First came the drought, then through September and early October a foot of snow, a weekend of autumn and finally winter. Not exactly the best weather for harvesting good-quality forage and grain for most beef cattle. At least we had a return to good fall conditions by mid-October. Fortunately, what grain that was taken off yielded a fair amount of straw. Cereal straw bales can be easily used as an alternative forage to a shortage of grass hay for overwintering beef cows.
That’s what a friend of mine who runs about 400 Red Angus crossbred cows and calves plans to do. I pencilled out some beef diets using wheat and lentil straw as a forage base, added some grass hay complemented with barley grain, a 32:16 beef supplement and some molasses. Once calves are weaned he will feed this diet from end of November to about mid-March. Afterwards, he plans to reduce the amount of a straw and add some fair-quality hay that he purchased.
This overwintering feeding plan will work, because the best candidates for feeding straw as the main staple in winter diets are his mature early to mid-gestation beef cows, which only need to maintain a post-weaning body condition of 2.5-3.0 (re: 1 = thin, 5 = obese).
The opportunity of feeding comparably low-energy and low-protein straw to beef cows against finding and purchasing better-quality grass hay is real enough, but limited in two major ways: 1) A big beef cow is only able to consume about 20-25 lbs, of straw, and 2) Rumen microbes can only digest 60-65 per cent of that amount of straw during the day. As a result, big pregnant beef cows with some fat cover can handle about half of their dry matter intake from straw with the other half of their diet complemented with better nutritious feeds.
The following wintering-gestation diet (Angus X Diet) that I proposed to the above beef producer uses two different types of straw and feedstuffs that he has on his farm. I have compared it to other rations I had put together for producers in other years. All of these well-balanced straw-based diets are fed to 1,200-1,400 lb. early- to mid-pregnant beef cows.
There are many ways to review the current total costs of these straw-based diets; the average being about $2.25 per cow per day. This is a 50 per cent increase over similar rations ($1.50 per cow per day) that I designed about the same time, last year. Much of this increase is due to the double-digit percentage cost increase of forages, grains and protein byproducts; most likely caused by this summer drought, and followed by poor harvest weather.
Although these diets are balanced to take care of the nutrient requirements of early- to mid-gestation cows, producers will likely be forced to feed more dietary energy to their cow herds as frigid winter weather sets in. As a result, when I make such changes, I use a timeless rule of thumb as follows: for every 1 C drop in temperature below 0 C, the beef cow’s TDN energy-maintenance requirements are increased by about two per cent. This means that if daily windchill temperature is -10 C, there is an increase of about 20 per cent in the cow’s basic dietary energy needs and thus, it might mean adding an extra two to three pounds of grain to each of the above diets.
Such increased overwintering feeding costs are not lost on the above 400-beef cow producer. He told me that given this poor harvest weather he is looking for some sprouted grain (around 45 lb./bu.) as a substitute for $4.25 bu. barley in the rations that I build. We roughly estimate by doing so, he might save as much as $7,000 to $8,000 on 120 days of gestating cow feeding costs.