By Sarah Sommerfeld, PAg, Regional Forage Specialist
Saskatchewan Ministry of Agriculture
Putting up high quality feed can be a challenge and the variability in forage quality can be high. Plant maturity at cutting is the single greatest factor that determines overall forage quality. As forage plants mature, protein content, digestibility and amount of forage an animal can eat decreases. Other factors such as rainfall and nutrient levels in the soil also affect the protein and mineral content of the forage. After cutting, weathering of hay in the windrow, leaf retention during baling and moisture content at time of baling also impact forage quality.
Feed testing your forages can help to manage the winter feeding period. The protein and energy requirements of the cow herd increase through pregnancy and lactation (See table one). Feed test information can be used to design a balanced ration that meets cow requirements based on the stage of production. Feed testing can prevent over feeding, and more importantly, under feeding of the cow herd.
Each type of forage should be submitted for a feed test. For instance, if a producer harvests an alfalfa/grass mixed stand, a pure alfalfa stand and barley greenfeed, samples from each of these fields should be collected and submitted for feed analysis separately.
When submitting forage samples for feed testing, it is important to collect a sample that is representative of the forage supply. A hay probe is the best tool to use to collect forage samples. A hay probe allows for a cross section of the bale to be sampled, collecting both stems and leaves. Collect a single sample from up to about 20 bales from the same field or lot. Combine the probe core samples into one composite sample for analysis. When sampling large round bales, samples should be collected on the round side from the lower half of the bale, where there is a minimal amount of weathering. Hay probes are available for use from each Saskatchewan Ministry of Agriculture Regional Office at no charge.
When submitting the forage sample, take the time to describe the forage properly. For example, a description of “70 per cent brome grass, 30 per cent alfalfa” or “barley greenfeed” provides greater detail than “hay”. Choosing the most appropriate feed analysis is important. A standard forage quality test provides information on moisture, energy, fibre and mineral content. Feed test results are reported on an “as fed” and a “dry matter” basis. Dry matter basis means that all the moisture has been removed, which is important when comparing nutrient content between forages or other feed ingredients.
For more information on feed testing your forage supply this fall, contact the Regional Forage Specialist at 306-867-5559, visit the Ministry of Agriculture website at www.agriculture.gov.sk.ca and watch the web video Importance of Feed Testing or contact the Agriculture Knowledge Centre at 1-866-457-2377. For hay probe availability and use, contact your local Saskatchewan Ministry of Agriculture Regional Office.
Protein and energy requirements of beef cows
Cows (all values as 100 per cent Dry Matter)
Crude Protein 8 per cent; Total Digestible Nutrients 55 per cent minimum
Crude Protein 9 per cent; Total Digestible Nutrients 60 per cent minimum
Crude Protein 11 to 12 per cent; Total Digestible Nutrients 65 per cent minimum