Study on the nutritive value of dextrin as a carbohydrate source for pigs weaned at 21 days of age

Two experiments were conducted to compare the nutritive value of dextrin to that of various carbohydrate sources and to determine the optimal incorpor ation ratio with lactose for pigs weaned at 21 days of age. In each experim ent, eighty pigs (BW 6.43+/-0.18 kg in experiment 1 and 6.93+/-0.19 kg in 2 ) were used as an experimental unit and allotted to 20 groups (4 pigs/group , 5 groups/treatment) using a completely randomized block design. Each grou p was assigned to one of 5 dietary treatments. Dextrin (control), maize sta rch and 3 different sources of sugar (lactose, glucose, and sucrose) compos ed 5 dietary treatments for experiment 1. Five 5 graded lactose:glucose rat ios (100:0, 75:25, 50:50, 25:75 and 0:100, diet A, B, C, D and E, respectiv ely) were used as the treatments in experiment 2. In experiment 1,pigs fed the diet containing maize starch showed the lowest (P<0.05) average daily g ain (ADG) and average daily feed intake (ADFI). During the second week, ADG improved (P<0.05) for the pigs fed diets containing dextrin and 3 differen t sources of sugar (lactose, glucose and sucrose) compared to pigs fed maiz e starch diets. For the third week after weaning, pigs fed diets with maize starch, lactose, glucose and sucrose had improved ADFI compared with pigs fed the dextrin diet (P<0.05). Overall, there were no significant differenc es in ADG and ADFI among treatments. However, pigs fed the dextrin diet had improved feed conversion ratio (FCR) compared with pigs fed other diets (P <0.05). During the initial 14 d postweaning (phase I), no significant diffe rences were found in digestibilities of gross energy (GE), dry matter (DM), crude protein (CP) and crude ash (CA) among treatments. During the third w eek postweaning (phase II), the digestibilities of GE and CP of pigs fed th e diet containing sucrose were higher than those of the other treatments. I n experiment 2, overall, no significant differences were found in ADG, ADFI and FCR. During the initial 14 d postweaning (phase I),no significant diff erences were found in nutrient digestibilities except for gross energy (GE) digestibility. GE digestibility obtained from diet A was greater (P<0.05) than that from diet D, while those for diets B, C and E were intermediate.