You could easily make a pig pen with a deep litter system. if you dedicate a 60ft square shed you could more than make enough grain fodder. Pigs are an animal that can do well on 100 percent of their diet as fodder. But I would supplement with veggies and commercial grain. Here is a list of a bunch of grains with different applications for fodder
Alfalfa is a highly palatable legume that has been grown as livestock feed since the fourth century. It is valued for its high nutritional quality and is an excellent source of essential vitamins, minerals and amino acids. Hydroponically grown alfalfa fodder is more digestible than its field-grown, dried hay counterpart, increasing feed efficiency and reducing the need for concentrates.
Barley is a cereal grain that is commonly used in the finishing rations of cattle in the United States and Canada. These sprouts are high in protein and fiber, and are naturally balanced in protein, fat and energy. Compared to corn, barley fodder has 95% of the energy and higher digestibility. Barley fodder is one of the most nutritious sprouts and is full of essential nutrients, vitamins and minerals. Feeding barley fodder will improve the overall health and wellbeing of your animals
Millet is a grass that is rich in B vitamins and high in fiber. It has been grown as a staple feed for thousands of years and is one of the world's most important cereal crops. Millet fodder sprouts are highly digestible and nutritious. They are high in minerals and essential amino acids. Millet is similar to corn and is low in protein compared to other feedstuffs. Millet is also fairly starchy. It is commonly mixed with other seeds, such as oat or barley, to provide a more complete ration.
Oat is a cereal grain that is one of the most important sources of livestock and animal feed in the world. It is commonly fed to horses and ruminants due to its excellent nutritional qualities that aid with maintaining optimal rumen and hindgut function. Hydroponically grown oat fodder is high in fiber and low in starch, making it an easily digestible feed. Oat is also rich in nutrients and essential minerals and is one of the richest sources of protein compared to other feedstuffs.
This cereal grain has garnered attention over the last couple of years as an alternative to feedstuffs with fluctuating prices that are used in livestock rations, such as corn. When grown hydroponically, red wheat fodder has many nutritional advantages. Of all the classes of wheat available in the United States, red wheat has the highest protein composition. It is also high in energy and the starches in wheat ferment quickly in ruminant digestion.
Ryegrass is a highly palatable and protein-rich grass that is grown primarily for pasture and silage. It is valued for its high nutrient composition and digestibility. Due to its excellent nutritional quality it is commonly used as pasture for lactating dairy cows. Sprouted ryegrass fodder contains many of the same benefits of its more mature, pasture-grown counterpart and the feed value of ryegrass fodder is highly comparable to corn.
Sorghum is a grass that is rich in antioxidants and high in fat. There are numerous varieties of sorghum and it is grown all over the world as a staple for humans and livestock. In the United States, sorghum is grown primarily for its grains that are used in livestock rations. Hydroponically grown sorghum fodder has many nutritional advantages and, in fodder production, it is commonly used as a supplement to provide more fat.
I copied and pasted from a website. sorry for how wordy it is