首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 78 毫秒
1.
目前蛋鸡饲养管理水平的高低已经成为蛋鸡养殖是否盈利的重要条件之一.在经济发达国家,1只蛋鸡的年产蛋量高达40千克,鸡群终生死淘率不到7%;而同样品种的蛋鸡在国内,1只蛋鸡的年产蛋量只有30千克左右,鸡群的终生死淘率高达20%.为何同样品种在国内却发挥不出优秀的生产性能,其中一个重要原因就在于饲养管理水平低.所以改变过去的养殖观养鸡的观念,提高饲养管理水平,成为农村蛋鸡养殖户急需解决的两大问题.  相似文献   

2.
高温季节,随着产蛋鸡采食量的减少,营养物质的摄入量明显降低,鸡体抵抗力降低,死淘率升高,产蛋率下降,严重影响着蛋鸡的生产效益。因此如何防止热应激、仍保持蛋鸡高产,采取合理有效的饲养管理措施  相似文献   

3.
蛋鸡热应激的防治   总被引：1，自引：0，他引：1  
<正>高温季节,随着产蛋鸡采食量的减少,营养物质的摄入量明显降低,鸡体抵抗力降低,死淘率升高,产蛋率下降,严重影响着蛋鸡的生产效益。因此如何防止热应激、仍保持蛋鸡高产,采取合理有效的饲养管理措施至关重要,也是广大蛋鸡养殖户亟待解决的一个问题,  相似文献   

4.
产蛋期蛋鸡死淘率高是许多鸡场存在的问题.国外商品蛋鸡产蛋期死淘率一般为5%左右.在我国由于饲养管理粗放,通常高于国外,约为10%,饲养条件差的鸡场可达20%.直接影响了养鸡者的经济效益.死淘率高受很多因素影响,只有找出原因,才能采取有效措施.  相似文献   

5.
近几年来，蛋鸡在产蛋期死淘率不断上升，影响了蛋鸡的产蛋性能，难以取得最好的经济回报。据报道，优良品种鸡产蛋期存活率应达９５％以上，但经过我县疫病监测中心对陕西商南地区、湖北孝感地区、南阳１３个县市及驻马店市等１１５０多个场家的监测发现产蛋期死淘率超过１０％以上，甚至高达２０％以上，通过大量的调查和分析，并参考有关的文献，认为造成上述情况的原因主要是疫病防治措施不力和饲养管理水平较差所致。１ 发生原因１．１ 疫病防治方面 疫病防治是养鸡业的关键。据统计，产蛋期死淘鸡中有７０％死于疾病。尽管目前我国比…  相似文献   

6.
蛋鸡产蛋期死淘率高是许多鸡场存在的难题。国外商品蛋鸡产蛋期死淘率约为５％左右，我国饲养管理粗放，一般高于国外，约为１０％，饲养条件差的鸡场有的可达２０％，直接影响了养鸡的效益。死淘率高受很多因素影响，只有找出原因，才能采取有效措施，我们认为造成产蛋期死淘率高的主要原因有：１．营养不平衡、营养过剩或不足，导致一些营养代谢病，使死淘率升高（１）饲料能量过高。过多的能量转化成体脂肪，造成脂肪肝综合征，使鸡群产蛋率下降，死淘率升高。死亡的鸡肝脏破裂，肝脏脂肪浸润，腹脂肪，心冠脂肪增厚，肠系膜沉积了大量的…  相似文献   

7.
当前,蛋鸡业的发展已进入微利时代.饲养管理水平的高低已成为当前养蛋鸡是否赢利的重要条件之一.在国外,一只褐壳罗曼蛋鸡的终生产蛋率达43斤以上,鸡群的终生死淘率在6%以下.而在国内终生产蛋率只达到35斤左右.鸡群的终生死淘率在20%以上.为何国外优良的品种在国内却发挥不出其优秀的生产性能,其中一个很重要的原因就在于饲养管理水平的低下以及观念的落后.所以改变我们过去养殖观念、提高我们的饲养水平已迫在眉睫.  相似文献   

8.
蛋鸡产蛋期死淘率高是许多鸡场存在的难题。国外商品蛋鸡产蛋期死淘率一般为５％左右。在我国由于饲养管理粗放，通常高于国外，约为１０％，饲养条件差的鸡场有的可达２０％，直接影响了养鸡的效益。死淘率高受很多因素影响，只有找出原因，才能采取有效措施。一、主要原因１．营养不平衡、营养过剩或不足，导致一些营养代谢病，使死淘率升高。（１）饲料能量过高：过多的能量转化成体脂肪，造成脂肪肝综合征，使鸡群产蛋率下降，死淘率升高。死亡的鸡肝脏破裂，肝脏脂肪浸润，腹脂肪、心冠脂肪增厚，肠系膜沉积了大量的脂肪。（２）饲料中…  相似文献   

9.
农业部提出“十一五”末我国畜牧总产值占农业总产值50％以上，畜禽饲养周翅孤淘率要求控制在7％以下，如何提高畜禽的商品率，降低死淘率呢？笔者通过多年的饲养实践，对降低蛋鸡产蛋期死淘率几点体会总结如下，供蛋鸡生产者及业界同仁参考。  相似文献   

10.
蛋鸡非典型新城疫是由副粘病毒引起的鸡传染病,多发生15~40日龄、60~90日龄及产蛋鸡群,常与鸡大肠杆菌病、支原体、传染性法氏囊病等混合感染.发病鸡群死淘率高,给养殖场(户)造成重大经济损失.……  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

13.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

14.
Tropical Animal Health and Production -  相似文献   

15.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

16.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

17.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

18.
Comparison of different tests to diagnose feline infectious peritonitis   总被引：1，自引：0，他引：1  
  相似文献   

19.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

20.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号