雏鸭胸腺生长指标的动态观测及组织学观察

通过对1～49日龄雏鸭胸腺发育的组织学观察及胸腺重量、胸腺指数和外周血T淋巴细胞α-醋酸萘酯酶阳性率（ANAE^＋）的测定，研究了雏鸭胸腺的生长及组织发育规律。结果显示，胸腺重量随日龄增长逐渐增加；胸腺指数在28日龄时达最高；1～28日龄时外周血T淋巴细胞ANAE^＋上升幅度较大；21～28日龄时胸腺小叶数量增多，并显著增大；28日龄时皮质部主要为小淋巴细胞；胸腺小体有3种形态。表明，雏鸭在1～14日龄时胸腺生长较缓慢，21～28日龄时生长十分迅速，28日龄时胸腺中大部分T淋巴细胞已发育成熟，35～49日龄时胸腺发育已趋于稳定；胸腺小体是具有高度活性的结构，与清除退变上皮有关。     

雏鸭腔上囊的生长及组织发育

通过对1～49日龄雏鸭腔上囊绝对质量和生长指数测定以及组织学观察,探讨雏鸭腔上囊生长及组织发育规律。结果:随日龄增长,腔上囊绝对质量逐渐增高;腔上囊生长指数21日龄达最高;黏膜大皱褶高、宽度、淋巴滤泡面积、皮质宽度均不断增加;小结相关上皮向腔面形成突起,并不断增高增宽。结果表明,雏鸭腔上囊1～14日龄生长较为缓慢,14～35日龄生长较快,35～49日龄发育基本趋于稳定,其中21～28日龄是雏鸭腔上囊生长发育的高峰时期,28日龄时,雏鸭腔上囊组织结构基本发育成熟。     

高铜对雏鸭胸腺影响的病理学研究

本文旨在研究高铜对雏鸭胸腺的病理学影响。选用1日龄天府肉鸭360只,随机分为6组,分别喂以对照日粮（Cu 8 mg/kg）和高铜日粮（Cu 100 mg/kg,高铜Ⅰ组;Cu 200 mg/kg,高铜Ⅱ组;Cu 400 mg/kg,高铜Ⅲ组;Cu600 mg/kg,高铜Ⅳ组;Cu 800 mg/kg,高铜Ⅴ组）6周。与对照组比较,高铜Ⅲ组、高铜Ⅳ组、高铜Ⅴ组雏鸭胸腺出现不同程度的病变,生长指数显著降低（P〈0.05或P〈0.01）,淋巴细胞的静止期增长及增殖指数明显下降（P〈0.05或P〈0.01）,淋巴细胞的调亡率显著升高（P〈0.05或P〈0.01）;高铜Ⅰ组和高铜Ⅱ组雏鸭胸腺上述指标变化不明显。结果表明,日粮铜含量高于400 mg/kg时,不同程度地抑制雏鸭胸腺的发育,导致雏鸭细胞免疫功能受损。     

鸭坦布苏病毒对雏鸭免疫系统的影响

为研究鸭坦布苏病毒(DTMUV)对雏鸭免疫系统的影响,本试验对5日龄雏鸭静脉接种DTMUV,并于接种后不同时间取雏鸭脾脏、胸腺、法氏囊进行组织病理学、抗原和凋亡检测。结果显示,DTMUV感染雏鸭的脾脏、胸腺、法氏囊均严重受损。接种DTMUV后4d,脾脏淋巴细胞减少,胸腺可见严重细胞崩解和大面积坏死区域,法氏囊滤泡轻度萎缩;接种后6d免疫器官病变最为严重,其中胸腺静脉严重栓塞,淋巴细胞变性坏死,空泡化也更加严重;接种后8d免疫器官病变均有所减轻,至16d,免疫器官结构基本恢复正常。通过免疫组织化学方法在感染雏鸭的脾脏、胸腺、法氏囊中均检测到DTMUV抗原;细胞凋亡试验显示DTMUV能够显著引起脾淋巴细胞凋亡。综上所述,DTMUV可严重损伤雏鸭免疫器官,且这种损伤常发生于感染早期,并于感染后8d出现好转。     

维生素C对笼养蛋雏鸭生长性能的影响

试验在玉米-豆粕型日粮中添加不同水平维生素C,研究其对笼养蛋鸭育雏期(1～28d)生产性能的影响。采用单因素随机分组设计的方法,选用1日龄平均体重相近(43.02±1.19)g的金定蛋雏鸭288只,随机分为6个处理组,各处理组日粮中分别添加VC0、150、300、400、800、1400mg/kg,结果表明:雏鸭日粮中适当的添加VC可提高雏鸭生产性能,VC的添加量过高过低都会影响蛋雏鸭的生产性能;在1～7日龄日粮添加VC800mg/kg,8～28日龄添加VC300～400mg/kg为适宜。     

雏鸭的培育技术

培育30日龄以内的雏鸭称为育雏，育雏阶段是鸭雏开始接触外界环境，也是生长最快的时期。培育出健壮、发育良好的雏鸭，不仅关系到雏鸭本身的生长速度和成活率，而且还关系到鸭以后的健康状况和生产性能。这是一项最重要的基础工作，也是养鸭成败的关键。l雏鸭的生物特性1．l体温调节能力差，对外界环境适应性弱刚出壳的雏鸭，绒毛稀短，各种生理机能尚未健全，尤其体温调节机能较差，对环境温度变化反应敏感，故应进行适当的保温，以提供适宜的环境温度，使之逐步适应新的环境。l，2胆小怕惊雏鸭胆小，异常动静会造成鸭群受惊恐惧，影响生…     

雏鸭感染鹅源H5N1亚型禽流感病毒后疫器官淋巴细胞增殖功能变化

以21日龄雏鸭为研究对象,应用细胞培养技术和四甲基偶氮唑盐(MTT)检测法,对鹅源H5N1亚型禽流感病毒(AIV)感染雏鸭胸腺、法氏囊和脾脏的T或/和B淋巴细胞增殖功能变化进行了较全面系统的动态检测.结果发现,鹅源H5N1亚型中强毒AIV感染雏鸭后,其上述免疫器官T或/和B淋巴细胞对ConA或LPS的增殖反应均不同程度地低于相应对照雏鸭,表明AIV感染雏鸭后,其免疫器官的细胞免疫和体液免疫功能明显受抑制,上述免疫病理改变可能是导致感染雏鸭免疫抑制的主要原因之一.     

维生素D对蛋雏鸭生长性能及免疫功能的影响

试验选取1日龄健康、体重相近的金定蛋雏鸭180只,随机分为5个处理组,每个处理6个重复,每个重复6只试鸭。采用玉米-豆粕型基础饲粮,Ⅰ组试验鸭饲喂基础饲粮,Ⅱ～Ⅴ组分别饲喂在基础饲粮中添加110、220、550、1000 IU/kg维生素D的试验饲粮,试验期4周。旨在研究不同维生素D添加水平对1～28日龄蛋雏鸭生长性能及免疫功能的影响,以探讨维生素D的适宜添加量。结果表明,添加550 IU/kg维生素D能显著提高蛋雏鸭平均日增重、降低料重比(P<0.05),显著提高IgA、IgG、T3、T4含量(P<0.05),并显著降低Cort含量(P<0.05)。由此可见,在玉米-豆粕型基础饲粮中添加适量的维生素D可提高蛋雏鸭生长性能及免疫功能。通过二次回归模型分析,估测蛋雏鸭日粮中维生素D的适宜添加量为523.1～560.6 IU/kg。     

北方蛋鸭管理要点

1雏鸭的培育 1．1温度1日龄雏鸭，温度36℃；2-7日龄，温度36—28℃；8-14日龄，温度28～21℃；15～30日龄，温度21～16℃。     

怎样育好肉用雏鸭

怎样育好肉用雏鸭四川省江津市农牧渔业局畜牧站凌承建肉鸭，一般是指６０～７０日龄可供上市的菜鸭。其雏鸭生长特别迅速，对饲养管理条件要求高，稍一不慎易引起生长不良，甚至成活率不高等，这将对肥育期的增重和经济收益造成很大影响。现将我市成功的雏鸭饲养管理经验...     

SPF雏鸡感染REV后免疫器官免疫功能的动态变化

试验通过对 1日龄 SPF雏鸡人工感染网状内皮组织增殖病病毒 ( REV) ,观察了免疫器官胸腺、法氏囊和脾脏 T、B淋巴细胞增殖反应的动态变化。结果表明 ,雏鸡感染 REV后胸腺 T淋巴细胞的增殖反应于7、2 1、4 2和 4 9日龄明显降低 ( P<0 .0 5) ,于感染后 1 4、2 8和 3 5日龄极显著减弱 ( P<0 .0 1 ) ;脾脏 T淋巴细胞的增殖反应分别于感染后 1 4～ 2 8d和 3 5～ 4 9d较对照组雏鸡明显或极明显降低 ( P<0 .0 5,P<0 .0 1 )。法氏囊和脾脏 B淋巴细胞增殖反应分别在感染后 7～ 4 9d和 1 4～ 4 9d极显著减弱 ( P<0 .0 1 )。免疫器官胸腺重量和脾脏重量与体重比值及体重分别于感染后 7～ 4 9、7～ 3 5、7～ 4 9d明显降低 ( P<0 .0 5,P<0 .0 1 )。说明SPF雏鸡感染 REV后 ,免疫器官 (胸腺、法氏囊和脾脏 )淋巴细胞发生变性坏死、数量减少和功能降低 ,机体的细胞免疫和体液免疫功能均发生明显降低或抑制     

Early clinical and morphologic alterations in the pathogenesis of furazolidone-induced toxicosis in ducklings

Clinical and pathologic alterations during the development of furazolidone-induced toxicosis were investigated in a group of 35 newly hatched male Pekin ducklings fed a ration containing 700 mg of furazolidone/kg of feed for 27 days. A control group (n = 25) was fed the same ration without added furazolidone. Every 3 days, ducklings were weighted and palpated for ascites and 3 were chosen at random for euthanasia to determine the severity of lesions and to obtain hearts for gross measurements and ultrastructural study. Clinical alterations in treated ducklings consisted of decreased feed consumption with lower weight gain and nervous signs. Gross pathologic alterations included cardiomegaly with dilatation of all chambers and thinning of the myocardium, pericardial effusion, pulmonary edema and congestion, ascites, and testicular enlargement. Gross lesions were not observed before day 8. The earliest lesion (day 9) was cardiac chamber dilatation, with the left ventricle and left atrium most commonly and most severely dilated. Hearts from ducklings euthanatized on days 6, 12, 18, 24, and 27 were examined ultrastructurally. Myofibrillar lysis was first observed on day 12 in 1 duckling (of 3) and in at least 1 duckling from subsequent euthanasia periods. Myofibrillar lysis did not appear to be uniform among the cardiac chambers.     

伊维菌素在樱桃谷鸭体内证治药物动力学研究

本试验利用证治药动学的方法,研究了伊维菌素在樱桃谷鸭体内药物动力学变化,旨在验证黄曲霉毒素B1中毒后中药制剂＂保肝护肾脱霉素＂的药理作用。将117只健康1日龄的樱桃谷鸭随机平均分成3组,Ⅰ组（正常组）饲喂健康饲料,饲喂28d。Ⅱ组（病理组）前7d饲喂健康饲料,8-21d饲喂含有黄曲霉毒素B1的霉变饲料,22-28d饲喂健康饲料。Ⅲ组（中药反证组）前7d饲喂健康饲料,8-22d饲喂含黄曲霉毒素B1的霉变饲料,22-28d饲喂健康饲料,与此同时对每只鸭子每天口服保肝护肾脱毒素液5mL,口服7d,第29天,给上述3组试验鸭口服伊维菌素溶液,分别在给药前（0h）和给药后时间点从鸭的颈静脉采血,采用高效液相荧光色谱法进行检测。结果显示,黄曲霉毒素B1造成的病理损伤,能改变伊维菌素内服在鸭体内的药动学特征,表现出吸收减慢,吸收程度减弱,消除速率减弱的药动学特征。经过中药制剂＂保肝护肾脱霉素＂反证后,伊维菌素的吸收及消除速度都有不同程度地增加。试验结果表明,从药动学角度说明中药制剂＂保肝护肾脱霉素＂对黄曲霉毒素B1造成的病理损伤有修复作用。     

高铜对雏鸭胸腺形态的影响研究

为探索高铜对雏鸭胸腺形态的影响,选用1日龄天府肉鸭360只,随机分为6组,分别喂以对照日粮（Cu8mg／kg）和高铜日粮（Cu100mg／kg,高铜Ⅰ组;Cu200mg／kg,高铜Ⅱ组;Cu400mg／kg,高铜Ⅲ组;Cu600mg／kg,高铜Ⅳ组;Cu800mg／kg,高铜V组）6周。结果表明：与对照组比较,高铜Ⅲ组...     

鸡传染性贫血病毒感染胸腺集落刺激因子对骨髓粒单系祖细胞增殖功能的影响

本文研究了鸡传染性贫血病毒感染鸡胸腺ＣＳＦ对正常鸡骨髓粒单系祖细胞（ＣＦＵ—ＧＭ）增殖功能的影响．结果表明，雏鸡感染ＣＩＡＶ后１４天胸腺ＣＳＦ对ＣＦＵ—ＧＭ刺激作用与对照鸡比较未见明显异常．感染后２１天，刺激作用较对照鸡明显增强（ｐ＜０．０１）；感染２８天以后，其刺激作用达正常成水平．结果证明，ＣＩＡＶ感染引起的骨髓造血机能障碍与胸腺ＣＳＦ活性无关．     

一株鹅源鸭疫里氏杆菌与鸭源分离株的致病性比较

从某发病的鹅场分离到 1株血清 1型的鸭疫里氏杆菌 ,与同地区分离到的 1株血清 1型鸭源鸭疫里氏杆菌分离株 ,分别经腿肌注射的途径攻雏鸭和雏鹅。结果表明鸭源分离株对雏鸭和雏鹅的致病性比鹅源分离株强 ,而且这 2株鸭疫里氏杆菌对雏鹅的致病性比雏鸭强     

Chicken anemia virus in broilers: dynamics of the infection in two commercial broiler flocks

Chicken anemia virus (CAV) can cause a disease syndrome characterized by severe anemia, bone marrow atrophy, and severe immunosuppression in young chicks. Maternal antibodies prevent these clinical signs but do not prevent infection, transmission of the virus, or immunosuppression. The clinical disease is rare today because of the widespread practice of vaccinating breeders, but the subclinical form of the disease is ubiquitous. The dynamics of CAV infection, CAV antibody responses, relative lymphoid organ weights, and associated lesions were studied in two broiler flocks from a commercial producer. Both groups had detectable CAV antibodies at hatch, which waned over the first 3 wk of life. Both groups had detectable CAV DNA in both thymi and bursae over the same period. At 35 days of age, virus was detectable by polymerase chain reaction in 16 of 20 chickens, and 7 of 20 had detectable antibodies. By 42 days of age, virus was detectable in 18 of 20 chickens, and 18 of 20 had antibodies to CAV. We observed a decrease in relative thymic weights beginning at 35 days of age, coincidental withthe detection of CAV in the thymus. Bursal sizes began to decrease at 28 days of age, coincidental with a rise in antibody titers to infectious bursal disease virus. In this study, we demonstrated that under typical field conditions CAV infections in broilers have unique dynamics unlike those reported in egg laying strains of chickens managed under specific-pathogen-free conditions.     

Comparison of the persistent efficacy of the injectable and pour-on formulations of doramectin against artificially-induced infection with Dictyocaulus viviparus in cattle

The persistent efficacy of the injectable and topical formulations of doramectin was compared against experimental challenges with infective larvae of Dictyocaulus viviparus in two separate studies. Four groups of 10 randomly-assigned calves, negative for lungworm larvae by the Baermann technique, were used in each study. Calves were treated subcutaneously in the midline of the neck or poured down the midline of the back with saline (1 ml/50 kg. injection: 1 ml/10 kg. pour-on) on Day 0 or doramectin (200 microg/kg = 1 ml/50 kg. injection: 500 microg/kg = 1 ml/10 kg. pour-on) on Day 0, 7, or 14. Two additional calves from the same pool of animals were randomly assigned as larval-viability monitors and received no treatment. Calves were inoculated daily with a gavage of approximately 100 larvae of D. viviparus from days 35 to 49 for the injectable study and days 28 to 42 for the pour-on study. The two larval viability monitor calves received approximately 3000 infective larvae in the same manner on Day 49 or 42 for the injectable and pour-on studies, respectively. Equal numbers of calves from each treatment group as well as the larval viability monitor calves were necropsied on days 14 and 15 after the last lungworm inoculation to enumerate the worm burden. The worms recovered were quantified and identified. For each study, geometric mean worm recoveries for each treatment group were back transformed from the natural log-transformed data (worm count +1) and were used to estimate percentage reduction. Doramectin injectable solution was 100.0% efficacious against lungworms for up to 49 days and the pour-on formulation was 100.0%, 93.1% and 81.5% effective in reducing lungworm infection resulting from challenge infection for up to 28, 35, and 42 days post-treatment, respectively.     

中药添加剂对海南文昌鸡免疫功能的影响

将180只雌性文昌鸡随机分为5组,每组3个重复,每重复12只。第1组为空白对照组,饲喂基础日粮;第2组为抗生素对照组,在基础日粮中按600 mg/kg添加金霉素;第3、4、5组分别在基础日粮中添加0.1%、0.2%和0.3%的中药添加剂。试验共进行6 w,每周称重,计量采食量。分别于28、35d时接种禽流感疫苗。第49 d、56 d时每组随机取8只鸡,翅静脉采血制备血清,血凝抑制试验检测禽流感疫苗抗体滴度。56 d时将各组已采血8只鸡屠宰后打开腹腔,取胸腺、法氏囊称重并计算免疫器官指数。结果表明,0.2%中药添加剂能显著提高文昌鸡日增重(P<0.05),提高法氏囊指数(P<0.05);0.2%和0.3%中药添加剂均能提高禽流感疫苗抗体滴度(P<0.05)。结果提示,本中药添加剂能够提高海南文昌鸡生产性能和免疫功能。