铬在肉鸡日粮中的应用

研究人员从 3 0多年来的研究中认识到 ,铬是哺乳动物和鸟类碳水化合物和脂类代谢所必需的。如今 ,不断地有证据表明 ,日粮铬在家禽的代谢中起着极为重要的作用。此外 ,近来的研究表明 ,商品肉鸡日粮中添加铬可以起到有利的作用。虽然许多养鸡者都已提出 ,铬应该成为一种极为重要的营养性添加剂。但是 ,官方机构 ,如美国全国科学研究院动物营养委员会 ,仍然没有对任何一种动物最终提出铬的最低日粮需要量。同时 ,还不确知究竟哪种形式的铬才是生物利用率最高而效益成本比也最高的 ,虽然 ,和其它微量矿物质一样 ,这也可能是有机形式的 ,包括螯…     

铬在肉鸡日粮中的应用

经过长达30多年的研究，研究者们一致认为铬(Cr)对哺乳动物和禽类的碳水化合物和脂类代谢是必不可少的。当今，证实日粮中Cr在家禽代谢中起关键作用的证据仍继续增加。另外，最近的研究表明在商品性肉鸡日粮中添加Cr具有有益作用。     

肉鸡日粮中补铬的研究

选用 40 0只 1日龄艾维茵肉仔鸡 ,随机均分为四组 (公母各半 )。Ⅰ组喂基础日粮作对照组 ,Ⅱ、Ⅲ和Ⅳ组分别于基础日粮中添加 1× 1 0 -4 、2× 1 0 -4 和 3× 1 0 -4 吡啶羧酸铬(以铬计 ) ,试验期 42天。结果表明 :日粮补铬对生产性能和屠宰率无显著影响 (P >0 0 5 ) ;补铬可显著降低腹脂率和血清中胆固醇的含量 (P <0 0 5 ) ;补铬可显著提高胸肌率 (P <0 0 5 )。     

铬在肉鸡日粮中的应用应激情况下添加更为重要

铬的研究始于３０多年前，研究者发现铬为哺乳动物和禽类碳水化合物及脂类代谢所必需。目前，大量研究不断证实日粮中铬在家禽代谢中起着重要作用。此外，最近研究表明，在商业化肉仔鸡生产中应用铬，可能会对其带来有益作用。 尽管许多研究表明，铬为营养性添加剂的主要成分之一，但官方机构如美国国家研究中心动物营养委员会至今尚未给出许多动物日粮中铬的最低应用量，同时，尽管铬同其他微量元素一样，有许多有机形式，包括柠檬酸铬、化合物铬、吡啶羧酸铬及烟酸铬，但其最大生物活性及效价形式等问题仍然存在。 研究表明，铬存在于所有…     

日粮添加铬制剂可减缓肉鸡免疫抑制

为研究在热应激(23.9~37℃)条件下,不同水平有机铬和无机铬(Cr)对肉鸡生产性能、免疫功能和血清无机物浓度的影响,韩国忠南国立大学的研究人员将1日龄150只肉雏鸡随机分为5个处理组,每个处理3个重     

肉鸡日粮中的微量元素定额

近20年来,在家禽对微量元素的需要量及其在饲料中的含量方面进行了大量的研究,但微量元素的定额问题还尚未获得解决.对于不同种类、年龄和生产力的家禽,所推荐的微最元素添加剂标准都一样.关于家禽对某些微量元素的需要量尚无一致意见.例如,一些研究者认为,在1公斤饲料中5毫克铜的含量对雏鸡已足够,而另一些研究者认为应不少于8毫克.在对产蛋母鸡的试验中曾查明,每公斤日粮中铜的水平由5毫克提高到15毫克,对其产蛋量和该元素在体内的聚积无重大影响.从其他文献资料得知,当     

肉鸡日粮配比中的辩证关系

众所周知,饲养肉鸡需要有配比合理、功能完善的配合饲料。在肉鸡饲料的配比设计上,养殖户只有充分重视各种营养元素的辩证关系,注重搞好各种成分之间的搭配平衡,才能配制出营养均衡、价格合适、具有竞争优势的配合饲料。     

二十八醇在肉鸡日粮中的应用

二十八醇在肉鸡日粮中的应用浙江省粮食科学研究所许仁溥，沈华近年的研究表明，米糠油中含有一种微量物质二十八醇，对人体及动物具有很强的生物活性，参与机体能量代谢，增强运动耐久力和消除疲劳的能力。二十八醇在美国、日本已商品化，作为一种新的天然营养保健品应市...     

Chromium propionate improves performance and carcass traits in broilers

There is evidence to suggest that poultry may have a dietary requirement for metabolically available chromium (Cr) that exceeds the amount provided through wheat soybean meal diets. The objective of the present study was to investigate the effects of dietary supplemental organic Cr from Cr propionate at different dose levels (control = 0 μg/kg, T1 = 200 μg/kg, T2 = 400 μg/kg) on the growth performance, carcass traits, and meat quality of broilers. Weight gain and feed intake of each treatment were recorded at the start and after 14, 28 and 35 d, and feed conversion ratios (FCR) were calculated accordingly. At 35 d of age, birds were randomly selected and euthanized for carcass evaluation. Results of the first trial indicate that both Cr propionate treatments increased final body weight (P < 0.05), feed efficiency (P < 0.05) and body weight gain (P < 0.0001). Furthermore, Cr propionate supplementation improved (P < 0.0001) all carcass characteristics. Interestingly, with increased Cr dosage, carcass yield, dressing percentage and breast meat yield increased linearly (P < 0.0001). The second study reveals that the feed intake in the control group was significantly higher compared to both Cr propionate supplemented groups (T1 & T2). Furthermore, the Cr propionate supplemented T2 group displayed a significantly lower FCR than the control and T1 group (P = 0.027). Finally, Cr propionate supplementation increased the dressing percentage compared to control birds (P < 0.0001). In the third experiment, Cr propionate supplementation (T1 & T2) increased final body weight and decreased FCR compared with the control treatment. These effects were highly significant (P < 0.0001) throughout all feeding phases of the trial. Cr propionate supplementation also increased (P < 0.0001) carcass yield, dressing percentage, breast meat yield, leg and thigh weights compared with the control treatment. In conclusion, growth performance, feed conversion, carcass yield, breast and leg meats of broiler birds can be significantly improved by dietary inclusion of Cr propionate. Cr propionate can be supplemented to broiler birds from 1 d old of age at a level that provides 200 or 400 μg/kg organic Cr and can increase the efficiency of broiler production.     

低蛋白质日粮在肉鸡营养中的应用

近年来随着畜牧业规模化和集约化程度的不断提高,畜产品已满足了人们日益增长的需要,同时也带来了一些负面影响。解决该问题的有效方法是降低氮摄入量和保持氨基酸的充足供给以满足动物的营养需要。通过营养学技术,以可消化氨基酸需要量代替粗蛋白配制氨基酸平衡的日粮,通过补充合成氨基酸,降低日粮蛋白水平(2%～4%),从而使氮的排出量显著减少。这样既节省了蛋白质资源又减轻了环境污染,而且不影响动物生产性能。     

Interactions between xylanase and glucanase in maize-soy-based diets for broilers

1. The effect of various doses of xylanase and glucanase on the performance and ileal nutrient digestibility of broiler chickens fed on maize/soy-based diets was evaluated.

2. A total of 960 male broilers were used in separate growth and digestibility trials with each involving 10 treatments and 6 replicates. The 10 treatments included a positive control reference diet, a negative control diet with a lower energy density and 8 further diets where xylanase and glucanase were added to the negative control, individually and in combination.

3. Birds which received the negative control diet returned poorer (6 points; P < 0·05) feed conversion ratios compared with those fed on the positive control, confirming the lower energy density of the negative control diet. Ileal digestibility of energy determined at 21 and 42 d was also significantly lower for the negative control compared with the positive control. At d 21 birds that received the negative control diet returned lower ileal amino acid digestibility (for most amino acids) compared with their counterparts fed on the positive control whereas at d 42 this effect was not apparent.

4. Supplementation of the negative control with both glucanase and xylanase improved feed conversion ratio (FCR) and ileal nutrient digestibility. When both enzymes were added simultaneously a sub-additive effect (i.e. simultaneous use resulted in benefits greater than either enzyme independently but less than the sum of the individual effects) was observed, with the best performance achieved with the combination of xylanase (16 000 BXU/kg) and glucanase (30 000 BU/kg).

5. It can be concluded that the removal of oil to accommodate the anticipated energy digestibility improvement with enzymes can have deleterious effects on FCR and ileal amino acid digestibility in young broilers which enzymes may not adequately mitigate. Thus, in order to maximise the response to non-starch polysaccharide degrading enzymes in maize/soy-based broiler diets, it may be beneficial to consider a combination of xylanase and glucanase and to apply moderation when removing added fat in the starter diets.     

转基因稻谷在肉仔鸡日粮中的应用研究

试验以不同品质稻谷替代40%玉米饲喂肉仔鸡,探讨对其生长情况、内脏器官及血液指标的影响。将200只1日龄AA肉仔鸡随机分成4组,每组50只,公母各半,采用单因素有重复试验设计,对照组饲喂玉米-豆粕型基础日粮,Ⅰ、Ⅱ、Ⅲ组分别用普通稻谷、新高赖氨酸转基因稻谷组、陈高赖氨酸转基因稻谷组替代40%玉米配制日粮。试验分2个阶段,前期1～21日龄,后期22～42日龄。试验结果表明:①3种品质稻谷替代40%玉米对肉仔鸡前期促生长作用明显,其中新、陈高赖氨酸含量转基因稻谷组料肉比均比对照组显著降低(P<0.05);后期普通稻谷组料肉比最低,新高赖氨酸含量转基因稻谷组肉仔鸡平均体重最高。②3种品质稻谷能促进前期肉仔鸡肝脏生长,其中高赖氨酸转基因稻谷组提高最为显著(P<0.05);后期肾脏指数3个稻谷组均比对照组显著提高(P<0.05)。③3种品质稻谷对早期血液生化指标存在一定影响;后期葡萄糖浓度3个稻谷组均比对照组显著提高(P<0.05),其它各项指标差异不显著。3种品质稻谷替代40%玉米配制日粮饲喂肉仔鸡是可行的。     

日粮中添加半胱胺对艾维茵肉用仔鸡生产性能的影响

半胱胺（Cystimine,简称CS）对动物的作用近年来研究较多,它可以作用于体内的生长抑素（SS）,并间接影响与生长相关的激素水平,从而促进动物的生长,改善其生产性能。韩正康（1992）、王艳玲等（1993）届彩梅等（2002）的研究表明,CS能促进鸡、兔等动物的生长,提高饲料转化率,并使血液中SS含量明显降低,生长激素（GH）水平显著升高。但由于半胱胺的化学结构中含有非常     

肉鸡和蛋鸡日粮中添加植酸酶的研究进展

近几年来,随着生物技术的发展,使大规模商业化生产植酸酶成为可能。由于反刍动物瘤胃中的微生物可以产生大量的植酸酶,因而可以很好地利用饲料中的植酸磷（Reid等,1947）,而猪和家禽等单胃动物由于肠道中植酸酶活性微弱,并且易被日粮中的某些成分（如钙）所抑制,因而不能有效利用饲料中的植酸磷。需要额外添加无机磷。因此,在猪和家禽的饲料中应用植酸酶以提高植酸磷的利用率日益引起重视,研究也不断深入。在美国乔治亚州亚特兰大国际家禽科学论坛上,植酸酶在肉鸡和蛋鸡日粮中添加的重要意义成为与会者探讨的中心话题。研究覆盖了添加的植酸酶与饲料中已经存在的植酸酶是如何发生反应的,在单一饲料和混合饲料中是如何反应的,不同商业植酸酶的作用如何等。现将主要内容编译介绍如下。     

Performance of broilers fed on diets containing cooked potato flake

The chemical analysis of dried cooked potato flake suggests that the material might be used in diets for broilers. Starter and finisher diets containing 0, 10, 20 and 40% potato flake in place of maize meal were formulated, and fed ad libitum in pellet form to broilers. Performance of the birds and characteristics of the pellets were measured.

The performances of birds given diets containing 0, 10 and 20% potato were similar. Birds given the diet containing 40% potato grew at a slower rate, ate less food but converted food as efficiently as birds receiving other diets.

Wetness of the litter and hardness of the pellets both increased as the proportion of potato in the diet increased, and these are suggested as the main factors limiting the proportion of potato used in the diet. It is proposed that these factors may be overcome by attention to the litter and by feeding diets containing potato in smaller sized particles.     

Growth of broilers fed on diets containing dried poultry manure

Sixty 7‐d‐old male broiler chicks were housed in individual metabolism cages and offered one of six purified diets for 14 d. The diets were formulated to have the same ME contents but had different nitrogenous supplements: diet A, was the basal diet, containing PRG essential amino acid (EAA) mixture equivalent to 15 g N/kg; B, basal+12% glutamic acid (GA); C, basal plus EAA mixture equivalent to EAA content of 20.09% DPM; D, basal + EAA+12% GA; E, basal + 20.09% autoclaved DPM; F, basal + 20.09% unautoclaved DPM. The rank order of final body weights at 21 d of chicks fed on these diets were D(292 g) > B(258 g), (F254 g), E(253 g) > C(206 g) > A(180 g), (P<0.05). Chicks fed on diet C had better food conversion efficiencies (FCE) than those fed on diet A (0.449 and 0.374 respectively) and D was better than B (0.592 and 0.533 respectively).

In a second experiment, carried out under field trial conditions using commercial‐type diets formulated to contain DPM, 24 groups, each of about 40 male or female broiler chicks, were given diets containing 0% (P) or 5% (Q) DPM from 1 d of age for 4 weeks. From 4 to 8 weeks one of three diets with 0% (R), 5% (S) or 10% (T) DPM was fed according to a 2 (sexes) x 2 x 3 factorial design. Between o and 4 weeks feeding DPM had no significant effect on body weight or food consumption, but birds fed diet Q had an improved FCE (P<0.05). Between 4 and 8 weeks birds fed on S and T were heavier than the controls at 6 weeks, but this increase was not significant at 8 weeks (P> 0.05). Food consumption was not affected, but the FCE improved with increasing inclusion of DPM. At 8 weeks of age birds fed on Q, were heavier than birds fed on diet P.     

低蛋白质日粮补充合成氨基酸在肉鸡营养中的应用

本文综述了低蛋白质日粮补充合成氨基酸对内鸡生长性能和氮排出量的影响以及应用低蛋白质日粮需注意的问题.