China Animal Husbandry and Veterinary Medicine ›› 2022, Vol. 49 ›› Issue (9): 3382-3390.doi: 10.16431/j.cnki.1671-7236.2022.09.012

• Nutrition and Feed • Previous Articles     Next Articles

Effects of Two Different Organic Zinc Sources Supplementation on Growth Performance and Zinc Metabolism of Newborn Heifers

WO Yeqianli1, GAO Duo1, MA Fengtao1, JIN Yuhang1, LIU Zhuo2, SUN Peng1   

  1. 1. State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China;
    2. Shijiazhuang Junlebao Dairy Co., Ltd., Shijiazhuang 050000, China
  • Received:2022-02-17 Online:2022-09-05 Published:2022-08-24

Abstract: 【Objective】 This study aimed to investigate the effects of supplementation with two different organic zinc sources on the growth performance and zinc metabolism of newborn dairy heifers.【Method】 Thirty newborn Holstein heifers with similar body weight (BW 39.4 kg±0.8 kg) were selected and randomly divided into 3 groups, with 10 heifers in each group.Heifers in the control group (CON) was fed basal diet without organic zinc supplementation, and heifers in organic zinc groups were fed with 522.82 mg/d of zinc proteinate (Zn-Pro) or 467.88 mg of zinc methionine (Zn-Met) (equivalent to 80 mg Zn).The experiment lasted for 14 d.Before morning feeding on day 1 and 14, the body weight of each calf was measured to calculate the average daily gain.Milk intake was recorded daily and used to calculate average daily feed intake and F/G.The feces score was assessed by a specialized person before morning feeding every day, and the incidence of diarrhea was calculated.Before morning feeding on day 14, the serum samples were collected for the determination of calcium, phosphorus, zinc, copper and iron concentrations, activities of alkaline phosphatase and superoxide dismutase, metallothionein concentration, malondialdehyde concentration and total antioxidant capacity.【Result】 Compared with the CON group, supplementation with Zn-Met significantly increased the average daily gain of dairy heifers (P<0.05), supplementation with Zn-Pro and Zn-Met decreased the incidence of diarrhea and increased the serum zinc concentration of heifers (P<0.05), and the serum zinc concentration of heifers in Zn-Met group was significantly higher than that in Zn-Pro group (P<0.05).Compared with the CON group, supplementation with Zn-Met significantly decreased the serum copper concentration of heifers (P<0.05), but there was no significant difference between the Zn-Pro group and the control group(P>0.05).Compared with the CON group, supplementation with Zn-Pro and Zn-Met both significantly increased the serum concentration of metallothionein (P<0.05), but only Zn-Met increased serum activity of alkaline phosphatase (P<0.05).Superoxide dismutase activity and total antioxidant capacity in serum of heifers were increased by Zn-Met supplementation (P<0.05), but supplementation with Zn-Pro had no significant effect (P>0.05).Supplementation with Zn-Pro and Zn-Met reduced the concentration of malondialdehyde in serum of dairy heifers (P<0.05).【Conclusion】 Supplementation with Zn-Met in the diet improved the growth performance, reduced the incidence of diarrhea, and improved the zinc metabolism of dairy heifers, whose effects were better than that of Zn-Pro.Therefore, it was suggested to add 80 mg Zn/d as Zn-Met to the diet of dairy heifers.

Key words: zinc proteinate; zinc methionine; newborn heifer; growth performance; zinc metabolism

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