Small Grains Can Be Excellent Forage for Dairy Cattle
Dairy Pipeline: July 1998
Charles C. Stallings
Extension Dairy Scientist, Nutrition
(540) 231-4758; email: email@example.com
Recently there has been some discussion about using rye as a feed for lactating dairy cows and one report indicates that rye should not be fed. Our experiences in Virginia indicates that rye can be used as a feed for lactating dairy cows when fed as pasture, silage, or hay. Rye and barley harvested as boot or vegetative stage contains relatively high levels of protein. In a study we conducted at Virginia Tech we found that boot cut barley silage contained 17 to 19% crude protein and 31% acid detergent fiber. Digestibility was 75% indicating extensive digestion during passage through the GI tract. Observations from the Virginia Tech Forage Testing Lab indicate that rye silage typically contains 36% dry matter, 14% protein, and 40% acid detergent fiber. In addition the protein solubility is 79% of the total protein indicating much of the protein is available in the rumen. What do these observations mean when formulating rations? It is best not to use boot harvested rye or barley as the only forage for lactating diary cows. The exception might be when cows are grazing rye pasture. When feeding rye or barley silage in total mixed rations mix with corn silage if possible to increase palatability, energy content, and reduce ration protein solubility. Rumen resistant protein supplements should be used for part of the supplemental protein in order to keep rumen degradable protein from exceeding 65% of the total ration protein. When fed in a balanced ration vegetative rye and barley can supply a portion of the forage requirement for lactating dairy cows. With cows on pasture, rye or barley might supply all of the forage. Rye should be harvested before seed head emergence because nutrient content declines rapidly. Barley can be harvested at boot and soft dough stages. Wilting is necessary when harvested as boot, but soft dough can be direct cut. The advantage of harvesting barley at boot stage would be higher protein content. The disadvantage would be the extra time before harvest.