Alfalfa vs Timothy for Rabbits: Complete Calcium & Nutrition Comparison

April 22, 2026

Alfalfa or timothy? The wrong choice can cause bladder sludge in adult rabbits or stunt growth in kits. Here is the clearest side-by-side comparison available, based on 2026 Ametza lab data.

Quick Answer

Rabbit kits (under 6 months), pregnant & nursing does, underweight rabbits: Alfalfa.
Adult rabbits (6+ months), maintenance, seniors: Timothy.
Guinea pigs over 6 months, chinchillas: Timothy.
Guinea pig pups under 6 months, pregnant sows: Alfalfa.

Full Nutrient Comparison (Ametza 2026 Lab Data)

Nutrient	Alfalfa Pellet	Timothy Pellet	Why It Matters
Protein	17.2%	10.8%	Growth & lactation need high protein; adults do not
Fiber	22.1%	28.4%	Higher fiber = better GI motility in adults
Calcium	1.38%	0.52%	Excess calcium in adults causes bladder sludge
Phosphorus	0.28%	0.21%	Ratio with calcium matters (2:1 Ca:P ideal)
Lysine	0.92%	0.38%	Growth amino acid — critical for kits
Vitamin A	High	Moderate	Growth, reproduction, immune function
TDN (energy)	62%	56%	Alfalfa is more energy-dense

The Calcium Question

This is where most rabbit owners go wrong. Rabbits absorb nearly all dietary calcium (unlike humans, who self-regulate), and excess calcium is excreted through urine as calcium carbonate — the white, chalky residue known as bladder sludge. Prolonged high-calcium intake leads to stones, urinary blockage, and chronic UTIs. An adult rabbit on alfalfa will develop sludge within 6–12 months. The transition to timothy at 6 months old is not optional — it is preventive medicine.

For pregnant or nursing does, calcium demand triples to build kit skeletons and produce milk. Alfalfa is essential during this window, then switch back to timothy at weaning.

Protein Matters Too

Kits grow from 50g at birth to 1,800g at weaning — a 36x increase. That growth requires 17–18% dietary protein and high lysine. Timothy's 10.8% protein cannot sustain this. A kit on timothy will be 10–15% underweight at 8 weeks and may never reach full adult frame.

When to Switch from Alfalfa to Timothy

Standard timeline:

Birth – 4 weeks: mother's milk + free-choice alfalfa for doe
4 – 8 weeks: weaning onto alfalfa pellets, free-choice alfalfa hay
8 weeks – 6 months: unlimited alfalfa pellets + alfalfa hay
6 – 7 months: gradual 4-week transition to timothy pellets and timothy hay
7 months+: timothy for life (except during pregnancy/lactation)

Follow our 10-day transition protocol when changing hay types.

Species-Specific Notes

Guinea Pigs

Guinea pigs cannot synthesize vitamin C, but that is independent of the alfalfa/timothy question. Both species need timothy after 6 months to avoid bladder stones (guinea pigs form calcium oxalate stones, which are surgical emergencies). See our guinea-pig-specific timothy pellets.

Chinchillas

Chinchillas evolved on dry, low-protein Andean grasses. They should never be fed alfalfa long-term — it is too rich. Use timothy or orchard-grass pellets exclusively.

Goats

Dairy goats benefit enormously from alfalfa's protein and calcium during lactation. See Ametza dairy-goat alfalfa pellets.

FAQ

Can adult rabbits have any alfalfa?

A small pinch as a treat (1 tbsp per week) is fine. Daily alfalfa for adults is not.

My vet said alfalfa causes obesity — is that true?

Alfalfa has 11% more calories than timothy. Combined with a sedentary house-rabbit lifestyle, this leads to weight gain. Portion control fixes it; total elimination is not required for young rabbits.