As we progress through the spring and into grass season, many of us have the temptation to “kick the cows out to grass.” After feeding, calving and doing chores all winter, turnout is a welcome relief. While grazing is generally cheaper than feeding, turnout also represents the beginning of a season of lost profit potential for many operations.
I often use the example of a hayfield when I am speaking about grass. Harvesting of a pasture or a hayfield is essentially the same concept — the difference is in the method not the theory. We would not cut our hayfield down and then cut it again in a week. Rather we would take a first cut, and then allow the field to regrow before taking a second cut. Depending on how low the first cut was taken, weather and timing, the period between first and second cuttings may vary. The reason we wait is that it allows us to maximize productivity of the stand in our preferred combination of yield and quality.
When we use cows to harvest forage things get a little bit trickier. They don’t generally cut a 12- or 16-foot wide swath from one end of the field to another, but rest assured they are cutting grass down — it’s just a bit harder to assess.
The challenge is that if we are interested in maximizing the quality and quantity of forage, we need to prevent cattle from cutting the same grass before it recovers (in the same way we waited on our hayfield). Fortunately, grass wants to work with us in this regard. Many species will not resume growth until three days to two weeks after grazing. This means we have a bit of leeway in moving cows before they are “recutting” our crop. Of course if it is wet and warm this growth speeds up, but conversely when it is hot and dry regrowth slows down and we don’t have to move as quickly.
The less forage we take on a pass through a pasture, the less time the plant takes to recover. This is not as reasonable an option with a haybine where we are more limited by agronomics and machine function. The old rule of take half and leave half is not a bad place to start, but some situations might be better if we took 30 per cent and made more passes during the season. The more leaf area we leave behind, the more quickly the plant will recover from grazing.
Measuring grazing production
There are several options to measure production in our pastures but one of the simplest is tracking Animal Unit Grazing Days (AUGD) and AUGD per acre. Basically an animal unit (AU) is 1,000 pounds of animal. A 1,500-pound cow is 1.5 AU, a 1,500-pound cow with an 800-pound calf that eats grass is 2.3 AU (1.5 + 0.8). If we know how many animals we turned out and about how much they weigh, we can pretty easily figure out our animal units. It is important to remember to account for growth of calves as well, since hopefully our number of animal units will increase over the grazing season.
The second step is recording when cattle went into and out of the pasture. If we took our 1,500-pound cow into the pasture and took her out 90 days later we have harvested 135 AUGD (90 days x 1.5 AU).
If the pasture is five acres, we have harvested 27 animal unit grazing days — AUGD/Acre (135/5). This measurement is the grazing equivalent of bushels per acre.
Compared to the averages
There is some very interesting data that has come out of the AgriProfit$ program, which is an economic benchmarking program operated by Alberta Agriculture. The program uses producer data and tracks pastures by type, region, costs and returns. Let’s look at some broad production averages from this program over three years across two different pasture types. I took the liberty of converting their AUM values to AUGD (1 AUM = 30 AUGD).
The differences are staggering. If we assume a land rent of $80 per acre in central Alberta for the grass/legume pasture, and $20 per acre in the southern Alberta native prairie, we would see a cost difference ranging from $0.69/AUGD for the top 25 per cent, up to $2.05 in central Alberta, and a range from $0.60 /AUGD for the top 25 per cent up to $1.52 in the southern Alberta prairie.
If you multiply this out across every acre and the number of cows that represents a huge missed profit opportunity in the industry. For example, let’s use a 100-head cow herd of 1,500-pound cows, grazing for 200 days. (summer grazing costs = cost per AUGD * 1.5 AU * 200 days)
The savings in this example come from saving the number of acres needed, however the flip side for an operation with a set acreage already is that you can run more animal units on the same resource base.
If we just look at the numbers from a straight production mindset, grazing management has the potential to double production and in some situations where resources such as rainfall are less limiting may triple production for the bottom quartile. Imagine if you could turn 20-bushel canola into 40 or 60 simply through long-term management.
In another article we’ll cover some concepts for how to move into the top 25 per cent.