Winter feed affects calving
If beef cows eat mostly poor-quality hay all winter and are in thin body condition going into spring, they could have more calving trouble, give less milk, and have calves with weakened immune systems.
“Because of the drought, a lot of CRP hay was fed around the country,” says Karl Hoppe, a beef producer who serves as an Extension livestock specialist at the North Dakota State University Carrington Research Extension Center.
As a rule, CRP hay tends to be low in quality, because the program permits haying only in mid- to late summer, which is after plants reach or exceed maturity. In dry years, plants mature more quickly, and forage quality declines significantly by the time fields are harvested. Old residue in the forage further depresses feed quality.
Hoppe tested the nutritive quality of his CRP hay harvested in late August and early October. Because harvesting occurred so late, all forage was well past maturity. Thus, there were no differences in feed samples that could be correlated with harvest date.
The CRP hay had 43% to 50% total digestible nutrients (TDN) and crude protein of 5.8%. Feed quality of the CRP hay was barely better than straw. Hoppe’s wheat straw tested 40% TDN and 5% crude protein.
“Better-quality hay will run between 52% and 60% TDN, with a crude protein of 7% to 10%,” he says. “If alfalfa is mixed in with the grass, the crude protein will test between 12% and 16%.”
In poor-quality hay, minerals may also be short, especially phosphorus. Hay from CRP fields and other poor-quality forage can have half the amount of phosphorus of better hay. “Phosphorus in poor hay can run from .8% to .11%, while good hay will have .16%,” says Hoppe.
Cow condition determines how well cows winter on poor-quality feed. Animals coming into winter in good shape can often maintain their body condition and handle calving with no trouble.
Cows that were thin in fall will be in poor body condition throughout the winter if all they get is poor-quality hay with no supplements.
“Cows coming into calving season in poor shape tend to have more calving problems,” says Hoppe. “They usually don’t produce as much milk as they might in better condition, and colostrum will be diminished. Reduced colostrum makes calves more vulnerable to scours and respiratory disease. The incidence of calves in poor shape will be greater, and this tendency to perform poorly could follow them into the feedlot.”
Third trimester is key
If out-of-condition cows have received poor-quality feed for much of the winter, improving the ration quality before calving can help offset problems.
“The last trimester of gestation is the most important time for calf development and the production of colostrum,” says Hoppe.
“Test your feed so you know what you’re feeding. Then try to mix in enough good hay so you have a decent ration,” Hoppe notes. “Since vitamin A and minerals are likely to be limited, consider providing supplements.”