By Barry Yaremcio, Guest Columnist
Different areas of the province are either in dry conditions or in a drought. Some cereal, legume (pea and lentil) and canola crops are under stress and are not likely to make it to harvest. These crops can be used as feed for ruminant animals.
Plants that are suffering from a lack of moisture and are experiencing hot conditions stop growing and try to produce a seed head no matter how small. They will mature up to six weeks earlier than normal. To conserve moisture, bottom leaves will dry up and drop from the stem (senescence). Seed bushel weights will be lower than normal. Canola plants will blossom, and if stress is sufficient, the flowers will turn orange and pods may not form or if they do form, many will be empty or contain very few seeds.
When plants undergo this stress, feed quality drops rapidly. Acid Detergent Fibre and Neutral Detergent Fibre levels increase, which results in reduced energy content in the forage and can restrict the amount of feed an animal is able to consume. With leaf loss, protein content declines. The longer the plant is exposed to these conditions, the lower the quality.
The overall recommendation is to cut or graze the crops as soon as possible. If making silage, it will not take long after cutting to be in the 60 to 65% moisture range for chopped silage. Bale silage should be in the 45 to 55% moisture range.
In previous years, we learned that cattle are very willing to eat canola either as greenfeed or silage. It may take a day or two for them to adjust to the taste of the feed, but it is something that is a viable alternative to hay.
There are a few concerns that need to be addressed:
- Plants that are under stress can accumulate nitrate. Usually, levels are not high enough to prevent the cut feed from being used. If nothing else, test for quality and nitrate and the concerns can be addressed at that time.
- Canola that received higher amounts of sulfur fertilizer may have higher levels than normal. A sulfur analysis should be included in the feed testing program.
- Don’t cut too close to the ground. White mould that is found in feed is generally caused by dirt contamination. When using a swather or disc bine, cut at a level where some stubble is left standing. This should prevent dirt getting into the swath. Set the rake and pickup height so that they don’t scratch the dirt.
Weeds that are present are a good source of nutrients. There are a few weeds that can contain anti-nutritional factors such as oxalates or nitrates but it is best to evaluate on a case by case basis.
Barry Yaremcio, a beef specialist, is a guest columnist this week.