热应激对蛋鸡繁殖性能影响研究进展

高温环境对动物的生长发育、生产与繁殖性能都带来不利的影响.随着集约化的饲养管理,蛋鸡的繁殖性能不可避免地受到炎热环境的危害,从而影响养殖业的经济效益.论文从热应激状态下蛋鸡产蛋量及蛋质量、卵巢重量及卵泡数量、HPG轴激素及相关类固醇激素含量的变化来探讨热应激对蛋鸡繁殖性能的影响,并对可能的机制进行综述,为指导生产实践、...     

热应激对蛋鸡的影响

为了从环境因素上提高鸡的热应激反应,本文详尽论述了高温对蛋鸡的生产性能,免疫功能及一些生理、生化指标受高温的影响。     

热应激状况下维生素C对蛋鸡免疫性能的影响

日粮中添加维生素C可提高家禽的生产性能和免疫性能[1-2]。试验研究在环境温度32℃时,维生素C的不同添加剂量对新城疫接种蛋鸡免疫性能的影响。1材料与方法1.1材料新城疫疫苗,Lasota系500羽活疫苗,陕西维康生物发展有限公司生产;维生素C,山东农业大学保健品厂生产。1.2试验设计     

热应激环境下磷脂VC对蛋鸡生产性能的影响

选37周龄罗曼蛋鸡288只,在热应激(平均舍温29.5℃,最高舍温35.2℃)环境下,研究了日粮中添加不同剂量磷脂VC对蛋鸡生产性能的影响。结果表明,与对照组相比,添加300mg/kg的磷脂VC组的采食量提高了6%(P<0.01)@产蛋数和产蛋率分别提高3.6%和3.2%(P<0.05),破蛋率、死亡率和失重率降低。100mg/kg的磷脂VC组可改善蛋鸡生产性能的各项指标但效果不显著。表明日粮中添加300mg/kg磷脂VC能明显提高热应激蛋鸡的采食量和产蛋率,改善蛋鸡的生产性能。     

急性热应激对蛋鸡生产的影响

本文通过对南京市青龙山蛋鸡场和象山蛋鸡场在急性高温热应激下生产记录与环境温度测试的分析。发现急性高温热应激可使蛋鸡死亡率迅速增加近16.58～20.7倍,产蛋率下降28.9％。同时讨论了热应激对不同朝向的鸡舍和不同跨度的自然通风鸡舍的影响。     

蛋鸡热应激的研究进展

热应激是我国大部分地区夏季饲养蛋鸡普遍存在的问题。热应激不仅使蛋鸡产蛋率下降,蛋重减少,破损率提高,种蛋受精率和孵化率降低,而且会导致鸡的抵抗力和免疫力下降甚至大批死亡,造成巨大的经济损失。因此,随着集约化蛋鸡饲养业的发展,蛋鸡热应激的研究已成为畜牧...     

维生素E水平和免疫应激处理对蛋鸡生产性能的影响

试验旨在研究维生素E水平和免疫应激对蛋鸡生产性能的影响。采用3×3双因子设计,270只19周龄健康来航蛋鸡随机分为9组,每组5个重复,每重复6只鸡。其中,3个日粮VE水平分别为0、40和100IU/kg,3种免疫应激方式分别为不注射、肌注生理盐水和肌注减蛋综合症疫苗。结果表明:VE对免疫应激给鸡群生产性能带来的不良影响具有部分缓解作用,在免疫应激状态下,鸡群对于VE的营养需求量增加。     

铬对热应激蛋鸡影响的研究

<正>随着养殖业的高密度集约化发展,家禽面临越来越多应激因素的挑战,应激综合症的发生率不断上升,且日益成为妨碍畜牧业发展最突出的因素之一。蛋鸡被羽厚且无汗腺,在高密度集约化饲养管理方式     

热应激对蛋鸡的影响及综合防治

热应激是外界环境温度升高使得鸡体内温度急剧升高而导致生理机能紊乱的一种过热症,可使蛋鸡产蛋率下降,蛋重减轻,蛋的营养成分降低,种蛋受精率和孵化率降低等.本文通过对蛋鸡热应激的综合分析,建立了一整套防治有效的措施,以促进养鸡业的健康发展.     

Effect of lemon verbena powder and vitamin C on performance and immunity of heat‐stressed broilers

An experiment was conducted to investigate the effect of lemon verbena powder and vitamin C on performance and immunity of broilers under heat stress. The experiment was carried out with a total of 160‐day‐old male Ross 308 broiler chickens in a completely randomized design. From 25 days of age, the birds were assigned to four diets including control diet and treatment diets which were supplemented with 2 levels of lemon verbena (0.5% and 1.0%) and one level of vitamin C (250 mg/kg) in 16‐floor pens with 10 chickens each and reared to 42 days of age. To induce chronic heat stress, birds were exposed to an ambient temperature of 35 ± 2 °C for 8 h daily (from 09:00 AM until 17:00 PM) between 25 and 42 days of age. At the end of experiment, one chick/pen was randomly selected, and the performance and blood parameters were evaluated. Dietary supplementation of 1.0% lemon verbena increased (p < 0.05) average weight gain and feed intake by 5.81% and 3.29%, and reduced feed conversion ratio by 2.59% respectively compared to control group. Birds fed diets containing 1.0% lemon verbena had significantly higher relative weight of bursa of fabricius and breast (p < 0.05). LDL decreased by 15.85% and 17.57%, for birds fed 0.5% and 1.0% lemon verbena respectively. The ratio of heterophyl to lymphocyte was reduced (p < 0.05) by 20.68% via significant decrease in heterophyl by 15.55% and significant increase in lymphocyte by 4.51% in birds fed lemon verbena at the rate of 1.0% compared to those fed the control diet. 1.0% lemon verbena and vitamin C elevated (p = 0.0005) the level of glutathione peroxidase by 51.81% and 27.90%, respectively. In conclusion, lemon verbena and vitamin C improved some performance data and blood metabolites which somehow suppressed the negative effects of heat stress.     

N-乙酰半胱氨酸对热应激蛋鸡生产指标及抗氧化指标的影响

为了探索N-乙酰半胱氨酸(NAC)对热应激蛋鸡生产性能的影响及可能机制,选择产蛋率、体重相近的38周龄健康海兰褐蛋鸡144只随机分为4组,每组6个重复,每个重复6只,分为常温对照组(NC,基础日粮)、高温对照组(HC,基础日粮)、高剂量NAC添加组(HNAC,基础日粮+0.5%NAC)和低剂量NAC添加组(LNAC,基础日粮+0.1%NAC),对照组在室温环境饲养,3个试验组在高温环境饲养,饲养28 d并比较海兰蛋鸡生产指标、鸡蛋品质及血清抗氧化能力。结果显示:与HC组比较,日粮中添加0.5%NAC能够显著提高产蛋率,降低料蛋比,提高鸡蛋的哈夫单位(P0.05);日粮中添加0.1%NAC能够显著提高蛋鸡产蛋率和哈夫单位(P0.05),但对料蛋比无显著影响(P0.05);NAC的添加对热应激蛋鸡日采食量、平均蛋重及蛋黄颜色无显著影响(P0.05)。结果表明:日粮中添加一定剂量NAC有利于提高蛋鸡生产性能及鸡蛋品质。     

Influence of high dietary vitamin E supplementation on egg production and plasma characteristics in hens subjected to heat stress

1. The effects of different dietary concentrations of vitamin E (alpha-tocopherol acetate) were investigated in 2 experiments on laying hens exposed to chronic heat stress at 32C. 2. In the first experiment, egg production and plasma concentrations of calcium and egg yolk precursors were measured in 24 hens before, during and after a stress period of one week and fed on diets containing 10 or 500 mg vitamin E/kg. 3. In the second, larger experiment, egg production and food intake were measured in 300 hens housed in 2 temperature-controlled rooms and fed on diets containing 10, 125 or 500 mg vitamin E/kg. Birds in room 1 were stressed from 24 to 28 weeks of age and those in room 2 from 32 to 36 weeks. 4. In experiment 1, egg production and egg weight were significantly higher (72.6 vs 51.2%, P < 0.05 and 66.6 vs 63.1 g, P < 0.005 respectively) during and after the period of stress in the group given 500 mg vitamin E/kg. Plasma concentrations of calcium, vitellogenin (zinc) and VLDL (triglyceride) were also higher in this group. 5. In experiment 2, egg production was significantly higher (65.4 vs 56.2%, P < 0.05) during and after the period of heat stress in birds in room 1 fed on the diet containing 500 mg vitamin E/kg. Egg production was also higher (49.9% vs 44.7%) on this treatment during the stress period in room 2, though the difference was not significant (P < 0.10). Egg weight and food intake were unaffected by treatment in either room. 6. It is concluded that dietary supplementation with extra vitamin E can, at least in part, alleviate the adverse effects of chronic heat stress in laying hens, perhaps by maintaining the supply of egg precursors in plasma.     

Carbonic anhydrase and its isozymes in heat stressed white Leghorn hens

Experiments were conducted to study the effect of heat stress on uterine tissue carbonic anhydrase levels and their isozyme patterns in relation to production of no- and thin-shelled eggs. Birds exposed to naturally occurring heat stress had lower enzyme levels in their uteri than birds kept in an air-conditioned pen. 4 isozyme bands of carbonic anhydrase were visible in uterine tissue homogenate from both groups of birds. Isozymes were suppressed in heat-stressed birds, as was evident from staining intensities of the bands. This provided evidence to the effect that heat stress not only decreased the total quantity of carbonic anhydrase in the uteri of the hens but also suppressed its isozyme fractions, leading to greater production of no-shell and thin-shelled eggs.     

维生素C和维生素E的抗鸡热应激作用

1　热应激对鸡的影响11　热应激　鸡作为恒温动物,仅在严格的环境温度范围内保持体温。10～32℃是鸡维持正常体温的环境温度范围,21～26℃是鸡生存的适宜环境温度,此时鸡用于维持体温所付出的代谢能最少;26～32℃是尚能维持正常体温的温度范围;高于32℃则是鸡生理功能趋于紊乱的温度范围,即出现热应激。12　鸡热应激时的组织、生理、生化及免疫反应121　呼吸频率提高,肺通气量加大,发生热喘息,ＣＯ2排出量增加,致使血液中ＣＯ2分压下降,ｐＨ值升高,严重时出现呼吸性碱中毒。122　心律加快,肝、肾、胃肠道血液流量相对减少,血钙、血钾、血磷…     

饲粮添加Vc对腹水肉鸡缺氧诱导因子-1α基因表达及机体氧化与抗氧化能力的影响

通过饲粮添加1.5mg/kg三碘甲状原氨酸(3,3′,5-triiodothyronine,T3)诱导肉鸡产生腹水综合征(AS),研究了饲粮中添加不同剂量的VC对肉鸡机体氧化与抗氧化能力、肺脏缺氧诱导因子-1α(HIF-1α)基因表达及AS发病率的影响。结果表明:饲粮中添加不同剂量的VC可不同程度降低肉鸡心脏指数和AS发病率,1000mg/kgVC可显著降低肉鸡心脏指数(P<0.05);饲粮VC可增加AS肉鸡肝脏和血液的总抗氧化能力,降低MDA的含量,饲粮添加100、1000和10000mg/kgVC可显著降低AS肉鸡肝脏和血液MDA的浓度(P<0.05),添加100、500和10000mg/kgVC可显著提高血液T-AOC活性(P<0.05);VC可以显著(P<0.05)或极显著(P<0.01)降低AS肉鸡肺脏HIF-1αmRNA和蛋白质表达水平,在1000mg/kg时,HIF-1α蛋白的表达量达到极显著性差异(P<0.01);从血液生化指标来看,VC可降低AS肉鸡血液中乳酸的水平和乳酸脱氢酶(LDH)的活力,在500、1000mg/kg时达到显著性差异(P<0.05)。以上结果表明饲粮中添加1000mg/kgVC对肉鸡AS有较好的防治效果。     

Effect of dietary vanadium and vitamin C on egg quality and antioxidant status in laying hens

This study assessed the effect of dietary vanadium (V) and vitamin C (VC) on production performance, egg quality and antioxidant status in laying hens. A total of 360 laying hens (31‐week‐old) were randomly allotted into a 3 × 3 factorial arrangement treatments (four replicates and 10 chicks per replicate) with three levels of dietary V (0, 5 and 10 mg/kg) and three levels of vitamin C (0, 50 and 100 mg/kg) for 12 weeks. The effect of V and VC did not alter egg production, egg weight, average daily feed intake and feed conversion ratio during 1–12 week. Albumen height and Haugh unit value were linearly decreased (p < 0.001) by addition of V, whereas the effect of 100 mg/kg VC was observed to counteract (p < 0.05) this effect in V‐containing treatments during 1–12 week. Hens fed V‐containing diet laid lighter (linear effect, p < 0.05) coloured eggs (higher lightness value, lower redness and yellowness value), and the VC exerted no influence on it during 1–12 week. The serum superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px) activities, ability to inhibit hydroxyl radical, were significantly decreased, and the malondialdehyde (MDA) and V contents were increased (p < 0.05) by effect of V during 4, 8 and 12 week. The effect of VC alone and the interactive effect between VC and V were shown to increase serum (p < 0.05) SOD activity in 4 week and decrease MAD levels in 12 week. The result indicate that V decreased the egg quality and caused the oxidative stress at level of 5 mg/kg and 10 mg/kg, and the addition of 100 mg/kg vitamin C can alleviate its egg quality reduction effect and can mitigate the oxidative stress to some extent.     

维生素C对蛋鸡新城疫免疫性能的影响

试验将60只体重相近的49日龄海兰褐蛋鸡随机分为A、B、C、D、E5组,每组4个重复,每个重复3只。B、C、D、E4组颈部皮下注射新城疫Ι系疫苗进行免疫,分别在B、C、D、E组日粮中添加0、200、400、800mg/kg的维生素C,分四周测血清中的HI效价及脾脏、胸腺、法氏囊等脏器指数。结果表明:添加维生素C可提高HI效价,对新城疫疫苗免疫效果有促进作用,其中400mg/kg的维生素C效果较好;C、D、E组的脾脏、胸腺、法氏囊等脏器指数均高于B组,说明添加维生素C能促进脾脏、胸腺、法氏囊等免疫器官生长发育,进而影响细胞免疫和体液免疫。     

The effect of vitamin C supplementation on plasma concentration and urinary excretion of vitamin C in cattle

We investigated the plasma concentration and urinary excretion of vitamin C in cows supplemented with vitamin C. Five cows (mean BW = 597 kg) were allocated to a 5 x 5 Latin square design and supplemented with a vitamin C preparation coated with hydrogenated soybean oil at 0, 10, 20, 40, or 60 mg of vitamin C per kg of BW per day for 9 d. Plasma and urine samples were collected for measuring vitamin C concentration. Urinary excretion of vitamin C was expressed as the ratio of vitamin C to creatinine. Plasma vitamin C concentration and urinary vitamin C excretion increased quadratically as dietary vitamin C increased (P < 0.001); that is, the lowest dose affected neither plasma vitamin C concentration nor urinary vitamin C excretion but the plasma vitamin C concentration and urinary vitamin C excretion increased (P < 0.05) with increasing supplementation of vitamin C at greater doses. This suggests that plasma vitamin C concentration affects urinary excretion of vitamin C in cattle and that plasma vitamin C concentration exceeded the renal threshold for vitamin C in the cows receiving vitamin C at 20 mg/kg of BW per day. Furthermore, increased urinary excretion of vitamin C appears to limit plasma vitamin C concentration in response to vitamin C intake. The daily excretion of vitamin C was estimated by the reported value of daily creatinine excretion, indicating that the daily amount of vitamin C excreted into urine was more than half of supplied vitamin C. Therefore, a large part of supplied vitamin C probably escapes ruminal degradation and is absorbed but excreted into urine.     

饲粮维生素C添加水平对大通牦牛精液品质和抗氧化功能的影响

选用体质量(1 030±90)kg的健康大通牦牛种公牛24头,采用单因子试验设计,随机区组法分为4组,分别为对照组(基础日粮)、Ⅰ组(基础日粮+200mg/kg维生素C),Ⅱ组(基础日粮+400mg/kg维生素C)、Ⅲ组(基础日粮+600mg/kg维生素C),试验周期120d。结果显示:饲粮中维生素C的添加显著提高牦牛精清中维生素C的含量,与对照组相比显著升高(P<0.01);与对照组相比,日粮中维生素C的添加,显著提高了牦牛射精总量、精子密度、鲜精和冻精活力以及精子顶体完整率,降低精子的畸形率;但600mg/kg组牦牛精液品质与400mg/kg组相比有不同程度的降低。与对照组相比,饲粮中不同水平维生素C的添加显著提高牦牛精清中总抗氧化能力(TAOC)、谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)的活性(P<0.01),降低精液中活性氧(ROS)和丙二醛(MDA)的含量(P<0.01)。结果表明:大通牦牛种公牛日粮中合理的维生素C添加剂量为400mg/kg。