饲用左旋咪唑对肉仔鸡免疫功能调节作用的研究

试验用刚出壳的ＡＡ 商品代肉用公雏 ３７８ 只,随机分成 ３ 组,每组 １２６ 只分成 ９ 个重复。以玉米 豆粕型日粮为基础日粮,喂给三种日粮即无药组（１ 组或对照组）、添加左咪唑（ｌｅｖａｍ ｉｓｏｌｅ,ＬＥＶ）１０（２ 组）和３０ｍ ｇ／ｋｇ 饲料（３ 组）。检测肉仔鸡每周体重、耗料量,４ 和 ６ 周龄胸腺、脾脏和法氏囊重量及其免疫器官指数,以及外周血中 Ｔ 或Ｂ淋巴细胞对不同丝裂原的反应性。结果表明：（１）在肉仔鸡日粮中添加 ３０ｍ ｇ／ｋｇ 的 ＬＥＶ 可使胸腺、脾脏和法氏囊的重量及其指数明显增加（Ｐ＜ ０．０５）;添加１０ｍ ｇ／ｋｇ 的ＬＥＶ 对免疫器官重量也有一定的促进作用,但差异并不显著（Ｐ＞ ０．０５）。试验证明ＬＥＶ 对免疫器官的生长发育有明显的促进作用。（２）４２ 日龄时３ 组肉仔鸡外周血Ｔ 淋巴细胞对丝裂原 Ｃｏｎ Ａ刺激的反应性以及 Ｂ 淋巴细胞对丝裂原 ＬＰＳ刺激的反应性明显高于对照组（Ｐ＜ ０．０５）,说明添加３０ｍ ｇ／ｋｇＬＥＶ 会增强细胞免疫和体液免疫功能。（３）随着日粮中 ＬＥＶ 添加量的增加,肉仔鸡的增重速率和饲料转化率都有相应改善,添加 ３０ｍ ｇ／ｋｇＬＥＶ 对二者的改善程度分别为 ７．３３％ 和 ５．１５％ ,?     

ORIGINAL ARTICLE: Lutein exposure,in ovo or in the diet,reduces parameters of inflammation in the liver and spleen laying‐type chicks (Gallus gallus domesticus)

These trials examined whether the demonstrated effects of embryonic and dietary carotenoid exposure on the inflammatory immune response in fast growing chickens also occur in slow growing chickens. The systemic and local inflammatory responses of chicks were examined in two experiments with two in ovo lutein levels (C+, carotenoid replete; or C?, carotenoid‐deplete), two dietary lutein levels (0 or 40 mg lutein/kg diet), and two inflammatory challenges [no exposure or lipopolysaccharide (LPS)‐vaccinated]. At 24 h after LPS vaccination, spleen weight was not affected by diet or in ovo lutein, but liver weight increased from C+ eggs (p < 0.01), and in LPS‐vaccinated chicks fed 0 mg lutein (p < 0.05), but not in chicks fed 40 mg lutein. Plasma carotenoids and liver carotenoids were reduced post‐LPS (p < 0.05). Splenic IL‐6 mRNA abundance was the greatest post‐LPS in C? chicks fed 40 mg lutein vs. C+ chicks fed 40 mg lutein (p < 0.05). Hepatic IL‐6, iNOS and TGFβ and splenic iNOS and TGFβ were not affected by in ovo or dietary lutein. The systemic and local inflammatory results are similar to those observed in fast growing chickens, and support that lutein‐depleted birds have greater inflammatory responses.     

Effect of dietary beta-carotene on the early embryonic development and uterine fluid composition of gilts

The role of beta-carotene in reproduction was investigated in gilts assigned to three dietary supplementations: VA (4000 IU vitamin A); VA + VA (4000 IU + 8300 IU); VA + BC (4000 IU + 100 mg beta-carotene) per kg diet for 14 weeks. Gilts were slaughtered at day 12 of gestation. In the VA + BC group, number of corpora lutea was lowest, but the number of embryos was greatest, resulting in a non-significant decreased prenatal mortality (p<0.07). The proportion of less developed spherical and tubular embryos compared with filamentous was greatest in the VA + BC group (p<0.01). No differences were observed for vitamin A and retinal binding protein (RBP) in the uterine fluid. When animals were grouped according to the development of blastocysts, vitamin A and RBP levels were higher in the VA + BC group with only filamentous embryos (p<0.01). This indicates that the supplementation of beta-carotene to gilts might affect embryonic losses possibly because of slower alterations in the uterine environment, resulting in a higher and less variable number of embryos, despite an apparently more heterogeneous development.     

Effects of supplemental ascorbic acid on performance, organ weight and plasma cholesterol concentration in broilers treated with propylthiouracil

1. Four experiments were conducted to determine if dietary ascorbic acid (AA) affects body weight gain, food intake, organ weights, plasma cholesterol concentration, and ascorbic acid concentration in the plasma and liver of growing male broilers treated with an antithyroidal agent, propylthiouracil (PTU). 2. In the first experiment, 15 mg AA was administered daily into the crop of chicks fed on a diet supplemented with or without PTU (500 mg/kg). Administration of AA reduced plasma cholesterol concentrations in the PTU-treated chicks. 3. In the other three experiments, chicks were given the basal diet or an AA-containing (3 g/kg) diet supplemented with or without PTU (250 mg or 500 mg/kg). Feeding AA partly prevented the decreases in body weight gain, gain:food ratio and weights of the bursa of Fabricius and thymus in chicks fed on the 250 mg/kg PTU diet, and also prevented the increase in plasma cholesterol concentrations in chicks fed on the PTU diet. 4. These results suggest that AA improves the performance of chicks with experimentally induced hypothyroidism.     

葡多酚对肉鸡生产性能和免疫机能的影响

试验旨在探讨日粮中葡多酚对肉鸡生产性能和免疫机能的影响。选用1日龄健康爱拔益加(AA)肉仔鸡公雏鸡240只,随机分配到对照组及试验Ⅰ、Ⅱ、Ⅲ组4个处理组中,空白对照组饲喂基础日粮(不含葡多酚),试验Ⅰ、Ⅱ、Ⅲ组分别在基础日粮中添加葡多酚7.5、15、22.5 mg/kg,试验期42 d。结果表明,在0~3周龄,试验Ⅲ组采食量最高,生长速度较快;在3~6和0~6周龄,试验Ⅰ组日增重和饲料效率最佳,而试验Ⅱ组略低于对照组。葡多酚对肉仔鸡的免疫器官发育无显著影响,7.5 mg/kg葡多酚有增加肉仔鸡外周血中CD3⁺、CD8⁺、αβ和γδ T细胞数量的潜力。因此,肉仔鸡日粮中添加适量葡多酚可促进生长,调节免疫机能。     

Zinc, copper and iron utilisation by chicks fed various concentrations of zinc

1. Zinc, iron and copper interactions were examined in chicks (New Hampshire X Single Comb White Leghorn) grown individually in stainless steel cages and fed on purified diets with three concentrations of zinc: control (37 mg Zn/kg), moderate (100 mg Zn/kg) and excess (2000 mg Zn/kg) in three studies. 2. Chicks given either moderate or excess zinc excreted more than twice as much 65Zn from a test diet as those fed on the control diet. Thus chicks given the moderate amount of zinc had concentrations of zinc in tissues similar to those of controls but chicks given excess zinc accumulated zinc in their tissues. 3. The specific activity of 65Zn in the tissues, especially in the bursa of Fabricius, of chicks given excess zinc was not reduced as much as would be predicted. Thus, ingestion of excess zinc appeared to reduce tissue turnover of 65Zn, especially in the bursa. However, humoral immune responses, as measured by antibody titres to sheep red blood cells, were not affected. 4. Chicks given excess zinc or pair-fed on the control diet retained less 59Fe from a test diet than chicks given control or moderate concentrations of zinc ad libitum. The iron concentrations in tibiae of chicks given excess zinc were depressed.     

实验性肉雏维生素A缺乏对免疫器官影响的形态学研究

150只一日龄罗曼混合肉雏被随机分为四组,分别饲喂含维生素A为0、750、3000和6000IU的日粮。在20、30和45日龄时,每组剖检5只鸡,分离并称重免疫器官后,取材,石蜡包埋,切片,镜检。结果表明:维生素A缺乏和不足使免疫器官组织萎缩,间质结缔组织增生,上皮角化,腔上囊和胸腺的相对重量明显减少(P<0.01)。对免疫器官的损害程度是腔上囊>胸腺>脾脏>盲肠扁桃体。提高日粮中维生素A含量有提高肉雏增重、饲料报酬和免疫器官相对重量之趋势。     

茶多酚和L-茶氨酸对热应激下蛋用仔公鸡生长性能及抗氧化能力的影响

本试验采用单因子试验设计研究茶多酚与L-茶氨酸在热应激下对蛋用仔公鸡生长性能及抗氧化能力的影响。选用1日龄蛋用仔公鸡180只,随机分为6组,每组3个重复,每个重复10只鸡。试验1组为对照组,饲喂基础日粮;试验2~6组分别在基础日粮中添加400 mg/kg茶多酚、200 mg/kg L-茶氨酸、200 mg/kg茶多酚+200 mg/kg L-茶氨酸、400 mg/kg茶多酚+200 mg/kg L-茶氨酸、600 mg/kg茶多酚+200 mg/kg L-茶氨酸,试验期28 d。结果表明,茶多酚可有效降低热应激下蛋用仔公鸡的料重比（P<0.05）,L-茶氨酸单独添加或与茶多酚同时添加对生长性能影响均不显著（P>0.05）;茶多酚可显著降低各组织器官的丙二醛（MDA）含量 （P<0.05）,显著提高各组织器官的谷胱甘肽过氧化物酶（GSH-Px）与过氧化氢酶（CAT）活性（P<0.05）;L-茶氨酸能显著提高各组织器官的CAT活性（P<0.05）,不同程度降低各组织器官的MDA含量;茶多酚与L-茶氨酸同时添加时,抗氧化能力与茶多酚的添加量不呈正比;400 mg/kg茶多酚+200 mg/kg L-茶氨酸组肝脏样总超氧化物歧化酶（T-SOD）与GSH-Px活性均显著降低（P<0.05）,MDA含量显著提高（P<0.05）。在热应激条件下,200 mg/kg茶多酚+200 mg/kg L-茶氨酸同时添加时,抗氧化效果较理想。     

Effects of dietary supplements of selenium, vitamin E or combinations of the two on antibody responses of broilers

1. The effects of selenium and vitamin E supplementation on some immune parameters were investigated in broilers. 2. Broiler chicks were fed on maize-soybean diets with different concentrations of vitamin E (0-200 mg/kg) and selenium (0-0.2 mg/kg diet) either alone or in combinations from 1 to 42 d of age. 3. Chicks were immunised against Newcastle disease virus (NDV) vaccine at 21 d of age and haemagglutination inhibition (HI) titres were determined after 10 d. 4. Chicks receiving supplements of 200 mg vitamin E/kg and 0.2 mg selenium/kg produced significantly higher HI antibody titres. This was associated with an increased serum concentration of total immunoglobulins and circulatory immune complexes. 5. The chicks given 200 mg vitamin E/kg and 0.2 mg selenium/kg had significantly heavier spleen and bursa. 6. These results suggested that vitamin E and selenium have synergistic effects on immune responses.     

葡甘露聚糖对饲喂黄曲霉毒素B1日粮肉仔鸡生长性能、血清指标及器官指数的影响

本文通过测定肉仔鸡生长性能、血清指标及器官指数,探讨葡甘露聚糖对黄曲霉毒素B1(AFB1)的吸附作用。选用180只体重接近的8日龄肉仔鸡随机分成3组,分别为基础日粮组、基础日粮 0.1mg/kgAFB1组、基础日粮 0.1mg/kgAFB1 0.1%葡甘露聚糖组,试验期21d。试验结果表明:(1)基础日粮中加入0.1mg/kgAFB1,肉仔鸡的体重、日增重、日采食量显著下降,料重比升高。血清中总蛋白、白蛋白含量显著下降,谷草转氨酶、谷丙转氨酶活性显著升高。肝脏、肾脏、心脏和脾脏肿胀,胸腺、法氏囊萎缩;(2)0.1mg/kgAFB1日粮中加入0.1%葡甘露聚糖,明显改善肉仔鸡的生长性能,以上相关指标基本恢复到正常水平。由此可知,葡甘露聚糖减轻或基本消除了AFB对肉仔鸡生长性能、组织器官的不良影响。     

Ameliorative effects of dietary clinoptilolite on pathological changes in broiler chickens during aflatoxicosis

The amelioration of aflatoxicosis in broiler chickens was examined by feeding two concentrations of natural zeolite (clinoptilolite). Clinoptilolite (ClI), incorporated into the diet at 1.5 and 2.5 per cent, was evaluated for the ability to reduce the deleterious effects of 2.5 mg total aflatoxin (AF) kg(-1)diet on growing broiler chicks from 1 to 21 days of age. A total of 360 broiler chicks were divided into six treatment groups [Control, AF, CLI (1.5 per cent), AF plus CLI (1.5 per cent), CLI (2.5 per cent), and AF plus CLI (2.5 per cent)] each consisting of 60 chicks. Compared to controls, the AF consuming chicks showed increases in the relative weights of liver and kidney; and gross-histopathologic hepatic lesions such as paleness, friability, diffuse hydropic degeneration and/or fatty change, bile-duct hyperplasia and periportal fibrosis. Glumerular hypertrophy, increases in the number of mesengial cells and hydropic degeneration of tubuler epithelium in kidneys of chicks fed diet AF alone were also observed. Atrophy and lymphoid depletion were seen in the thymuses and bursa of Fabricius from the chicks fed AF alone. The additions of CLI (1.5 and 2.5 per cent) to the AF -containing diet moderately (significantly in some cases) decreased the number of affected broilers and/or the severity of lesions. The addition of CLI to the AF-free diet did not produce any significant changes compared with the controls. These results suggest that CLI was effective for the protection of AF-toxication in broilers and it could contribute to a solution of the AF problem in poultry production.     

Effect of vitamin A and/or E on plasma enzymatic antioxidant systems and total antioxidant capacity of broiler chickens challenged with carbon tetrachloride

This study was conducted to investigate the effect of vitamin A and E supplementation on the antioxidant defences of broiler chickens against carbon tetrachloride (CCl(4))-induced oxidative stress at 4 weeks of age. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities as well as total antioxidant (TAO) level were analysed before and after CCl(4) challenge. Day-old Lohman broiler chickens (n = 144) were randomly assigned to six factorially arranged dietary treatments consisting of vitamin A [1.35 (control) or +20 mg/kg] and vitamin E [20 (control), +40 or +60 mg/kg]. The background of vitamins A and E in the basal diet was 4500 IU (1.35 mg) and 30 IU (20 mg) respectively. At 4 weeks of age, eight chickens from each treatment were bled before interperitoneal injection with 1 ml of CCl(4) (mixed with olive oil in a ratio of 1:1) and bled again 24 h post-injection. Vitamin E supplementation decreased (p < 0.05) the activity of both SOD and GPX and showed a tendency (p = 0.07) for TAO reduction. CCl(4) attenuated SOD and GPX activities as well as TAO level. The decrease was profound (p < 0.05) in chickens fed the basal diet as well as those fed basal diet supplemented with 20 mg vitamin A. TAO levels behaved similarly when chickens were challenged with CCl(4). After CCl(4) injection, SOD activities of all experimental groups were equivalent. The presence of vitamin A decreased (p < 0.05) plasma GPX activity in chickens fed the basal diet supplemented with 40 mg/kg of vitamin E. Results of this experiment suggested that vitamin E supplementation elevated antioxidant enzyme activities while vitamin A supplementation attenuated this effect. Vitamin E supplementation improved the total reducing power by maintaining comparable levels of TAO upon CCl(4) challenge. Further experiments need to be carried out to investigate the role of vitamin A in oxidative stress and to evaluate the lipid peroxidation products.     

益生素对乌骨鸡免疫机能和物质代谢的影响

选取1日龄健康活泼乌骨鸡450只,随机分成3组(A,B,C),每组设3个重复,每个重复50只。A组为对照组,喂基础日粮,B、C组为试验组,B组在基础日粮基础上添加125mg/kg黄霉素,C组在基础日粮基础上添加0.7%的益生素,以研究益生素对乌骨鸡免疫机能和物质代谢的影响。结果表明:C组与B组相比,免疫器官(法氏囊、脾脏、胸腺)的相对重和新城疫血凝抑制试验抗体效价差异极显著(P<0.01),与A组相比差异显著(P<0.05)。C组的表观氮存留率、干物质消化率和有机物消化率与A组相比分别提高了10%(P<0.05),8.3%(P<0.05),11%(P<0.05),但C、B组间差异不显著(P>0.05)。这说明,在提高乌骨鸡免疫机能方面,益生素比抗生素具有更大的优势;而在提高物质代谢方面,益生素可以与抗生素相匹敌。     

大蒜素对肉鸡免疫器官发育及T淋巴细胞阳性率的影响

将240只7日龄AA肉鸡随机分成4组,各组在玉米-豆粕型基础日粮中,分别添加0(对照)、12.5、37.5、62.5mg/kg的大蒜素,饲养期42天。结果表明:各组间肉鸡的免疫器官相对重量相比,添加大蒜素三个处理组35日龄法氏囊均比对照组(0mg/kg)显著增加(p<0.05),其中,37.5、62.5mg/kg两处理组21日龄胸腺和62.5mg/kg处理组35日龄脾脏均比对照组显著增加(p<0.05);T淋巴细胞阳性率结果显示,37.5mg/kg、62.5mg/kg两处理组明显高于对照组(p<0.05)。     

换羽期日粮维生素水平对蛋鸡强制换羽效果的影响

432只产蛋率为49.5%的60周龄的海兰褐商品蛋鸡随机分为3个组。开食时,A组(对照组)给予低维生素日粮(VA 3000IU/kg,VE10IU/kg,VD 300IU/kg,VC 20mg/kg,VK4mg/kg,多维20mg/kg);B组给予中等维生素日粮(5倍对照);C组给予高维生素日粮(10倍对照)。结果表明,与A组相比,B组、C组达50%产蛋率的试验天数显著(p<0.05)减少;换羽期产蛋率、产蛋量极显著(p<0.01)提高,料蛋比、死亡率和破软蛋率极显著(p<0.01)降低;C组换羽后破软蛋率、换羽后死亡率分别显著(p<0.05)和极显著(p<0.01)降低,且换羽后效益最好,比对照组提高18.13%。     

日粮铁缺乏对肉仔鸡机体抗氧化功能影响的研究

１日龄艾维茵肉仔鸡１００只,随机分为２组,每组设有重复,自由采食以玉米、淀粉、葡萄糖和大豆分离蛋白为主日粮,日粮中分别添加０（铁缺乏组）和１１０ｍｇ／ｋｇ铁（对照组）,饮用去离子水,分别于１和１４日龄皮下接种ＨＶＴ冻干苗、７和１４日龄滴鼻接种Ｌａｓｏｔａ系冻干苗。试验结果表明,肉仔鸡疫苗接种及饲养管理同前。铁缺乏组与对照组相比：４２日龄肝脏、胸腺、脾脏和法氏囊中过氧化氢酶（ＣＡＴ）活性显著降低（Ｐ＜０．０５）、肝脏、胸腺和脾脏中谷胱甘肽过氯化物酶（ＧＳＨ－Ｐｘ）活性显著降低（Ｐ＜０．０５）;４２日龄肝脏、胸腺、脾脏和法氏囊中脂质过氧化物（ＬＰＯ）含量显著升高（Ｐ＜０．０５）。铁营养状况与机体抗氧化功能密切相关,日粮铁缺乏机体抗氧化功能降低。     

Chronic effects of moniliformin in broiler and turkeys fed dietary treatments to market age

Floor pen studies were conducted, with broilers from 1 to 7 wk of age and with turkeys from 1 to 14 wk of age, to evaluate the chronic effects of moniliformin (M). Fusarium fujikuroi (M-1214) culture material was added to typical corn-soybean basal diets to supply 0, 25, or 50 mg M/kg diet (broilers) or 0, 12.5, 25, 37.5, or 50 mg M/kg diet (turkeys). Compared with controls, chicks fed diets containing 50 mg M/kg consumed more feed, had lower body weight gain, were less efficient in converting feed to body weight gain, and had increased relative heart and proventriculus weights. Chicks fed the diet containing 50 mg M/kg also had significantly higher mortality and decreased mean corpuscular volumes compared with controls. Broilers fed 25 and 50 mg M/kg also had increased serum gamma glutamyltransferase activities. Feed intake, body weight gain, and feed conversion of turkeys fed dietary M were not affected. At 6 and 14 wk, turkeys fed 25, 37.5, or 50 mg M/kg diet had increased (P < 0.05) relative heart weights when compared with controls. At week 14, turkeys fed diets containing 37.5 or 50 mg M/kg also had increased (P < 0.05) relative liver weights compared with turkeys fed 0, 12.5, or 25 mg M/kg diet. Lesions, observed only in the hearts of broilers and turkeys fed 50 mg M/kg, were loss of cardiomyocyte cross striations, increased cardiomyocyte nuclear size, and an increased number of cardiomyocyte mitotic figures (turkeys only). Results indicate that > or = 37.5 mg M/kg is hepatoxic and > or = 25 mg M/kg is cardiotoxic to turkeys and 50 mg M/kg diet is toxic to broilers fed to market age.     

Performance of Broilers Fed on Diets Containing Different Amounts of Chaya (Cnidoscolus aconitifolius) Leaf Meal

The performance and gut measurements of broilers fed on diets containing different amounts of chaya (Cnidoscolus aconitifolius) leaf meal (CLM) were examined in two experiments. In the first experiment, 60 Hubbard chickens (30 males and 30 females; 2 weeks old) were fed on five maize diets; these were formulated using 0, 150 (CLM150), 250 (CLM250) or 350 (CLM350) g CLM/kg, and the fifth diet contained soyabean. In the second experiment, 148 Ross male chicks, 1 day old, were fed on three isonitrogenous and isoenergetic maize–soyabean-based diets, which included 0 (control), 150 (C150) or 250 (C250) g CLM/kg. The diets were offered ad libitum for 2 or 3 weeks in the first and second experiments, respectively. Food intake, weight gain and the food:weight gain ratio were recorded. The weight of the gizzard and intestine and the weight and length of the caeca were also determined in the second experiment. In experiment 1, the birds fed on the maize–soyabean diet had a higher (p<0.05) weight gain and final weight than birds fed on maize only or on the CLM150 diets. There were no differences for any of the variables studied between the birds fed on the maize–soyabean diet and those fed on the CLM250, nor between males and females. In the second experiment, weight gain, food intake and the food:weight gain ratio for birds fed on C250 were lower (p<0.05) than those in birds fed on either the control or C150 diets. The weights of the gizzard and intestine were the lowest and the highest, respectively, in birds fed on C250 (p<0.05). The length and weight of the caecum from birds fed on the control diet were lower (p<0.05) than those of birds fed on either the C150 or C250 diets. The results from this study suggest that CLM may be included up to 150 g/kg in commercial diets without having an adverse effect on poultry performance, and may also be mixed with maize up to 250 g/kg to improve the performance of chickens fed on low-protein diets.     

Individual and combined effects of the Fusarium mycotoxins fumonisin B1 and moniliformin in broiler chicks

The individual and combined effects of feeding fumonisin B1 (FB1; 0, 100, 200 mg FB1/kg) and moniliformin (M; 0, 100, 200 mg M/kg) were evaluated using a 3 x 3 factorial arrangement of treatments. Significant mortality (P < 0.05) occurred in chicks fed all diets containing 200 mg M/kg (50%-65%). Compared with controls and chicks fed FB1, both feed intake and body weight gain were decreased (P < 0.05) in chicks fed diets containing 100 mg M/kg. Chicks fed M had heavier heart weights (P < 0.05) than control chicks or chicks fed FB1. Compared with controls, chicks fed diets containing 200 mg M/kg or a combination of 200 mg FB1/kg and 100 mg M/kg had increased kidney and liver weights (P < 0.05). Significant FB1 by M interactions (P < 0.05) were observed for serum total protein and aspartate aminotransferase. Mild to moderate periportal extramedullary hematopoiesis and mild focal hepatic necrosis were observed in chicks fed FB1 alone. An increased incidence of large pleomorphic cardiomyocyte nuclei, loss of cardiomyocytes, and mild focal renal tubular mineralization were observed in chicks fed M alone. Both cardiac and renal lesions were observed in chicks fed combinations of FB1 and M. Data indicate FB1 and M, alone or in combination, can adversely affect chick performance and health at these dietary concentrations. The interactive effects of FB1 and M were not synergistic and were less than additive in nature. At the dietary concentrations studied, M is much more toxic to broilers than FB1.     

黄连提取物对高饲养密度下肉鸡生长性能、血清生化指标及肠道微生物的影响

文章旨在研究高密度饲养条件下肉鸡日粮添加黄连提取物对其生长性能、血清生化指标及肠道微生物的影响。试验将640只平均体重为（42.12±0.16）g的肉鸡随机分为4组（T1～T4）,每组4个重复,每个重复40只。T1组肉鸡在高密度（20/m2）下饲喂基础日粮,T2组肉鸡在正常饲养密度（10只/m2）下饲喂基础日粮,T3组肉鸡在高饲养密度下饲喂基础日粮+20 mg/kg黄连提取物,T4组在正常饲养密度（10只/m2）饲喂基础日粮+20 mg/kg黄连提取物。在为期42 d的饲养试验结束后分析相关指标。结果：T4组22～42 d肉鸡平均日增重、22～42 d和1～42 d采食量最高（P＜0.05）,而T1组1～42 d肉鸡平均日增重和采食量最低（P＜0.05）。T1组肉鸡法氏囊重量分别较T2～T4组显著降低了18.53%、17.42%和18.89%（P＜0.05）。T4组肉鸡血清SOD和T-AOC活性最高（P＜0.05）,但血清丙二醛含量较T1组显著降低了29.04%（P＜0.05）。T1组肉鸡回肠大肠杆菌数量最高,分别较其他组显著提高了7.22%、6.93%和8.10%（P＜0.05）,但T1组肉鸡回肠乳酸杆菌数量较其他组显著降低了14.21%、15.74%和17.62%（P＜0.05）。T4组肉鸡回肠双歧杆菌数量较T1组显著提高了5.41%（P＜0.05）。结论：在高饲养密度条件下肉鸡日粮中添加20 mg/kg黄连提取物可以改善肉鸡生长性能和肠道有益菌数量,提高血清抗氧化指标,降低氧化应激。 [关键词]黄连提取物|饲养密度|肉鸡|生长性能|肠道微生物|血清生化