| The growth of gastrointestinal tract has a relationship with feed intake and nutriment digestion and absorption of calves,which plays a important role in calves’ growth and production.There are systematic macroorganism and their fermentation products in the rumen,which interplays with the rumen.So the good development of rumen will make calf adjust for the fodder early,advance the weaning date and improve economic benefits.The experiment aims to artificially inoculate the macroorganism by feed the new-born calves the healthy mature cow’s rumen fluid,and studies on its effect on calves’ growth and gastrointestinal intestinal tract.The thesis will proceed related experiments from the following aspests:1.This section studied the effects of rumen fluid drening on the growth performance of calves,including weight,size,body measurements,feed intake,feed conversion rate and diarrhea rate.Twenty healthy newborn Holstein calves were randomly divided into two groups(n=10)with similar body weights:rumen fluid drenching(RD)and Autoclaved rumen fluid drenching(AD),two groups received the same feed.The duration of experiment is 77 days.Feed intake and diarrhea was recorded everyday and body weight and body measurements was recorded every week since calves’ birth and then calculated the average daily gain and F/G of calves.The rumen fluid for drenching was collected from rumen of 2 adult healthy fistulous cows,and drenching were carried out 5 times at d3 d7 d21 d42 and d50.The drenching volume was 100 mL,200 mL,300 mL,400 mL and 500 mL respectively each time.The fluid for RD was drenched fresh but for AD was drenched after sterilizing.The results showed that rumen fluid drenching do not effect the growth performance of calves significantly,for there is no remarkable difference between 2 groups’ body weight,body height,body length,heart girth,circumference of cannon bone,feed intake,the average daily gain or F/G of calves(P>0.05).however,the diarrhea of RD was significantly lower than AD(P<0.01).2.This section studied the effect of rumen fluid drenching on the gastrointestinal fermentation function and the activity of small intestine digestive enzymes of calves.The experiment design was the same as the first part and the calves were slaughtered when they were 77days old.The results was as follows:Drenching rumen fluid had no influence on the pH,VFA,NH3-N in the rumen,and the activity of trypsin and chymotrypsin,lipase,lactase and α-amylase in the small intestine(P>0.05).However,the ratio of acetic acid and propionic acid in the rumen and caecum decreased significantly(P = 0.03).In addition,the ratio of acetic acid and propionic acid in the colon tended to decreased(P = 0.09).3.This section studied the effects of rumen fluid drenching on the morphological development of gastrointestinal tract of calves.The design of this section was as same as the section one.It is aimed to research the effect of rumen fluid drenching on weight of stomach,length of small intestine and the microscopic morphology of gastrointestinal epithelium.The results showed that rumen fluid drenching significantly enhanced the length of duodenal villous(P=0.02),while had no significance on the duodenal crypt depth(P>0.05).Meanwhile,rumen fluid drenching did not affect the weights of rumen and whole stomachus compositus,the length and width of rumen papilla,the length of small intestine,villous length or crypts depth in intestine except for duodenum(P>0.05).In conclusion,rumen fluid drenching in this experiment as an microbial inoculation to the rumen did not have a significant impact on growth performance of calves and development of gastrointestinal tract.However,it changed ruminal fermentation pattern and had a certain inhibitory effect on early diarrhea of calves.It indicates that the microorganism could be have established in the rumen through the rumen fluid drenching or ruminal ecology have been changed by microorganism or compound in drenching fluid. |
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