Study On Various Acidifiers Adding In Weanling Pig Diets

Two experiments was conducted to single out the better acidifiers and study the effects and mechanism of acidifiers in diets for weaning pigs. The acidifiers' components are the same (Citric Acid, fumaric Acid, Phosphorus Acid, Lactic Acid, Cider Acid, Tartaric Acid). In exp.1, Four acidifiers, AⅠ,AⅡ,AⅢ,and AⅣ, were single out. And based on these, In exp.2, 90 4-wk-old weaning pigs were used to study the effects of acidifiers. Five treatments and single facter were utilized. And one group (a negative control) was offered feed free of acidifier ad libitum, four groups were offered the same diet ad libitum supplemented with 0.2% AⅠ,AⅡ,AⅢ and AⅣ respectively. Exp.2 included four sections. Basic diets of the five treatments were same during three weeks. Part One for feeding. Feed intake, weight gain, average daily gain( ADG ), feed efficiency, rate of diarrhoea and livability of each group were measured. Part Two for Digestive physiology. Three selected piglets randomly from every treatment at the third weekend for slaughter test.to determine the pH of digestive tract, didestive enzyme; E.coli counts and lactobacillus counts in cecum and colon. Part Three for blood biochemical test. Totol serum protein, blood sugar and urea nitrogen were measured. Part Four for digestion trial. The whole-feces -collected method was used in digestion trial to measure apparent digestibility of crude protein, dry matter and general energy. The results shows:⑴Four acidifiers are well to pigs and AⅢ is the best and AⅠ is better.⑵0.2% Acidifiers added in the diets significantly rised the feed intake, gain weight and daily gain weight (P<0.01); remarkably improved feed efficiency and decreased the diarrheoa rate. The effect of AⅠ and AⅢ is better.⑶0.2% Acidifiers added in the diets obviously lowed the pH in stomach and small intestine; significantly promoted the activity of pepsin, trypsin in the jejunum and ileum(P<0.01), The effect of AⅢ is better; and decreased the activity of amylase in the jejunum and ileum(P<0.01)；decreased E.coli counts and increased the lactobacillus counts obviously (P<0.05), The effect of AⅢ is better.⑷0.2% Acidifiers added in the diets decreased the blood sugar and urea nitrogen on piglets respectively and increased the total serum protein.The effect of AⅠ is better⑸0.2% Acidifiers added in the diets obviously promoted the total counts of intake and the feces; increased the apparent digestibility of CP, DM and GE. The effect of AⅠ and AⅢ is better...