Effects Of Artificial Sweeteners On Growth Performance,Rumen Fermentation And Small Intestine Glucose Absorption Of Dairy Goats

Animals have different taste preferences for feed,pigs prefer sweet taste,cattle and sheep prefer sweet taste and umami taste.Appropriately increasing feed sweetness can theoretically improve palatability,feed intake and production performance of animals.As a substitute for sucrose,artificial sweeteners have the characteristics of high sweetness and relatively low adding cost.Saccharin sodium is the most widely used artificial sweetener,which can effectively improve feed intake and growth rate of monogastric animals.As a new type of artificial sweetener,Neotame has high sweetness and tastes closer to sucrose.In recent years,the synthesis technology has made a breakthrough in China and the production cost has been reduced.It has gradually become a widely used artificial sweetener.Artificial sweeteners can not only improve food intake,but also regulate glucose absorption in small intestine and digestive tract microflora.However,at present,there are few studies on the application of artificial sweeteners in ruminant production.The physiological structure of ruminant animals is different from that of monogastric animals,so the effects of sweeteners cannot be generalized.Therefore,two artificial sweeteners,Saccharin sodium and Neotame,were selected in this study to study the effects on the growth performance,rumen microflora,rumen fermentation and intestinal glucose absorption of dairy goats,in order to provide a theoretical basis for improving the performance of dairy goats by artificial sweeteners.Exp.1 Effects of artificial sweeteners on growth performance,rumen microflora and rumen fermentation and of dairy goatsEighteen healthy young dairy goats with similar body weight(34.90±0.68 kg)were randomly divided into three groups with 6 goats in each group.Control group: basal diet;Saccharin sodium treatment group: base diet +75 mg/kg DM Saccharin sodium;Neotame treatment group: basal diet +3.75 mg/kg DM Neotame,the sweetness of treatment group was the same.The experiment lasted for 42 days,including 14 days of pretest and 28 days of test.Feed intake was measured for 3 consecutive days every week during the trial period,and final weight was weighed for 2 consecutive days before the trial period ended.Blood,rumen fluid and stool samples were collected on the day after the trial.The results showed that:(1)compared with the control group,the two artificial sweeteners had no significant effect on feed intake(P>0.05),saccharin sodium significantly increased daily gain and feed conversion efficiency(P<0.05),Neotame had no significant effect on daily gain(P>0.05);(2)Compared with the control group,serum gamma-aminobutyric acid(GABA)and growth hormone(GH)were significantly increased in the two sweetener treatment groups(P<0.05),the level of five-hydroxytryptamine(5-HT)in Neotame group was significantly increased(P<0.01);(3)Saccharin sodium group significantly increased rumen fluid Rikenellaceae＿RC9＿gut＿group abundance,Neotame group significantly increased rumen Lachnospiraceae＿NK3A20＿group abundance,but the two treatment groups decreased rumen microbial diversity and partial flora abundance(P<0.05);(4)Neotame supplementation significantly increased butyric acid concentration in rumen fluid(P<0.05),Saccharin sodium had no significant effect on rumen fermentation(P>0.05).Exp.2 Effect of saccharin sodium on glucose absorption capacity in small intestine of dairy goatsSix healthy dairy goats with similar body weight were selected for tissue incubation and Ussing Chamber test in small intestine(duodenum,jejunum and ileum)to investigate the effects of saccharin sodium on sweet taste receptor(T1R2/T1R3)and glucose transporter(SGLT1/GLUT2)in small intestine in vitro.Eighteen young dairy goats with similar body weight(43.27±0.79 kg)in good condition were selected for the experience certificate.Dairy goats were randomly divided into two groups.Control group: fed basal diet +20 g/d protect rumen glucose;Saccharin sodium treatment group: fed the basal diet +75 mg/kg DM saccharin sodium +20 g/d protect rumen glucose.The experiment lasted for 42 days,including 14 days of pretest and 28 days of test.The final weight was weighed continuously for 2 days before the end of the trial period,and blood and fecal samples were collected on the day after the trial.In vitro studies showed that:(1)The expression of sweet receptors in jejunum increased significantly when small intestinal epithelial cells were stimulated by0.03% saccharin sodium solution in vitro(P<0.05),duodenum and ileal sweet taste receptors and glucose transporters had no significant changes(P>0.05);(2)There was no significant change in the glucose transport rate of jejunum tissue stimulated by 0.015% or 0.03%saccharin sodium solution at 15 m M glucose(P>0.05).(3)In vitro results showed that saccharin sodium treatment did not improve the growth performance of dairy goats compared with control group(P>0.05),and there was no significant difference between blood glucose and fecal VFA levels(P>0.05).In conclusion,the two artificial sweeteners had no significant effect on feed intake,but saccharin sodium improved the growth performance of dairy goats.Experimental analysis of the mechanism found that saccharin sodium did not significantly improve rumen fermentation capacity and small intestine glucose absorption capacity,and the reason for the improvement of growth performance of dairy goats needs further study.