Ninety piglets weaned at 21d were distributed into 3 dietary groups consisting of 5 replicates each: 1) US diet supplemented with 55 mg/kg of carbadox, and 2.5% each of plasma proteins and spray-dried blood cells in the first phase, 3,055 mg/kg of Zn in the first and second phases, and 180 mg/kg of Cu in the third phase; 2) EU diet based on vegetable proteins and no antibiotics; and 3) the same EU diet supplemented with 3,000 mg/kg of microencapsulated TL. The study was divided into 3 different phases: 0 to 7, 8 to 21, and 22 to 35 d. On d 7, 21, and 35, animals were weighed, and feed consumption and efficiency were determined. On d 14 and 35, one pig per pen was killed, and the intestinal contents and mucosa from the proximal, middle, distal jejunum and the ileum were sampled. Intestinal wall sections were fixed for histological analysis, and intestinal content was used for volatile fatty acids (VFA), ammonia, and polyamine analysis.
Throughout the study (d 0 to 35), the US diet had greater ADG and ADFI than the EU diet (P < 0.05). The EU diet supplemented with TL tended to have 11% greater ADG (P=0.17). A reduction of 10% in the proximal and middle jejunum villi length (P<0.05) and an increase in crypt size in proximal jejunum (P<0.05) was observed for those animals fed the EU die than those fed the US diet. The TL supplementation resulted in longer villi along the jejunum and less deep crypts in the proximal jejunum (+15.9 and -8.9%, respectively; P<0.05) than the unsupplemented EU diet. The TL diet increased the concentrations of cadaverine and putrescine in the small intestine (P<0.05) and seemed to increase cadaverine, histamine, putrescine, and spermine in the large intestine by 1.5- to 10-fold compared with the US or EU diet. At d 14 of the study, the cecal contents showed no differences in VFA concentrations. At d 35, cecal valeric acid concentration was greater for the EU-based diets compared with the US diet (P<0.05). Cecal acetic and propionic acid proportions were the greatest and the least (P<0.05), respectively, for the US diet. In conclusion, the use of slowly released tributyrin and lactitol seemed to be an effective tool to partially overcome the lack of animal proteins, carbadox, zinc oxide, and copper sulphate in the EU vegetable diets for piglets.
A Piva, E Grilli, L Fabbri, V Pizzamiglio, PP Gatta, F Galvano, M Bognanno, L Fiorentini, J Woli?ski, R Zabielski and JA Patterson. 2008. Journal of Animal Science. 86:2952-2961.