含可溶物玉米酒糟添加于肉牛犊日粮的试验研究

1引言玉米酒糟副产品已越来越常见,这也促使畜牧生产商不断的投诸于这种饲料。依阿华肉牛研究中心发现：在依阿华州,较饲育场其它生产商相比,牛犊饲养人员较少的利用这一饲料资源。而由Leopold可持续农业发展中心基金赞助的一项维期三年的试验项目正是旨在研究评价不同的饲喂生产雌性肉牛牛犊的方案。（注：此报告为第一年的研究结果。）     

基于修正双作物系数模型估算温室黄瓜不同季节腾发量

为估算温室黄瓜植株蒸腾与土面蒸发,该研究基于FAO-56推荐的双作物系数模型,应用温室内实测微气象、叶面积指数(LAI)及土壤水分数据,对模型中基础作物系数(Kcb)和土面蒸发系数(Ke)进行修正,并基于修正后FAO-56Penman-Monteith(P-M)模型,确定温室参考作物蒸发蒸腾量(ET0),进而估算温室黄瓜蒸发蒸腾量(ETc)和植株蒸腾(Tr)。基于Venlo型温室内黄瓜不同种植季节(春夏季和秋冬季)Lysimeter和茎流计观测的黄瓜ETc和Tr,对修正后的双作物系数模型预测结果进行验证。结果表明,应用修正后的双作物系数模型估算的温室黄瓜ETc和Tr与实测值具有较好地一致性,春夏季温室黄瓜全生育期ETc估算值与实测值的日均值分别为3.05和2.94 mm/d,秋冬季分别为2.53和2.76 mm/d。修正后的双作物系数模型估算春夏季温室黄瓜日ETc的决定系数(R2)、均方根误差(RMSE)和模型效率系数(Ens)分别为0.95、0.41 mm/d和0.93;估算秋冬季ETc的误差计算结果依次为0.91(R2)、0.48 mm/d(RMSE)和0.90(Ens)。修正后的双作物系数模型估算春夏季日平均Tr与实测值分别为2.37和2.19mm/d,秋冬季分别为1.43和1.34 mm/d。研究结果还显示,不同种植季节温室黄瓜全生育期日平均Tr占ETc的比例分别为64.62%(春夏季)和68.59%(秋冬季)。该研究成果不仅为制定准确的温室黄瓜灌溉制度提供了理论依据,而且对实现温室环境智能化控制及减少温室内无效的土面蒸发具有重要意义。     

Use of atropine to reduce mucosal eversion during intestinal resection and anastomosis in the dog

OBJECTIVE: To determine whether atropine altered the degree of mucosal eversion during jejunal resection and anastomosis in the dog. STUDY DESIGN: Part I: Prospective, blinded, randomized, controlled study using a therapeutic dose (0.04 mg/kg systemic) of atropine. Part II: Prospective, unblinded, assigned, controlled study using a pharmacologic (0.04 mg/kg local arterial) dose of atropine. ANIMALS: Part I: Twenty-two young adult female Beagle dogs used during a nonsurvival third-year veterinary student surgical laboratory (small intestinal resection and anastomosis). Part II: Ten young adult female Beagle dogs used immediately after completion of a nonsurvival third-year veterinary student orthopedic surgical laboratory. METHODS: Part I: Dogs were randomly assigned to receive either atropine (0.04 mg/kg), or an equal volume of saline, given intramuscularly (premedication) and again intravenously prior to intestinal resection. Part II: In each dog, atropine (0.04 mg/kg)/saline was alternately given in the proximal/distal jejunum. RESULTS: Part I: There was no clinically or statistically significant difference between systemic atropine and saline solution on the degree of jejunal mucosal eversion after resection. Part II: There was a statistically significant decrease in jejunal mucosal eversion with atropine compared with saline solution when injected into a local jejunal artery. CONCLUSION: Systemic atropine (0.04 mg/kg) does not alter the degree of jejunal mucosal eversion during resection and anastomosis. Jejunal intraarterial atropine (0.04 mg/kg) reduced jejunal mucosal eversion during resection and anastomosis. CLINICAL RELEVANCE: The clinical usefulness and consequences of jejunal arterial atropine administration to reduce mucosal eversion remain to be determined.     

Variations in muscle fiber composition between successfully and unsuccessfully raced quarter horses

Muscle biopsy samples were removed from the m gluteus medius of 47 retired running Quarter Horse (QH) mares. Horses were separated based on bloodline, past racing history and percentage Thoroughbred (TB). The bred to run and raced (BRRA) and bred to run and not raced (BRNR) groups possessed a lower percentage (P<.01) of fast-twitch low oxidative (FT) fibers (BRRA 38.6 and BRNR 36.2±2.54 respectively). These horses also possessed a higher percentage (P<.01) of fast-twitch high oxidative (FTH) fibers (BRRA 52.5 and BRNR 48.5±2.54, respectively) than not bred to run and not raced (NBNR) horses. Horses that were bred to run had higher (P<.05) FTH to FT fiber ratios (1.44) than horses that were not bred to run (.94). Successful racehorses possessed a lower percentage (P<.05) of slow-twitch (ST) fibers and a higher percentage (P<.05) of FT fibers than unsuccessful racehorses. Success or failure was determined by Speed Index. No differences (P>.05) were found in the percentage FTH fibers between successful and unsuccessful horses.     

Two anatomic resources of canine pelvic limb muscles based on CT and MRI

Advances in magnetic resonance (MR) imaging and three-dimensional (3D) modeling software provide the tools necessary to create sophisticated, interactive anatomic resources that can assist in the interpretation of MR images of extremities, and learning the structure and function of limb musculature. Modeling provides advantages over dissection or consultation of print atlases because of the associated speed, flexibility, 3D nature, and elimination of superimposed arrows and labels. Our goals were to create a diagnostic atlas of pelvic limb muscles that will facilitate interpretation of MR images of patients with muscle injury and to create a 3D model of the canine pelvic limb musculature to facilitate anatomic learning. To create these resources, we used structural segmentation of MR images, a process that groups image pixels into anatomically meaningful regions. The Diagnostic Atlas is an interactive, multiplanar, web-based MR atlas of the canine pelvic limb musculature that was created by manually segmenting clinically analogous MR sequences. Higher resolution volumetric MR and computed tomography (CT) data were segmented into separately labeled volumes of data and then transformed into a multilayered 3D computer model. The 3D Model serves as a resource for students of gross anatomy, encouraging integrative learning with its highly interactive and selective display capabilities. For clinicians, the 3D Model also serves to bridge the gap between topographic and tomographic anatomy, displaying both formats alongside, or even superimposed over each other. Both projects are hosted on an open-access website, http://3dvetanatomy.ncsu.edu/     

Purification and Characterization of an Antioxidant Protein from Pearl Oyster (Pinctada fucata martensii)

Protein from pearl oyster (Pinctada fucata martensii) was purified and characterized. Results showed that the pearl muscle protein (PMP) was composed of a single polypeptide with a molecular weight of approximate 11.6 kDa and contained 95.1% of the protein and 4.92% of the carbohydrate of the oyster. The polypeptide appears to be a glycoprotein, since the Fourier transform infrared (FTIR) spectroscopy of the PMP shows the typical characteristics of protein and polysaccharides. The denaturation temperature of the PMP was 81.3°C by differential scanning calorimetry. Circular dichroism spectroscopy showed that the PMP has a highly ordered structure. The PMP (200 μg/mL) showed a high oxygen radical absorbance activity (ORAC) of 6.57 μmol Trolox/μmol protein. Its antioxidant activity was stable at temperatures from 30–80°C and pH 2–10. The antioxidant activity was significantly inhibited by Zn²⁺, Ca²⁺, and EDTA and enhanced by Mn²⁺. The results suggest that the PMP could be used as a potential natural antioxidant.     

Death from anthropogenic causes is partially compensatory in recovering wolf populations

There is substantial interest in how mortality rates affect animal populations, but mechanisms explaining when and under what circumstances particular causes of death incur demographic responses are far from clear. In theory, small or expanding populations should experience additive mortality from anthropogenic causes of death, but whether such effects are homogenous across a population or expressed only in certain high-risk individuals is open for debate. We used competing risks models to analyze mortality patterns among radio-collared wolves (Canis lupus, n = 711) from three populations in northwestern United States (1982-2004), and evaluated the degree to which anthropogenic mortality was additive vs. compensatory to natural demographic processes. Almost 80% (n = 320) of wolves dying of known fates were killed by anthropogenic causes (legal control, illegal killing, harvest in Canada, vehicle collision), and additive effects of anthropogenic mortality were most pronounced in northwestern Montana where wolf exposure to humans and livestock was high compared to either the Greater Yellowstone Area or central Idaho, where anthropogenic risk was lower. In contrast, risk from natural hazards was lower in northwestern Montana than in the other areas, implying some degree of compensatory mortality from anthropogenic risk. Animals recruited to the study following human-wolf conflict had markedly higher anthropogenic risk than those recruited for standard monitoring purposes, and juvenile wolves as well as dispersers, succumbed to higher anthropogenic risk. Multivariate models revealed that increasing wolf population density promoted higher anthropogenic risk and reduced natural risk, indicating that partially-compensatory effects of anthropogenic mortality actually became increasingly additive with population density. The observed compensatory mortality and hazard heterogeneity in our study implies that demographic responses to mortality risk may be complex and more subtle than previously thought; the density-dependent effect of anthropogenic mortality portends a stabilizing influence of humans on recovering wolf populations. We conclude that future assessment of the role of anthropogenic mortality should include individual-based hazard estimation as a complement to traditional population-level approaches.