Research has shown that whole grain feeding improves growth rate and feed efficiency when fed to lambs compared to pelleted or mash feeds. A Canadian study showed that feed intake may increase by 25%, growth rate is 20% higher with whole grain, and feed efficiency is improved by 10%. Whole grain produces a firmer more desirable finish on the carcass. It does not cause damage to the rumen. When feeding whole grain, there is less probability of overeating disease and acidosis. When forage is fed with the grain, additional evidence shows that whole grain is preferable to pellets. Feed intake is higher and utilization of forage is higher.
In another Canadian study, whole corn produced slightly faster and more efficient gains. However, its value is no more than barley or wheat because the advantage of higher energy is offset by its lower protein content. Barley and wheat have produced similar results, perhaps with a slight advantage to barley. Oats fall well behind in terms of live weight gain, feed efficiency, and dressing percentage. The value of oats is no more than 80% the price of barley. There is also some evidence to suggest that oats may produce a less desirable flavor in the meat than the other grains. The best choice of grain will vary with location, supply, and price.
In the late 1980's, Virginia Tech conducted studies comparing whole grain diets with high-energy pelleted diets for finishing lambs. The whole grain diets produced the highest rates of gain, best feed efficiency, and lowest cost of gain. In the Virginia study, once the lambs had adjusted to full-feed, all the roughage was removed from the diet. The feeding of whole grain provides lambs with a built-in roughage factor. Only about one-third of the grain is cracked when first eaten by the lambs. The remainder of the grain must be regurgitated during rumination for further mastification. This action of mastification and chewing contributes more saliva to the digestive process, thus increasing the buffering capacity of the rumen.
How to Feed Whole Grains
Whole grains can be fed using a simple mixture of the whole grain with a commercial protein-vitamin-mineral supplement (30-40% protein). When combining soybean meal with whole grains, limestone should be added to the ration to provide a satisfactory balance of calcium and phosphorus in the ration. Grains contain more phosphorus than calcium and if fed without a supplement may result in urinary calculi in wethers and rams. When feeding lambs, the ratio of Ca:P should be at least 2:1. The addition of ammonium chloride to the ration will also help to prevent urinary calculi.
Ewes can be fed whole grains during flushing, late-gestation, and lactation. In years of drought, it may be more economical to supplement ewes with whole grain than hay. Thin ewes can be flushed with 0.5 to 1 lb. of corn or barley per day. Four to six weeks prior to lambing, ewes should be supplemented with approximately 0.75 to 1 lb. of grain per day. This can be whole grain. Mineral (Ca) supplementation will only be necessary if a grass hay is being fed. Protein supplementation will be necessary if the hay is poor quality (<10% CP). During lactation, whole grains can be fed to provide supplemental energy. The amount (if any) of protein supplement required will depend upon the quality of hay being fed. For example, a good quality alfalfa hay negates the need for protein supplementation, except for very high producing ewes. If pasture or hay supplies are short, supplementing with whole grain will help to limit the amount of hay or pasture needed. Supplementing with grain is most economical when hay must be purchased. However, ewes need to consume roughage (0.5-1 lb. DM/day) to maintain rumen function.
What About Goats?
Whole grains can be fed to goats successfully. In 2002, we conducted a study comparing a whole barley-protein supplement diet with a commercial pelleted meat goat diet. The performance of the buck kids were similar for both diets, but the goats consuming the whole grain diet produced gains at half the cost.