With the recent long winter, on some farms and ranches hay supplies are short or completely used up. In some areas of the province, purchasing hay is not an option, so some producers are turning cows out on banked grass that was not grazed last fall because of the early snowfall.
“Forage quality in banked grass in the spring is not as good as it was last fall,” says Barry Yaremcio, beef and forage specialist with Alberta Agriculture and Rural Development.
“Weathering has reduced the amount of protein and energy present in the forage. It is possible for protein content to be two to three units lower (if 10 per cent last fall – could be eight per cent or less this spring) and energy could be down by five points or more (TDN of 62 last fall – could be 57 per cent or less this spring). Digestibility of the forage is usually lower in the spring as well.”
Lactating cows require a ration that contains 65 per cent TDN and 11 per cent protein on a dry matter basis. If the forage is not meeting these requirements, it is necessary to feed grain and a protein source such as peas, canola meal or a pelleted supplement.
“It is important to meet nutritional requirements of the lactating cow,” says Yaremcio. “A protein or energy deficiency that reduces the amount of milk produced at peak lactation (eight to 10 weeks after calving) lowers the total amount of milk produced over the entire lactation. If total milk yield is reduced by two to three pounds a day at peak lactation compared to the animals’ potential, the loss will continue on for the entire lactation. It takes seven pounds of milk to produce one pound of gain for a young calf. The lower milk production could reduce calf weaning weight by 30 to 40 pounds.
“If energy in the forage does not meet requirements, a cow will mobilize fat from her body to produce milk, and weight loss will occur. Reproductive efficiency is reduced when cows lose weight after calving. An animal that is 100 pounds lighter at breeding compared to at calving weight will take 15 to 30 days longer to come into heat and first-service conception rates are reduced by 25 to 30 per cent.”
Next year, when calves are born in the second cycle compared to the first, the calf will be 21 days younger at weaning, and could be 40 pounds lighter. At today’s price of $1.25 per pound for a 700-pound calf, that could result in a loss of $50 per calf. Combine the reduction of weight gain from a younger calf with the drop in milk production, income from each calf could be reduced by $100.
“It is very difficult to see a small drop in cow body weight,” says Yaremcio. “To be noticeable to the eye, a 100- to 200-pound reduction in weight is needed. By the time this happens, the damage is done and the problems mentioned above will probably occur.”
If there are questions about the quality of the banked forage, supplement with four to five pounds of grain and a pound of protein supplement per cow every second day to improve the overall nutrition of the cow. Continue with this feeding practice until new grass is very visible through the carry-over grass. These practices may cost $15 to $20 more in total to get the cows onto new pasture, but the return in the fall with heavier calves will be more than the feed costs.
Another option to improve calf weight gain is to put out a self-feeder and let the calves consume creep feed free choice.