On small farms, I've seen cattle kept in a cherry orchard, and an apple orchard. They were moved to a different pasture when the time came to pick the fruit. So sometimes the same land can be used for both, at least on a small scale. And the trees provide shade for the cattle on hot summer days.
When I said that fruit is more efficient than animal products, I was only talking about GLUCOSE, not overall calories. You need to consider how protein vs carbs are metabolized in the body, not just look at calories per gram.
I'm not just talking theoretically. I tried a raw carnivore diet while doing lots of heavy exercise every day (both aerobic and anaerobic). My appetite skyrocketed, as did my food bill. I found that adding a small amount of carbs (50-100g per day) significantly reduced my appetite for meat, while maintaining performance.
First, I disagree with the statement that fruit is a more "efficient" source of calories relative to animal products (assuming a mix of muscle, organ and fat here). Carbohydrates (from sugars, in this case) yield something like 5 calories per gram. A chunk of the average cow (assuming 50% fat, 50% protein) yields something like 6-7 calories per gram. So by the gram, you get more calories from animal food than from fruit.