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  

吴贞贤  杨正德 《中国家禽》1997,(3):9-11

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   

无核葡萄胚发育及早期离体培养的研究:Ⅲ.培养方式对离体胚发育的影响     

孟新法  张利  张潞生  王素珍 《中国农业大学学报》1992,(4):393-396

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   

Use of progesterone in microspheres for maintenance of pregnancy in mares.     

B A Ball  C Wilker  P F Daels  P J Burns 《American journal of veterinary research》1992,53(8):1294-1297

Administration of progesterone in poly(d-,l-lactide) microspheres was used to maintain pregnancy in mares after luteolysis was induced by treatment with prostaglandin F2 alpha at day 14 of pregnancy. Mares were given vehicle only (control, n = 6) or 0.75 g (n = 7), 1.5 g (n = 8), or 2.25 g (n = 5) of microencapsulated progesterone at days 12 and 22 of pregnancy. Serum progesterone concentrations were determined daily, and pregnancy was evaluated by transrectal ultrasonography on alternate days. Significantly (P less than 0.05) more mares given 1.5 or 2.25 g of progesterone (6 of 8 and 4 of 5 mares, respectively), but not those given 0.75 g (3 of 7 mares), maintained pregnancy through day 32, compared with control mares (0 of 6). Progesterone concentrations decreased significantly (P less than 0.025) in all groups after administration of prostaglandin F2 alpha at day 14, and significant (P less than 0.05) effects of time and treatment on progesterone concentrations were found between days 12 and 22, and 22 and 32. Although treatment with 1.5-g and 2.25-g doses of microencapsulated progesterone improved maintenance of pregnancy, compared with that of vehicle-treated controls, administration of 2.25 g of microencapsulated progesterone appeared to be most efficacious in maintenance of pregnancy during the study interval.  相似文献   

Subconjunctival cyst associated with Thelazia gulosa in a calf.     

P E Miller  B G Campbell 《Journal of the American Veterinary Medical Association》1992,201(7):1058-1060

A large subconjunctival cyst of 4 weeks' duration was surgically excised from the left eye of a 7-month-old Simmental calf. Two white, partially mineralized, approximately 1-cm-long, fertile female nematodes subsequently identified as Thelazia gulosa were found embedded in the cyst wall. Thelazia spp are generally regarded as nonpathogenic or mildly pathogenic in cattle in North America, despite reported infection rates ranging from 12.2 to 34.2%. Additionally, parasitic subconjunctival nodules associated with Thelazia spp rarely have been reported in the past, and cyst formation has not been described. It was postulated that in this calf, immature or adult worms may have penetrated normal tissue barriers, or entered via an earlier conjunctival wound, and created an inflammatory response with subsequent cyst formation.  相似文献   

Ovarian follicular characteristics, embryo recovery, and embryo viability in heifers fed high-fat diets and treated with follicle-stimulating hormone.     

D P Ryan  R A Spoon  G L Williams 《Journal of animal science》1992,70(11):3505-3513

Postpubertal beef heifers (n = 55) were used to examine the effects of high-fat diets, independently of energy intake, on nonesterified fatty acid and lipoprotein metabolic patterns, ovarian follicular dynamics, and embryo recovery/viability after FSH superstimulation. High-lipid (HL) diets (5.4% added fat) increased (P < .01) serum concentrations of cholesterol, but not of nonesterified fatty acids, during the 35-d period before FSH treatment. Development of medium-sized (5 to 9.9 mm) follicles was enhanced (P < .05) during this period in heifers fed the HL diet. The HL diet increased total cholesterol (P < .05) and progesterone (P = .14) concentrations in follicular fluid obtained at ovariectomy (n = 10) 60 h after the onset of FSH treatment, but neither estradiol-17 beta nor androstenedione was affected. Granulosa cells recovered from FSH-induced, estrogen-active follicles in heifers fed the HL diet produced greater quantities of progesterone (P = .06) and less estradiol-17 beta (P < .05) in vitro than did granulosa cells from heifers fed the normal lipid diet. Dietary treatment did not influence FSH-stimulated recruitment of medium and large follicles, number of ovulations, embryo recovery, or embryo viability. Data suggest that increments in dietary fat intake can alter specific aspects of ovarian steroidogenic potential and can increase the population of medium-sized follicles theoretically available for maturation and harvest during the estrous cycle. However, conditions that limited the latter process in the current experiment are not understood and require further investigation.  相似文献   

Welfare of farmed fish.     

P Lymbery 《The Veterinary record》1992,131(1):19-20

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Hypokalaemic episodic polymyopathy in cats fed a vegetarian diet     

A. LEON  SAF BAIN  WR LEVICK 《Australian veterinary journal》1992,69(10):249-254

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   

A context for recruitment correlations: why marine fisheries biologists should still look for them     

A. V. TYLER 《Fisheries Oceanography》1992,1(1):97-107

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   

福建黄兔繁殖性状相关研究   总被引：5，自引：0，他引：5  

徐龙  林和官 《福建畜牧兽医》1994,16(2):13-15

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   

Proliferative response of mammary gland mononuclear cells to recombinant bovine interleukin-2.     

P M Torre  P K Konur  S P Oliver 《Veterinary immunology and immunopathology》1992,32(3-4):351-358

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