Grazing your herd through the winter on standing forages in pasture is one way to reduce costs and improve your bottom line. It avoids the expense of baling, moving feed and then feeding. But is the feed giving your livestock what they need to survive and thrive? Here’s some data from a variety of locations to help you with the answer.
In his series of articles walking readers with him through his 2014-2015 grazing season, our resident Grass Whisperer, Troy Bishopp, went the extra mile to give his fellow graziers information that would help them to make the transition to winter grazing. He even tested his standing forage so that they would have an idea of what to expect. Here’s what he learned:
“The Paddock 10 forage sample came back. This may not represent the quality of the green forage that they’re eating because I took a sample with green, brown and seedheads mixed together. I chose this sample because the cows will eventually go back and clean-up after they’ve grazed off the best stuff in the first 8 hours. But as Kathy Voth points out, its possible that my green forage is quite high in protein and they are balancing their diet by adding the older, browner forage to balance the high protein.
“According to the nutritional needs of an early to mid gestation 850lb heifer, this feed just meets their daily requirement. The energy should be 60 ME, and we’re at 56. However since they can eat all they want they tend to get what they need.
“Penn State’s Craig Williams and Virginia Ishler, and Cornell’s April Wright Lucas and Larry Chase helped me calculate the value of this feed. Based on the cost of the ingredients, they say my pasture is worth between $53 and $62 dollars per ton. Meanwhile, This forage displaces $150/ton hay (delivered). This is a key factor for reducing feed costs by planning out your grazing, letting the animals harvest it themselves and getting the fertility transfer not to mention you have rested plants going into nest grazing season. (Are you wondering, like I am why they pasture that is feeding my cattle is worth less than what I’d pay for hay? This is an interesting discussion opportunity.)”
Troy’s experience is similar to results of three years of forage testing in southwestern Manitoba According to their testing,
“Total digestible nutrients (TDN) in stockpiled forage decline over winter. Fifty per cent TDN is sufficient to feed a dry cow in early to mid gestation. All of the stockpiled grasses tested retained more than 50 per cent TDN over winter and spring. However, energy levels in stockpiled alfalfa dropped significantly between October and December. By early December, testing showed alfalfa did not have adequate TDN to maintain a dry cow.”
As the graph above shows, many of the grasses meet the needs of dry cows. However, after November in Manitoba, stockpiled grasses don’t contain adequate energy to support lactating cows that require 60 per cent to 65 per cent TDN to maintain milk production, or of young, growing stock that need 65 per cent to 70 per cent TDN to gain 2 pounds per day. Their forage tests for Crude Protein and Relative Feed Value, below, tell a similar story. But as you look at these graphs, keep in mind that your forage values may decline at different rates, depending on your latitude and climate. Discussion with your local forage extension specialist or NRCS or Conservation District staff can help you calibrate this information to your area.
Standing Annual Forages
Karla H. Jenkins, Aaron Berger and Gary Herbert of University of Nebraska-Lincoln conducted research on behalf of farmers and ranchers planting annual forages in pasture who want to graze them through the winter. Those producers wanted to know if these annual forages would provide adequate nutrition through these colder months.
For the study researchers planted annual forages after irrigated wheat was harvested, and some additional water was applied to the forage crop. (The total tonnage and the quality produced would likely vary if the forage was planted earlier in the summer and on dryland acres.) Then they tested them through the winter season. Interestingly, as you can see from the table below, quality changed very little over the winter.
“While some nutrient loss did occur, all forages studied in both years maintained enough quality to support rumen function without additional protein. The available nutrients would also support about 1-1.5 lb/d gain on weaned calves if quantity was adequate,” said Karla Jenkins.
She also noted that the severe drought in the first year of the study raised nitrate levels about the recommended 1600 ppm for safe grazing when they harvested just prior to the frost, but that nitrate dissipated over the winter until forage was safe to graze in March. She cautions producers to sample forages for nitrates and nutrient content before beginning grazing.