【作者】 王浓章；

【导师】 袁慧； 卓琦；

【作者基本信息】 湖南农业大学 ， 养殖， 2003， 硕士

【摘要】 本研究以四点麻肉鸭作为试验对象，分别研究硒的促生长作用和在其中毒时的病理变化。 选150只14日龄健康肉鸭随机分为5组，每组设3个重复，其中Ⅰ_（1）～Ⅳ_（1）组为试验组，分别口服0.025mg／mL（含纯硒0.011 mg／mL）、0.075mg／mL、0.25 mg／mL、0.75mg／mL浓度的亚硒酸钠水溶液1mL／只／d，Ⅴ_（1）组为对照组，以观察硒对肉鸭的促生长作用；另选50只相同的肉鸭随机分为5个组，Ⅰ_（2）～Ⅳ_（2）组为中毒试验组，分别口服1.0mg／mL、3.0 mg／mL、5.0 mg／mL、10.0mg／mL亚硒酸钠水溶液1.0mL／只／d，Ⅴ_（2）组为对照组，口服生理盐水1.0mL／只／d，以研究硒中毒时的病理变化。研究结果表明： 1．硒对肉鸭具有促生长作用。在为期28d的生长试验中，定期观察与测定硒对肉鸭的生长作用。结果表明在15～28日龄、29～42日龄和15～42同龄阶段，与对照组相比，Ⅰ_（1）组日增重分别提高4.4％、5.9％、5.1％，Ⅱ_（1）组分别提高19.5％，10.5％，15.2％，且均差异极显著（P＜0.01）；而Ⅲ_（1）组在整个试验中与对照组相比差异不显著（P＞0.05）；Ⅳ_（1）组与对照组相比日增重则分别下降11.0％、14.4％和13.0％，且差异极显著（P＜0.01）。整个试验过程中Ⅰ_（1）、Ⅲ_（1）、Ⅳ_（1）组的成活率为100％，Ⅱ_（1）组成活率为96.7％。试验结果表明：每只每天口服1mL浓度为0.025 mg／mL和0.075 mg／mL的亚硒酸钠对肉鸭具有显著促生长作用，其中0.075mg／mL的效果较好；添加0.25mg／mL的亚硒酸钠对肉鸭无促生长作用；0.75 mg／mL的亚硒酸钠可抑制肉鸭的生长，并出现轻微硒中毒症状。平均采食量：15～28日龄：与对照组相比，Ⅰ_（1）、Ⅲ_（1）组差异不显著（P＞0.05）；Ⅱ_（1）组提高7.9％，且差异极显著（P＜0.01），Ⅳ_（1）组采食减少5.1％，且差异极显著（P＜0.01）；29～42日龄：Ⅰ_（1）、Ⅲ_（1）组差异不显著（P＞0.05）；Ⅱ_（1）组提高4.4％，且差异显著（P＜0.05），Ⅳ_（1）组采食减少5.7％，且差异显著（P＜0.05）。饲料转化效率：与对照组比较，试验期Ⅰ_（1）组提高5.2％，且差异显著（P＜0.05）；Ⅱ_（1）组提高7.3％，且差异极显著（P＜0.01）；Ⅲ_（1）差异不显著（P＞0.05）；Ⅳ_（1）减少8.6%，且差异极显著（尸<0.01）。 2.肉鸭硒中毒时的病理学变化是:随着服硒量的增加，中毒症状逐渐加剧。12)、HZ、Hl、2。组肉鸭于服硒ld后出现中毒症状，IV。2。组于服硒后lh便出现明显的中毒症状，并于9d内全部死亡。试验结束时，I、2。组死亡率为O，H。:。组死亡率为20%，111、:。组死亡率为50%，W、2，组为100%。其主要临床症状为:IV、2)组肉鸭表现为呼吸急促，运动失调，头肿大，离群闭目呆立，食欲废绝，口、鼻流出砖红色液体，排绿色或白色稀粪;H、2)、111。2。组肉鸭表现出精神沉郁、食欲下降，呼吸困难，消瘦，排绿色或白色稀粪;I、:。组中毒症状轻微，主要表现为头轻度肿大、眼结膜潮红，并呈一过性，食欲下降，生长性能降低。其剖检病理变化为:W。2。组肝脏肿大、坏死并伴有出血斑、淤血，肺水（气）肿和淤血，’肾有弥漫性出血点，脾白髓淋巴细胞萎缩变性、数量减少，网状细胞增生、肿大;I。小11。2)、111（2）组消化道出血严重，肝、心、肾出血和坏死。光学显微镜下观察:第4组肝细胞肿胀并出现局部核溶解，’肾小球肿大并颗粒变性，且毛细血管充血，肺泡内有红细胞;I（2）、H（2、、m。2）组还表现为肝、心、肾、脾等实质细胞变性、坏死及组织内充血、出血为特征。此外，肝、胃、心肌、肌肉、羽毛、血液硒含量测定结果显示:随着服硒量的增加，各组织器官中硒含量呈上升趋势，其中以IV、2。组最高，肝脏硒含量高于其他组织。 结论:每只每天口服lmL浓度为0.025⁰.O75mg/mL的亚硒酸钠对肉鸭具有促生长作用，月₀.O75mg/mL亚硒酸钠在提高采食量、降低料肉比和促生长效果较佳。每只每天口服lmL浓度为10.Omg/mL的亚硒酸钠能使肉鸭发生急性中毒，其中毒症状为呼吸急促，运动失调，头肿大，离群闭目呆立，食欲废绝，口、鼻流出砖红色液体，排绿色或白色稀粪;主要病理变化是:肝脏脂肪变性、出血、肝细胞肿胀，局部出现核溶解;肾颗粒变性、出血;心肌水肿、出血、颗粒变性;肺泡出血;脾白髓淋巴细胞萎缩变性、数量减少，网状细胞增生、肿大。更多还原

【Abstract】 We use meat-duck as our experiment object to study the promoting growth effects of selenium and its pathologic changes.One hundred and fifty meat-ducks which are fourteen days old are divided into five groups at random to investigate the promoting growth effects of selenium, and each group has three repeats. The I (1)-IV (1) group are tested groups, and are feeded 0.025 mg / mL (containing pure selenium 0.011 mg / mL), 0.075mg / mL, 0.25 mg / mL, 0.75mg/mL of Na2SeO3 solution respectively. Each meat-duck ingested 1mL per day. The V CD group is control group. Additionally, the same fifty meat-ducks are divided into five groups optionally to observ pathologic changes of selenium. The I (2)~IV(2) group are toxic groups and are feeded 1.0mg/mL, 3.0 mg / mL,5.0 mg / mL.. 10.0mg / mL of Na2SeO3 solution respectively, and the V(2) group is control group and are feeded physiological saline. The results show that:1. The selenium can apparently promote growth of meat-duck. During 28 days of the experiment, we observ and take measure of growth effects of selenium. The results indicate: during the phases of 15-28 days and 29-42 days and 15~42 days, ADG (average daily gain) of I (1) group is respectively increased by 4.4 %, 5.9%, 5.1% as compared to the control group. In the same manner, ADG of II (n is respectively increased by 19.5 % , 10.5 % , 15.2 % and their difference is notable (P < 0.01) . However, the difference of the third group and the control group is not obvious (P > 0.05) and ADG of IV(1) is descended by 11.0 %, 14.4 % and 13.0 % contrasting the control group and the difference between two is notable (P<0.01) .The survival percents of I (1), III(1) IV (1) groups are 100%, the survival percent of II <p is 96.7%. The experiment results indicate that: adding 0.025 mg / mL and 0.075 mg / mL of Na2SeO3 solution can promote growth of meat-ducks, and the effect of 0.2 mg / mL is better. Adding 0.25 mg / mL of Na2SeO3 solution has no effect on growth of meat-ducks. On the contrary, 0.75 mg / mL of Na2SeO3 solution can restrain growth of ducksand cause slightly poinsoning. API (Average Feed Daily Intake) : at 15~28-day-old, contrasting with the control group, the differences of AFI between I(1), III(1) and the control group are not obvious (P > 0.05) . The AFI of II (1) is boosted by 7.9% and the difference of two is very notable (P < 0.01) . The fourth is reduced by 5.1% and their difference is obvious (P < 0.01) . At 29- 42-day-old, the AFI of I()1, III (1) is similar with the control group (P > 0.05) ; the AFI of II(1) is promoted by 4.4%, and P < 0.05; the AFI of IV(1) is reduced by 5.7% and P < 0.05. FCE(Feed Conversion Efficiency): contrasting with the control group, the FCE of I (1) is increase by 5.2% and P < 0.05; the FCE of II(1) is increase by 7.3% and P < 0.01; the difference of FCE between III(1) and control group is inconspicuous; the FCE of IV(1) is reduced by 8.6% and P < 0.01.2. The pathological changes of selenium are: the symptom of poisoning is exacerbated along with the increase of selenium intake. The I(2), II(2), III(2) group of ducks appear the symptom of poisoning after the selenium intake a day. And IV <2>group are indicative of obvious symptom of poisoning after the selenium intake an hour and die in nine days. When the experiment is finished, the death rate of I(2), II(2), III(2), IV(2) are respectively 0, 20%, 50%, 100%. The major criteria are: the ducks of IV(2) group appear shortnessofbreath, locomotor ataxia, head tumefaction, parting from flock, shutting eyes, abandon of appetite, brick red fluid from mouth or nose, and excreting green or white loose stool; the II (2), III (2) group of ducks all appear psyche depressed, inappetence, respiratory difficulty, macilency, and excreting green or white loose stool; the symptom of poisoning of I (2) is mild than others, such as lowgrade tumefaction of head and moisst of conjunctiva, which is temporary, inappetence, decline of capability of growing. And dissected changes are: the IV(2) group’s liver is tumefied and gangrened along with更多还原