Effects Of Starch Source And Sodium Carboxymethyl Cellulose Level On Pellet Quality,Production Performance And Cecal Flora Of Meat Rabbits

The purpose of this experiment was to study the effects of dietary starch source and sodium carboxymethyl cellulose(CMC-Na)on the quality,production performance,nutrient apparent digestibility and cecal flora of meat rabbit pellet feed.The test adopts 2×3 two factor factorial design,six kinds of experimental diets were prepared by selecting two starch sources(corn starch and potato starch)(the addition amount was 9%)and three CMC-Na addition levels(0,5 and 10g/kg).144 Iraqi meat rabbits with an average weight of(1.16±0.02)kg at the age of 35 days were randomly divided into 6 groups,with 6 replicates in each group,and4 rabbits in each replicate(half male and half female)were fed the above six experimental diets respectively.5-day pre feeding period and 30-day formal trial period.The results showed as follows:(1)Quality of pellet feed: compared with corn starch source,potato starch source significantly reduced the powder content,pulverization rate and starch gelatinization degree of pellet feed,and significantly improved the bulk density of pellet feed(P < 0.05);The addition of 5g/kg CMC Na significantly reduced the powder content of the particles,and the addition of 5g/kg and 10g/kg CMC-Na significantly increased the particle bulk density and reduced the pulverization rate(P<0.05);There was no significant interaction between starch source and CMC-Na level on the processing quality of pellet feed(P>0.05).(2)Production performance: compared with corn starch source,potato starch source significantly increased the average daily food intake(ADFI)of meat rabbits in early and whole period(P<0.05);The addition of 5g/kg CMC-Na to the diet significantly increased the ADFI of meat rabbits,and the addition of 10G/kg CMC-Na significantly decreased the ADFI of pre-,mid-and full-term(P< 0.05);Starch source and CMC-Na level had significant interaction with ADFI in meat rabbits(P < 0.05).There was no significant difference in average daily gain and feed weight ratio of meat rabbits in each group(P>0.05).(3)Apparent digestibility of nutrients and intestinal digestive enzyme activity: compared with corn starch source,potato starch source significantly improved the digestibility of crude protein in meat rabbits(P<0.05);The apparent digestibility of dry matter,total energy,crude protein and fiber of meat rabbits were not significantly affected by the addition of different levels of CMC-Na(P>0.05);There was no significant interaction between starch source and CMC-Na level on dietary nutrient digestibility of meat rabbits(P>0.05).Compared with corn starch source,potato starch source significantly increased amylase activity in duodenum,jejunum and ileum of meat rabbits(P<0.05);The addition of 10G/kg CMC-Na significantly increased the amylase activity of duodenum,jejunum and ileum of meat rabbits(P<0.05);Starch source and CMC-Na level had no significant interaction on pepsin,cecal cellulase,duodenal and jejunal ileal amylase activities in meat rabbits(P >0.05).(4)Blood biochemical indexes: compared with potato starch source,corn starch source significantly increased the content of serum insulin(INS)in meat rabbits(P<0.05);The level of CMC-Na had no significant effect on the levels of serum INS,glucagon(GC),blood glucose,total cholesterol(TC)and triglyceride(TG)in meat rabbits(P>0.05);There was significant interaction between starch source and CMC-Na level on serum TC in meat rabbits(P<0.05).(5)Cecal flora fermentation parameters and flora structure: compared with corn starch source,potato starch source significantly increased the contents of acetic acid,propionic acid and butyric acid in rabbit cecum(P < 0.05).Starch source and CMC-Na level had no significant effect on the diversity of cecal flora in meat rabbits(P>0.05);Adding 10g/kg CMC-Na to different starch sources,the similarity of cecal flora of meat rabbits was high,and there was no obvious clustering law in other groups;The dominant bacterial groups in rabbit cecum were Firmicutes(57.02%),Clostridium(50.97%),spirillera(28.48%),spirulinaceae(15.23%)and unclassified genus(13.11%);Compared with corn starch source,potato starch source significantly increased Firmicutes,clostridia,actinomycetes and bacterium in rabbit cecum＿enrichment、uncultured＿The relative abundance of rumen(P<0.05),the addition level of CMC-Na on Bifidobacterium and gut＿metagenome、Bacteroides＿coprophilus、human＿gut、Parabacteroides＿The relative abundance of merdae was significantly affected(P<0.05).In conclusion,potato starch source and addition of 5 or 10g/kg CMC-Na were beneficial to improve the quality of pellet feed;Corn starch source reduced ADFI,but did not affect weight gain.Starch source and CMC-Na only interacted with ADFI and serum total cholesterol in meat rabbits.Under the test conditions,it is recommended to use corn starch source and add 5 or 10g/kg CMC-Na adhesive.