Small intestine histomorphometry of beef cattle with divergent feed efficiency

Abstract

BackgroundThe provision of feed is a major cost in beef production. Therefore, the improvement of feed efficiency is warranted. The direct assessment of feed efficiency has limitations and alternatives are needed. Small intestine micro-architecture is associated with function and may be related to feed efficiency. The objective was to verify the potential histomorphological differences in the small intestine of animals with divergent feed efficiency.MethodsFrom a population of 45 feedlot steers, 12 were selected with low-RFI (superior feed efficiency) and 12 with high-RFI (inferior feed efficiency) at the end of the finishing period. The animals were processed at 13.79 ± 1.21 months of age. Within 1.5 h of slaughter the gastrointestinal tract was collected and segments from duodenum and ileum were harvested. Tissue fragments were processed, sectioned and stained with hematoxylin and eosin. Photomicroscopy images were taken under 1000x magnification. For each animal 100 intestinal crypts were imaged, in a cross section view, from each of the two intestinal segments. Images were analyzed using the software ImageJ®. The measurements taken were: crypt area, crypt perimeter, crypt lumen area, nuclei number and the cell size was indirectly calculated. Data were analyzed using general linear model and correlation procedures of SAS®.ResultsEfficient beef steers (low-RFI) have a greater cellularity (indicated by nuclei number) in the small intestinal crypts, both in duodenum and ileum, than less efficient beef steers (high-RFI) (P < 0.05). The mean values for the nuclei number of the low-RFI and high-RFI groups were 33.16 and 30.30 in the duodenum and 37.21 and 33.65 in the ileum, respectively. The average size of the cells did not differ between feed efficiency groups in both segments (P ≥ 0.10). A trend was observed (P ≤ 0.10) for greater crypt area and crypt perimeter in the ileum for cattle with improved feed efficiency.ConclusionImproved feed efficiency is associated with greater cellularity and no differences on average cell size in the crypts of the small intestine in the bovine. These observations are likely to lead to an increase in the energy demand by the small intestine regardless of the more desirable feed efficiency.

Differential gene expression in the duodenum, jejunum and ileum among crossbred beef steers with divergent gain and feed intake phenotypes

“…Another study by Montanholi et al . () evaluated the relationship between cellularity and residual feed intake (RFI) in cattle. Their results suggest that the duodenum and ileum of low RFI animals have greater cellularity with no difference in average cell size, which suggests that these animals have an increase in energy demand to support the larger number of cells.…”

Organoids are promising tools for species‐specific in vitro toxicological studies

“…Until now, research connected with the morphology of bovine intestine was mostly related to food production and consumption, e.g., sausage casings(Wijnker, Tersteeg, Berends, Vernooij, & Koolmees, 2008) and the effects of animal diet on the mucosal architecture(Montanholi et al, 2013). Large animal organoids have not been analyzed in depth like the 3D in vitro models derived from humans and rodents had.…”

“…Using bovine organoids in in vitro toxicology evaluations is difficult due to the lack of knowledge about the types of differentiated cells that are present in the bovine intestinal epithelium and their similarities to the murine/human epithelium. Until now, research connected with the morphology of bovine intestine was mostly related to food production and consumption, e.g., sausage casings(Wijnker, Tersteeg, Berends, Vernooij, & Koolmees, 2008) and the effects of animal diet on the mucosal architecture(Montanholi et al, 2013). Livestock species-specific intestinal organoids(Table 1), which nowadays are successfully generated(Derricott et al, 2018;Powell & Behnke, 2017), have little use in in vitro toxicology, as this technology is mostly applied for insights into large animal (swine, bovine) host-pathogen interactions and disease responses(Derricott et al, 2018).…”

Feed efficiency in beef cattle: relationship with digestibility, antioxidant activity, oxidative stress, growth performance, and carcass characteristics

“…In other vital organs, DiCostanzo et al (1990) noted a tendency for a correlation between maintenance energy requirements and liver weight (r = 0.4, P ≤ 0.16) but no correlation (P ≥ 0.20) between maintenance energy and spleen, kidney, lungs, or heart weight in 14 mature Angus cows. More recently, Montanholi et al (2013) suggested that energetic use in the small intestinal tissue of highly efficient cattle was greater than in lowly efficient cattle. Montanholi et al (2013) selected the 12 most efficient (-0.53 kg/d RFI) and 12 least efficient (0.64 kg/d RFI) steers from a group of 45 crossbred steers that were finished with a high moisture corn-based diet for 140 d. At harvest, duodenum and ileum tissue were collected on the feed efficiency extremes and upon evaluation, the authors (Montanholi et al, 2013) noted greater cellularity in both the duodenum and ileum of the most versus least efficient steers (33.16 vs. 30.30 and 37.21 vs. 33.65, nuclei number) despite no difference in cell size.…”

“…More recently, Montanholi et al (2013) suggested that energetic use in the small intestinal tissue of highly efficient cattle was greater than in lowly efficient cattle. Montanholi et al (2013) selected the 12 most efficient (-0.53 kg/d RFI) and 12 least efficient (0.64 kg/d RFI) steers from a group of 45 crossbred steers that were finished with a high moisture corn-based diet for 140 d. At harvest, duodenum and ileum tissue were collected on the feed efficiency extremes and upon evaluation, the authors (Montanholi et al, 2013) noted greater cellularity in both the duodenum and ileum of the most versus least efficient steers (33.16 vs. 30.30 and 37.21 vs. 33.65, nuclei number) despite no difference in cell size. Montanholi et al (2013) concluded that although the increased cellularity would likely increase energetic requirements, but that increases in intestinal metabolic activity likely provide greater energetic benefit than cost, thus improving efficiency.…”