The Effect Of Feed Flavor Agents On Feed Intake, Feeding Behavior And Mechanism Of Action In Pigs

Three experiments were carried out in this paper to investigate the optimum adding level for combination sweetener and the effect of different sweeteners on the performance in pigs,the effect of different feed flavoring agents on feed intake and intake behavior as while as the effect of on digestive enzymes and regulatory factors secretion and expresssion of feed intake in pigs.Exp.l The effect of combination sweeteners on the growth performance in pigsTwo studies were carried out in this experiment to investigate the optimum adding level for combination sweetener and the effect of different sweeteners on the performance in pigs. The first one was conducted by using single factor design,30 male and 30 female pigs of 50-d-old (Landrance X Yorkshire) were selected and allocated by BW to 1 of 5 treatments (3 replicates pens of 4 pigs per pen for each treament).Pigs in different treatment were fed diets containing 0 mg/kg,50 mg/kg,100 mg/kg,150 mg/kg or 200 mg/kg combination sweetener. On d 1,15,29,weigh each pig.The results showed as follows:1) The treatments with combination sweeteners produced a greater average daily feed intake(ADFI) and average daily gain(ADG) than the control. Compared with the control, the ADFI of combination sweeteners treatment was enhanced by5.4%,7.2%%,8.9%and 4.1% respectively and the ADG was enhanced by 3.9%,3.2%%,4.8% and 3.0% respectively.2)There was no difference for the feed utilization rate.The second trail to investigate the effect of different kind of sweeteners on the growth performance in pigs,the trail was conducted by using single factor design,32 male and 32 female pigs of 120-d-old (Landrance x Yorkshire x Duroc) were selected and allocated by BW to 1 of 4 treatments (4 replicates pens of 4 pigs per pen for each treament).Pigs in different treatment were fed diets containing the basal diet (control) and the basal diet added with 100 mg/kg Saccharin Sodium (saccharin sodium group),50 g/kg sucrose (sucrose group) and 150 mg/kg combination sweetener (combination sweetener group).The experiment last 21d and on d 1,22, weigh each pig.The results showed as follows:1) Compared with the control, Sucrose and combination sweetener can enhance the ADFI and ADG of pigs. The ADFI of sucrose group and combination group was significantly increased by 6.6%(P＜0.01) and 5.3%(P＜0.05) respectively and the ADG was enhanced by 10% and 7.9% respectively.2) In the saccharin sodium group,the ADFI and ADG were 3.7% and 2.3% lower relative to the control respectively.3) Compared with the control, the feed to gain ratio of saccharin sodium group, Sucrose group and combination sweetener group was enhanced by 1.89%,3.51%, 2.53% respectively.Our results indicated that combination sweetener can increase the feed intake of pigs, a higher dose or a lower dose is not better for the feed intake, the optimum dose is 150mg/kg combination sweetener in this experiment.our results also indicated that it is feasible for combination sweetener to substitute sucrose applied in feed diet to improve feed intake in pigs.Exp.2 The effect of different flavoring agents on feed intake and feeding behavior in pigsTwo studies were carried out in this experiment to investigate the effect of different feed flavoring agents on feed intake and intake behavior in pigs.The first one was conducted to investigate the effect of the sow milky flavor which is the similar to the sow's milky on the intake behavior and feed intake in weanling pigs,it was done with free choice method,4 piglets were selected and tagged, there were 4 replicates, and each piglet is a replicate.Basal dietary(Control dietary) and flaovr dietary(Basal dietary+400 mg/kg milky falvor) were supplied at the same time.The trail lasted 96h, each grouped dietary feed intake was recorded each day and main data was collected by monitoring with the camera. The results showed that sow's milky flavor signify-cantly increased intake frequency and intake time during experiment period, com-pared to the control dietary, the average daily intake frequency and intake time were increased by 19.5%(P<0.002) and 9.6%(P<0.05) respectively. Meanwhile, the average feed intake of per second in the flavor dietary was more than 0.008g/s than control dietary, and it was enhanced by 7.80% compared to control dietary.The increase of the feed intake was proved by the change of the intake behavior. Com-pared with the control dietary, the average daily feed intake of flavor dietary was enhanced by 18.1%. The second one was conducted to investigate the effect of the different flavors on feed intake and intake behavior in pigs by auto intake system. The trial was conducted by single factor design,30 male pigs of 95-d-old (Land-rance X Yorkshire) were selected and allocated by BW to 1 of 5 treatments (1 pigs of each replicate and 6 replicates for each treament).Pigs in different treatment were fed diets containing the basal diet(control group), the basal diet added with 400 mg/kg apple-banana flavor (fruit flavor group),400mg/kg sow milky flavor (milky flavor group),150mg/kgcombination sweetener(sweetener group)and 400 mg/kg fruit flavor +400mg/kg milky flavor+150mg/kg sweetener (complex flavors group).The experiment last 14 d. Auto intake system which was produced by France ACEMO Company was used to collect feed intake information and data. The results showed as follows:1) Feed flavoring agents can increase the performance of the pigs. The ADFI of fruit group,milky group,sweetener group and complex was respectively enhanced by 12.5%, 15.9%, 11.3% and 3.4% comparing with the control,the ADG was respectively increased by 25.3%, 26.3%, 13.6% and 10.3% and the the feed utilization rate was respectively increased by 9.6%, 11.3%, 1.9% and 6.9%.2) The feed intake speeds of fruit group,milky group,sweetener,group and complex group were increased by 21.2%,6.1%, 30.0% and 22.8% respectively. The intake times were 5.6%,19.2%, 14.9% and 14.0% shorter than the control. Our results indicated that the flavors can enhance the performance of the pigs by changing the intake behavior, and it was better in the first trial days or during pigs encountering stress.We also confirm that the weanling pig was preference to sow's milky flavor which can enhanc average daily intake frequency, intake time, intake speeds as while as make weanling pigs gain more chance of taking feed and then take more feed.Exp.3 The effect of different flavoring agents on digestive enzymes and regulatory factors of feed intake in pigsThe experiment was conducted to investigate the effect of different feed flavor-ing agents on digestive enzymes and regulatory factors secretion and expression of feed intake in pigs.The trial was conducted by single factor design,30 male pigs of 95-d-old (Landrance x Yorkshire) were selected and allocated by BW to 1 of 5 treatments (lpigs of each replicate and 6 replicates for each treament). Pigs in different treatment were fed diets containing the basal diet(control group), the basal diet added with 400 mg/kg apple-banana flavor (fruit flavor group),400mg/kg sow milky flavor (milky flavor group),150mg/kgcombination sweetener (sweetener group) and 400 mg/kg fruit flavor+400mg/kg milky flavor+150mg/kg sweetener (complex flavors group)..Blood sample collection was carried out at 8:00 clock on dayl,8,15.through cave anterior respectively. On day 8 and 15, make the animal take feed freely and collected blood sample at 0 h,2 h after the end of feed intake.The serum were used for NPY,Ghrelin,CCKg and leptin examination. On day 15, after the animal was feed 2 h, the animal was slaughtered and chymus of gastrointestinal were collected for enzymes examination. Hypothalamus,gastric mucosa and duodenum samples were collected for NPY,Ghrelin,CCK.8 expression examination. The results showed as following:1) Compared with the control, the pepsin of milky flavor group and sweetener group increased 76.1% and 6.5%, and the fruit flavor was similar with the control. All the flavor groups trypsase,lipase,amylase activities were higher than the control.Com-pared with the control, fruit flavor,milky flavor group,sweetener and complex flavor trypase increased by 16.5%,20.1%,11.1% and 8.1% respectively, and the lypase increased by 9.2%, 60.4%,42.3 and 2.5% respectively, the amylase increased 27.3%,68.7%,6.1%,4.33%respectively.2) The addition of fruit flavor, milky flavor and sweetener increase the secretion of NPY and Ghrelin. Compared with the control, fruit flavor milky flavor and sweeter increase hypothalamus NPY mRNA expression 43%,48% and 53% respectively, increase gastric mucosa Ghrelin mRNA expression 79%,113% and 90% respectively. (3) Compared with the control, the addition of flavors in the first one week, fruit flavor and milky flavor change regulatory factors secretion mode before and after feed intake. And a downing trend in the leptin secretion was found after the addition of flavors. This experiment results showed that the increase of feed intake had a correlation with the addition of fruit flavor,milky flavor and sweetener, because the addition of flavoring agent could incresase hypohalamus NPY mRNA and gastric mucosa Ghrelin mRNA expression, increase serum NPY and Ghrelin secretion, increase digestive enzymes activities. Finally, there is a decrease trend in leptin secretion in the first week after the addition of flavors.