PSI-25 Improvements in the jejunal villus morphometry and increases in the number of goblet cells with the addition of humic substances from vermicompost in weaned pigs

Abstract An experiment was carried out with the objective of evaluating the effects of the addition of humic substances (HS) from vermicompost in the feed on the histology measurements and number of goblet cells in the jejunal villus in piglets at weaning. Piglets (n = 200) were housed in groups of five in elevated pens and were assigned to one of four treatments: 1 = Positive control diet (PC) with antibiotic growth promoter (AGP), 2 = Negative control diet (NC) without AGP, 3 and 4 = Diets without AGP added with 2500 and 5000 ppm HS, respectively. HS were extracted from a vermicompost made of sheep and pig manure using an alkaline solution and added in dry form to the feed. A basal sample of 5 cm of jejunum was taken from 10 piglets at weaning; the same was done on d 3 and 7 post-weaning, selecting 5 piglets per treatment. The samples were processed to apply different stains: () eosin and hematoxylin for morphometric analysis: villus height, villus thickness, villus area, crypt depth and the villus eight to crypt depth ratio; 2) Pass Schiff to quantify neutral goblet cells; 3) Alcian Blue pH 1.0 for heavily sulfated goblet cells; and 4) Alcian Blue pH 2.5 for non-sulfated acid goblet cells. Ten villi per animal were evaluated. Images were analyzed with Leica interactive measurement software. The results were subjected to ANOVA in a randomized complete block design. Regarding the histology of villus in the jejunum, on d 3 post-weaning the pigs added with HS had a greater villus height (3 = 317.75, 4 = 310.46 vs 2 = 278.08 and 1 = 307.12 µm; P < 0.05; SEM = 10.86), villus width (3 = 94.64, 4 = 95.04 vs 2 = 85.39, and 1 = 93.51 µm; P < 0.01; SEM = 2.32); and villus area (3 = 95841, 4 = 93678 Vs 2 = 76646 and 1 = 93471 µm2; P < 0.01; SEM = 4343), compared with the NC. The crypt depth was greater in piglets added with HS (3 = 236.78, 4 = 241.85 vs 1 = 194.65 and 2 = 203.01 µm; P < 0.01; SEM = 6.57) compared with the PC and NC. On d 7 postweaning, the piglets added with HS showed greater villus height (3 = 293.24, 4 = 282.45 vs 1 = 258.95 and 2 = 253.03 µm; P < 0.01; SEM = 7.89); villus area (3 = 101354, 4 = 94,575 vs 1 = 85,633 and 2 = 82,125 µm2; P < 0.01; SEM = 3818) and crypt depth (3 = 326.82, 4 = 337.28 vs 2 = 283.88 and 1 = 321.53 µm; P < 0.01; SEM = 8.285) compared with the PC and NC. The number of neutral, heavily sulfated and non-sulfated goblet cells at 3 and 7 d post-weaning were significantly reduced in all treatments compared with weaning; but with the addition of HS a greater number (P < 0.05) of goblet cells per villus were shown. The results suggest that HS from vermicompost improves the intestinal morphometry and increases the number of goblet cells that produce protective intestinal mucus at 3 and 7 d post-weaning in pigs.