Effects of starter diet protein levels on serum immune,antioxidant,and hormone indices of suckling donkey foals

LAN Xiangli; SUN Yanan; WANG Hongyu; MA Chen; HONG Min; HAN Xiaohua; ZENG Shenming; LIU Zhiyou

doi:10.13557/j.cnki.issn1002-2813.2025.24.021

Abstract：The experiment aimed to investigate the effects of starter diet protein levels on the serum immune,antioxidant,and hormone indices of suckling donkey foals.A total of 21 healthy female donkey foals of two-month-old with an average body weight of(52.0±2.5)kg were selected and randomly divided into three groups,with seven replicates per group,and one donkey foal per replicate.They were respectively fed starter feed with protein levels of 20.03%(high protein group),18.02%(medium protein group),and 16.01%(low protein group).The pre-test period was 15 days.The formal test period was 45 days.The results showed that the body height,bady length,and chest circumference of the donkey foals in each group were similar,with no significant differences(P>0.05).As the protein level of the starter diet increased,the serum immunoglobulin G(IgG)content in donkey foals was significantly increased(P<0.05),and the interleukin-1β(IL-1β)content was significantly decreased(P<0.05).The serum immunoglobulin M(IgM)content in the high protein group was significantly higher than that in the low and medium protein groups(P<0.05),and the interleukin-2(IL-2)content in the medium protein group was significantly higher than that in the low and high protein groups(P<0.05).The activities of serum catalase(CAT)and superoxide dismutase(SOD)in the medium and high protein groups were significantly higher than those in the low protein group(P<0.05),and the activity of glutathione peroxidase(GSH-Px)in the high protein group was significantly higher than that in the low and medium protein groups(P<0.05).The content of malondialdehyde(MDA)in the medium and high protein groups was significantly lower than that in the low protein group(P<0.05).The levels of serum adiponectin(ADP)and insulin-like growth factor-1(IGF-1)in the high protein group were significantly higher than those in the low and medium protein groups(P<0.05).The study shows that when the protein level in the starter diet is from 18.02%and 20.03%,it can enhance the immune function and antioxidant capacity,and promote the glucose and lipid metabolism of donkey foals.