Limit feeding: A viable option to reduce winter hay needs for the cow herd
Limit feeding diets high in concentrate, or by-product feeds, can be an effective strategy to reduce the amount of hay fed without sacrificing cow productivity. A typical dietary intake (on a dry matter basis, DM) is around 2.0 to 2.5 percent of body weight (BW). For a 1,250-pound cow offered hay free choice that equates to around 30 to 35 pounds of hay on an as fed basis (assuming 88 percent dry matter). Although ruminants require roughage to maintain proper rumen function the minimum amount needed is a 0.5 pounds of forage per 100 pounds of BW (0.5 percent of BW). For a 1,250-pound cow that is a little more than 6.0 pounds of forage on a DM basis (~7.0 pounds as fed). Grain and by-product feeds are more nutrient dense and, with proper management, can be used to replace nutrients lost due to reduced hay intake. Limit fed diets can reduce the overall DM intake to around 1.5 percent of BW, while still meeting nutrient requirements. Limit feeding is a sound nutritional management practice; however, there are several things that need to be considered before embarking down this road.
Many concentrate feeds contain high levels of starch which presents some risk of digestive upset and metabolic disorders when fed at high levels. With proper management and careful ingredient selection these associated risks can be significantly minimized. The rate of rumen fermentation is greater for some grains than others. Feeding an ionophore can assist with preventing digestive disturbances and improve feed efficiency. Also, selecting feedstuffs high in digestible fiber like soy-hulls, wheat middlings, or dry distillers grains with solubles (DDGS) can significantly reduce or eliminate starch from the diet without affecting energy density.
It is important when utilizing a limit feeding system to analyze the nutrient composition of the hay source and any byproduct feeds to ensure the diet is adequately balanced. Additionally, the mineral composition of the diet should be carefully evaluated. It is likely the traditional mineral program will not be appropriate.
In addition to evaluating the actual diet costs, the added costs associated with increased labor and feed storage and handling facilities need to be factored into a decision to use this type of feeding system. Some feedstuffs store well in bins and others, like DDGS, do not. All should be kept dry to prevent spoilage. Many producers are not set up to handle or feed bulk commodities. If this is the case, commercial feeds manufactured as pellets/cubes may be an option. However, processing will increase costs. Additionally, access to a scale to weigh feed is necessary to prevent over and under feeding problems.
Limit fed diets also require a higher level of management. When starting a limit feeding program animals should be gradually adapted to the diet. This can be done by replacing the forage portion with concentrate over a 14 to 21 day period. Feed delivery can be a challenge as the cows will be ready to eat. Feed should be delivered at a similar time each day and 30 inches of bunk space should be provided for each animal. Preventing access to the feed bunks until the feed is laid out would be best, particularly if you do not have equipment that allows for mixing the hay and concentrate together. If this is not possible then deliver the hay first and then the concentrate. This will allow the cows to consume the hay first and assist with preventing digestive upset from consuming too much concentrate. Fences should be in good repair. Hungry, bored cattle will crowd and reach through fences. Also, make sure that cattle have access to plenty of water – normally about 15 to 20 gallons per cow per day.
Since limit fed diets are restricted intake diets, the cows may appear hungry and will not show as much fill as with typical forage diets. They will be at the fence at feeding time and emotionally it is hard for producers to see cattle that appear hungry. If the diets are balanced properly, the cow’s nutritional requirements will be met. Producers must resist the urge to feed the cows more. The goal is to have cows in adequate condition while reducing feed costs, and feeding more than is needed will implode the goal. However, body condition should be closely monitored during the feeding period and diets should be adjusted to maintain desired condition. It is possible to get animals over conditioned on limit fed diets. Limit fed diets should also be balanced and adjusted to match requirements for the cow’s stage of production.