van Heugten E, Spears J W, Kegley E B, Ward J D, Qureshi M A
Department of Animal Science and Interdepartmental Nutrition Program, North Carolina State University, Raleigh 27695-7621, USA.
J Anim Sci. 2003 Aug;81(8):2063-71. doi: 10.2527/2003.8182063x.
This study was conducted to determine the effect of zinc level and source on growth performance, tissue Zn concentrations, intracellular distribution of Zn, and immune response in weanling pigs. Ninety-six 3-wk-old crossbred weanling pigs (BW = 6.45 +/- 0.17 kg) were assigned to one of six dietary treatments (four pigs per pen, four replicates per treatment) based on weight and litter origin. Treatments consisted of the following: 1) a corn-soybean meal-whey diet (1.2% lysine) with a basal level of 80 ppm of supplemental Zn from ZnSO4 (control; contained 104 ppm total Zn); 2) control + 80 ppm added Zn from ZnSO4; 3) control + 80 ppm added Zn from Zn methionine (ZnMet); 4) control + 80 ppm added Zn from Zn lysine (ZnLys); 5) control + 40 ppm added Zn from ZnMet and 40 ppm added Zn from ZnLys (ZnML); and 6) control + 160 ppm added Zn from ZnSO4. Zinc supplementation of the control diet had no effect on ADG or ADFI. Gain efficiency was less (P < 0.05) for pigs fed 80 ppm of Zn from ZnSO4 than for control pigs and pigs fed 160 ppm of Zn from ZnSO4. Organ weights, Zn concentration, and intracellular distribution of Zn in the liver, pancreas, and spleen were not affected (P = 0.12) by Zn level or source. Skin thickness response to phytohemagglutinin (PHA) was not affected (P = 0.53) by dietary treatment. Lymphocyte proliferation in response to PHA was greater (P < 0.05) in pigs fed ZnLys than in pigs fed the control diet or the ZnML diet; however, when pokeweed mitogen was used, lymphocyte proliferation was greatest (P < 0.05) in pigs fed the ZnMet diet than pigs fed the control, ZnLys, ZnML, or 160 ppm ZnSO4 diets. Antibody response to sheep red blood cells was not affected by dietary treatments. Supplementation of 80 ppm of Zn from ZnSO4 or ZnMet and 160 ppm of Zn from ZnSO4 decreased (P < 0.05) the antibody response to ovalbumin on d 7 compared with control pigs, but not on d 14. Phagocytic capability of peritoneal exudate cells was increased (P < 0.05) when 160 ppm of Zn from ZnSO4 was supplemented to the diet. The number of red blood cells ingested per phagocytic cell was increased (P < 0.05) in pigs fed the diet supplemented with a combination of ZnMet and ZnLys and the diet with 160 ppm of Zn from ZnSO4. Results suggest that the level of Zn recommended by NRC for weanling pigs was sufficient for optimal growth performance and immune responses, although macrophage function may be enhanced at greater levels of Zn. Source of Zn did not alter these measurements.
本研究旨在确定锌水平和锌源对断奶仔猪生长性能、组织锌浓度、锌的细胞内分布以及免疫反应的影响。将96头3周龄的杂交断奶仔猪（体重=6.45±0.17千克）根据体重和窝别来源分配到六种日粮处理之一（每栏4头猪，每个处理4个重复）。处理包括以下几种：1）玉米-豆粕-乳清日粮（赖氨酸含量1.2%），从硫酸锌补充基础水平80 ppm的锌（对照；总锌含量104 ppm）；2）对照+从硫酸锌添加80 ppm锌；3）对照+从蛋氨酸锌（ZnMet）添加80 ppm锌；4）对照+从赖氨酸锌（ZnLys）添加80 ppm锌；5）对照+从ZnMet添加40 ppm锌和从ZnLys添加40 ppm锌（ZnML）；6）对照+从硫酸锌添加160 ppm锌。对照日粮补充锌对平均日增重（ADG）或平均日采食量（ADFI）没有影响。饲喂80 ppm硫酸锌锌的猪的生长效率低于（P<0.05）对照猪和饲喂160 ppm硫酸锌锌的猪。锌水平或锌源对肝脏、胰腺和脾脏的器官重量、锌浓度以及锌的细胞内分布没有影响（P=0.12）。日粮处理对皮肤对植物血凝素（PHA）的厚度反应没有影响（P=0.53）。饲喂ZnLys的猪对PHA的淋巴细胞增殖大于（P<0.05）饲喂对照日粮或ZnML日粮的猪；然而，当使用商陆有丝分裂原时，饲喂ZnMet日粮的猪的淋巴细胞增殖大于（P<0.05）饲喂对照、ZnLys、ZnML或160 ppm硫酸锌日粮的猪。对绵羊红细胞的抗体反应不受日粮处理的影响。与对照猪相比，从硫酸锌或ZnMet补充80 ppm锌以及从硫酸锌补充160 ppm锌降低了（P<0.05）第7天对卵清蛋白的抗体反应，但在第14天没有。当日粮中补充160 ppm硫酸锌锌时，腹膜渗出细胞的吞噬能力增加（P<0.05）。饲喂补充了ZnMet和ZnLys组合的日粮以及饲喂160 ppm硫酸锌锌日粮的猪，每个吞噬细胞摄取的红细胞数量增加（P<0.05）。结果表明，美国国家研究委员会（NRC）推荐的断奶仔猪锌水平足以实现最佳生长性能和免疫反应，尽管在更高锌水平下巨噬细胞功能可能会增强。锌源没有改变这些测量结果。
