Effects Of Different Levels Of Lactic Acid Daily Ration On The Production Performance And Biochemical Indicators Of Weanling Piglet

The effect and mechanism of Lactic acid (LA) in diets for weaned pigs were studied through its effect on production performance, digestive physiologic parameters, blood biochemical parameters and apparent digestibility of crude protein (CP). Five treatments and single factor were utilized. 75 of 3-crossbred piglets at the age of 28days were selected and divided randomly into 5 groups, each for 15 pigs. The levels of citric acid addition were 0%, 0.6%,1.2%,1.8% and 2.4%,Respectively, basic diet of the five treatments were same during four weeks, The trial included four sections. Experiment One for feeding . Feed intake, weight gain, average daily gain (ADG),feed efficiency, rate of diarrhoea and livability of each group were measured during the experiment One. Experiment Two for slaughter test. Selected three piglets randomly from every group at the second weekend for slaughter test to determine the pH of digestive tract ,digestive enzyme, E.coli counts and lactobacillus counts in cecum and colon. Experiment Three for blood biochemical test. Selected three piglets randomly from every group for measureing serum insulin, blood sugar, total serum protein, urea nitrogen. Experiment Four for digestion trial.The whole-faece-collected method was used in digeslion trial to measure apparent digestibility of crude protein .The results showed that:1. Effect of LA on production performanceFeed intake was rised by the supplementation of 1.2%-1.8%LA,but feed intake of 2.4% LA group was decreased.1.8% LA supplement improved and significantly improved the piglets weight gain and average daily gain.Feed efficiency was improved obviously at two weeks before after weanling and decreased their rate of diarrheoa by the supplementation of 1.2%-1.8% LA2. Effect of CA on digestive physiologic parametersIncreasing the LA addition of diets piglets lowed the pH in small instestine and promoted the development of their digestive tract. The pH of stomach was lowed significantly with 1.8% and2.4% LA and increased distinctly the activites of pepsin and trypsin in jejunum (P﹤0.05) ,but no significant effect on ileum trypsin and jejuno-ileum anylopsin.E.coli counts were decreased significantly and increased the lactobacill-us counts in cecum and colon with 1.8% and 2.4% LA addition(P﹤0.05).3. Effect of LA on blood biochemical parametersThe results indccated that increasing the LA addition of diets, the blood sugar and urea nitrogen of piglets were respectively decreased, the insulin and total serum protein were respectively increased.4. Effect of LA on apparent digestibility of CP1.2%-2.4% LA Supplement improved the digestibility of CP, but significant indifference.5. Identitied the Evidence of Addition Level and Effect on LADiet acid-binding capacity was an important factor influenced the additon effect of LA. It was the best effect that addition of 1.8% LA brought diet acid-binding capacity down to 20.