Effects of different doses of sodium monensin on rumen papillae and tissue histology of feedlot Nellore cattle

Abstract

The experiment was designed to determine the effects of different doses of sodium monensin (MON) on rumen papillae and tissue histology of feedlot Nellore cattle. The experiment was designed as a completely randomised block, replicated 12 times, in which 60 20-month-old yearling Nellore bulls (402.52 ± 33.0 kg) were fed in individual pens for 84 days according to the following doses of MON expressed in ppm (on a dry-matter basis): 0, 9, 18, 27 and 36. The adaptation program consisted of ad libitum feeding of two adaptation diets over a period of 14 days, with concentrate level increasing from 68% to 84% of diet dry matter. Orthogonal contrasts were used to assess linear, quadratic, cubic and quartic relationships between doses of MON and the dependent variable. No significant (P > 0.10) MON effect was observed for number of papillae, mean papillae area, papillae area as a percentage of absorptive surface and rumenitis incidence. However, as the dose of MON increased, the absorptive surface area, papillae surface area and mitotic index were affected (P < 0.05) cubically, in which animals fed 9 and 36 ppm presented larger absorptive surface area and greater number of cells in mitosis. Thus, based on the results, feeding of MON affected rumen papillae and tissue histology of feedlot Nellore cattle. The doses of 9 or 36 ppm of MON should be considered as the most feasible options, because they promote better development of rumen epithelium.

Different doses of sodium monensin on feedlot performance, carcass characteristics and digestibility of Nellore cattle

“…In addition, the reasons just described may be consequences of the reduction in methane production, which results in lower energy losses (Hristovet al, 2013), and contributes to greater NEg and NEg/expected NEg ratio (Table 2), greater ruminal production of propionate (Oliveira et al, 2007), as well as larger absorptive surface area and greater mitotic index of ruminal papillae. Such effects were observed in a similar study (Pereira et al, 2014), resulting in greater carcass fat deposition.…”

Assessment of corn wet distillers grains fed to crossbred bulls on feeding behavior, rumen morphology, liver abscesses and blood parameters

“…This result may be explained by the greater selection of concentrate ingredients (particles smaller than 1.8 mm), suggesting that F1 Angus-Nellore bulls had more preference for the intake of small particles. Opposite results were reported by researchers [ 27 ] evaluating Nellore bulls fed high concentrate diets, whereby the number of papillae, mean papillae area, papillae area as a percentage of absorptive surface, and rumenitis incidence were similar. Differences among studies on rumen papillae variables may be due to chemical composition of the experimental diets, specially starch amounts and NDF content.…”

“…Samples were collected for further morphology and histology evaluations of the ruminal epithelium, as described [ 27 ]. Briefly, to evaluate the ruminal papillae morphology, a 1-cm 2 fragment of each rumen was collected from dorsal cranial sac (atrium ruminis) and placed into a phosphate buffer solution for future morphometric measurements according to Resende Júnior et al [ 28 ].…”

The effect of monensin concentration on dry matter intake, ruminal fermentation, short-chain fatty acid absorption, total tract digestibility, and total gastrointestinal barrier function in beef heifers1

“…The lack of response for SCFA absorption in the present study can be explained as monensin concentration did not affect total SCFA concentration or mean ruminal pH and may suggest that there were no measurable effects of monensin on function of the ruminal epithelium or whole animal. Unfortunately, papillae surface area was not measured in the present study, but monensin inclusion has been reported to influence morphometric measurements of ruminal papillae, impacting absorptive surface area and mitotic index (% of basal cells; Pereira et al, 2014). That said, although it appears that monensin inclusion can, most likely, indirectly affect ruminal epithelial morphology, the increase in surface area may not correspond to functional differences in SCFA absorption.…”