StettlerLocal.com October 18, 2021, contributed by Yaremcio Ag Consulting, Ltd.
With feed supplies being tight, extending the grazing season by grazing canola and cereal crop regrowth is an option that should be considered.
Young plants are very high-quality feed. Canola regrowth at the flowering stage or cereal crops at the heading stage; are high in protein and energy, and low in fibre. Approximately the same value as a high-quality first cut alfalfa grass hay. This makes this material excellent for cow calf pairs, or weaned cows.
There are a few concerns when considering regrowth as grazing material.
Depending on the crop yield either as silage or for grain and the fertility of the field, there is a possibility of nitrate accumulation in the regrowth. The key to handling high nitrate levels is to introduce the animals slowly to this feed. When nitrate levels exceed 1% on a dry matter basis, feed half of their daily feed intake in the morning as hay or other forage that does not contain nitrate. Around noon, let the animals into the regrowth so they can graze. Remove the animals that evening and repeat this process for 3 to 5 days. After the fifth day, the cows do not need to be removed from the area. As an additional precaution, place a bale of low-quality grass hay in a feeder in the regrowth area. Animals adjust to the nitrate and become tolerant over time.
With canola regrowth, the additional concern is high sulfur content in the plants. Ingested sulfur changes to sulfuric acid when exposed to water in the rumen. This reduces rumen pH which kills off the strains of bacteria that produce thiamine. Thiamine is required to prevent the brain from swelling. Without thiamine, Polio can occur and animals can die in a short period of time.
As with any change in a feeding program, watch the cows and determine if everything is normal. If the cows have not experienced eating canola greenfeed or fresh plants previously, it can take 3 to 4 days for them to adjust to the new feedstuff and be willing to eat it.