with static chambers is presented. It classifies data series into three categories according to criteria based on the application of a particular non‐linear model and provides statistical data analyses for all categories. The two main categories are non‐linear and linear concentration data, for which data are analysed by, respectively, the non‐linear model and linear regression. The third category is represented by concentration data within the range of experimental error, or noise, from sites with no significant flux. Data in this category may be analysed by linear regression or simply classified as no flux. The particular non‐linear model has been selected among alternatives because its exponential curvature generally fits non‐linear static chamber concentration data well, and because it can be proven, mathematically, to be robust against horizontal gas transport through the soil or leaks in the chamber. The application of the HMR procedure is demonstrated on 244 data series of nitrous oxide accumulation over time. On average, 47% of these data were non‐linear, with an average flux increase over linear regression of 52%. The classification and analysis of data with a small signal‐to‐noise ratio requires special attention, and it is demonstrated how diagnostic graphical plots may be used to select the appropriate data analysis. The HMR procedure has been implemented as a free add‐on package for the free software R and is available for download through CRAN ( http://www.r‐project.org ).     

不同区域奶牛子宫内膜炎病原菌的分离鉴定及分布特征

【目的】对中国6个区域奶牛子宫内膜炎病原菌的种类和区域分布特征进行研究,为筛选出最佳治疗药物以减少子宫内膜炎对畜牧业造成经济损失提供数据支持。【方法】分别从赤峰区域、张家口区域、潍坊区域、重庆区域、宝鸡区域和北京区域选择不同规模的奶牛养殖场中患子宫内膜炎的奶牛,用采样器每个区域采集60份(6个区域共计360份)患病牛的子宫内容物,通过革兰氏染色和生化鉴定的方法鉴定分离纯化的奶牛子宫内膜炎病原菌,并分析病原菌的分布特征。【结果】潍坊、赤峰、北京区域引起奶牛子宫内膜炎以单一感染为主。宝鸡、张家口、重庆区域引起奶牛子宫内膜炎以混合感染为主。赤峰、重庆、张家口、潍坊、宝鸡、北京区域引起奶牛子宫内膜炎的病原菌以革兰氏阳性菌为主。赤峰奶牛子宫内膜炎的主要致病菌是葡萄球菌。重庆奶牛子宫内膜炎的主要致病菌是链球菌。张家口奶牛子宫内膜炎的主要致病菌是大肠杆菌。潍坊奶牛子宫内膜炎的主要致病菌是链球菌。宝鸡奶牛子宫内膜炎的主要致病菌是葡萄球菌。北京奶牛子宫内膜炎的主要致病菌是蜡样芽孢杆菌。     

Plasma haptoglobin concentration in swine after challenge with Streptococcus suis

Eight 15-week-old pigs, reared under specific pathogen-free conditions, were inoculated with Streptococcus suis serotype 2. The animals were monitored before and after challenge by measuring rectal temperature, recording specific clinical symptoms and collecting blood samples for haptoglobin determination. Twenty-four hours after infection, the average haptoglobin plasma concentration of the animal group increased significantly and reached a maximum 4 days post-inoculation, followed by a constant mean level until the end of the trial on day 10. In spite of individual differences between the animals, an increase in haptoglobin concentration of at least 2.5 times above normal was observed in all infected pigs 1 day after challenge. Twenty-four hours after challenge, lameness was observed in five animals and an elevated body temperature was observed in seven of the eight experimental infected animals. These are the classical clinical symptoms of streptococcal infection. Haptoglobin was shown to increase in acute S. suis infection in pigs.     

Incorporating free-flowing rivers into global biodiversity targets: Prioritization and targeted interventions to maintain ecological integrity

1. Free-flowing rivers (FFRs) are important surrogates for freshwater biodiversity as there are increasingly fewer rivers that reflect intact habitat and species diversity from source to sea. The status and changes in the ecological condition or protection of FFRs is not explicitly reported on in global biodiversity targets. Indices are proposed for reporting such changes to the Sustainable Development Goals (SDGs) 6 and 15, Aichi Target 11, and the post-2020 global biodiversity framework.
2. FFRs were identified at a countrywide scale in South Africa for protection, planning, monitoring, and assessing changes in their ecological condition and protection status. They were selected and prioritized using criteria co-produced with national, provincial, and local river managers and policy makers. Given the high competition for water resources and the unlikely possibility for strictly protecting all FFRs, a subset of FFRs, termed ‘flagship FFRs’, was identified.
3. Methods for reporting changes in the protection levels of prioritized FFRs at a countrywide scale were developed, which included indices of FFRs related to global targets: the loss of the extent of FFRs in a natural and largely natural ecological condition for SDG 6; changes in the connectivity of FFRs included in the post-2020 global biodiversity framework targets; and changes in protection levels of FFRs for Aichi Target 11 and SDG 15.1.2.
4. Flagship FFRs attracted targeted management initiatives and thus maintained their connectivity and ecological condition. This was not true when all FFRs were considered; in the broader set of FFRs, longitudinal fragmentation increased and ecological condition declined from 2011 to 2018.
5. Considering the increasing pressures rivers are likely to experience from human and climate change impacts, particularly in semi-arid to temperate environments, urgent prioritization and monitoring of FFRs is called for so that a targeted set of protection and management strategies can be applied.