Letter to the Editor Domestic Rabbits Magazine

7/31/2025

Dear Editor,

I am writing to submit a rebuttal to the recent article titled “Rabbits 101: Hay is for Health” published in your magazine, which advocates for free choice (ad libitum) hay feeding making up 80–90% of a rabbit’s diet. As a rabbit researcher and breeder with extensive experience and knowledge grounded in peer-reviewed scientific literature, I must respectfully disagree with these recommendations.

Rebuttal to “Rabbits 101: Hay is for Health” — Point by Point

Claim: “Rabbits should have free choice (ad libitum) access to hay, which should make up 80–90% of their diet.” Response: Contrary to this claim, pellets—not hay—are the true nutritional cornerstone of a rabbit’s diet. As Dr. T.E. Reed, rabbit nutrition specialist, states: “There is a vast difference in the nutritional value of hay, depending on the type of hay, the quality of forage prior to preparation, and the type and manner of the curing process of hay.” Even under best-case conditions, most commercially available timothy hay — after months of storage — contains only 3–9% protein, far below the 16–20% required for maintenance, growth, and reproduction (Lebas et al., COST 848, 2000–2004). Timothy Hay (best quality): 13.8% protein, 31.8% fiber (dry matter basis). Digestible protein is only 42–47% for mature cuts (Voris et al., 1940; Richards et al., 1962).

Alfalfa Hay: Higher in protein (18.3%), but calcium-rich and variable in digestibility. Even alfalfa hay cannot sustain optimal growth as the sole feed (Fernandez-Carmona et al., 1998; Villamide et al., 2010).

Loose hay is low in protein (3–9%), significantly below the 16–20% protein required for maintenance, growth, and reproduction (Lebas et al., COST 848, 2000–2004). Diets overly reliant on hay dilute essential nutrients, resulting in malnutrition. Free choice hay feeding encourages excessive intake of indigestible fiber, which leads to multiple problems: Fiber levels above 20–22% accelerate gut transit time, impairing nutrient absorption and causing digestive disorders such as mucoid enteropathy (Moore, 2022).

Excess indigestible fiber combined with protein fosters harmful bacterial overgrowth and ammonia toxicity by disrupting the digestive microflora balance (Moore, 2022).

Hay’s lignin content decreases digestibility of proteins and energy, increases stomach retention time, and raises the risk of functional impactions.

Excessive hay during critical growth stages slows development, hindering rabbits from reaching market weight efficiently.

While rabbits require both short and long fiber particles for digestive health, “long fiber” is a misnomer since pellets already provide sufficient fiber length for proper cecal fermentation and motility (Al-Khalaifah, 2019).

Loose hay fiber’s coarse texture causes abnormal jaw stress and dental damage (Böhmer et al., 2017).

Excessive loose hay dilutes the nutritional density of the diet and slows growth in young rabbits, preventing them from reaching market weight on schedule. Commercial meat and show breeders avoid this problem by relying on balanced pelleted diets with hay as a supplement — not the other way around.

Claim: “Hay supports digestion and maintains dental health by providing natural abrasives and insoluble fiber.” Response: Scientific evidence contradicts this. Digestive Impact of Excess Hay Feeding hay ad libitum frequently results in excess indigestible fiber (>20–22%), which: Accelerates gut transit time, impairing nutrient absorption and causing digestive disorders such as mucoid enteropathy (Moore, 2022).

When combined with protein, encourages harmful proteolytic bacterial overgrowth and ammonia toxicity (Moore, 2022).

Increases lignin content, which lowers digestibility of protein and energy and raises risk of functional impactions (Gidenne, 1992).

Dental Health: The Hay Myth Recent findings show that loose hay can cause — not prevent — dental issues. The claim that hay prevents dental disease is contradicted by Böhmer et al. (2017) demonstrated that chewing hay produces excessive vertical bite forces, resulting in tooth elongation, splitting, periodontal disease, jawbone intrusion, and malocclusion. Thus, hay actually increases dental disease rates rather than preventing them.

Claim: “Pellets do not provide the long-stem fiber or chewing resistance that loose hay provides.” Response: Pellets contain fiber particles of adequate length (0.3–0.5 mm) to maintain gut motility and cecal fermentation without causing dental trauma (Al-Khalaifah, 2019). Loose hay’s longer, abrasive fibers are unnecessarily harsh and damaging (Böhmer et al., 2017).

Claim: “Hay provides essential environmental enrichment and natural foraging behavior stimulation.” Response: Enrichment does not equal nutrition. Controlled hay portions, rabbit-safe chew toys, compressed hay cubes, and pellet-foraging toys provide behavioral benefits with minimal dietary risk. While hay can provide behavioral enrichment, it is not a substitute for balanced nutrition.

Claim: “Hay should be fed unlimited, using hay racks, boxes, or litter corners to make it accessible.” Response: Unrestricted hay access increases exposure to parasites such as coccidia, fur and ear mites, and E. cuniculi if not carefully stored. Pellets, being heat-processed, are safer. Hay should be regarded as a dietary supplement rather than the main nutrient source.

Summary: A pellet-centric diet providing 80–100% of nutrition, with balanced protein and fiber, is the scientifically supported gold standard for domestic rabbits (Lebas et al., COST 848; Moore, 2022). Overfeeding loose hay dilutes nutrition, contributes to dental disease, and predisposes rabbits to digestive disorders. Rabbits thrive best on complete pellets supplemented with moderate amounts of hay. The “hay-first” ideology is misleading and risks reduced lifespan and welfare (UK Vet Survey, 2021). Thank you for considering this evidence-based perspective. I urge your readers to critically evaluate feeding advice and rely on up-to-date scientific consensus for the best care of their rabbits. _

_________________ References

Lebas, F., Gidenne, T., et al. (2000–2004). Recent Advances in Rabbit Nutrition, COST 848.

Moore, L. (2022). Rabbit Nutrition and Nutritional Healing, 3rd ed., Revised.

Böhmer, C., et al. (2017). Shape Variation in the Craniomandibular System and Dental Problems in Domestic Rabbits. Vet Sci, 4(1):5.

Al‑Khalaifah, H. S. (2019). Effect of fiber particle size on rabbit digestive efficiency. Pak J Nutr, 18(3):101–108.

Gidenne, T. (1992). Effect of fibre level, particle size and adaptation period on digestibility and rate of passage… Br J Nutr, 67(1):133–146.

Richards, M.P., et al. (1962); Voris, L., et al. (1940). Timothy Hay Digestibility Studies.

Fernandez-Carmona, J., et al. (1998). Alfalfa in Rabbit Diets.

Villamide, M.J., et al. (2010). Protein Utilization of Alfalfa.

Sincerely,

Mary Conley

Rabbit Researcher, Author, and Breeder