NEW ENGLAND, N.D. – Cow/calf producers who have changed to later calving dates have said they would not go back to early calving, even if they could.

 “Calving dates are a very controversial topic,” said Doug Landblom, NDSU Dickinson Research Extension Center beef cattle specialist. “Most producers have a pretty good idea of what they want to do. They have a calendar within which they work and they are not usually willing to deviate from that.”

There are many advantages – and some disadvantages – for later calving.

In fact, it takes a “different mindset” to move from February-April calving to a May-June calving. But, for those that do choose to try it, Landblom said there are many reasons for staying with it.

In February-April calving, there is cold, snow and ice, but in the May-June calving, there is green grass and rain.

 “We can work in shirt sleeves rather than working in insulated coveralls,” Landblom said.

In May-June calving cows, most cows give birth without assistance.

Calving in extreme cold difficult.

“When we’re calving in below zero (temperatures), calves can die of exposure pretty easy,” he added.

Other advantages to calving later in the spring:

- There is less calving difficulty in mid to late spring.

“There is a lot less dystocia, because calves tend to turn over in the birthing position more correctly than they do in colder months when cows are calving out of synch with nature,” Landblom said.

- Labor and handling are reduced when calving later.

“Often producers see calving and farming as a collision. However, because cows calving in synch with nature very little assistance is needed; farming isn’t a problem. If you are checking calves and farming at the same time, there is the opportunity to look at those calves early in the morning and late at night, and you are still working in daylight,” he said.

- While there are some young producers, a lot of producers these days are older. As someone ages, it is much easier to work in the warmer months.

- Another advantage for moving the calving date to May-June is the marketing aspect, and the potential to capture more profit. Seasonally, demand is greater for feedlot cattle and cattle going to grass, which generally results in a better price.  

- Opportunities in later calving include a chance for calves to graze cover crops in the fall; retained ownership; and extended grazing of perennial pasture and grazing on crop residue after harvest.

Landblom has interviewed cattle producers in the past, and some of the comments from those in the later calving group included:

- They say they check cows once a day, and tag at the same time, and find they have less scours and other diseases because cows birth on green grass.

“There are less calving problems overall when calving later,” he said.

- They “really take advantage of the weather and get away from the blizzards,” such as the Atlas blizzard in 2013 that killed thousands of calves.

- They gain the opportunity to match third trimester feed requirements to the environment.

Pregnancy rates need attention

Late calving is associated with pregnancy rate problems if producers do not pay attention to it.

The bull turnout date for May-June calving is Aug. 1. At this time in the Northern Great Plains, pastures are becoming more mature and forage crude protein decline results in crude protein levels that are below the nutrient requirement for lactation.

Cows that are of larger frame size will have more difficulty getting pregnant than moderate size cows that do not produce as much milk.

This forage quality and lactation interaction is a disadvantage for later calving. However, moderate-sized cows (1,350 pounds) of moderate milking ability do not have much difficulty lactating and getting pregnant with their next calf.

Meeting nutrient requirements to increase pregnancy rate

Nutritional requirements between the middle of gestation to the first 90 days of lactation increase substantially.

For first calf heifers, the increase is approximately 22 percent and for the cows, the increase is 34 percent. “Lactation is critical, because physiologically cows will attempt to meet lactation needs before getting pregnant again,” he said. In the struggle, “lactation energy needs are met first before pregnancy.”

Cows require a certain amount of crude protein and Total Digestible Nutrients(TDN) daily, depending on their mature weight.

“Seventy percent of fetal growth occurs in the last 60 days of pregnancy. And, assuring that calves get colostrum as soon as possible after calving insures that calves receive critical immunity necessary to fight disease,” Landblom said.

Study compares winter feeding methods

DREC conducted a two-year study to compare winter grazing management.

The treatment groups included a control group that was fed hay only; a second group that grazed cover crops, corn and sunflower residue for 73 days, and a third group that grazed stockpiled tame grass pasture and cornstalk residue for 107 days.

The control group consumed 4,724 pounds of hay and cost $209.

The cover crop/residue group was fed 1,824 pounds of hay after grazing and was done costing $141 and the group that grazed stockpiled grass pastures and cornstalk residue consumed 891 pounds of hay after grazing was completed costing $73 per cow.

Body condition score (BCS) at the end of the study was one of the most important key points, because research has shown that cows in a body condition between 5 and 6 breed back well.

Cows need to have a body condition score of 5 to 6 before calving; because once a cow begins lactating increasing body condition is very difficult under range conditions.

The control group had a start weight of 1,490 and an end weight of 1,695 with an average daily gain (ADG) of 1.53 pounds, a start BCS of 5.7 and an end BCS of 6.5.

The group grazing cover crops/corn/sunflower residue had a start weight of 1,500 and an end weight of 1,646 with an average daily gain (ADG) of 1.1 pounds, a starting BCS of 5.6 and an end BCS of 6.3.

The group grazing stockpiled grass pastures/corn residue had a start weight of 1,470 and an end weight of 1,582 with an average daily gain (ADG) of .84 pounds, a start BCS of 5.4 and an end BCS of 5.4.

For cow fertility, BCS is an important consideration, and alternative forages and residues can play a part in that. Ending pregnancy rate was 89 percent for the control group, 95 percent for the cover crop/cornstalk/sunflower residue cows, and 89 percent for the grass and cornstalk residue cows, which illustrates the importance of matching cows of moderate size and milking ability to the range resource.

“Even though there are rebreeding challenges, cattlemen have matched cow size and milking ability to the range resource minimizing pregnancy rate issues,” Landblom said.

In the final analysis, cattlemen that calve during May and June would never return to battling the elements calving in late-February through March and April.