Feeding pigs in extensive production: Part 2

Complete feed rations are Important for the nutrition of your pigs


In this article, the second in a two-part series , several management and procurement approaches are discussed relative to feeding pigs in extensive settings. Feed may be formulated and manufactured on-farm, but also purchased in ready-to-feed bags or ready-to-feed bulk. Once again, the cost of feed decreases with increasing responsibility for grinding, formulating, mixing, storage and quality control. Taking on responsibility for devising the nutritional program and making the feed must result in equivalent or improved production and a cost improvement that accounts for the added time and knowledge (more time formulating, buying individual ingredients, more automation for bulk procurement of ingredients, equipment and power to manufacture feed, automation for delivery to bins, and delivery to feeders).

Mixing Complete Feeds

If purchasing one ton of feed at a time is too much, you may consider planning ahead for the mixing of two different complete feeds. This can be advantageous as it still allows you to purchase feeds in one-ton quantities which is less expensive than buying smaller quantities. Mixing two complete diets together eliminates the over-feeding of nutrients as pigs get older and the under feeding of pigs if price of feed is encouraging the avoidance of purchasing too much of the expensive starter diet. Mix proportions of a “dense” ration with a “less dense” ration to get a “moderately dense” ration. For example, a grower 1 diet containing 1.1% total lysine could be mixed 1-to-1 with a finisher diet containing 0.8% lysine, and the resulting feed would be 0.95% lysine and appropriate as a grower 2 diet. This simple example assumes that other amino acid concentrations will be portioned similarly and that the minerals and vitamins in both the grower 1 and finisher diets are equal. If not similar, then the ‘mixed diet should be evaluated for any estimated concentrations that do not meet the minimum of NRC Pork Production. You can blend by the scoop, bucket or bushel basket full. You use the feed quickly and avoid loss of available nutrients with extended storage. You do not have to store feed until the next reproductive cycle, when you have pigs of a given maturity once again. And you do not have to own a grinder-mixer.


Purchasing one ton of bulk complete feed may still be an option, even if you do not have enough pigs to eat all of it in an appropriate amount of time. With topdressing, one ton of a “less dense” ration is purchased, and then daily portions are top-dressed with soybean meal or another protein source with each feeding. You may buy one bag of soybean meal at a time. The amount of soybean meal will vary and decrease as pigs grow; anywhere from a quarter to one full cup (about 150 grams) per pig per day. One cup of 47.5% soybean meal provides about 4.7 g of lysine. The farmer who grows soybeans or other protein sources can use these to top-dress, keeping in mind that soybeans must be cooked or steamed prior to feeding.

Grind and Mixing Feed at Home

A farmer may grind and mix their own rations if they have accurately determined that the cost savings in doing so are real. The cost of procuring all ingredients, equipment, delivery, processing, interest, depreciation and labor must be considered. The decision to process feed on the farm must not only be cost effective, but also requires the owner be responsible for being knowledgeable about formulations and feed quality.

Feed processing on the farm can be done with varying amounts of complexity. Most simply, a PTO drive grinder mixer may be used to grind grains and mix with a purchased complete supplement, often called a ‘vitamin and mineral mix’, or ‘vitamin-mineral pre-mix, which includes all other ingredients. As the size of the swine enterprise increases, justification for complexity increases, and a farmer may consider purchasing individual lots of a protein source, a calcium source, a phosphorus source, salt, a trace mineral premix, and a vitamin premix. In an older Pork Industry Handbook bulletin, Bloome and others suggests at 200 to 400 tons per year (30 to 60 sows farrow-to-finish) as the break-even volume of feed for a PTO grinder-mixer. The North Carolina State University Swine Nutrition Guide 7 suggests that 500 to 750 tons of feed per year justify use of a stationary mill and mixer for on-farm feed processing. It takes about 70 to 100 sows in farrow-to-finish production to justify raising corn, oats, or other grains and the costs of labor, transportation, feed manufacturing, and feed storage. Other questions to consider when deciding whether to process feed on-farm are presented in a Pork Information Gateway resource by Holden and Starkey.

Alternative Feedstuffs

Periodically, extensive producers have access to a surplus low-cost byproduct which they would like to feed to swine. These vary considerably in nutrient profile and availability based on location and season, making general guidelines for their use challenging. The challenges with feeding these alternative feed stuffs are: knowing nutrient availabilities and amino acid relationships in that alternative feed stuff. Thaler and Holden have provided upper inclusion limits (amount or percentage) for various alternative feed stuffs. Farmers should seek the advice of a nutritionist, extension specialist, or consultant to evaluate ingredient and finished feed quality.  When managed appropriately, there are many local sources of vegetables, dairy whey, root crops, and other alternative feeds that add variety to pigs’ diets and may reduce feed costs. Older swine husbandry book, some now available electronically, have nutritional values for some of these alternatives, but recognize there can be considerable variation around these averages.

Pasture and forage

Many extensive producers raise their herds on pasture or in woodlots, and the right kind of forages can add significant nutrients to swine feeding programs. According to the factsheet, Forages for Swine from Pork Information Gateway, sows on good quality pasture can be fed less often and with a smaller amount of concentrate. Forage adds protein, fiber, and essential vitamins and minerals to the diet, but should not be considered as a substitute for a grain-based complete diet. The nutritional value of forages depends upon the type and quality of plants in the pasture. As a rule of thumb, high quality forage can substitute for up to 20-30% of the diet. At the 20% mark, the farmer should consult with a nutritionist to make adjustments in formulation of the complete diet to ensure all nutritional requirements are being met. Opportunities for foraging grain or crop fields after harvest may be available seasonally. Silage may also be fed to sows[v], if protein and energy levels are maintained at appropriate levels in the overall diet, according to the factsheet, Forages for Swine from the University of Missouri

Feed Co-op

In the history of swine production in North America, we can read about the formation of producer cooperatives. This is another historical approach which extensive swine farmers can consider. Like-minded extensive farmers can more easily experience the economies of scale by cooperatively buying complete feed or feed ingredients in larger quantities. Historically, this was referred to as a ‘feed co-op.’ If large enough, they could save substantial amounts of money by buying other supplies and equipment together as well. Of course the co-op needs to be managed and records maintained, so this benefit is not without some expense or effort.


Often mentioned in nutrition discussions is the fact that feed typically represent 60 to 75% of variable production costs in pig production. Extensive farmers looking to decrease feed costs must decide if the reduction in all costs with a potential alternative approaches does exist, and that they have the ability to control the quality of processing and presentation. The feed procurement approach should achieve desirable nutrition, health and productivity.

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