China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (4): 1375-1384.doi: 10.16431/j.cnki.1671-7236.2023.04.009

• Nutrition and Feed • Previous Articles     Next Articles

Effects of Dietary β-carotene Supplementation on Lactation Performance, Blood Routine,Serum Biochemical and Immune Indexes of Dairy Cows during the Lactating Peak Period

HU Honglian1, LI Chao2, CHEN Liqing2, SONG Liwen1, ZHAO Meng1, ZHANG Jianxia2, WANG Dian3, GAO Min1   

  1. 1. Institute of Animal Nutrition and Feed, Inner Mongolia Academy of Agricultural & Animal Husbandry Sciences, Hohhot 010031, China;
    2. College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China;
    3. Inner Mongolia Youran Dairy Co. Ltd., Hohhot 010010, China
  • Published:2023-04-06

Abstract: 【Objective】 This experiment was conducted to study the effects of dietary β-carotene supplementation on lactation performance,blood routine indexes and serum biochemical and immune indexes of dairy cows during the lactating peak period.【Method】 Twenty healthy Chinese Holstein dairy cows during the dry period with an average body weight of (550.00±32.71) kg and parities of 2-3 were randomly divided into 4 groups with 5 cows in each group.The cows in control group were fed a basal diet,the cows in experimental groups were fed the basal diet supplemented with 600,1 200 and 1 800 mg/d β-carotene,respectively.The experiment lasted for 150 days from 60 days before calving to 90 days after calving.During the experiment,the milk yield and milk composition of dairy cows were measured.Blood was collected from the tail vein to determine the blood routine indexes,and isolated serum was used to determine the indexes of biochemistry and immune at the end of the experiment.【Result】 Compared with the control group,dietary β-carotene supplementation had no significant effect on milk yield,milk fat rate,milk protein rate and lactose rate of dairy cows (P>0.05).600,1 200 mg/d β-carotene supplementation significantly reduced somatic cells number of dairy cows (P<0.05).Dietary β-carotene supplementation had no significant effect on blood white blood cell count (WBC),red blood cell count (RBC),platelet count (PLT),hemoglobin (HGB) and hematocrit (HCT) (P>0.05).1 200 and 1 800 mg/d β-carotene supplementation significantly increased serum triglyceride (TG) content (P<0.05),600,1 200 mg/d β-carotene supplementation significantly increased serum high density lipoprotein (HDL) content (P<0.05).600 and 1 800 mg/d β-carotene supplementation significantly reduced the serum CD4+ content of dairy cows (P<0.05),1 200 mg/d β-carotene supplementation significantly decreased the contents of serum CD8+,tumor necrosis factor-α (TNF-α),interleukin-1 β (IL-1β),interleukin-2 (IL-2) and interferon-γ (IFN-γ) contents,and significantly increased CD4+/CD8+ ratio in serum of dairy cows (P<0.05).【Conclusion】 In conclusion,appropriate of β-carotene in diet could reduce somatic cell count in milk and inflammatory cytokines,and enhance cellular immune function of dairy cows during the lactating peak period,and 1 200 mg/d was the appropriate supplemental level.

Key words: β-carotene; dairy cows; inflammatory factors; T cell subsets; immune function

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