植酸酶对3～6周的肉仔鸡磷需求的影响

进行2个相同设计方案的试验。选用3周龄的有充足磷饲料喂养的人工笼养雄仔鸡,在3～6周龄这一阶段分别喂给0.10%～0.45%(递增量为每次0.05%)的非植酸磷(non-phyta-tephophorous;即npp)。在日粮中添加800IU/kg的植酸酶。测定包括体增重、饲料转化率、发病率,胫骨灰分和粪磷情况。非线性回归方程被用来评价要得到最佳体增重、饲料转化率、发病率、胫骨灰分和粪磷时非植酸磷的需求量。在无植酸酶的情况下,得到的胫骨灰分率、增重率和饲料转化率的非植酸磷量分别是0.33%、0.186%和0.163%。这一数据非常符合现今NRC(1994)的推荐量。而添加800IU/kg的植酸酶后,得到最佳胫骨灰分率、增重率和饲料转化率的非植酸磷含量分别是0.24%、0.151%和0.109%。粪磷在低磷状态下显著减少。     

低有效磷饲粮添加植酸酶对肉仔鸡生产性能的影响

以艾维因肉仔鸡为试验动物，研究了低有效磷饲粮中添加植酸酶对生产性能的影响。１００只艾维因肉仔鸡随机分为５组，每个组设４个重复。第１组喂标准饲粮，第２、３、４、５组为低有效磷（０．２０％）饲粮，分别加植酸酶ＯＦＴＵ／ｋｇ、３５０ＦＴＵ／ｋｇ、５００ＦＴＵ／ｋｇ、６５０ＦＴＵ／ｋｇ，饲养试验分０￣３周、４￣６周两个阶段，试验期为５周。试验结果表明，在低有效磷饲粮中添加植酸酶可提高肉仔鸡生产性能，降低鸡后期单位增重饲料成本，以植酸酶最大添加量６５０ＦＴＵ／ｋｇ组的效果为最佳，但生产性能未达到标准饲粮组水平。     

葡萄糖酸钠和植酸酶对肉仔鸡磷利用的影响

选取280只3周龄的从雄性商品内鸡进行试验,研究玉米一豆粕型低磷饲粮中添加葡萄糖酸钠和植酸酶对内鸡磷利用的影响.试验采用2×3+1设计,其中葡萄糖酸钠两个水平(0,2%),植酸酶3个水平(0,500,1000 U/kg).另设一满足NKC(1994)钙、磷需要的正常饲粮,共构成7个处理,每个处理5个重复,每个重复8只鸡.试验期为3-6周龄.自由采食和饮水.结果表明:与正对照组相比.低磷基础饲粮显著降低了肉仔鸡的胫骨灰分含量(P<0.001);添加2%葡萄糖酸钠显著提高了肉仔鸡的血清钙水平(P=0.035);添加植酸酶提高了肉仔鸡的钙(P=0.020)、磷表观存留率(P＝0.036)和胫骨灰分含量(P<0.001).未观察到葡萄糖酸钠和植酸酶之间存在互作(P>0.05).这些结果说明,葡萄糖酸钠和植酸酶均可改善后期肉鸡对磷的利用.     

植酸酶对肉仔鸡钙、磷利用率影响的研究

试验研究肉仔鸡日粮中添力。植酸酶对于物质、钙、磷利用率的影响。试验分4个处理,每个处理4个重复,每个重复15只鸡。试验在第4周进行,分别饲喂处理1（含总磷0．56％）,处理2（合总磷0．40％加植酸酶500FTU／kg）、处理3（含总磷0．50％加植酸酶500FTU／kg）、处理4（含总磷0．50％加植酸酶250FTU／kg）。结果表明：处理3、处理4于物质利用率、钙的利用率、磷的利用率和对照组差异不显著（P＞0．05）。但都表现出提高的趋势,干物质利用率分别提高3．40％、3．99％,钙的利用率分别提高4．81％、4．5％,磷的利用率分别提高2．03％、4．65％。处理2干物质利用率与对照组差异不显著（P＞0．05）,与处理3、处理4差异显著（P≤0．05）。钙的利用率与其它处理差异显著（P≤0．05）。磷的利用率低于其它处理（P＞0．05）。     

植酸酶对肉仔鸡生产性能和钙磷消化率的影响

 研究了3个不同品牌的微生物植酸酶在两个不同磷酸氢钙添加水平（0.44%和0.77%）下对肉仔鸡生产性能和钙磷消化率的影响。试验结果表明：与正常磷酸氢钙添加水平（1.1%）的对照组相比,降低磷酸氢钙用量并添加植酸酶后肉仔鸡的采食量和日增重与对照组接近,饲料转化率有一定提高,死淘率和腿病发生率与对照组差异不显著。降低磷酸氢钙用量并添加植酸酶能够一定程度的提高肉仔鸡对灰分的消化利用率（P＞0.05）,显著提高磷的消化利用率（P＜0.05）,并大幅提高24日龄肉仔鸡的钙表观消化率（P＜0.01）,小幅提高42日龄肉仔鸡的钙表观消化率（P＞0.05）, 不同品牌植酸酶的作用效果存在一定差异。     

植酸酶对肉仔鸡生产性能及钙、磷利用率的影响

试验研究肉仔鸡低有效磷日粮中添加植酸酶对生产性能及钙、磷利用率的影响。选取960只1日龄AA肉仔鸡,随机分为8个处理,每个处理6个重复,每个重复20只仔鸡（公母各半）,试验分为前期（1-21 d）和后期（22-42 d）两个阶段。第I组为正对照组PC（试验基础日粮,前、后期有效磷水平分别为0.47%、0.43%）,第II组为负对照组NC（前、后期分别降低有效磷水平0.06%、0.1%）,第Ⅲ-第Ⅴ组分别为NC＋500 U/kg包衣植酸酶、NC＋1 000U/kg包衣植酸酶,NC＋1 0000 U/kg包衣植酸酶,第Ⅵ组为NC＋500 U/kg粉状植酸酶,第Ⅶ组为NC＋500 U/kg微丸植酸酶,第Ⅷ组为NC＋500 U/kg进口粉状植酸酶。结果表明：（1）除Ⅶ组后期采食量较正对照组有显著提高外,各处理组平均日采食量、平均日增重差异均不显著（P〉0.05）,Ⅶ组前期料重比较正、负对照组均有显著降低（P〈0.05）,且正对照组全期料重比显著低于负对照组（P〈0.05）,所有酶处理组后期和全期料重比均较负对照组有所降低,但差异不显著（P〉0.05）。（2）Ⅵ组前期DM和EE消化率显著高于正对照组,除Ⅲ组外所有酶处理组前期能量和P消化率均显著高于正、负对照组（P〈0.05）;Ⅶ和Ⅷ组后期DM消化率显著高于正对照组（P〈0.05）,Ⅳ组后期EE消化率显著高于正、负对照组,除Ⅲ组外所有酶处理组以及负对照组后期P消化率均显著高于正对照组（P〈0.05）。（3）Ⅲ组前期胫骨长度显著高于正、负对照组,Ⅳ和Ⅴ组及负对照组后期胫骨长度均显著大于正对照组（P〈0.05）;Ⅴ组后期胫骨Ca含量显著高于正、负对照组,所有酶处理组前、后期胫骨P含量均较负对照组有所升高,但差异不显著（P〉0.05）。试验结果表明低有效磷日粮中添加植酸酶对饲料利用率有一定的改善作用,有效提高饲料代谢能以及磷的消化和沉积。     

钙和非植酸磷浓度对肉仔鸡利用植酸酶效果的影响

通过比较在添加植酸酶(试验1)和不添加植酸酶(试验2)时的生产性能和骨骼质量参数的表观回归曲线,研究不同水平C a和非植酸磷(NPP)的日粮中添加植酸酶的效果。在这2个试验中,0~16日龄的Cobb×Cobb肉仔鸡饲喂玉米-豆粕型基础日粮。试验1采用4×4因子设计,钙水平分别为:0.38%、0.58%、0.78%和0.98%,NPP水平分别为:0.2%、0.3%、0.4%和0.5%。试验2采用混合循环试验设计,日粮中C a水平为0.38%、0.47%、0.68%、0.89%和0.98%,NPP水平为0.20%、0.24%、0.35%、0.46%和0.50%。需要指出的是,设计中同时含有一个最低水平的C a和NPP(0.38%C a和0.20%NPP)组合。所有C a和NPP的组合均添加657U/kg的N atuphos 5000植酸酶,此外,其中的4个组合(0.38%C a和0.20%NPP,0.47%C a和0.24%NPP,0.68%C a和0.35%NPP及0.89%C a和0.46%NPP)不添加植酸酶,用以确定试验中多个表观回归曲线间比较特殊变量的可行性。通过比较添加与不添加植酸酶的表观曲线,结果显示:在高C a低NPP条件下,植酸酶对生长性能和骨质量的影响最明显,但当C a水平降低或NPP水平提高的情况下,植酸酶的影响程度有所下降。第3个试验证明了在高C a低NPP比低C a低NPP时,植酸酶更能发挥其功效。以上数据说明,在添加植酸酶时,不能仅以单独的NPP等价量来确定其添加量。     

植酸酶对肉仔鸡生产性能及钙、磷利用率的影响

试验研究肉仔鸡低有效磷日粮中添加植酸酶对生产性能及钙、磷利用率的影响。选取960只1日龄AA肉仔鸡,随机分为8个处理,每个处理6个重复,每个重复20只仔鸡（公母各半）,试验分为前期（1-21 d）和后期（22-42 d）两个阶段。第I组为正对照组PC（试验基础日粮,前、后期有效磷水平分别为0.47%、0.43%）,第II组为负对照组NC（前、后期分别降低有效磷水平0.06%、0.1%）,第Ⅲ-第Ⅴ组分别为NC＋500 U/kg包衣植酸酶、NC＋1 000U/kg包衣植酸酶,NC＋1 0000 U/kg包衣植酸酶,第Ⅵ组为NC＋500 U/kg粉状植酸酶,第Ⅶ组为NC＋500 U/kg微丸植酸酶,第Ⅷ组为NC＋500 U/kg进口粉状植酸酶。结果表明：（1）除Ⅶ组后期采食量较正对照组有显著提高外,各处理组平均日采食量、平均日增重差异均不显著（P〉0.05）,Ⅶ组前期料重比较正、负对照组均有显著降低（P〈0.05）,且正对照组全期料重比显著低于负对照组（P〈0.05）,所有酶处理组后期和全期料重比均较负对照组有所降低,但差异不显著（P〉0.05）。（2）Ⅵ组前期DM和EE消化率显著高于正对照组,除Ⅲ组外所有酶处理组前期能量和P消化率均显著高于正、负对照组（P〈0.05）;Ⅶ和Ⅷ组后期DM消化率显著高于正对照组（P〈0.05）,Ⅳ组后期EE消化率显著高于正、负对照组,除Ⅲ组外所有酶处理组以及负对照组后期P消化率均显著高于正对照组（P〈0.05）。（3）Ⅲ组前期胫骨长度显著高于正、负对照组,Ⅳ和Ⅴ组及负对照组后期胫骨长度均显著大于正对照组（P〈0.05）;Ⅴ组后期胫骨Ca含量显著高于正、负对照组,所有酶处理组前、后期胫骨P含量均较负对照组有所升高,但差异不显著（P〉0.05）。试验结果表明低有效磷日粮中添加植酸酶对饲料利用率有一定的改善作用,有效提高饲料代谢能以及磷的消化和沉积。     

在低磷日粮中添加微生物植酸酶对肉仔鸡生长性能和养分利用率的影响

前言在几乎所有的种子植物中,植酸磷(phytateP)是磷的主要贮藏形式。这种植酸磷的利用率较低(NRC,1994),因而可以使用无机磷源来满足家禽的磷需要量(Yi等,1996)。因此,大量的磷未被吸收,便通过家禽粪便排出。而且,现已知道,植酸磷会降低其他必需矿物质的生物利用率,因为植酸具有粘结剂的作用,可使无机复盐与各种二价阳离子(如钙、镁、锌、铁和钾)结果在一起(Cosgrove,1980;Reddy等,1982)。在常见的玉米-大豆日粮中,没有发现天然的植酸酶活性,摄入体内的总磷只有29%被吸收(Pallauf和Rimbach,1992)。在利用玉米-大豆日粮开展的研究中,一些…     

Dietary cholecalciferol and phosphorus influence intestinal mucosa phytase activity in broiler chicks

1. The role of cholecalciferol and phosphorus in the regulation of intestinal mucosa phytase was investigated in broiler chicks. 2. A total of 144 7-d-old male broiler chicks were grouped by weight into 6 blocks of 4 cages with 6 broiler chicks per cage. Four maize-soybean meal-based mash diets were randomly assigned to cages within each block. The 4 diets consisted of cholecalciferol at 0 or 75 microg/kg and total phosphorus at 3.6 or 7.0 g/kg in a 2 x 2 factorial arrangement. The birds were given the experimental diets for 12 d under conditions which excluded ultraviolet light. 3. Broiler chicks fed on diets with the higher concentration of cholecalciferol had higher Vmax and Km of the mucosa phytase, weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, phosphorus (P) and calcium (Ca), and increased retention of dry matter, nitrogen, P, Ca and energy. 4. Broiler chicks receiving diets with the higher P concentration showed lower Vmax and Km of the intestinal mucosa phytase but greater weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, P and nitrogen, and increased retention of dry matter, energy, nitrogen and Ca. 5. In conclusion, both dietary P and cholecalciferol influenced the activity of intestinal mucosa phytase.     

Effect of early nutrition on fattening and growth of broiler chicks at 7 weeks of age

1. Six experiments were carried out with male and female broiler chicks in a factorial arrangement to evaluate the combined effects of fat concentration or energy-to-protein (E:P) ratio in diets fed from 1 to 7 or 14 d of age, and of the E:P ratio in diets fed from 1 or 2 to 7 weeks of age on fattening and performance of the birds. 2. Diets with a wide E:P ratio fed from 1 or 2 to 7 weeks consistently and significantly increased abdominal fat pad size at 7 weeks of age. On the other hand, in 5 of the experiments, the nutritional treatments from 1 to 7 or 14 d did not significantly affect this variable in chicks fed on diets with either the narrow or the wide E:P ratio. 3. Body weights and food utilisation at 7 or 14 d were consistently and significantly improved by increasing dietary fat concentration and using diets with a narrow E:P ratio. However, at 7 weeks of age, in only two of the experiments were body weights still significantly affected by early nutrition. 4. Diets with a wide E:P ratio consistently and significantly reduced the performance of chicks up to 4 weeks of age. Nevertheless, at 7 weeks of age the performance of these chicks tended to be better (at times significantly so) in most of the experiments, despite their excess fattening.     

The tryptophan requirement of broiler chicks.

The "available" tryptophan requirements of male and female broiler chicks were determined at 7-d intervals from 0 to 56 d, using a diet-dilution technique. Availability of tryptophan in the diets was estimated by growth assay with chicks. 2. The tryptophan requirements were 2.4 (males) and 2.2 g/kg of diet (female) from 0-7 d, and 1.7 g/kg (males and females) from 7-35 and 35-56 d. The absolute requirement of the chick for tryptophan increased with age and was significantly different for male and female birds. 3. A highly significantly predictive equation relating tryptophan requirement to mean body weight and gain was established.     

Effects of ethylenediaminetetraacetic acid on phytate phosphorus utilization and efficiency of microbial phytase in broiler chicks

Previous studies have suggested that organic acids may improve P utilization in animals. To evaluate the ability of ethylenediaminetetraacetic acid (EDTA) to improve phytate P utilization and the possible synergistic effect between EDTA and microbial phytase (MP) an experiment was conducted using 360 Ross 308 broiler chicks. The experiment was carried out using a completely randomized design with a 3*2 factorial arrangement (0, 0.1 and 0.2% EDTA and 0 and 500 IU MP). Four replicate of 15 chicks per each were fed dietary treatments including (i) P-deficient basal diet [0.2% available phosphorus (aP)] (NC); (ii) NC + 500 IU MP per kilogram of diet; (iii) NC + 0.1% EDTA per kilogram of diet; (iv) NC + 0.1% EDTA and 500 IU MP per kilogram of diet; (v) NC + 0.2% EDTA per kilogram; and (vi) NC + 0.2% EDTA + 500 IU MP per kilogram of diet. Weight gain (WG), feed efficiency and serum Ca, P and alkaline phosphatase (ALP) were assessed. Addition of 0.2% EDTA to low aP diets resulted in significantly lower feed consumption (FC) and WG, but 0.1% EDTA did not depress WG compared to NC. Phytase supplementation of P-deficient diets significantly improved WG and feed efficiency, but it had no effect on FC. Microbial phytase supplementation significantly decreased ALP concentration. Results obtained in our study suggest no synergistic effect between phytase and EDTA in broiler chicks.     

Response of broiler chickens to fowl cholera vaccination at 1 to 6 weeks of age.

Broiler chickens, in groups of 10, received a single vaccination by the stick-wing route at 1, 2, 3, 4, 5, 6, or 11 weeks of age with live Clemson University strain of Pasteurella multocida. Twenty non-vaccinates kept in isolation served as controls. Cholera serum antibody titers in all chickens were determined by enzyme-linked immunosorbent assay at weekly intervals. Chickens vaccinated once at 1, 2, 3, 4, 5, and 6 weeks, respectively, attained 25.2%, 28.7%, 34.7%, 46.2%, 51.8%, and 64.6% of the titers of those vaccinated once at 11 weeks of age. Variation in antibody response was greatest in chickens vaccinated at 1 or 2 weeks of age. Additionally, chickens vaccinated at 1 or 2 weeks of age showed the longest response time (5 weeks) to reach maximum antibody titers after a single vaccination. When the original vaccinates were revaccinated at 11 weeks of age, all showed a secondary response equal to or greater than that seen in chickens vaccinated once at 11 weeks of age. Age of the chickens at the time of vaccination and antibody titer were positively correlated (r = 0.997). Overall antibody responses to vaccination were higher and much more uniform as birds increased in age.     

Limiting amino acids in low protein maize-soyabean meal diets fed to broiler chicks from 3 to 7 weeks of age

1. An experiment with separately housed male and female broiler chicks was carried out during the period of 3 to 7 weeks of age to determine the limiting amino acids (AA) in a low protein maize-soyabean meal diet. Chicks were fed on diets containing 170, 180, 190 and 200 g crude protein (CP)/kg with or without combined additions of L-threonine (Thr), L-tryptophan (Trp) and L-arginine (Arg) to those in the 180, 190 or 200 g CP/kg diets and a 170 g CP/kg diet with or without combined additions of Thr, Trp, Arg, L-isoleucine (Ile), L-leucine (Leu) and L-valine (Val) to those in the 190 g CP/kg diet. The diets were iso-energetic and contained the same concentrations of lysine (Lys) and sulphur-containing amino acids. 2. Decreasing the dietary CP had a significantly negative effect on performance. 3. No significant effects on performance were found when diets with 180 and 190 g CP/kg were supplemented with Thr, Trp and Arg to those in the 200 g CP/kg diet. 4. There were no significant differences in performance between the groups fed on the diets with 170, 180 and 190 g CP/kg when the 170 and 180 g CP/kg diets were supplemented with Thr, Trp and Arg to those in the 190 g CP/kg diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

黄羽肉鸡有效磷需要量的研究

试验旨在研究实际生产中黄羽肉鸡日粮有效磷水平。选择600只16日龄石歧黄羽肉鸡,随机分成6个处理,每处理5个重复,每重复20只鸡。试验分两个阶段,16～35日龄为中鸡阶段,36～50日龄为大鸡阶段,中鸡料有效磷分别为0.45%、0.42%、0.39%、0.36%、0.33%、0.30%,大鸡料有效磷分别为0.40%、0.37%、0.34%、0.31%、0.28%、0.25%。结果表明:①各有效磷水平组间日增重、日采食量及料肉比无显著差异(P>0.05)。②35日龄时0.45%、0.42%与0.39%组骨骼灰分显著高于0.36%、0.33%与0.30%组(P<0.05),其中0.42%与0.39%组骨骼灰分含量极显著高于0.36%、0.33%组(P<0.01);0.45%、0.42%、0.39%、0.36%组骨骼磷含量显著高于0.30%组(P<0.05)。③50日龄时0.40%、0.34%与0.31%组骨骼灰分显著高于0.25%组(P<0.05),其中0.40%、0.34%极显著高于0.25%组(P<0.01);0.40%、0.37%组骨骼钙含量极显著高于0.25%(P<0.01);0.40%、0.37%骨骼磷含量显著高于0.25%组。综上结果表明,以生产性能为指标,16~35日龄阶段与36~50日龄阶段黄羽肉鸡日粮有效磷水平分别为0.30%与0.25%;若以胫骨发育为参照指标,其日粮有效磷水平应不低于0.36%和0.25%。