“Consider Early Weaning early”
by Chris Reinhardt, feedlot specialist
Normally we only consider early weaning when we are in the throes of a nasty drought. However, given what we now know about calf and cow nutrition, we may want to expand our thinking.
Late summer forage quality in pastures declines, even in good rainfall years. The decreased energy and protein content of late summer grass does not support a great deal of calf gain. Doubly challenging is that this late season forage also does not support a great level of lactation by the calf’s dam, so calf ADG declines considerably late in the grazing season. Assuming you’ve received adequate moisture, late season calf gain may be estimated in the range of 0.5 to 1.5 lb per day; many years on western range late season ADG may drop to near zero.
Although the actual amount of milk and grass consumed by calves varies greatly among calves and from season to season, it can be stated broadly that the calf’s first choice for a source of nutrients, as long as he can get away with it, is his mother’s milk. Calves are fully functional ruminants by 60-90 days of age, and are fully capable of making use of good quality forage, but milk is always their first choice for nutrients, rather than their last. So every day they will go to their mother and consume as much milk as they can. And as the calf grows and it’s appetite climbs, mother’s milk decreases, effectively pushing the calf to go to grass more and more in order to supplement his nutritional needs.
This constant demand for milk by the calf places a tremendous pull on the dam’s nutrient reserves. Early in the season, when grass is both lush and plentiful, the cow can often produce a greater quantity of milk than the small calf can utilize because of the lactation curve and the abundant nutrient supply available to the dam. However, as grass matures and nutrient supply declines, the cow will pull energy from her own reserves (her body fat) to sustain lactation to prepare the calf for the winter.
If we work backwards from calving, the target body condition for beef cows at the time of calving is usually a condition score 5.0, indicating muscling, and a slight cover of fat, but no fat pockets obvious, and 2-3 ribs visible. Cows which are in a thinner condition than this target usually have a longer post-partum interval and delayed post-calving first estrus, resulting in later conception—or even an open cow come next preg check.
So if the cow goes into the winter in poor body condition, we need to feed those reserves back into the cow or risk late breeding next summer and late calving in subsequent years or even open cows next fall. It is estimated that for each 2 weeks we leave cows grazing late season pasture with calves still suckling them, after about September 1, cows lose about 0.25 of a condition score, which is worth about 20-25 lbs. That means if we leave the calves on cows until November 1, we’ve milked about 100 lbs of body condition off the cows.
If calves are only gaining 0.5-1.0 lb per day on their dam late in the season, we can do better. By weaning (especially utilizing low-stress weaning methods), we can improve the nutritional supply available to the calf, meeting all the needs for energy, protein, vitamins, and minerals. Weaning during favorable weather also has the advantage of reducing stress and the risk of disease brought on by inclement, cold, wet, fall weather.
In turn, the now dry cow can maintain and oftentimes actually increase body condition without the demands of lactation, resulting in cows going into winter in better flesh, requiring less supplemental nutrition to achieve the target body condition 5.0. That means less out of pocket cost to maintain the herd.
The disadvantages of early weaning are lower weaning weights, and weaning and feeding calves separate from cows requires good quality feeds, equipment, decent facilities, and labor. But the advantages are reduced disease, improved daily gains late in the season, and improved cow body condition going into the winter.
It’s usually true that your standing forage is your cheapest feed resource. But I’m not advocating NOT using that precious resource, only re-directing it’s use to optimize it’s value: allow the cows to graze themselves into good body condition rather than feeding that same condition onto them later in the winter with costly purchased feeds, and provide the calves with extra nutrition other than the relative pittance of milk Mama is putting out at the end of lactation. It’s time to reconsider what we do and why we do it. “Because we’ve always done it this way…” is the worst reason to do anything. If there are legitimate, defensible reasons for what you do on your operation, then keep on truckin’. If not, seek wise counsel to find perhaps better, more efficient, and more effective practices that may lead to better outcomes for your calves, your cows, and hopefully, your bottom line.