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1.
本试验旨在研究不同能量和蛋白质水平饲粮对宁乡猪生长性能、胴体品质及肉品质的影响。选用体重约18 kg的宁乡猪仔猪72头,随机分为3组(每组4个重复,每个重复6头):对照组饲喂基础饲粮(前、中、后3期蛋白质水平分别为14.03%、12.06%、11.01%;全期消化能为12.15 MJ/kg);试验A组饲喂在基础饲粮的基础上3期蛋白质水平各降低约2个百分点、全期消化能降低1.25 MJ/kg的低营养水平饲粮;试验B组饲喂在基础饲粮的基础上3期蛋白质水平各降低约3个百分点、全期消化能降低2.50 MJ/kg的超低营养水平饲粮。试验期180 d。结果表明:1)试验组前期料重比和平均日增重较对照组显著提高(P<0.05);从全期来看,3个组间生长性能差异不显著(P>0.05)。2)试验B组的肥肉率较对照组和试验A组显著降低(P<0.05),瘦肉率有提高趋势。与对照组相比,试验组胴体垂直长均极显著提高(P<0.01);试验B组胴体斜长、皮厚显著提高(P<0.05)。3)试验组背最长肌pH 1 h显著降低(P<0.05),其他肉品质性状各组间差异不显著(P>0.05)。由此可见,降低饲粮能量和蛋白质水平,对宁乡猪生长性能和肉品质没有明显负面影响,且能提高屠宰性能,改善胴体组成。在本试验中,超低营养水平饲粮对胴体组成的改善效果优于低营养水平饲粮。  相似文献   

2.
日粮组成和能量水平对乌金猪肉品质的影响   总被引：4，自引：1，他引：3  
本文旨在研究不同日粮组成和能量水平对乌金猪肉品质的影响,确定最优肉品质所需的日粮适宜能量水平.选取体重(15.18±0.85)kg的乌金猪90头,公、母各占1/2,随机分为5组,每组18头,下设3个重复,每个重复6头.试验采用单因子随机分组设计,以中国肉脂型生长肥育猪饲养标准能量需要设计中能量水平(组Ⅲ,消化能12.98 MJ/kg),以NRC(1998)生长肥育猪饲养标准能量需要设计最高能量水平(组Ⅰ,消化能14.22 MJ/kg),此两个能量水平间设计中高能量水平(组Ⅱ,消化能13.60 MJ/kg),在中能量水平下依次分别设计中低能量水平(组Ⅳ,消化能12.36 MJ/kg)和最低能量水平(组Ⅴ,消化能11.74 MJ/kg),每个能量水平间的梯度为0.62 MJ/kg.各组在不同生长阶段日粮蛋白质、微量元素、氨基酸等水平基本固定.试验期至100 kg体重,分别在30、60和100 kg体重时屠宰,测定肉品质指标及肌肉营养成分,采用模糊综合评定系统分析并确定最优肉品质日粮适宜能量水平.结果表明,不同日粮组成和能量水平对乌金猪不同生长阶段肌肉pH、系水力、剪切力、烹煮损失和滴水损失有明显影响,组Ⅰ、Ⅲ、Ⅴ及其日粮的组间差异显著(P<0.05),大理石纹在60和100 kg体重时差异显著(P<0.05).随着日粮能量水平的降低,肌肉中粗蛋白质含量提高,在100 kg体重时达显著水平(P<0.05);粗脂肪、肌内脂肪和肌苷酸含量降低,不同生长阶段组Ⅰ、Ⅲ、Ⅴ及其日粮的组间差异显著或极显著(P<0.05或P<0.01).以大理石纹、剪切力、滴水损失为评定肉品质的代表指标,通过综合评定确定30、60和100 kg体重时最优肉品质适宜的日粮能量水平分别为13.10、13.08和13.11 MJ/kg.研究结果可为乌金猪的合理饲养和改善肉品质提供科学依据.  相似文献   

3.
旨在研究不同能量和蛋白质水平日粮对豪猪生长性能、血清生化指标及经济效益的影响。试验设计采用2×2双因素随机设计,选取3月龄体重相近的豪猪60头,公母各30头,随机分成5组,每组3个重复,饲喂不同能量和蛋白饲粮,分别为对照组(18.54 MJ/kg, 13.96%,原场饲喂粮)、试验组Ⅰ组(16.25 MJ/kg, 15%)、Ⅱ组(16.25 MJ/kg, 16%)、Ⅲ组(17.5 MJ/kg, 15%)和Ⅳ组(17.5 MJ/kg, 16%)。试验期共67 d,其中预饲期7 d,正试期60 d。结果:4个试验组平均日增重均极显著高于对照组(P0.01),饲粮的能量和蛋白水平对豪猪的生产性能不存在交互作用(P0.05),提高饲料的能量水平可极显著提高豪猪的平均末重和平均日增重(P0.01),对豪猪的料重比也有显著提高(P0.05);血清中的尿素氮含量试验组Ⅳ显著高于对照组(P0.05),其余组间差异不显著(P0.05);4个试验组血清中的谷丙转氨酶和谷草转氨酶含量极显著低于对照组(P0.01)。饲粮的能量和蛋白水平对尿素氮存在交互效应(P0.05),但对总蛋白、白蛋白、谷丙转氨酶、谷草转氨酶不存在交互效应(P0.05);试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组与对照组相比,每千克增重饲料成本分别降低了37.2%、38.88%、44.01%和44.86%,且差异极显著(P0.01);饲粮的能量与蛋白水平对豪猪的经济效益不存在交互作用(P0.05),提高饲粮的能量水平可显著提高饲粮的经济效益(P0.05),提高饲粮的蛋白质水平对豪猪的经济效益无显著影响(P0.05)。本试验表明:饲粮总能水平为17.5 MJ/kg、蛋白水平为16%(Ⅳ组)时,豪猪的生产性能和经济效益最佳且血清生化指标较其他组表现更好。  相似文献   

4.
本试验旨在探究不同能量和蛋白质水平饲粮交替饲喂对妊娠母猪繁殖性能、血浆激素含量及抗氧化指标的影响。试验分为2个阶段,配制6种试验饲粮,妊娠前期试验饲粮:低能量低蛋白质水平饲粮(12.54 MJ/kg、15.55%)、中能量中蛋白质水平饲粮(13.27 MJ/kg、16.47%)、高能量高蛋白质水平饲粮(13.44 MJ/kg、17.86%);妊娠后期试验饲粮:低能量低蛋白质水平饲粮(12.73 MJ/kg、15.96%)、中能量中蛋白质水平饲粮(13.27 MJ/kg、16.47%)、高能量高蛋白质水平饲粮(13.84 MJ/kg、18.13%)。选取2胎、体重相近的加系大白母猪48头,随机分为对照组(早上饲喂中能量中蛋白质水平饲粮,下午饲喂中能量中蛋白质水平饲粮)、试验Ⅰ组(早上饲喂低能量低蛋白质水平饲粮,下午饲喂高能量高蛋白质水平饲粮)、试验Ⅱ组(早上饲喂高能量高蛋白质水平饲粮,下午饲喂低能量低蛋白质水平饲粮),每组16个重复,每个重复1头母猪。每天饲喂2次。妊娠前期中能量中蛋白质水平饲粮每次饲喂1.125 kg,低能量低蛋白质水平饲粮每次饲喂1.150 kg,高能量高蛋白质水平饲粮每次饲喂1.140 kg;妊娠后期中能量中蛋白质水平饲粮每次饲喂1.805 kg,低能量低蛋白质水平饲粮每次饲喂1.800 kg,高能量高蛋白质水平饲粮每次饲喂1.800 kg。试验期114 d。结果表明:1)与对照组相比,试验Ⅰ组妊娠36~90 d的平均日增重(ADG)显著增加(P<0.05);试验Ⅰ组总产仔数高于对照组(P>0.05);试验Ⅰ组活仔数高于对照组(P>0.05)。2)与对照组相比,试验Ⅰ组妊娠35 d的血浆过氧化氢酶(CAT)活性显著升高(P<0.05),试验Ⅰ组妊娠80 d的血浆CAT活性极显著升高(P<0.01),且试验Ⅰ组较试验Ⅱ组显著升高(P<0.05);与对照组相比,试验Ⅱ组妊娠80 d的血浆丙二醛(MDA)含量极显著降低(P<0.01),试验Ⅰ组妊娠35 d的血浆MDA含量显著高于试验Ⅱ组(P<0.05)。3)与对照组相比,试验Ⅰ组妊娠80 d的血浆瘦素(LEP)含量显著升高(P<0.05);试验组妊娠105 d的血浆胰岛素样生长因子-Ⅰ(IGF-Ⅰ)含量极显著低于对照组(P<0.01)。综上所述,与早、晚饲喂相同营养水平饲粮相比,早、晚交替饲喂不同能量和蛋白质水平饲粮可提高妊娠母猪的繁殖性能,影响血浆中激素含量和抗氧化指标。  相似文献   

5.
为了研究不同能量水平日粮对21～45日龄艾维茵肉仔鸡生产性能和屠宰性能的影响,试验选择21日龄150只艾维茵肉鸡,随机分成3组,每组5个重复,每个重复10只鸡,在相同蛋白质水平下(19.50%),试验Ⅰ组、Ⅱ组和Ⅲ组肉仔鸡分别用12.50 MJ/kg、12.90 MJ/kg和13.30 MJ/kg的能量水平日粮饲喂,预试期为3 d,正试期为21 d,检测日增重、日采食量、料重比、胴体重、腹脂率、全净膛率、胸肌率以及腿肌率。结果表明:试验Ⅱ组和试验Ⅲ组的平均日增重、日采食量均显著高于试验Ⅰ组(P0.05),试验Ⅱ组和试验Ⅲ组间平均日增重、日采食量均差异不显著(P0.05),各组间料重比差异显著(P0.05);试验Ⅱ组和试验Ⅲ组的胴体重、腹脂率显著高于试验Ⅰ组(P0.05),试验Ⅱ组和试验Ⅲ组间胴体重、腹脂率差异不显著(P0.05),各组间全净膛率、胸肌率、腿肌率均差异不显著(P0.05)。说明日粮能量水平为12.90 MJ/kg时,肉鸡的生产性能和胴体性能表现较好。  相似文献   

6.
采用2×2因子设计,能量和蛋白质各设2个水平,分别在NRC推荐水平上提高或降低10%,以考察饲料能量、蛋白质水平对生长猪生产性能的影响.试验以NRC水平为对照,共5个处理,每个处理4个重复,每个重复4头猪.将80头生长猪随机分为5个处理.试验结果:与对照组相比,高能高蛋白组(15.6MJ/kg,18.7%)日增重显著降低(P<0.05),其他处理组差异都不显著(P>0.05);低能低蛋白组(12.78MJ/kg,15.3%)日增重显著低于其他两个处理组;高能和高蛋白均显著降低采食量,料肉比有所降低,但差异不显著.结果表明适宜能量和蛋白质水平为NRC水平.  相似文献   

7.
本研究旨在探讨日粮中不同能量和蛋白质水平对荣昌烤乳猪品系生长性能和肉质性状的影响,建立荣昌烤乳猪品系适宜营养水平.试验按照2×3因子设计,设2个能量水平(14.10和15.06 MJ/kg),3个蛋白质水平(16%、18%和20%).试验选用(24±2)日龄断奶、体重(5.01±0.73)kg的荣吕烤乳猪系健康仔猪120头,随机分为6个组,每个组4个重复,每个重复5头猪.试验期21 d.结果表明:(1)日粮能量水平显著影响仔猪日增重(P=0.006)和料肉比(P=0.030),高能水平下仔猪生长性能优于低能水平.日粮蛋白质水平显著影响仔猪日采食最、日增重和料肉比(P<0.05),蛋白质水平18%组生长性能优于16%和20%组.能量和蛋白质的交互作用除了对日增重影响差异显著(P=0.021)外,对其余生长性能指标影响不显著(P>0.05);(2)日粮能量水平极显著影响肌肉粗蛋白质含量和蒸煮损失(P<0.01),对肌肉总色素和肌纤维密度的影响显著(P<0.05).日粮蛋白质水平极显著影响肌肉粗蛋白质、肌内脂肪和蒸煮损失(P<0.01),对其余肉质性状指标影响不显著(P>0.05).能量和蛋白质的交互作用对肌肉粗蛋白质、肌纤维直径和肌纤维密度影响极显著(P<0.01),对肌肉总色素及蒸煮损失的影响显著(P<0.05).综上可知,日粮能量和蛋白质水平显著影响荣昌烤乳猪品系生长性能和肉质性状,5～11 kg荣昌烤乳猪品系适宜的消化能水平为15.06 MJ/kg,粗蛋白质水平为18%.  相似文献   

8.
为了研究日粮能量与蛋白质水平对拜城油鸡生长期营养物质表观消化率的影响,试验选取270只8周龄拜城油鸡并随机分成9个处理组,每个处理组设3个重复,每个重复10只鸡。试验期共8周。试验组日粮根据生长阶段设计为8～11周龄:3个能量水平(11.70MJ/kg、12.12MJ/kg、12.54MJ/kg)、3个蛋白质水平(17%、18%、19%)共9种日粮;12～15周龄:3个能量水平(10.20MJ/kg、10.60MJ/kg、11.00MJ/kg)、3个蛋白质水平(16%、15%、14%),共9种日粮。结果表明:8～11周:第6组能量、干物质和有机物表观消化率极显著高于第2组(P0.01),第7组粗蛋白表观消化率极显著高于第1～3组(P0.01);对钙和磷的表观消化率无显著影响(P0.05)。12～15周:第4组能量表观消化率显著高于第1～2组(P0.05),第8组的干物质表观消化率显著高于第1～2组(P0.05);对钙和磷的表观消化率无显著影响(P0.05)。综合以上指标,在本试验条件下,生长期拜城油鸡日粮能量和蛋白质水平建议为:8～11周龄拜城油鸡适宜能量和蛋白质水平分别为12.12MJ/kg和17%;12～15周龄拜城油鸡适宜能量和蛋白质水平分别为11.00MJ/kg和15%。  相似文献   

9.
为了研究不同蛋白质水平日粮对深县猪生长性能、养分消化率和血液生化指标的影响,试验选择体重(15.33±1.95)kg的健康深县猪64头,随机分成4组,每组4个重复,每个重复4头猪。对照组日粮蛋白质水平为16.88%,试验Ⅰ组、试验Ⅱ组、试验Ⅲ组日粮蛋白质水平分别为15.00%、16.00%、17.00%。结果表明:试验Ⅱ组的平均日增重显著高于对照组、试验Ⅰ组(P0.05);试验Ⅱ组的料重比显著低于对照组、试验Ⅰ组(P0.05);粗蛋白与粗脂肪表观消化率各试验组与对照组之间差异不显著(P0.05),试验Ⅱ组显著高于试验Ⅰ组(P0.05);总能表观消化率试验Ⅱ组显著高于对照组、试验Ⅰ组(P0.05);试验Ⅱ组、试验Ⅲ组血液白蛋白和总蛋白含量均显著高于对照组(P0.05)。综合各项指标,在本试验条件下,生长期深县猪日粮适宜的蛋白质水平为16.00%。  相似文献   

10.
为了研究不同能量水平日粮对生长育肥期八眉三元猪生长性能、屠宰性能和肉质性状的影响,以确定其适宜的日粮能量水平试验设计3个试验组,即低能量组(G1, 11.70 MJ/kg)、中能量组(G2, 12.95 MJ/kg)和高能量组(G3, 14.23 MJ/kg),试验期为117 d。结果显示:随能量水平增加,猪的平均日增重显著上升(P0.05),料肉比显著下降(P0.05);体斜长及眼肌面积随能量水平增加而减小(P0.05),平均背膘厚增加(P0.05);能量水平的变化对脏器的生长无明显影响(P0.05),但对内脏脂肪的沉积有促进作用;各组肉色、大理石花纹评分、肌苷酸含量、pH_(45min)及熟肉率等指标均无明显差异(P0.05);肌肉的系水力随能量水平的增加而增加(P0.05)。试验结果表明,中能量水平日粮组能够获得与高能量日粮组相近的生长性能、屠宰性能及肉品质,是三元猪的最适能量选择。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
Tropical Animal Health and Production -  相似文献   

14.
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   

15.
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   

16.
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   

17.
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   

18.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

19.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

20.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

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