Effects Of Alfalfa Saponins And Alfalfa Meal On The Growth Performance And Regulation Mechanism Of Weaned Piglets And Finishing Pigs

The objective of this study was to research the effects of alfalfa saponins and alfalfa meal on growth performance, meat quality, immune status, antioxidization capacity, lipid metabolism, and digestive physiology of weaned piglets and finishing pigs.The first experiment: Piglets were weaned at 9.2kg and allocated to 4 treatments with three replicates of each treatment and four weaned piglets per replicate according to birth date, litter, and gender, using complete random single factorial design. Factor was different level of alfalfa saponins (0%, 0.25%, 0.5%, and 1.0%). The results showed that: (1) Piglets fed with 0.25% and 0.50% alfalfa saponins were superior in average daily gain, relative growth rate to that of control group, growth performance was improved, at the same time, diarrhea ratio decreased. (2) Alfalfa saponins had no influence on the feed digestive ratio except for digestive ratio of crude fat. (3) Thrombocyte of blood was decreased, red blood cell and white blood cell of blood was improved when the piglets was fed with alfalfa saponins, for example, those of blood in 0.50% group were very significantly higher than that of control group (p<0.01). (4) Serum glutamaic pyruvic transominase and urea nitrogen content of trial group were significantly lower than that of control group. With the alfalfa saponins level increased, the blood glucose was decreased slowly; however, there was no significant difference among the four treatments. (5) As alfalfa saponins increased, the content of total protein and albumin were raised, but there were no significant difference among the four treatments; IgG content of groups fed with alfalfa saponins was significantly higher than that of control group, but there were no significant differences for IgA and IgM among the four groups. The concentration of growth hormone and insulin of group II and group III were significantly higher than control group, and the level of swine plague antibody titer was slightly higher than control group. (6) The triglyceride and cholesterol content of serum and liver of groups fed with alfalfa saponins were significantly lower than that of control group, and LDL-C concentration of serum was decreased with the increasing of alfalfa saponins; However, the HDL-C concentration was increased with the amount of alfalfa meal increasing; with the alfalfa saponins level increased, the cholesterol content of eye muscle was decreased slowly; however, there was no significant difference among the four treatments. (7) Total VFA of cecum and colon of groups fed with alfalfa saponin were significantly higher than that of control group. There was no significant difference in pH value of gastrointestinal tract (P>0.05). (8) The alfalfa saponins can improve lipase and trypinase activity of pancreas and serum.The second experiment: To study the effects of alfalfa meal and saponins on growth performance, meat quality, immune performance, serum biochemical index, antioxidization capacity, total VFA, and digestive enzyme activity, 60 finishing pigs (initial BW= 60±2.32kg ) were divided into five treatments (0%, 7% alfalfa meal, 14% alfalfa meal, 21 % alfalfa meal, 0.3% alfalfa saponin), 3 replicates each treatment, 4 pigs each replicate. The results showed that: (1) Finishing pigs fed with 7% , 14% alfalfa meal and 0.3% alfalfa saponins were superior in average daily gain, and group of 0.3% alfalfa saponins had the highest average daily gain. The average daily gain fed with 21% alfalfa meal decreased. The feed intake decreased with increasing of alfalfa meal; however, the feed intake of group fed with alfalfa saponins was not decreased. Feed conversion rate of finishing pigs fed with 7% alfalfa meal was the best among the five groups. (2) Serum biochemical index of growthing pigs was deeply influenced by adding alfalfa meal and saponins, and the glutamic-pyruvic transominase activity was lower than that of control group, and triglyceride and cholesterol content of serum and liver of groups fed with alfalfa saponins were lower than that of control group; However, alkaline phosphatease activeities and HDL-C concentration were improved with the adding of alfalfa meal and saponin. (3) There were significant differences in serum immunoglobulin content among the four groups. And the IgM concentration increased and IgG conentration decreased with increasing of alfalfa meal. (4) Groups fed with alfalfa meal and saponins had no significant difference on eye muscle area (P>0.05). Mean backfat thickness was decreased with the increasing of alfalfa meal and alfalfa saponins. Lean percentage increased with the increasing of alfalfa meal and alfalfa saponins. (5) Finishing pigs fed with alfalfa meal and saponins had no significant effects on meat colur, pH value and marble stripe, eye muscle fiber diameter decreased slightly. The fat content of muscular apparatus was significantly lower than that of control group. The lipase and trypsinase activity of pancreas was significantly higher than that of control group, but alfalfa meal and saponin had no effects on amylase activity of pancrea. The results of duodenum were similar to that of pancreas.