This particular question is asked almost more than any other. I beg all Dexter breeders to please, stop answering it! Why? There is no right answer, and your answers are causing more harm than good.
The number of cows you can maintain per acre depends on the following:
1. Your climate and microclimate.
2. Your soil.
3. The amount of rainfall and how evenly it was distributed throughout the year.
4. Your amount of maintenance of the pasture (THIS IS HUGE).
5. Your amount of fencing, do you rotate your cattle? Daily? Weekly? Monthly?
6. What have you seeded? What kind of grass do you have?
7. Only the best situations of perfect pasture, perfect maintenance, and perfect climates, can allow you to graze your cattle year-round. Everyone else will need to feed hay during their off season(s) when it is too hot/cold/dry to grow grass. New buyers will not know this and experienced breeders forget to tell them!
8. Consider the movement towards suburban farming: Someone who has 30 acres and 20 Dexters has very different pasture dynamics than someone who has 3 acres and 2 Dexters. This is because the person with more land can rotate pastures more effectively, giving the pastures more time to rest between grazing periods.
For a climate example, areas of Colorado that are technically “perfect for cattle” may require 25 acres per cow, or more. Areas of coastal Washington State may be able to maintain 5 cows per acre during the warm summer months, but everything will turn to mud when the sunshine disappears and the cows will need to be fed hay throughout half the year.
As far as maintenance, most people don’t start to maintain their pasture until they get a few cows, so there is always the adjustment period of several years as they fiddle with different varieties of seed, getting the pH adjusted with lime, fertilizing, building more cross-fencing, or even overcoming noxious weeds.
The biggest problem is Dexter breeders are much too willing to answer this question, based on the experience they have from their own pasture. Your personal head count, after several years of maintenance, will almost never apply to the person on the phone calling about getting his first cows. The result is an epidemic of half-starved Dexters; as a result of buyers that were not only given incomplete information about pasture management, but were also told “Dexters will thrive on poor pasture.” There are too many Dexters out there that are not “thriving.” Please, direct these questions to the buyer’s local agriculture extension office, or somewhere the buyer can find local knowledge and continuing support to help them through several years of learning and adjusting.
Thank you for the most honest answer I have read in ten years of researching the miniature cattle breeds. This answer would apply to any miniature breed of cattle being sold in today’s hobby farm market. Some extension agents and advisers will not give an answer because of the lack of knowledge regarding the miniature/smaller breeds of cattle. They always refer to how you would feed a standard size animal. Breeders need to educate first time buyers before offering any animal for sale. Most first time buyers are folks from the city wanting to “play” farmer and have little idea of pasture management.