Wo Yeqianli, Jin Yuhang, Gao Duo, Ma Fengtao, Ma Zhu, Liu Zhuo, Chu Kangkang, Sun Peng
State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
Beijing Dairy Cow Center, Beijing, China.
Front Vet Sci. 2022 Jul 1;9:911330. doi: 10.3389/fvets.2022.911330. eCollection 2022.
Two experiments were conducted to identify the optimal dose of zinc proteinate (ZP) in the diet for dairy calves and then to compare early supplementation with the ZP or zinc methionine (ZM) on the growth performance, incidence of diarrhea, antioxidant status, and immune function of dairy calves during their first month of life. In Experiment 1, forty newborn female Holstein dairy calves were randomly divided into four groups ( = 10): a control group (without ZP supplementation, ZP0) or groups that received ZP supplementation at 40, 80, and 120 mg zinc/day, respectively (ZP40, ZP80, and ZP120). The experiment lasted 14 days, and the growth performance, incidence of diarrhea, and serum zinc concentration were analyzed. In Experiment 2, thirty-six newborn female Holstein dairy calves were randomly allocated to three groups ( = 12): a negative control group (without zinc supplementation, CON), a positive control group (supplemented with 80 mg zinc/day in the form of zinc methionine, ZM), and a ZP group (supplemented with 80 mg zinc/day in the form of ZP). The experiment lasted 28 days, and the growth performance, incidence of diarrhea, serum zinc concentration, serum antioxidant indicators, and concentrations of plasma immunoglobulins and cytokines were determined on days 7, 14, 21, and 28. Results showed that in Experiment 1, supplementation with ZP to yield 80 mg zinc/day increased the ADG ( < 0.01) and serum zinc concentration ( < 0.01), and decreased the F/G ( < 0.01) and the incidence of diarrhea ( < 0.05) during days 1-14. In Experiment 2, compared with the CON group, ZP increased the ADG ( < 0.01), serum zinc concentration ( < 0.01), and plasma immunoglobulin G (IgG; < 0.01) and IgM ( < 0.01) concentrations, but reduced the incidence of diarrhea ( < 0.01), serum malondialdehyde ( < 0.01), and plasma interleukin-1β ( < 0.01) concentrations during days 1-28. Overall, ZP supplementation to yield 80 mg zinc/day improves the growth performance and immune function, and decrease the incidence of diarrhea of dairy calves, which was comparable to the same dose of zinc in the form of ZM.
进行了两项试验，以确定犊牛日粮中蛋白锌（ZP）的最佳剂量，然后比较在犊牛出生后第一个月内，早期补充ZP或蛋氨酸锌（ZM）对其生长性能、腹泻发生率、抗氧化状态和免疫功能的影响。在试验1中，40头新生雌性荷斯坦犊牛被随机分为四组（每组n = 10）：对照组（不补充ZP，ZP0）或分别以每天40、80和120 mg锌的剂量补充ZP的组（ZP40、ZP80和ZP120）。试验持续14天，并分析生长性能、腹泻发生率和血清锌浓度。在试验2中，36头新生雌性荷斯坦犊牛被随机分为三组（每组n = 12）：阴性对照组（不补充锌，CON）、阳性对照组（以蛋氨酸锌形式每天补充80 mg锌，ZM）和ZP组（以ZP形式每天补充80 mg锌）。试验持续28天，并在第7、14、21和28天测定生长性能、腹泻发生率、血清锌浓度、血清抗氧化指标以及血浆免疫球蛋白和细胞因子浓度。结果显示，在试验1中，以每天80 mg锌的剂量补充ZP可提高平均日增重（P < 0.01）和血清锌浓度（P < 0.01），并降低1-14天期间的料重比（P < 0.01）和腹泻发生率（P < 0.05）。在试验2中，与CON组相比，ZP提高了平均日增重（P < 0.01）、血清锌浓度（P < 0.01）以及血浆免疫球蛋白G（IgG；P < 0.01）和IgM（P < 0.01）浓度，但降低了1-28天期间的腹泻发生率（P < 0.01）、血清丙二醛（P < 0.01）和血浆白细胞介素-1β（P < 0.01）浓度。总体而言，以每天80 mg锌的剂量补充ZP可改善犊牛的生长性能和免疫功能，并降低腹泻发生率，这与相同剂量的ZM形式的锌相当。
