Drought Management Part II: Comparison of Early Weaned Calf Management Methods
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Author: Douglas Landblom
DREC Beef Cattle and Integrated Systems Specialist
Dickinson Research Extension Center
Office: 701-456-1109; Mobil: 701-690-8245
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Precipitation from recent back to back blizzards with record snowfalls provide ample hope that the drought of 2021 has been resolved and a normal growing season is on the horizon. While this early spring moisture will insure crops and pasture begin the season in good to excellent growing condition, there is no assurance summer and fall precipitation will sustain pasture growth for normal cattle carrying capacity. For this reason, and since drought is not uncommon in North Dakota, especially western North Dakota, early weaning of calves 90 days sooner than normal was discussed in a previous Dickinson REC Update. Summarizing that Update, terminating lactation among 1,433 lb. cows reduced nutrient requirements for cows producing either 20 or 30 pounds of milk/day by 5.7 and 10.1%, respectively, cow body condition score increased 0.6 basis points, which subsequently reduces winter feed cost, and over a 90-day period native range forage disappearance was reduced 36%, or the equivalent of 1.1 month of grazing per animal unit.
Of course, before early weaning calves one needs to decide whether the calves will be sold directly after weaning or kept and fed for later sale. Assuming the early weaned calves are to be kept and fed for later sale, feeding and management methods were evaluated for four feeding methods. Steer calves from 252 cows were divided into four groups: 1) Normal Wean (Nov) – Feedlot, 2) Normal Wean (Nov) – Graze Unharvested Corn, 3) Early Wean (Aug) – Feedlot, and 4) Early Wean (Aug) – Graze Unharvested Corn. Corn fields that were grazed had different corn production yields. Fields where EW-Corn calves grazed yielded 3.18 ton of dry matter per acre and the fields where the NW-Corn calves grazed yielded 2.76 ton of dry matter per acre. The EW-Corn calves grazed unharvested corn for 81 days whereas the NW-Corn calves grazed corn for 38.5 days. The difference in the number of corn grazing days for the NW-Corn calves was due to lower yield per acre and dry matter field losses of 1.25 ton per acre. Steer total gain and ADG for the NW- feedlot, NW-Corn, EW-Corn, and EW-feedlot was 161lbs. and 1.99 lb./day; 85 lbs. and 2.21 lb./day; 179 lbs. and 2.21 lbs./day; and 168 lb. and 2.07 lbs./day, respectively. When the weaning systems’ backgrounding cost per pound of gain and net return per steer were determined, the EW steers that grazed unharvested corn had the lowest feed cost/lb of gain and the greatest net return compared to the other early weaning treatments. The EW steer corn grazing efficiency resulted in net return that was 19.0% greater than the NW-Feedlot and 31% greater than the EW-Feedlot. Although, the NW-Corn Grazing steer ADG was similar to the EW-Corn Grazing treatment, the reduced number of grazing days (38.5 vs 81 days) did not yield sufficient gain to offset farming and grazing cost of production.
Animal health after weaning can be a very serious problem due to the effect of weaning stress and subsequent sickness. Bovine respiratory disease (BRD) is the most common disease among feedlot cattle that affects calves after weaning and is brought on by a cascade of viral and bacterial infections of the upper respiratory tract. The problem is enhanced when vulnerable naïve stressed weaned calves are comingled in a feedlot confinement. Using best management practices, calves in the research received an initial immunization before spring turnout on native pasture and then were re-vaccinated 3-4 weeks before each weaning date and again at weaning with modified live vaccine preparations that included IBR, BVD types I and II, PI3, BRSV plus Mannhiema haemolytica, 7-way Clostridial vaccine that included H. somunus, and were poured with Ivermectin. Due to differences in the weaning systems protocol, EW-feedlot steers (422 lb.) were shipped to the feedlot at the University of Nebraska (UN, Panhandle REC, Scottsbluff, NE) mid-August whereas NW-Corn steers (715 lb.) didn’t arrive at the UN feedlot until the first week of January. Early weaned steers managed extensively grazing unharvested corn did not require treatment for BRD illness while grazing and a low 3.75% required treatment during feedlot growing-finishing after corn grazing was completed. However, EW-feedlot steers that were shipped directly to the Panhandle Research Extension Center feedlot mid-August experienced a greater number of BRD illness treatments. There were 17.5% of the steers treated with antibiotics once, 8.77% needed a second treatment, and 3.51% required a third treatment for BRD pneumonia, which illustrates the value of unconfined corn grazing and delayed feedlot arrival. Corn grazing and delayed feedlot arrival allowed the calves sufficient time to mature physiologically and immunologically before feedlot confinement.
A second question of interest following early weaning and grazing of unharvested corn was to determine the system value for cows grazing the remaining corn stalk residue. Leading corn grazing with weaned calves who consume the higher quality plant parts followed by cows after weaning in which approximately 40-50% of the remaining stalk residue is consumed results in very efficient use of the corn crop. For forage-type corn yield in western ND, it was determined that 0.8 to 0.9 acre of stalk residue will support a 1450 lb cow per month during the first and second trimesters of pregnancy. In addition, protein supplementation (range cake, protein lick tub, alfalfa hay) and free choice mineral are required to balance nutritional requirements when grazing corn stalk residue. Current hay values range from $150 to $200/ton. Using a median value of $175/ton ($0.0875/lb), a 1450 lb cow consuming 2.25% of body weight will consume 32.6 lbs. of hay/day costing $2.85/day will save $87/month; dramatically lowering winter feed cost. When hay cost returns to normal ($80/ton, $0.040/lb), corn residue replacement for hay for the 1450 lb cow will be $1.30/day or a savings of $39.80/month.
Although, most beef producers have no interest in early weaning calves, combining EW corn grazing followed by cow corn residue grazing has a greater return to labor and management than growing corn for grain.
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