LAUSR

Trace element and mineral intake are important for proper function of the immune system and various metabolic processes. The objective of this experiment was to evaluate the effect of a dacitic tuff breccia (DTB), classified as a hydrated sodium calcium aluminosilicate, in the diet of nursery pigs. Dietary treatments were: 1) Control diet (CON), 2) CON + 0.25% DTB (DTB1), and 3) CON + 0.50% DTB (DTB2). Pigs (6.79 + 0.064 kg; 26d of age) were individually housed and fed dietary treatments for 21 d (n=48; 16/trt). At the end of the experiment, blood, jejunal, and ileal samples were collected for a typical metabolic panel and basic histologic and morphologic measurements. DTB2 fed pigs tended (P=0.07) to have greater ADG than CON and DTB1 fed pigs (392, 397, 430g/d for CON, DTB1, DTB2, respectively), and greater (P=0.008) ADFI (591, 592, 669g/d for CON, DTB1, DTB2, respectively). Gain:Feed was not different (P=0.75) among treatments (0.655, 0.663, 0.644 for CON, DTB1, DTB2, respectively). Crypt depth in the jejunum was greater (P=0.04) for DTB1 compared to CON fed pigs but did not differ from DTB2 fed pigs (254.7, 292.0, 275.6mm for CON, DTB1, DTB2, respectively). Villous height, villous:crypt, number of goblet cells and intraepithelial lymphocytes did not differ among treatments in both ileum and jejunum (P >0.17). Total white blood cell (WBC) count did not differ (P >0.10). However, the proportion of WBC that were monocytes was lower (P=0.024) in DTB1 compared to CON and DTB2 fed pigs (1.27, 0.79, 1.45% for CON, DTB1, DTB2, respectively). Blood Urea Nitrogen (BUN) concentration tended (P=0.06) to be linearly decreased with increasing DTB concentrations (9.27, 8.80, 7.75mg/dL). DTB inclusion at 0.5% in nursery pig diets tended to improve growth performance, while inclusion at 0.25% increased jejunal crypt depth and reduced monocytes:WBC and increasing DTB concentrations tended to decreased BUN linearly.