Nutritional protocols to preserve cell tight junctions of the gastrointestinal tract and to decrease blood inflammatory markers of feedlot cattle

Author(s)

Breno Leite Demartini

• Document type: Master's Dissertation
• Press: Botucatu. 2022-09-02.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
• Defense date: 2022-08-15
• Advisor: Danilo Domingues Millen

Abstract

This project aimed to evaluate the effect of different corn grain processing in 2 diets with or without rumen-protected calcium salts of fatty acids, as well as organic zinc and 3 chromium on the morphometry and integrity of the epithelium of the gastrointestinal tract, 4 blood inflammatory markers, and fecal starch content in feedlot Nellore cattle. The experiment 5 was conducted using 150 Nellore bulls, with initial body weight of 403.98 ± 23.82 kg, blocked 6 by weight. On day 0 of the experimental period, one animal per pen (n=30) was slaughtered as 7 a reference; thus, the study proceeded with 120 animals, randomly divided into 30 pens (n=4 8 per pen). The experimental period was 112 days, which included 20 days of adaptation and 92 9 days of finishing with different high-performance diets according to the treatments: 1) Finely10 ground corn; 2) High-moisture corn; 3) Finely-ground corn + calcium salts of fatty acids; 4) 11 High-moisture corn + calcium salts of fatty acids; 5) High-moisture corn + calcium salts of fatty 12 acids + Zn and Cr. Sodium monensin was added at 25ppm in all treatments. Blood and feces 13 samples were collected during the study for analysis of blood inflammatory markers and fecal 14 starch content, respectively, at beginning and at the end of the study. After slaughter (reference 15 and final) fragments of the rumen, jejunum and cecum were collected for analysis of the 16 integrity of the intestinal epithelium, through morphometry, histology and 17 immunohistochemistry of the tight cell junctions. Animals that consumed calcium salts of fatty 18 acids had lower concentrations of some inflammatory markers (haptoglobin, LPS binding 19 protein, C-Reactive protein; P<0.05), as well as lower fecal starch contents on day 56 and lower 20 total starch consumption (P<0.05). Protocols using high-moisture corn showed lower dry matter 21 intake (DMI), total starch consumption, lower fecal starch content on days 56 and 112 and even 22 lower inflammation of the cecal zonula occludens (P<0.05). Given the results found, the 23 protocol with high-moisture corn did not impair the cecal barrier function, possibly by reducing 24 the total intake of starch, however, with the change of the starch fermentation site to the rumen, 25 the incidence of rumenites increased. The protocol using calcium salts of fatty acids reduced 26 the concentrations of haptoglobin, LPS binding protein and C-Reactive protein in the blood, 27 lower incidences of rumenites, probably due to lower total starch intake, alleviating rumen 28 fermentation. The introduction of organic Zn and CR did not show any improvement in the 29 health of the TGI of the animals studied. Thus, in this study, protocols with the introduction of 30 calcium salts of fatty acids or the processing of high-moisture corn proved to be advantageous 31 in promoting digestive and animal health. (AU)

• FAPESP's process: 20/11555-7 - Study of digestive system tight junctions and inflammatory markers of feedlot nellore cattle fed diets for high performance
• Grantee: Breno Leite Demartini
• Support Opportunities: Scholarships in Brazil - Master