Effect of dietary concentrate level on digestibility of nutrients in each region of the gastrointestinal tract and rumen fermentation in goats

Abstract

This study evaluated the effects of high concentrate diets (HCD) on the rumen fermentation and the digestibility of nutrients in different sites of the gastrointestinal tract (GIT) in goats. Four goats were used in a crossover design. The goats were fitted with a ruminal cannula and flexible T-cannulae proximal duodenum and terminal ileum. Treatments were as follows: low concentrate group (LCG) and high concentrate group (HCG). Duodenal flow and forestomach digestibility of starch were significantly higher in the HCG than those in the LCG (p < 0.05); There was no significant difference in ileum flow and digestibility of starch in the small intestine, large intestine and total GIT (p > 0.05). The digestibility of crude protein (CP) in the forestomach was significantly higher in the HCG than in the LCG (p < 0.05); the flow of the duodenum and ileum of CP, and the CP digestibility of the small intestine, large intestine and total GIT were not significantly different between groups (p > 0.05). The duodenal and ileal flow of neutral detergent fiber (NDF), the NDF digestibility of the different segments and total GIT were not significantly different between groups (p > 0.05). Compared to the LCG, the ruminal pH of the HCG was significantly lower (p < 0.05). The HCG concentrations of microbial crude protein, ammonia nitrogen and isovaleric acid were significantly higher (p < 0.05) than the LCG. The foam strength, foam production and viscosity of the rumen fluid in the HCG were higher than the LCG (p < 0.01). These results showed that when the goats were fed with HCD, the digestibility of nutrients was not significantly impaired, but the risk of frothy rumen bloat increased.

Implications

• Due to a serious shortage of high-quality roughage in China, producers commonly used a high-concentrate diet in ruminants, which can improve animal production performance.

• Gastrointestinal digestive function plays a vital role in the absorption of nutrients and the healthy growth of animals.

• Therefore, this research evaluated the digestibility of various nutrients in different segments of the gastrointestinal tract (GIT) under HCD feeding by using three-site cannula goats as experimental animals.

• The results indicated that the GIT of goats could fully digest nutrients such as starch and protein under HCD feeding conditions.

Keywords:

• High concentrate diet
• goats
• digestibility
• rumen fermentation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Data curation, Zhisheng Wang and Bai Xue; formal analysis, Xuejiao Zhang, Lizhi Wang and Zhisheng Wang; funding acquisition, Lizhi Wang; investigation, Quanhui Peng; methodology, Xuejiao Zhang; project administration, Lizhi Wang; software, Xuejiao Zhang and Bai Xue; visualization, Quanhui Peng; writing – original draft; writing – review & editing, Xuejiao Zhang and Lizhi Wang.

Data availability statement

None of the data were deposited in an official repository.

Additional information

Funding

This paper was financially supported by the Science & Technology Department of Sichuan Province [2021YFH0154] and Sichuan Beef Cattle Innovation Group [SCCXTD-2022-13].