【Objective】Differ ent expression profiles of polypeptides in follicle fluid from superovulated cattle and calves were studied in order to provide references for further research on follicle fluid of calves and in vitro oocyte culture system of calves.【Method】The matrix-assisted laser desorption ionization mass spectrometry(MALDI-TOF MS)was used to analyze the peptide fragments in follicular fluid of superovulated cattle and calves.Based on signal peak information of polypeptide,protein search was conducted in MASCOT database.【Result】The models of polypeptide expression profiles of the two groups were successfully established,respectively.There were 30-40 peak signals in cattle group,and 60-80 peak signals in calves.By comparing the peak lists from the two different samples,it was found that 2 specific peaks of 1218.58 and 1509.77 m/z appeared in cattle group,similarly,and 1 specific peak of 953.54 m/z in calf group.At last,MASCOT library was used to search the information of polypeptides,and then some proteins related to these polypeptides information were gained.The results showed that 18 kinds of proteins existed in cattle group,and 11 kinds of proteins in calves.【Conclusion】The results showed that the polypeptide information peak quantity of calf follicular fluid protein was higher than that of adult cattle,while the total number of proteins in follicle fluid from the calves was less than that of the adult cattle group,which could be one of reasons why the developmental competence of oocytes from calves was poorer than that of adult cattle.

In order to define the best superovulation program,the best month old of calves and the best repeated superovulation time interval,different superovulation programs were conducted on different months old calves(1～6 months old) in this study.The results showed that the superovulation program 4,of which the average number of eggs collected was 80.0 missiles,the average number of oocytes recovered was 43.3 missiles and the average number of eggs available was 37.8 missiles,were significantly higher than the other four programs(P0.05).It suggested that program 4 was fitted for superovulation of 3 months old calves;program 4 was much better than other 4 programs in 2 months old,3 months old,4 months old,5 month old calves with the average number of eggs of 33.5,41.0,34.5 and 32.8 missiles respectively,and the difference between each other was not significant.The results of 1 month and 6 months old calves with the average number of available eggs of 10.8 and 18.3 missiles was significantly lower than the other four age groups(P0.05),it suggested that the superovulation treatment program 4 was most suitable for 2 to 5 months calves.Moreover,we also found that the results of superovulation interval of 2 weeks group with average number of eggs available of 6.3 missiles were significantly worse than the interval of 3 weeks,4 weeks and 5 weeks group(P0.05) with that of 16.7,23.7,23.0 missiles,respectively.The superovulation difference between 3 weeks,4 weeks,5 weeks groups was not significant indicated that the best time interval of 3 to 4 weeks was best for repeated superovulation treatment on calves.