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81.
根据饲料可消化氨基酸研制肉仔鸡无鱼粉饲粮试验   总被引:1,自引:0,他引:1  
选用240只AA商品代出壳肉仔鸡进行试验,以探讨根据饲料中可消化氨基酸含量,研制菜籽粕型无鱼粉低蛋白肉仔鸡饲粮的饲用效果。结果表明:以可消化氨基酸为基础研制的菜籽粕型无鱼粉肉仔鸡低蛋白平衡饲粮,可降低饲粮蛋白质水平1-1.5个百分点,试验鸡49日龄体重达2158.26克、料肉比2.15:1,增重和饲料转化率均达到或接近鱼粉型高蛋白饲粮的效果;每吨菜籽粕型无鱼粉饲粮可比鱼粉型饲粮降低原料成本72-8  相似文献   
82.
荔枝果实中含有玉米素、二氢玉米素和二氢核糖基玉米素。果实发育过程中细胞分裂素(CTK)含量的动态是:谢花后两周内含量最高,然后下降并稳定在低水平。用外源6一卞基氨基嘌呤(6一BA)处理,仅在果实发育初期有明显保果作用。果实采后贮藏期间CTK含量稳定在低水平;贮藏前用6一BA处理,能延迟果实衰老,提高果品质量。  相似文献   
83.
对5个无核葡萄品种的试验表明,不同培养方式对离体胚发育的影响是很明显的,其中4个品种胚发育率液体培养高于固体培养,‘京早晶’在液体培养中胚发育率高达73.7%,是目前国内外胚发育率最高的报道;液体培养比固体培养胚的发育程度高,发育整齐,无畸形胚,易成苗.  相似文献   
84.
The crossreactivity of mouse monoclonal antibodies (MoAbs) (Tab. I) prepared against human HLA-DR and HLA-DP antigens was studied in various bovine cells: lymphocytes from lymph nodes and peripheral blood, adherent (B) and nonadherent (T) lymphocytes, monocytes, granulocytes and platelets. In the immunofluorescence test, MoAbs Bra13, Bra14, Bra20, Bra22, Bra30, Bra70, HL-38 reacted with bovine B lymphocytes and monocytes, but not with other tested cells (Tab. III, IV). These antibodies, except Bra22, were positive with B lymphocytes in the complement dependent cytotoxic test (Tab. II). The similarity of the bovine antigens and HLA-DR antigens determined by used MoAbs was also proved by immunoblotting. Monoclonal antibodies Bra38 and BraFB6 did not react with the bovine cells and separated antigens. The epitope (HLA-DR) recognized by the antibody Bra38 is probably absent in cattle. The presence of HLA-DP analogue determined by the antibody BraFB6 has not been confirmed. The crossreactive MoAbs could be used for the detection of B lymphocytes and macrophages in veterinary immunology.  相似文献   
85.
A monoclonal blocking enzyme-linked immunosorbent assay (ELISA) and an indirect haemagglutination assay (IHA) were applied to serum samples from 124 specific pathogen-free (SPF) breeding and multiplying herds, which participate in the routine serological surveillance of the Danish SPF programme. Clinical and pathological observations of the herds and microbiological culturing of Mycoplasma hyopneumoniae were used to calculate herd sensitivity, herd specificity and herd predictive values for the two serological assays. The ELISA was superior to the IHA in herd sensitivity and herd specificity, with values of 93 per cent and 96 per cent, respectively, for the ELISA, and 61 per cent and 92 per cent for the IHA. During the six month period of evaluation 2.5 per cent of the herds were infected with M hyopneumoniae each month. At this level the IHA was found to have a positive herd predictive value of 16 per cent, compared with 39 per cent for the ELISA. The negative herd-predictive value on the same level was 99.8 per cent for the ELISA and 98.9 per cent for the IHA. If the assays were applied to a group of herds with a herd prevalence of M hyopneumoniae infection of 30 per cent (as is the case with the production herds in the Danish SPF programme) the predictive value of a positive herd diagnosis would be 91 per cent for the ELISA and 76 per cent for the IHA, and the predictive value of a negative herd diagnosis would be 97 per cent with the ELISA and 85 per cent with the IHA.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
86.
A previously undocumented hypokalaemic condition with a cyclical nature, comprising acute bouts of polymyopathy followed by spontaneous recoveries, is described in the cat. Cats being fed a high protein vegetarian diet developed recurrent episodes of polymyopathy, characterised by ventroflexion of the head and neck, stiff forelimb gait, lateral head-resting and generalised muscle weakness. Plasma potassium concentrations (mean +/- standard deviation) were reduced from 3.28 +/- 0.33 mmol/l at the beginning of the experiment to 2.45 +/- 0.24 mmol/l during bouts of myopathy. This hypokalaemia was associated with increased creatine kinase activities indicative of muscle damage, and decreased urinary potassium concentrations, and was caused by insufficient dietary potassium. Cats that received the same diet supplemented with potassium did not develop hypokalaemic polymyopathy. Spontaneous recoveries of affected cats were not associated consistently with increases in plasma potassium concentrations. Plasma taurine concentrations decreased and glutamic acid increased markedly in all cats fed the experimental diet. There was no evidence of thiamin deficiency associated with the high glutamic acid intake. Veterinarians should be aware that hypokalaemic cats, and in particular those on potassium-deficient diets, may show cyclical disease with episodes of polymyopathy recurring after periods of spontaneous clinical recovery. This condition in cats may be a useful animal model for familial hypokalaemic periodic paralysis in humans.  相似文献   
87.
In many cases when ecologists want to investigate a process, they often look for the best system on which to conduct the research, "best" meaning that the possibility of discovering mechanisms is optimized or made easier in some way. In fisheries we do it backwards. The species and system are given to us by economics, and we then fly in the face of the difficult circumstances to find mechanisms that are elusive anyway. These difficult circumstances constitute in some sense the first set of statistical problems. Using examples from the Northeast Pacific, I review the characteristics of cohort time series that make some species more tractable; propose a conscious process of conceptualization to assist in the formulation of clear, germane hypotheses; highlight the contrast between modeling in the sense of statistical fitting versus simulation models of processes; explore how the first round of models integrates with the second round of planning for new data collection at sea and in the lab; and, finally, propose how to judge success in terms of an operational approach.  相似文献   
88.
福建黄兔繁殖性状相关研究   总被引:5,自引:0,他引:5  
本文对310只母兔的繁殖性状进行了测定分析,结果表明;妊娠期与产仔数、产活仔数及活仔窝重呈负相关,相关系数分别为-0.426*、-0.350*和-0.515头4胎内母兔,胎次对产仔性能无影响,对母兔泌乳性能有一定影响。同样条件下胎次增加。泌乳性能提高,第3胎较第2胎有显著提高。  相似文献   
89.
Methods of augmenting bovine mononuclear cell responsiveness during physiological transitions of the udder may enhance resistance of the mammary gland to intramammary infections. Interleukin-2 is required for proliferation of T-lymphocytes and may contribute to B-lymphocyte proliferation. Recombinant bovine interleukin-2 (rBoIL-2) was evaluated as a potential immunoenhancer of bovine mammary gland mononuclear cells. Bovine mononuclear cells were isolated from five primiparous Holstein cows at 14-18 and 28-32 days of involution and at 7-13 days prior to parturition. Bovine blood and mammary gland mononuclear cells were highly responsive to rBoIL-2. Response of mammary gland mononuclear cells to rBoIL-2 was comparable with response of blood mononuclear cells. These data suggest that rBoIL-2 may be an effective immunoenhancer of bovine mononuclear cells during the non-lactating and prepartum periods.  相似文献   
90.
A disease causing the decline of papaya (Carica papaya) plants was noticed in the Jordan Valley in 1982. The disease caused severe yellowing of the upper leaves and dieback of the apex. The disease was not transmissible mechanically and continued efforts to associate viruses and viroids have so far been unsuccessful. Epidemiological observations suggested that the disease is airborne and probably caused by a mollicute. In order to test this hypothesis, plots were covered by an insect-proof net and with white nets providing 15, 30 and 50% shade. The 30%, 50% and insect-proof nettings provided complete protection, and the 15% netting reduced disease incidence to <2%, compared with>37% in the uncovered control plot. Spraying plants at weekly intervals with a commercial whitewash solution was also found to be effective in reducing disease incidence. The advantages of using a range of netting field treatments as a simple means for obtaining information on the epidemiological nature of a new disease are described.  相似文献   
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