不同锌源对肉仔鸡肠道形态及金属硫蛋白表达的影响

为研究同一添加水平的4种锌源对AA肉仔鸡小肠形态及金属硫蛋白（MT）表达的影响,选取1日龄AA肉仔鸡480只,随机分成4组,每组6个重复,每个重复20只鸡。在玉米-豆粕型基础饲粮（含锌22.68 mg/kg）中分别添加硫酸锌（ZnSO4）、赖氨酸锌（Lys-Zn）、蛋氨酸锌（Met-Zn）、甘氨酸锌（Gly-Zn）,配制成4种含锌量均为90 mg/kg的试验饲粮,ZnSO4组为对照组,试验期21 d。结果表明：4种锌源对肉仔鸡小肠形态和肝脏MT 含量均无显著影响（P>0.05）。 Gly-Zn和Met-Zn组小肠MT mRNA相对表达量和胰脏MT含量显著高于对照组（P<0.05）,但Lys-Zn组与对照组差异不显著（P>0.05）。在3种氨基酸螯合锌中,Lys-Zn组胰脏MT含量、十二指肠MT mRNA相对表达量显著低于其他两种螯合锌组（P<0.05）。由此可见,Gly-Zn和Met-Zn对促进肉仔鸡小肠MT mRNA表达,提高胰脏MT含量效果较好。     

肉仔鸡日粮中锌营养状况评价指标的研究

选用384只1日龄商品代从内公鸡随机分成8个处理组,分别饲喂不添加锌的玉米-豆粕型基础日粮(对照组,舍锌28.37 nag/kg)和在对照组基础日粮中以无机硫酸锌形式添加20、40、60、80、100、120 mg/ks和140 mg/kg锌的试验日粮.试验期7 d.研究日粮中添加不同水平无机锌对内仔鸡生长性能、组织锌含量、含锌酶活性以及含锌蛋白及其基因表达的影响,以考察这些指标对评价肉仔鸡锌营养状况的意义.结果表明:肉仔鸡生长性能未受到添加锌水平的显著影响(P>0.24),而胫骨锌、胰脏锌含量以及胰脏金属硫蛋白(MT)含量及其基因表达受锌水平影响极显著(P<0.01),胫骨锌和胰脏锌含量随锌水平增加呈渐近线趋势变化.胰脏MT含量及其基因表达则呈线性上升趋势.这些指标均可以作为反映肉仔鸡锌营养状况的指标.从相关系数比较来看.胫骨锌和胰脏锌与饲粮锌的相关性比胰脏MT含量及其基因表达更密切.胰脏MT含量及其基因表达随锌水平增加线性上升.可用作评价不同锌源生物学利用率的有效指标.     

0～21日龄肉仔鸡饲粮中锌适宜水平研究

本文研究了不同水平无机锌对肉仔鸡生长性能、含锌酶活性及组织锌含量的影响,并对每一指标进行曲线拟合（二次曲线与渐近性）,从中筛选合适的指标以确定肉仔鸡实用饲粮中锌的适宜水平。选用1日龄AA肉公鸡384只,随机分为8个处理组,每个处理6个重复,分别饲喂玉米-豆粕型基础饲粮（对照组）和锌添加水平为20、40、60、80、100、120 和140 mg/kg （硫酸锌）的饲粮, 试验期21 d。结果表明：（1）随饲粮锌水平的增加日增重和采食量有显著增加（P〈0.05）,添加20 mg/kg锌组鸡的日增重和采食量显著高于对照组;（2）血浆5′-核苷酸酶活性随饲粮锌含量增加呈明显的二次曲线变化（P〈0.01）,估测的锌适宜添加水平为52.13 mg/kg;（3）胰脏锌与胫骨锌含量随饲粮锌水平的增加呈渐近线上升趋势（P〈0.01）,以此2指标确定的锌适宜添加水平分别为30.78与33.86 mg/kg;（4）含锌酶中碱性磷酸酶（AKP）及铜锌超氧化物歧化酶（CuZnSOD）活性以及肾脏锌含量随饲粮锌水平变化没有显著变化（P〉0.10）,表明上述指标均不适宜用来估测锌适宜水平。以上结果表明,0～21日龄,肉仔鸡饲粮中锌的适宜水平约为80 mg/kg。     

不同锌源对肉用仔鸡的饲养效果

主要研究以不同锌源对肉仔鸡的生产性能和血液锌，胰脏锌，胫骨锌含量的影响，以验证固相合成蛋氨酸锌对肉用仔鸡的饲养效果，结果表明，相对于无机的硫酸锌，日粮中添加蛋氨酸锌能有效提高肉鸡的生产性能，提高胫骨中的锌含量，同时也表明液相合成蛋氨酸锌与固相合成蛋氨酸锌饲养效果相当。     

日粮蛋氨酸螯合锌和硫酸锌水平对肉仔鸡生产性能的影响

试验探讨了日粮中不同硫酸锌和蛋氨酸螯合锌水平对肉用仔鸡生产性能、血液生化指标和胫骨锌及铁浓度的影响.选用1日龄岭南黄肉鸡720只,按体重和性别随机分为6组,每组4个重复,每个重复30只鸡.在玉米豆粕型基础日粮中分别以硫酸锌和蛋氨酸螯合锌形式添加40、80和120mg/kg锌饲喂试验鸡,预饲10d,正式试验期为21 d.结果表明,日粮锌源和锌水平对肉仔鸡平均日增重、平均日采食量、血清碱性磷酸酶活性、血清葡萄糖和总蛋白浓度以及胫骨锌和铁含量无明显影响,在锌添加水平为40mg/kg时,蛋氨酸螯合锌处理组耗料增重比显著低于硫酸锌组(P<0.05).     

日粮钙,锌水平对肉仔鸡增重及胫骨状况的影响

选用１日龄艾力肉仔鸡２４０只，随机分为６组，分别给予６种日粮处理，即在玉米－豆粕型 添加两种钙水平，三种锌水平（０ｍｇ／ｋｇ、１００ｍｇ／ｋｇ及１０００ｍｇ／ｋｇ）。结果表明，日粮锌及钙锌互作对肉仔鸡增重有极显著影响，但高钙对肉仔鸡增重无显著影响；日粮钙、锌水平对肉仔鸡胫骨钙、锌含量有极显著影响，对胫骨长影响显著；但胫骨磷含量不受日粮钙、锌水平的影响。     

日粮锌源对肉仔鸡肝脏金属硫蛋白基因表达的影响

试验选用150羽Avian肉仔鸡,随机分成3组,分别饲喂不加锌的基础日粮和添加60mg/kg硫酸锌和氨基酸络合锌的日粮,以管家基因GAPDH为内参,采用RT-PCR方法研究两种锌源对肉仔鸡肝脏金属硫蛋白（MT）mRNA基因表达的影响。结果表明,日粮添加两种锌源锌均能够提高肝脏MTmRNA的丰度,但与硫酸锌相比,日粮添加氨基酸锌显著提高了肝脏MTmRNA基因表达的水平（P〈0.05）。     

五种锌源对肉仔鸡生长性能、金属硫蛋白基因表达及组织锌含量的影响

为了探究同一添加水平的5种锌源对AA肉仔鸡生长性能、小肠金属硫蛋白(MT)mRNA及组织锌含量的影响,试验采用单因子随机设计,将240只1日龄AA肉仔鸡随机分成5组,选用玉米-豆粕型基础日粮(含锌22.68 mg/kg),在日粮中分别加入2种无机锌(ZnO、ZnSO4)和3种氨基酸螯合锌[赖氨酸锌(Lys-Zn)、蛋氨酸锌(Met-Zn)、甘氨酸锌(Gly-Zn),含锌量均为90 mg/kg],试验期为21 d,测定肉仔鸡生产性能、组织锌含量及MT mRNA相对表达量。结果表明:5种锌对肉鸡生长性能、肝脏和血液锌含量均无显著影响(P0.05)。Gly-Zn和Met-Zn组的胰脏、胫骨锌含量和小肠MT mRNA相对表达量显著高于2个无机锌组(P0.05);Lys-Zn组胰脏、胫骨锌含量和空肠MT mRNA相对表达量显著高于ZnO组(P0.05),与ZnSO4组无显著差异(P0.05),但有升高趋势。3种氨基酸螯合锌组中,Gly-Zn组和Met-Zn组胫骨锌含量、十二指肠MT mRNA相对表达量显著高于Lys-Zn组(P0.05);2种无机锌组中,ZnO组胰脏、胫骨锌含量显著低于ZnSO4组(P0.05)。说明Gly-Zn和Met-Zn能显著提高肉仔鸡小肠MT mRNA表达水平,增加组织锌含量。     

不同锌源及水平对蛋鸡生产性能、蛋品质、血液生化指标以及蛋锌含量的影响

试验研究不同锌源及水平对蛋鸡生产性能、蛋品质、血液生化指标以及蛋锌含量的影响。选用21周龄健康的罗曼蛋鸡720只,随机分为5个处理,每个处理6个重复,每个重复24只鸡。对照组饲喂基础饲粮(锌含量测定值20.56 mg/kg),其他4组分别在基础饲粮中添加35、70 mg/kg的氨基酸络合锌(Av-Zn)或硫酸锌(锌含量实测值分别为40.11、80.39、36.62、76.10 mg/kg)。试验预试期7 d,正试期56 d。结果表明:(1)锌源之间对平均日蛋重和损蛋率差异显著(P<0.05);(2)锌源及水平对蛋壳重有显著影响(P<0.05);(3)不同锌源对蛋鸡血清锌离子、SOD活性以及Cu Zn-SOD活性均没有显著影响(P>0.05);不同水平的锌对蛋鸡血清锌离子有极显著影响(P<0.01)、对Cu Zn-SOD活性有显著影响(P<0.05),对SOD活性并没有显著影响(P>0.05);(4)锌源对第14、28、42、56 d蛋黄锌的影响差异显著(P<0.05);锌水平对第14、28、42 d蛋黄锌含量的影响差异不显著(P>0.05),但对第56 d蛋黄锌含量差异极显著(P<0.01)。锌源和锌水平之间对14、28、42、56 d蛋黄锌含量的影响差异不显著(P>0.05)。由此可见,添加70 mg/kg氨基酸络合锌能生产富锌鸡蛋,同时对蛋鸡的正常生产没有影响。     

肉用仔鸡饲粮锌适宜浓度的研究

本文应用５因素２次回归几乎正交旋转组合设计，采用玉米一豆饼型饲粮（含锌３１．４５ｍｇ／ｋｇ）对４３２＊只ＡｒｂｏｒＡｃｒａ公雏〔３６组、１２只／组）的饲＊钙、负、ｖ。３、Ｂ、锌５因素进行研究，通过建立肉仔鸡体重和组织锌沉积与５因素间的回归模型、预测１０－２周龄的肉＊用仔鸡最大体重和组织锌沉积时，饲粮锌的适宜浓度。＊回归模型的数学分析结果表明：胫骨灰锌沉积与饲粮＊钙、磷、ＶＤ３、锰、锌间建立的回归方程式极显著（Ｐ＜＊０．０１）。获得最大胰脏、胫骨和血清锌沉积的饲粮锌适＊宜浓度范围为１３０－１５０ｍｇ／ｋｇ；获得最大体重的饲粮＊锌适宜浓度为８３ｍｇ／ｋｇ。本试验结果推荐０～２周龄肉用仔鸡饲粮锌的适宜浓度为８３－１５０ｍｇ／ｋｇ。     

Effect of intravenously injected zinc on tissue zinc and metallothionein gene expression of broilers

1. The effect of intravenously injected zinc (Zn) on tissue Zn concentrations and pancreas metallothionein (MT) gene expression in broilers was investigated to detect differences in the tissue utilisation of Zn from different Zn sources.

2. A total of 432 male chickens were randomly allotted on d 22 post-hatch to one of nine treatments in a completely randomised design. Chickens were injected with either a 0.9% (w/v) NaCl solution (control) or a saline solution supplemented with Zn sulphate or one of three organic Zn chelates with weak (Zn-AA W), moderate (Zn-Pro M) or strong (Zn-Pro S) chelation strengths at two injected Zn dosages calculated according to two Zn absorbability levels (6 and 12%).

3. Bone and pancreas Zn concentrations, pancreas MT mRNA levels and MT concentrations increased on d 6 and 12 after Zn injections as the injected Zn dosages increased. Chickens injected with the Zn-Pro S had lower bone Zn concentration than those injected with the Zn-Pro M or Zn-AA W on d 6 after injections. However, no differences among Zn sources were observed in bone Zn concentration on d 12 after injections, pancreas Zn concentrations, pancreas MT mRNA levels and MT concentrations on both d 6 and d 12 after injections.

4. It was concluded that the injected Zn-Pro S was the least favourable for bone Zn utilisation of broilers. The pancreas Zn concentration and pancreas MT gene expressions might not be sensitive enough to detect differences in the tissue utilisation of injected Zn in broilers between organic and inorganic Zn sources or among organic Zn sources.     

饲粮高铁对肉仔鸡十二指肠黏膜铁转运载体基因表达及组织微量元素含量的影响

本试验旨在研究饲粮铁含量对肉仔鸡组织重要微量元素铁、锰、铜、锌含量及十二指肠黏膜主要铁转运载体基因表达的影响,探讨铁对肉仔鸡微量元素吸收和代谢的影响及其机制。将336只1日龄商品代罗斯308肉公雏按照体重随机分成4个组,每组6个重复,每个重复14只鸡。对照组饲喂不额外添加铁的基础饲粮(实测铁含量为78 mg/kg),铁添加组分别饲喂以七水硫酸亚铁(FeSO_4·7H_2O)形式添加100、250或500 mg/kg铁的试验饲粮(实测铁含量分别为166、308和579 mg/kg)。试验期21 d。各组试鸡分别于7、14和21日龄屠宰分析肝脏、心脏、胰腺、十二指肠黏膜和胫骨灰中铁、锰、铜、锌含量及十二指肠黏膜中二价金属转运蛋白(DMT1)和膜铁转运蛋白(FPN1)mRNA表达水平。结果表明:1)500 mg/kg铁添加组1~7日龄和8~14日龄的平均日增重显著低于其他3组(P0.10),250和500 mg/kg铁添加组1~7日龄的平均日采食量显著低于其他2组(P0.10)。2)饲粮铁含量对肉仔鸡7、14、21日龄的血浆总铁结合力以及全血血红蛋白浓度(7日龄除外)和红细胞压积均无显著影响(P0.10),但显著影响7、14和21日龄血浆铁含量和铁饱和度(P0.10),二者均随饲粮铁含量增加而升高。3)7和14日龄心脏及7、14和21日龄肝脏、十二指肠黏膜、胰腺和胫骨灰铁含量均随饲粮铁含量的增加而升高,7、14和21日龄十二指肠黏膜、胰腺和胫骨灰锰含量均随饲粮铁含量的增加而降低;饲粮添加铁显著降低7日龄胰腺锌含量(P0.10),但对其他日龄胰腺和各日龄其他所测组织锌含量以及各日龄所测各组织铜含量均无显著影响(P0.10)。4)饲粮铁含量显著影响7、14和21日龄十二指肠黏膜DMT1和FPN1 mRNA表达水平(P0.10),各日龄DMT1和FPN1mRNA表达水平均随饲粮铁含量的增加而降低。以上结果提示,高铁饲粮可能通过调控十二指肠黏膜DMT1和FPN1基因的表达降低锰和锌在肠道的吸收,进而减少锰和锌在组织中的沉积。     

不同处理小麦麸对雏鸡肝脏和胫骨锌,铁,铜和锰沉积的影响

试验研究了用膨化、纤维素酶解、碱化和酸化处理的小麦麸对雏鸡饲粮中锌、铁、铜和锰在肝脏及胫骨中沉积的影响。结果表明,酸化处理使肝脏及胫骨锌、肝脏铁含量显著高于对照组(P<0.05),胫骨锌及肝脏铁的沉积率显著高于对照组(P<0.05);碱化处理使胫骨锌及肝脏铁含量显著高于对照组,肝脏铁的沉积率显著高于对照组(P<0.05);纤维素酶解处理使肝脏铁含量显著高于对照组;膨化处理与对照组相比,锌、铁、铜及锰在肝脏和胫骨中的沉积都有增加的趋势,但统计结果不显著。     

The Immune Response and Performance of Calves Supplemented with Zinc from an Organic and an Inorganic Source

Two experiments were conducted to determine the effects of supplemental zinc (Zn) from an organic and an inorganic source on growth performance, serum Zn concentrations, and immune response of beef calves. Treatments consisted of: i) control (no supplemental Zn), ii) Zn sulfate, or iii) Zn-amino acid complex. Zinc sources were supplemented to provide 360 mg of Zn/d. Experiment 1 was a 28-d study using 84 steers (240 ± 1.5 kg) fed bermudagrass hay (21 mg Zn/kg DM) with 1.8 kg/d of the appropriate corn-based supplement. In Exp. 2, 75 heifers (176 ± 2.5 kg) were fed bermudagrass hay (38 mg Zn/kg DM) and the supplements for 140 d. In Exp. 1, ADG was greater (P<0.05) from d 15 to 28 in calves fed supplemental Zn-amino acid compared with those fed Zn sulfate, but ADG did not differ (P>0.10) among treatments for the entire 28-d study. In Exp. 2, there was no effect (P>0.10) on ADG as a result of Zn supplementation. In Exp. 2, Zn-supplemented heifers had a greater response (P=0.06) tophytohemagglutinin 24 h after an intradermal injection. In Exp. 2, calves supplemented with Zn-amino acid complex had a greater antibody response to a second vaccination for bovine respiratory syncytial virus than did control or Zn sulfate-supplemented calves (treatment by day interaction, P=0.06). There was not a consistent benefit of supplemental Zn on growth of calves, but there was a positive impact of supplemental Zn on some immune response measurements.     

The Immune Response and Performance of Calves Supplemented with Zinc from an Organic and an Inorganic Source

Two experiments were conducted to determine the effects of supplemental zinc (Zn) from an organic and an inorganic source on growth performance, serum Zn concentrations, and immune response of beef calves. Treatments consisted of: i) control (no supplemental Zn), ii) Zn sulfate, or iii) Zn–amino acid complex. Zinc sources were supplemented to provide 360 mg of Zn/d. Experiment 1 was a 28-d study using 84 steers (240 ± 1.5 kg) fed bermudagrass hay (21 mg Zn/kg DM) with 1.8 kg/d of the appropriate corn-based supplement. In Exp. 2, 75 heifers (176 ± 2.5 kg) were fed bermudagrass hay (38 mg Zn/kg DM) and the supplements for 140 d. In Exp. 1, ADG was greater (P<0.05) from d 15 to 28 in calves fed supplemental Zn-amino acid compared with those fed Zn sulfate, but ADG did not differ (P>0.10) among treatments for the entire 28-d study. In Exp. 2, there was no effect (P>0.10) on ADG as a result of Zn supplementation. In Exp. 2, Zn-supplemented heifers had a greater response (P=0.06) to phytohemagglutinin 24 h after an intradermal injection. In Exp. 2, calves supplemented with Zn–amino acid complex had a greater antibody response to a second vaccination for bovine respiratory syncytial virus than did control or Zn sulfate-supplemented calves (treatment by day interaction, P=0.06). There was not a consistent benefit of supplemental Zn on growth of calves, but there was a positive impact of supplemental Zn on some immune-response measurements.     

Bioavailability of zinc in several sources of zinc oxide, zinc sulfate, and zinc metal.

Three zinc depletion-repletion assays were carried out with chicks to determine Zn bioavailability in five sources of ZnO, three sources of ZnSO4.H2O, and two sources of Zn metal. A standard 23% CP corn-soybean meal diet was fed during the first 3 d posthatching, after which it was replaced with a Zn-deficient soy concentrate diet (13.5 mg Zn/kg) until d 7. On d 8 after an overnight period of feed withdrawal, chicks were fed for 12 d the Zn-deficient basal diet containing 0, 4.76, and 9.90 (Assay 1); 0, 5.06, or 10.12 (Assay 2); or 0, 4.73, or 9.13 (Assay 3) mg/kg supplemental Zn from analytical grade (AG) ZnSO4.7H2O (22.7% Zn) to generate a standard response curve. The AG and feed-grade (FG) Zn sources being evaluated were then provided at a level that would fall within the standard curve. Weight gain (Assays 1, 2, and 3) and total tibia Zn (Assay 1) responded linearly (P<.01) to Zn supplementation from ZnSO4.7H2O. Weight gain regressed on supplemental Zn intake gave standard-curve equations with fits (r2) ranging from .94 to .97. In Assay 1, regression of total tibia Zn (Y, in micrograms) on supplemental Zn intake (X, in milligrams/12 d) gave the equation Y = 13.2+6.74X (r2 = .90). Standard-curve methodology was used to estimate relative Zn bioavailability (RBV), with RBV of Zn in the ZnSO4.7H2O standard set at 100%. Four sources of FG ZnO were evaluated: Source 1 (78.1% Zn, hydrosulfide process, U.S.), Source 2 (74.1% Zn, Waelz process, Mexico), Source 3 (69.4% Zn, China), and Source 4 (78.0% Zn, French process, Mexico). Analytical-grade ZnO (80.3% Zn) was also evaluated. Feed-grade ZnO Sources 1 and 4 as well as AG ZnO produced average RBV values that were not different (P>.10) from the standard, but average RBV values for FG Source 2 and FG Source 3 were only 34 (P<.05) and 46% (P<.05), respectively. All sources of ZnSO4.H2O, which included two FG sources (source 1, 36.5% Zn; source 2, 35.3% Zn) and one food-grade source (36.5% Zn), were not different (P>.10) in RBV from the ZnSO4.7H2O standard. Two Zn metal products, Zn metal dust (100% Zn) and Zn metal fume (91.5% Zn), were also evaluated, and they were found to have Zn RBV values of 67 (P<.05) and 36% (P<.05), respectively. Feed-grade sources of ZnO vary widely in color, texture, Zn content, and Zn bioavailability.     

降低铜、锌含量添加植酸酶对育肥猪生长性能、养分表观消化率及血清生化指标的影响

本试验旨在探讨植酸水平较高饲料中育肥猪适宜的铜、锌添加水平。试验选取108头55 kg左右的苏姜猪,采用2×3因子设计将试验猪随机分为6组,每组3个重复,每个重复6头。将低、中、高剂量铜、锌与植酸酶添加、不添加组合成6种饲料,每组饲喂其中1种饲料。试验期42 d,测定试验期间育肥猪生长性能、养分表观消化率、血清生化指标及血清和掌骨铜、锌含量。结果显示,降低饲料中铜、锌含量并添加植酸酶未显著影响育肥猪生长性能（P>0.05）。将铜、锌水平从高剂量降低到中、低剂量极显著地提高了铜、锌的表观消化率（P<0.01）,极显著降低了血清铜含量（P<0.01）;从高剂量降低到中剂量极显著降低了血清碱性磷酸酶活性（P<0.01）。添加植酸酶极显著提高了粗蛋白质表观消化率（P<0.01）,显著提高了锌表观消化率和血清碱性磷酸酶活性（P<0.05）。铜、锌水平和添加植酸酶对血清和掌骨锌含量、血清铜蓝蛋白和乳酸脱氢酶活力均无显著影响（P>0.05）。综上所述,在较高植酸水平的饲料中将铜、锌含量降到中等水平可提高铜、锌表观消化率,而不影响生长性能。添加植酸酶有利于提高粗蛋白质、锌的表观消化率。因而建议育肥苏姜猪饲料中添加中剂量铜、锌（即25 mg/kg铜＋40 mg/kg锌）并添加植酸酶。     

饲粮添加不同水平维生素D_3对肉仔鸡生长性能和骨磷代谢利用的影响

本试验旨在研究饲粮中添加不同水平维生素D3(VD3)对肉仔鸡生长性能及骨磷代谢利用的影响。试验选用480只1日龄艾拔益加肉公雏,采用2×4双因子完全随机设计,设2个饲粮非植酸磷水平[0.45%和0.23%(实测值为0.44%和0.21%)]与4个VD3添加水平(0、1 000、2 000和4 000IU/kg),共8个组,每组6个重复,每个重复10只鸡。试验期21d。结果表明,与0.21%非植酸磷水平相比,0.44%非植酸磷水平显著提高肉仔鸡平均日增重(ADG)、平均日采食量(ADFI)、胫骨灰分含量和胫骨灰分磷含量(P0.05),显著降低料重比(F/G)和胫骨灰分磷绝对沉积率(P0.05);与不添加VD3相比,饲粮中添加VD3显著提高肉仔鸡ADG、15~21和1~21日龄ADFI、胫骨灰分含量和胫骨灰分磷绝对沉积率(P0.05),显著降低1~21日龄肉仔鸡F/G(P0.05);0.21%非植酸磷水平下,与不添加VD3相比,饲粮中添加VD3显著降低肉仔鸡死亡率(P0.05),显著提高21日龄肉仔鸡胫骨灰分磷重量(P0.05),添加2000IU/kg VD3显著提高14日龄肉仔鸡胫骨灰分磷重量(P0.05);0.44%非植酸磷水平下,与不添加VD3相比,饲粮中添加VD3显著提高肉仔鸡胫骨灰分磷重量(P0.05)。以上结果表明,饲粮中添加VD3可提高肉仔鸡的生长性能并降低死亡率,促进磷在骨骼中的代谢利用。     

Effects of organic zinc and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc content of broiler chicks

1. The purpose of this study was to investigate the effects of Bioplex Zn (a chelated zinc proteinate) and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc (Zn) content of broiler chicks. Treatment structure consisted of a 2 x 6 factorial arrangement with two inclusions of phytase (0 or 500 PU/kg) and 6 of Bioplex Zn providing 0, 2, 4, 8, 16 and 32 mg Zn/kg diet. A total of 864 chicks were randomly assigned to each of 12 dietary treatments with 6 replicate cages of 12 chicks. 2. Dietary inclusion of phytase increased feed intake, weight gain, plasma Zn content, tibia Zn content, tibia and ash weight. 3. Dietary supplementation of Bioplex Zn linearly increased feed intake, weight gain, gain to feed ratio, plasma Zn concentration, liver Zn concentration, tibia Zn content, tibia and ash weight. 4. An interactive effect of phytase and Bioplex Zn on feed intake, weight gain, tibia Zn concentration and tibia ash weight was found. 5. One slope, straight broken-line analysis of weight gain regressed on the supplemental Zn level provided as Bioplex Zn indicated that 12 mg/kg supplemental Zn without phytase and 7.4 mg/kg supplemental Zn with phytase were required for the optimal weight gain of chicks.     

饲粮锌水平对肉鸡组织锌含量的影响

以肉仔鸡(9～27日龄)为试验动物,采用大豆分离蛋白、蔗糖、玉米淀粉及去皮去胚玉米为主的半纯合饲粮,锌水平为10.5 mg/kg,在此基础上,分别添加20,40,60及80 mg/kg 锌,观察饲粮锌水平对肉仔鸡生长发育和组织锌含量的影响。18天的试验结果表明,低锌组(10 mg/kg)除肝脏较重外(P<0.05),其它组织器官发育及体增重均不受饲粮锌水平的影响。促使全鸡及血液锌含量明显增加的饲粮锌水平分别为30及50 mg/kg(P<0.05)。当饲粮锌水平从10 mg/kg 增至30 mg/kg 时,胰脏、肝脏和胫骨锌含量分别增加63%、92%及63%;随着锌水平的继续增加,肝脏及胫骨的锌含量增加的幅度较小,二者(y)与饲粮锌水平(x)呈指数曲线变化,y 肝=61.54e~(-8.67/x)(r=0.95,P<0.01);y 胫骨=53.19e~(-6.92/x)(r=0.88,P<0.01);胰脏锌含量与饲粮锌水平呈正向变化,直线相关:y=37.97±0.34x,(r=0.78,P<0.01)和幂曲线相关:y=18.81x~(0.284),(r=0.82,P<0.01)。胰脏沉积锌的能力远大于肝脏和胫骨。根据上述结果认为,胰、肝和胫骨锌是评价饲料锌效价的良好指标。