共查询到19条相似文献，搜索用时 250 毫秒
1.
在１９９３年－１９９５年期间，进行了外源褪黑激素对乌苏里貉冬皮成熟日期影响的研究。对４９６只乌苏里貉进行了皮下埋植褪激素植入物的试验，所用的植入物均为林北林业大学野生支物繁殖实验室研制的新型褪黑激素植入物。试验结果，在夏至前后期间用适量的外源褪黑激素处理，有促进乌苏里貉冬皮早熟的效果。 相似文献
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褪黑激素促进水貂冬皮早熟的研究 总被引：6，自引：0，他引：6
１９９４年进行了应用东北林业大学野生动物繁殖实验室研制的新型褪黑激亲（ＭＴ）植入物促进水貂冬皮早熟的研究。对２９３只成年和当年产水貂用ＭＴ植入物处理。试验结果表明，这种新型ＭＴ植入物的应用是安全而有效的。水貂用ＭＴ植入物处理后，表现食欲旺盛，死亡率降低。成年水貂在６月１５日用含５ｍｇＭＴ植入物处理，冬皮在１０月４日成熟．比正常对照组提早２个月。当年产幼水貂在７月１５日用含５ｍｇＭＴ或６ｍｇＭＴ植入物处理，或在７月２０日用含６ｍｇＭＴ的植入物处理，冬皮分别在１０月２０日和１０月１５日成熟，其提前天数分别为４０ｄ和５２ｄ。 相似文献
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褪黑激素植入物是用人工合成的褪黑激素(MT)制成的一种体内缓释植入物,可用特制的埋植器埋植于动物的皮下。该技术是国际毛皮兽养殖业公认的一项先进技术,于1985年首先在北美的毛皮兽养殖场应用。MT植入物在毛皮兽养殖业中的应用:(1)用于促进冬皮提前成熟。适时皮下埋植MT,成年毛皮兽(水貂、狐、貉)的冬皮可提前2~3个月成熟,当年生幼兽冬皮提前1个多月成熟。另外,埋植MT有增强动物免疫力的作用,使死亡率下降。(2)用于人工调控银狐和兰狐的繁殖季节(提前或延后),使之同步,以扩大高效益兰霜狐皮的生产规模。我国于1993年掌握了用国产化工… 相似文献
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选择自繁3月龄的公貂20只,公貉17只为试验组,设相同数量的貂、貉为对照组进行埋植褪黑激素的试验.试验结果表明:埋植褪黑激素后貂、貉的食欲、食量及体重均有增加;促进了夏毛的脱落及冬毛的生长,至取皮期貂、貉均提前一个月毛皮成熟;提高了经济效益,减少了饲养人员的劳动强度. 相似文献
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外源褪黑激素对毛皮动物毛皮生长、生理与生殖的影响研究 总被引：6，自引：2，他引：4
本文论述了褪黑激素（ＭＴ）的发现及其意义,埋植ＭＴ植入物能促使水貂、貉、狐等毛皮动物冬皮不同程度的早熟,也能让绒山羊在非生绒期长绒,让安哥拉兔夏毛产量增加,同时影响毛皮动物生理与生殖。 相似文献
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将１２日龄健康三黄雏鸡１２０羽随机分成１５组。对照组饲喂大江商品小肉鸡饲料，其它各组在饲喂上述饲料的基础上分别添加０．２、０．４、０．８、１．６、３．２、６．４、９．６、１４．４、２１．６、３２．４、４８．６、７２．９、１０９．３５、１６４、０２５ｍｇ／ｋｇ浓度的亚硒酸钠性硒，试验持续２８天。试验结果表明，在饲料中不影响雏鸡增重的含硒量为９．６ｍｇ／ｋｇ左右。饲料中含硒量达１４．４ｍｇ／ｋｇ以上时，雏鸡日增重较对照组极显著降低，料重比较对照组显著升高。并随剂量增大雏鸡出现死亡的时间提前，死亡率增加。邹鸡的血硒随饲料中含硒量增加而呈指数曲线上升，曲线方程为。 相似文献
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近年来,人工饲养貉在我国北方养貉重点市县区越来越多。但国内饲养的貉体型较小。为了改良体型小的貉,１９９７年１月１０日～１９９９年３月５日我们对采用体型大的种公貉人工采精、冻精、输精等技术进行了试验研究,效果很好。现将试验研究结果报告如下。１ 材料与方法１．１ 材料１．１．１ 采精种貉 选择１２只公貉,按顺序编号,１～４号为１２月龄种公貉４只,平均采精量１．２ｍＬ,５－８号为２４月龄种公貉４只,平均采精量１．４ｍＬ;９～１２号为３６月龄种公貉４只,平均采精量１．６ｍＬ。经试验１２只公貉均在不同温度… 相似文献
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人工埋植褪黑激素（Ｍｅｌａｔｏｎｉｎ，简称ＭＬＴ）可以引起水貂的秋施换毛提前。本文对秋季换毛提前的水貂皮进行了组织学研究。我们将毛被脱换与皮肤的组织学化联系起来，使用光学显徽镜对这些变化进行了定检验。检验指标如下：表皮与真皮厚度，毛囊长度，绒毛数量及及毛的活性等。这些指标发生相关变化。褪黑激素处理可使上述所有组织学指标较对照组提前５－６周。促进提前换毛的褪黑激素剂量为：雄性５ｍｇ以上，雌性２．５ｍ 相似文献
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The effect of prolonged exposure to exogenous melatonin on the reproductive status and growth rate of ewe lambs was investigated. Ewe lambs (born late March) were given intravaginal melatonin implants on 4 July (group J, n = 10) during anoestrus, or 20 December (group D, n = 10) during the breeding season. A third group (group C, n = 7) received empty implants on 4 July. Plasma progesterone concentrations were used to assess reproductive status. In the control group cyclic ovarian activity began on November 15 +/- 4 days, and ceased on January 28 +/- 8 days. In group J the onset of the breeding season was advanced by 4.9 weeks (occurring on October 12 +/- 4 days; P less than 0.001). The onset of anoestrus was also advanced in this group with 9 out of 10 of the ewes ceasing ovarian activity at least 3.4 weeks in advance of the control ewes (P less than 0.01). In contrast the timing of anoestrus was unchanged in group D, occurring on February 14 +/- 6 days. Melatonin treatment of ewe lambs from early July had no effect on growth rate, whereas treatment from mid-December had a depressive effect. Ewes therefore become refractory to the inductive effects of exogenous melatonin after long-term exposure. The results are consistent with the view that photorefractoriness is due to changes in the processing rather than the generation of the melatonin signal. 相似文献
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Wilson PR Walker IH Bond DB Middleberg A Staples LD 《New Zealand veterinary journal》1991,39(1):23-28
The efficacy of controlled-release melatonin implants to advance the onset of the breeding season was assessed in 1-year-old red deer hinds on five commercial deer farms in various localities in the North Island of New Zealand. Between 44 and 60 hinds in each of six herds were equally divided among treatment and control groups at each site. Melatonin treatment commenced between 27 November and 16 December and was achieved by the subcutaneous administration of two 18 mg melatonin implants. Three doses were given at about 30 day intervals. Two adult stags for each hind group were treated with three 18 mg melatonin implants concurrently on either two or three occasions. On each property, treated and control hinds were joined as one herd to treated stags commencing 30 January-10 February and concluding 15 May-2 June. The hinds in the four experimental herds underwent rectal ultrasound examination May-June to estimate conception rate and foetal age. Calving dates, hind and calf mortalities, weaning weights, and the antler growth cycle and harvesting data were recorded. Overall, treatment with melatonin resulted in an average advance of the median calving date of 22 days (range 12-36 days) when compared with untreated controls in the same herds. Pregnancy rates were 91.3-100% in treated hinds and 63.6-100% in untreated hinds. There were no differences in calf mortality or calf sex ratio between treated and untreated groups. No hind deaths could be attributed to melatonin treatment. The weaning weights of calves were 5.68 kg and 4.43 kg heavier for the male and female offspring of treated hinds respectively, compared with those of control hinds. Treated stags commenced rutting behaviour earlier than normal and the antler casting and growth cycle was advanced. Treatment resulted in advancement of the seasonal pattern of coat changes in hinds and stags, but no untoward side effects of the melatonin treatments were observed. 相似文献
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Asikainen J Mustonen AM Nieminen P Pasanen S Araja-Matilainen H Hyvärinen H 《Journal of animal physiology and animal nutrition》2002,86(11-12):367-375
The wild raccoon dog (Nyctereutes procyonoides, Canidae, Carnivora) goes through autumn fattening followed by winter sleep. Farmed raccoon dogs also exhibit autumn fattening but not winter sleep, as a result of daily feeding and lack of nests. We studied the effects of food deprivation and winter sleep or active winter feeding on the physiology and reproduction of farm-born raccoon dogs. Eighty-six animals were put on a 2-month fast in November-December. The fast caused no deleterious effects on the health of the raccoon dogs. In the spring the food-deprived animals had slightly more cubs per mated female than the fed animals. There was a significant negative correlation between the number of cubs obtained and the mean body mass of the females at the beginning of the mating season. The highest mean number of cubs was obtained by the females that weighed 5-7 kg. The results indicate that the raccoon dog is finely adapted to a long period of food deprivation in the winter. Furthermore, winter sleep and food deprivation could be introduced to farm conditions by providing the raccoon dogs with nestboxes and withholding food for a period of 6-8 weeks in mid-winter. 相似文献
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Three 2 x 4 factorial experiments were carried out from August to September with 30 juvenile male mink, 24 raccoon dogs, and 24 blue foxes to investigate the effect of dietary glycine supply (low or high) on the efficiency of these species to excrete hippuric acid with incremental benzoate intake (0, 1, 2, or 4 mmol/kg BW). For mink, two additional treatments with 1 or 2 mmol/kg BW of ethyl benzoate were included. A basal low-glycine diet was formulated to meet the minimum protein requirements of fur animals (30% of ME). This diet was supplemented with 0 or 3 g/kg of glycine, or with 0, 1.0, 2.07, or 4.15 g/kg of sodium benzoate for mink and blue foxes, and with 0 or 4.5 g/kg of glycine and 0, 1.58, 3.17, or 6.34 g/kg of sodium benzoate for raccoon dogs, respectively. Two additional diets with .76 or 1.53 g/kg of ethyl benzoate were made for mink. Fecal and urinary benzoic and hippuric acid excretion were measured for 3 d. The 24-h recovery of [14C]benzoic acid injected intraperitoneally was measured from urine, the liver, and the kidneys. All animals appeared healthy and no clinical signs of benzoate overdose were observed. Dietary benzoate level did not affect ADFI or ADG in any species. Glycine supplementation lowered ADFI in mink. The majority of ingested benzoates were absorbed from the gut (over 95%), except in blue foxes, which excreted 6 to 15% of ingested benzoates in feces with incremental increases in benzoate intake. Urinary free benzoic acid excretion accounted for 10% of the ingested benzoates in blue foxes but less than 5% in mink and raccoon dogs. When benzoate intake was 1 mmol/kg BW, mink, blue foxes, and raccoon dogs excreted 71, 77, and 34% of ingested benzoates as hippuric acid in urine, respectively. With higher benzoate intakes, urinary hippuric acid excretion decreased quadratically with mink to 20%, and linearly with blue foxes and raccoon dogs to 45 and 16%, respectively. The hippuric acid pathway appears to be the principal route of benzoate elimination in the mink and blue fox, whereas, in the raccoon dog, other pathways appear to be more important. In mink, the elimination of ethyl benzoate did not differ from that of sodium benzoate. Because glycine conjugation is the primary route of benzoate elimination, it is recommended that benzoate content in fur animal feeds should not exceed 1 g/kg feed on an as-fed basis. 相似文献
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Yongjun Xiao 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(3):186-190
Abstract Seasonal moulting was studied by quantitative histology and external observations in adult male raccoon dogs. Moulting of the underfur hairs is characterized by a heavy loss of old winter hair in spring and an intensive growth of new winter hair in autumn. Only few mature and growing underfur hairs were found in the hair cover in summer. The new intermediate and large guard hairs started to develop in April and May. All the new guard hairs had developed by the end of June. About 7 and 3.5 months were needed for the growth of new winter guard and underfur hairs respectively. At the end of November the winter fur was mature. The bundles with an intermediate guard hair contained more underfur hairs than the bundles with a large guard hair in the mature winter fur. The thickness of dermis and the grade of skin colour peaked in the autumn moult, indicating a close relation to the activity of hair follicles. 相似文献
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乌苏里貉生长发育规律研究及其生长曲线模型拟合 总被引：1，自引：1，他引：0
选取60只分窝乌苏里仔貉,按出生窝别、出生时间、性别、体重分为4组,生长期和冬毛期分别饲喂4种不同的试验E／粮,研究其生长发育规律,拟合其体重和体长生长模型。结果表明：乌苏里貉周平均日增重在8～12周龄和18～24周龄有2个高峰期（分别为40g／d和50g／d）,体长生长速度在9～14周龄和20～22周龄有2个高峰期（分别为0．3cm／d和0．2cm／d）;体重和体长适宜生长曲线方程分别为：Y=241．47＋42．242X＋19．041X^2-0．399X^3（R^2=0．994）,Y=9．517＋3．374X-0．067X^2（R^2=0．992）。 相似文献
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Cunningham CP Brown JM Jacobson GA Brandon MR Martinod SR 《American journal of veterinary research》2006,67(9):1564-1569
OBJECTIVE: To evaluate use of covered-rod (CR) silicone implants containing ivermectin for long-term prevention of infection with Dirofilaria immitisin dogs. ANIMALS: 145 adult male and female dogs. PROCEDURES: Dogs received implants of different sizes, and ivermectin concentrations and serum ivermectin concentrations were monitored for 16, 57, and 56 weeks, respectively, in 3 preclinical dose selection studies. Ability of implants to prevent infection with D immitis was evaluated in 2 further studies; dogs were challenged with 50 infective third-stage larvae 52 weeks after implant administration and necropsied 145 days after challenge, and the total number of adult heartworms was counted. A field study was then undertaken in which client-owned dogs received an implant and plasma samples were collected at intervals until week 52 for ivermectin analysis and heartworm antigen determination. RESULTS: Use of the implants resulted in maintenance of an ivermectin concentration > or = 0.2 ng/mL for 12 months. In challenge studies, no treated dogs had adult heartworms, in contrast to untreated dogs, which all had adult heartworms at necropsy. In the field study, dogs treated with an implant had negative results of heartworm antigen testing for 12 months. CONCLUSIONS AND CLINICAL RELEVANCE: The CR silicone implant containing 7.3 mg of ivermectin was 100% effective in preventing experimental infection with D immitislarvae and resulted in negative results for heartworm antigen in a field trial. This product has the potential to alleviate poor owner compliance with monthly prevention regimens. 相似文献