Effects Of Particles Sizes Of Feeds On Performance And Nutrient Digestibility In Early-Weaned Piglets Under Different Concocting Manners

The effects of different feeds processing and concocting manners on performance and nutrient digestibility in early-weaned piglets were investigated in this research. The former three experiments were conducted respectively to investigate the effect of particle size of feeds(milled through 0.5mm and 1.5mm mesh size) on performance and nutrient digestibility in 21d or 28d early-weaned piglets under three kinds of concocting manners(cooking, fluidifying, and pelleting). Matched-pairs experiment design was adopted and the formulas of the diets were the same in all experiments. Two kinds of diets with particle size of 309μm and 170μm were used which were milled through 1.5mm and 0.5mm mesh sizes respectively, the electrical energy were 15.4 kWh/t and 39.65kWh/t. Experiment 1: Eight Taihu and 8 Landrace 21d-weaned piglets(total of 16) were allocated to 2 treatments with 4 replications and 2 piglets in each replication, and feed on two particle size diets respectively, the diets were cooked before feeding(cooking for 1 minute). Experiment 2: The experiment design was same to experiment 1, 8 Landrace×Yorkshire and 8 Yorkshire Landrace 28d-weaned piglets were adopted and feed on two particle size diets respectively, the diets were fluidified before feeding(the ratio between feeds and water was 1: 2.5-1). Experiment 3: Fourteen 21-day-old Duroc×Landrace×Yorkshire were allocated to two treatments with 7 replications and 1 pig in each replication. The piglets were feed on two particle size diets respectively and the feeds were pelletized. All the experiments were carried out for 3 weeks and feed consumption, body weight gain and diarrhea were investigated. At the same time a digestion trial was conducted at 9th day in experiment 3 and continued for 6 days; the excreta were collected and dry matter apparent digestibility, protein apparent digestibility and energy apparent digestibility were evaluated. In the forth experiment, results of the former three experiment were combined to conduct statistical analysis.The results were as following: In experiment 1: The feeds were cooked before feeding, performance and Diarrhea index were not affected by particle size. The ADG of two treatments(0.5mm and 1.5mm) were 89g and 83g, F/G were 1.71 and 1.75, Diarrhea index were 0.25 and 0.35 and the cost of per kilogram gain were 5.18RMByuan and 5.24RMByuan respectively. In experiment 2: The diets were fluidified before feeding and the performance of 0.5mm treatment during the three weeks was better than that of the 1.5mm group, especially in the former two weeks. The ADG of two treatments(0.5mm and 1.5mm) were 117g and 109g, F/G were 1.61 and 1.75, and the cost of per kilogram gain were 4.5RMByuan and 4.62RMByuan respectively(P＞0.05). Diarrhea index of 0.5mm and 1.5mm group in three weeks were0.78 and 1.24(P＞0.05). Experiment 3: When feeds were pelletized, the decreasing of feeds particle size had the tendency to improve the performance of the early-weaned piglets. ADG, ADFI and F/G of 0.5mm and 1.5mm group were 178g and 152g(P=0.087), 227g and 205g(P=0.092) and 1.28 and 1.35(P=0.137).0.5mm particle size feeds show a tendency to decrease the Diarrhea index, which was decreased by 26.98％compared with that of the 1.5 mm group(P＞0.05). The digestion trial result shows that the nutrient digestibility in feeds of 0.5mm group was better than that of the 1.5 mm group and the dry matter apparent digestibility, protein apparent digestibility and energy apparent digestibility were improved by 2.04％(P＞0.05), 4.26％(P＜0.05) and 3.01％(P=0.078) in separately. The cost of per kilogram gain were 5.18RMByuan and 5.24RMByuan respectively, and the effect of fine grinding was better than that under the other concocting manner. Experiment 4: The performance of 0.5mm treatment during the three weeks was better than that of the 1.5mm group(P＜0.05), and the Diarrhea index was lower. The ADG, ADFI and F/G of 0.5mm and 1.5mm group werel51g and. 135g(P=0.03), 213g and 200g(P=0.05) and 1.45and 1.51(P=0.01). Conclusion: 1) Performance and digestibility of DM, CP and TE of 0.5mm treatment were greater than 1.5mm treatment(P＜0.05), and Diarrhea index was lower.2) The effect of particle size was greatest under the concocting manner of pelleting, fluidifying was lower, and the cooking was the lost.3) Along with the growth of pig, under any concocting manner, the difference of performance between 0.5mm and 1.5mm was less.4) Under three kinds of concocting manners, economic returns of 0.5mm group were higher than 1.5mm, pelleting＞fluidifying＞cooking.