Long-term application of animal slurries to grassland alters soil cation balance

Abstract. Soil samples from a 32-year grassland field experiment were taken from 0–5, 5–10, and 10–15 cm soil depths in February 2002. Plots received annual treatments of unamended control, mineral fertilizer, three rates of pig slurry and three rates of cow slurry, each with six replicates. Samples were analysed for cation exchange capacity (CEC), exchangeable cations (Na⁺, K⁺, Ca²⁺, Mg²⁺), pH and Olsen P. Exchangeable sodium percentage (ESP) was calculated as a sodicity indicator. Mean ESP was generally greater for slurry treatments than the control, with a trend of increasing ESP with application rate. This was particularly marked for cow slurry. At 0–5 cm depth ESP increased from 1.18 in the control to 1.75 at the highest rate of pig slurry and 5.60 at the highest rate of cow slurry. Similar trends were shown for CEC, exchangeable Na⁺, K⁺ and Mg²⁺, Ca²⁺ and Olsen P. The build-up of soil P due to slurry applications, together with this combination of physical and chemical factors, may increase the risk of P loss to surface waters, particularly from soils receiving high rates of cow slurry.     

红曲霉色素的提取

本实验确立了一种新的红曲霉色素提取方法:以红曲米为原料,乙醇为提取剂,得到的提取液再以正己烷提取分离。结果表明,此法所得的红曲霉色素是水溶性的,宜于用作食品添加剂。此外,还对影响提取的因素进行了探讨,并提供了最佳提取方案。     

Outcome of limb amputations in wapiti: 13 cases (1995-2001).

The object of this investigation was to determine the outcome of limb amputation in wapiti. Medical records of 13 wapiti that underwent limb amputation were reviewed to determine age, weight, sex, injury preceding amputation, limb amputated, amputation location, length of hospital stay, complications, and outcome. Ages ranged from 3 months to 8 years and weights from 70 kg to 280 kg. All animals were female. Eleven animals sustained catastrophic long bone fractures prior to amputation. Five animals had front limb amputations and 8 had hind limb amputations. Of these animals, 1 with a front limb amputaiton and 5 with hind limb amputations survived. Postsurgical inability to stand is associated with hospitalization of > 1 day. Of the 13 wapiti reviewed, 5 with hind limb amputations have produced and reared offspring. Hind limb amputation can be considered a viable alternative to euthanasia when catastrophic orthopedic injuries occur in female wapiti.     

离心式压缩机喘振问题分析

当压缩机内气体的流量较低时,气体容易出现旋转脱离现象,导致压缩机不能正常工作,采取增加压缩机内部液体的流量,在出口处设置单向阀防止气体倒流等措施,可有效地防止喘振的发生,保证输气管道的正常运行.     

Effects of Stocking Sac-Fry and Hatchery-Fed Fry on Production of Fingerling Channel Catfish Ictalurus punctatus

Abstract.— Channel catfish Ictalurus punctatus fry are typically held under hatchery conditions for 7 to 14 d after hatching to allow feeding and growth before they are stocked into nursery ponds to produce fingerling catfish. In an attempt to reduce hatchery operating costs, several catfish fingerling producers in Louisiana presently stock fry within 2 d after hatching before yolk absorption is complete. Fry at this stage of development are commonly referred to as "sac-fry." Although research has shown that fry can be stocked at the onset of yolk absorption with no detrimental effects on subsequent fingerling production, stocking sac-fry has been reported to result in reduced fingerling survival. To further investigate this topic, production trials were conducted in experimental outdoor pools over the course of two growing seasons to evaluate the effect of stocking fry of three different ages (2-, 7-, and 14-d post-hatch, DPH) on survival, growth (weight and length), condition factor (K), yield, feed consumption, and feed conversion ratio (FCR) of fingerling catfish. Results from both trials indicated that the age at which fry were stocked had no effect on production characteristics with the exception of growth. Specifically, fingerlings reared from fry stocked at 2 and 7 DPH were significantly larger than fingerlings reared from fry stocked at an age of 14 DPH. These findings suggest that the practice of stocking sac-fry may be a suitable alternative to the traditional procedure of holding and feeding fry under hatchery conditions prior to stocking. However, in order to fully evaluate the effects of early-age stocking of catfish fry on fingerling production, additional studies must be conducted under pond conditions. Furthermore, these studies must be coupled with a rigorous economic analysis before the practice of stocking sac-fry can be recommended to the catfish industry.     

A review of diet formulation strategies and feeding systems to reduce excretory and feed wastes in aquaculture

Significant efforts should be devoted to reducing waste outputs from aquaculture operations in order to lower the environmental impacts of aquaculture in many parts of the world. Since most aquaculture wastes are ultimately from dietary origin, reduction of waste outputs should first be through improvements of diet formulation and feeding strategies. The first step in the production of feeds producing less solid waste is to eliminate poorly digestible ingredients (such as whole grain or grain by-products used as binders and fillers in the feed formulae) and to use highly digestible ingredients with good binding properties. Further reduction of solid waste can then be achieved through careful selection of the ingredients to improve apparent digestibility and the nutrient balance of the feed. Nitrogen waste outputs can be reduced through the reduction of the digestible protein to digestible energy (DP/DE) ratio of the diet. Phosphorus waste outputs can be reduced through careful selection of the ingredients and optimization of the digestible phosphorus content of the diet to meet the requirement of the fish but avoid greatly exceeding this required level. Finally, feeding practices that minimize feed wastage should be adopted since feed wastage can have a very significant impact on waste outputs from fish culture operations.     

Complex vertebral malformation in a holstein calf: report of a case in the USA.

Complex vertebral malformation (CVM), a familial syndrome of Holstein calves, has been reported in aborted fetuses and in prematurely born, stillborn, and neonatal calves. Affected calves have anomalies in the vertebral column, including hemivertebrae, fused and misshapen vertebrae and ribs, scoliosis, and vertebral synostosis. Concurrent low body weight, symmetrical arthrogryposis, and cardiac anomalies have been documented in affected calves. The syndrome was identified and characterized in Holstein cattle in Denmark; however, a global distribution of this genetic disorder is likely based on identification of common ancestral sires widely used for artificial insemination. This is the first documented case of CVM in a Holstein calf in the USA.     

Toxoplasma gondii antibodies in exotic wild felids from Brazilian zoos.

Serum samples from 37 captive exotic felids in 12 zoos from six Brazilian states were assayed for antibodies to Toxoplasma gondii by the modified agglutination test using formalin-fixed whole tachyzoites. Titers greater than or equal to 1:20 were considered positive. Antibodies to T. gondii were found in 24 of 37 (64.9%) felids, including one European lynx (Lynx lynx), two jungle cats (Felis chaus), two servals (Leptailurus serval), two tigers (Panthera tigris), three leopards (Panthera pardus), and 14 of 27 lions (Panthera leo). This is the first serologic analysis for T. gondii infection in exotic wild felids from Brazilian zoos.     

Leptospira infection in two black rhinoceroses (Diceros bicornis michaeli).

Two black rhinoceroses (Diceros bicornis michaeli) developed clinical leptospirosis without hemolytic crises. The first rhinoceros presented with peracute depression, anorexia, rear leg trembling, dysuria, glucosuria, gastrointestinal discomfort, and decreased fecal output and died within 12 hr. Necropsy and histopathology revealed lesions within multiple organs. Leptospirosis was diagnosed postmortem based on positive fluorescent antibody staining of liver. The second rhinoceros presented 2 mo later with similar signs. It survived with treatment and was diagnosed with leptospirosis based on serology using microscopic agglutination testing and detection of urinary antigen using a fluorescent antibody technique. Leptospira kirschneri serovar grippotyphosa was postulated as the etiologic agent, with transmission probably occurring through wallow contamination by wild raccoons (Procyon lotor).