Hindgut Fermenter Review

What is a hindgut fermenter?

An animal that digests fibrous material in the caecum and colon.

Why is microbial fermentation important in hindgut fermenters?

It allows them to break down plant material, like cellulose, that mammalian enzymes cannot digest.

What is the primary energy source for hindgut fermenters?

Volatile fatty acids (VFAs) produced during fermentation.

What are the three main VFAs produced during fermentation?

Acetate, propionate, and butyrate.

What percentage of energy can VFAs supply to a horse?

Up to 70%.

Why are caecotrophs essential for rabbits?

They provide additional nutrients like vitamins and amino acids.

How does fermentation differ between foregut and hindgut fermenters?

Foregut fermenters ferment food before enzymatic digestion (in the rumen), while hindgut fermenters ferment it after enzymatic digestion (in the caecum and colon).

What role does the stomach play in hindgut fermenters?

It starts protein digestion and releases chyme into the small intestine.

How is the small intestine adapted for enzymatic digestion?

It has a large surface area for absorption and produces enzymes like amylase and lipase.

What is the main function of the large intestine in hindgut fermenters?

Fermentation and absorption of water and VFAs.

What is the role of microbes in the caecum and colon?

They digest cellulose and produce VFAs, gases, and B vitamins.

Why is saliva important for digestion in hindgut fermenters?

It lubricates food, starts enzymatic digestion, and buffers stomach acids.

How do hindgut fermenters prevent large particle reflux from the caecum?

They have a valve between the ileum and caecum (ileocecal valve).

What is the role of bicarbonate in rabbit digestion?

It buffers stomach acid and maintains pH for enzymatic activity.

What percentage of a rabbit’s faeces are caecotrophs?

Around 30%.

What structural adaptations make hindgut fermenters efficient at breaking down fibre?

A large caecum, elongated colon, and specialized microbes.

What anatomical feature prevents rabbits from vomiting

A well-developed cardiac sphincter at the stomach entrance.

Why is a high-fibre diet essential for hindgut fermenters?

To maintain gut motility, prevent obesity, and promote fermentation.

What can happen if hindgut fermenters are fed a low-fibre diet?

Gastrointestinal stasis, dental overgrowth, and colic.

Why is protein content in the diet of hindgut fermenters less critical?

They rely on microbial protein synthesis and recycling.

What is the risk of sudden dietary changes in hindgut fermenters?

It can disrupt the microbial population and cause digestive upset.

What types of carbohydrates should be avoided in hindgut fermenters?

Easily fermentable carbohydrates, like sugars and starches.

Why do hindgut fermenters require continuous access to food?

Their digestive system is designed for constant processing of small amounts of food, microbes are sensitive to ph changes and other factors

How does the caecum of rabbits differ from that of horses?

The rabbit’s caecum is relatively larger compared to body size.

How is the horse’s large intestine adapted for fermentation?

It has an enlarged colon with sacculations and haustra for fermentation.

Why is the horse more prone to colic than other hindgut fermenters?

Its digestive tract has complex flexures and narrow passages.

What is the function of the sacculus rotundus in rabbits?

It acts as a lymphoid tissue and separates the small and large intestines.

What is the purpose of haustra in the colon of hindgut fermenters?

To increase the surface area for fermentation and slow down ingesta movement.

What are common digestive disorders in hindgut fermenters?

Colic, gastrointestinal stasis, and acidosis.

What causes gastric ulcers in horses?

Prolonged periods without food, leading to acid buildup in the stomach.

Why are hindgut fermenters prone to bloating?

Accumulation of gas from microbial fermentation.

What is the impact of antibiotic use on hindgut fermenters?

It can disrupt gut flora and lead to dysbiosis.

What is the primary cause of diarrhoea in hindgut fermenters?

Rapid fermentation of inappropriate carbohydrates.

Why is hydration crucial for hindgut fermenters?

Water is necessary for fermentation and to prevent impaction.