Effect Of Main Chinese Herbs In Northwest China On Nutrition And Metabolism Of Lactating Yak And Calves

With the development of the livestock industry in Tibetan Plateau,the number of yak increased.Semi-intensive feeding system,such as supplementary feeding in winter and spring,is gradually raising in order to cope with the shortage of forage resources in winter and spring on the Qinghai-Tibet Plateau.Because of lactating and insufficient pasture biomass and nutrition supply,grazing lactating yak cows always face low productivity and body conditions.Early weaning of yak calves（3～4 months old）has been introduced and accepted in yak management system to increase the breeding rate of yak cows and growth of calves.However,early weaning practice resulted in stress,low immunity of calves,and increased disease infecting rate and mortality rate.Traditional Chinese herbs have long been used as feed additives to maintain health and cure disease.Futhermore,herbs perform healthy feeding management,which is the promising current research issue.Angelica sinensis,Codonopsis pilosula,Glycyrrhiza uralensis,Astragalus membranaceus were widely used herbs,and planted in northwest China,with the function of promoting immune ability,antioxidity,and inhibiting pathogenic bacteria.The dry root powder of Astragalus membranaceus and Angelica sinensis was supplemented to lactating yak cows,and the water extract of the dry root powder of Angelica sinensis,Codonopsis pilosula,Glycyrrhiza uralensis,Astragalus membranaceus were supplemented to early weaning yak calves to examine the feeding effects.The purpose is to find theoretical basis for using these herbs as feed additive.The research results are as follows:Part1 Effects of supplementing Astragalus and Angelica on blood physiological and biochemical indexes and milk quality of Lactating yak cowsTwenty-four healthy lactating yak cows with similar weight,age and calving time were randomly divided into two groups（12 of each）.The treatment group was daily supplemented with 350 g powder of Astragalus and Angelica（2.5:1）in a 68days’trial.The results showed that the concentration of serum creatinine（CREA）and malondialdehyde（MDA）were significantly lower in treatment group than control（P<0.05）.The content of serum immune globulin（Ig A,Ig G,Ig M）,interleukin（IL-2）,glutathione peroxidase（GSH-Px）,total superoxide dismutase（T-SOD）and growth hormone（GH）were significantly higher in herb feeding group than control（P<0.05）.The milk fat,protein,lactose,urea nitrogen and lactoferrin concentration were significantly higher in treatment group than control（P<0.05）.The somatic cell count was significantly lower in treatment group than control（P<0.05）.the current results showed that addition of Astragalus and Angelica improved the immunity,antioxidant capacity and milk quality of lactating yak cows.Part2 Research on early weaned calves with supplementing Chinese traditional herbal extracts.Twenty-five calves with similar genetic background were simultaneously weaned and randomly divided into 5 groups（with 5 calves in each group）to non-feed（control）or feed the water extract（80 m L/kg DMI）of Angelica sinensis,Codonopsis pilosula,Glycyrrhiza uralensis and Astragalus membranaceus.The experiment lasted for 75 days,including 15-day pre-feeding period and 60-day normal feeding period.The results were as the following:（1）Effects on growth performance.There were no significant treatment effects on final bodyweights of yak calves（P>0.05）.The average daily gain（ADG）of calves consuming Codonopsis pilosula root herbal extract were higher than other groups（P<0.05）,and consuming Astragalus membranaceus root herbal extract was higher than control（P<0.05）.（2）Effects on rumen fermentation and microbial composition.The concentrations of propionic acid,isobutyrate and isovalerate with calves consuming four Chinese herbal root extracts were higher than control（P<0.05）.Rumen NH₃-H concentration of calves consuming Angelica sinensis,Codonopsis pilosula and Astragalus membranaceus root extracts were significantly lower than control（P<0.05）.The rumen bacterial diversity was highest for yak calves consuming Codonopsis pilosula root extract.yak calves consuming Angelica sinensis and Glycyrrhiza uralensis root extracts had the higher abundance of Bacteroidetes and lower abundance of Firmicutes than control（P<0.05）.Yak calves consuming Codonopsis pilosula root extract had the highest abundance of Actinobacteria and Proteobacteria among the five groups（P<0.05）.The abundance of spirochetes in Astragalus membranaceus group was significantly higher than the other four groups（P<0.05）.The abundance of Succiniclasticum genus in calves consuming the four herbal root extracts were significantly lower than control（P<0.05）.（3）Effects on blood physiological and biochemical indexes.The supplementation of four herbal root water extracts increased serum glucose（GLU）,total protein（TP）and albumin（ALB）concentration of yak calves,while decreased concentration of total cholesterol（TC）and free fatty acid（FFA）（P<0.05）.The four herbal root extracts improved antioxidant capacity by detecting the serum malondialdehyde（MDA）and glutathione peroxidase（GSH）concentrations.（4）Studys on surem metabolism.The four herbal feeding treatments had different effects on serum metabolite content of calves in some extent.Yak calves consuming Glycyrrhiza uralensis and Astragalus membranaceus showed more significant effects（P<0.05）.Codonopsis pilosula herbal root extract downregulated the glyceryl phophatide metabolism,and the four herbal root extracts all upregulated amino acids anabolism.In conclusion,supplementation the dry root powder of Astragalus membranaceus and Angelica sinensis significantly improved the immunity and antioxidant capacity,and improved the milk quality of lactating yak cows.Feeding the early weaned yak calves with four traditional herbal root water extracts of Angelica sinensis,Codonopsis sinensis,Glycyrrhiza uralensis and Astragalus membranaceus showed regulating effect on rumen fermentation and microbial composition,improved immunity and antioxidant capacity,regulated protein and fat metabolism of yak calves.Supplementation of Astragalus sinensis and Codonopsis sinensis water root extracts showed promoting effect on growth performance of early weaned calves.