Watch Those First-Calf Heifers

DR. TERESA L. STECKLER

SIMPSON, ILL.
   Many cattlemen have been calving while others are just beginning. What a bad season for calving! The excessively cold temperatures, copious amounts of rain and mud, and now snow in early April. The changing weather makes it very hard to change rations to meet the nutritional needs of your cattle.
   As you know replacement heifers represent the next generation brood cow. If she’s going to make a career of being a brood cow, it is important that she raise a calf each and every year. The odds of her coming up short on the rent are greatest when she is a first-calf heifer and it is time to conceive her second calf.
   First-calf heifers require more labor, higher quality feeds, and they reward your efforts by weaning the lightest group of calves in the herd. This is temporary, because if you've done your homework with due diligence, they will reward you by being productive cows for a long time. 
   Also these first-calf heifers have several factors working against them: 1) required to nurse their first young calf, 2) reproductive tract needs to undergo repair (uterine involution) to prepare for the next pregnancy, and 3) she is required to maintain her own condition, all while she is still growing, in order to become pregnant during the subsequent breeding season. All of those factors are new to a heifer and she is required to do this at a time when she is introduced to the mature cow herd. In other words, a heifer that has just given birth needs to compete with older, more aggressive cows for feed and yet continue to grow to a mature weight and become pregnant to calve during the following calving season.
   Now consider the following: this spring’s weather that has resulted in poorly growing pastures, the lack of hay (or very poor quality hay) from last year’s lack of rain, and the above factors. The stress that first calf heifers experience is immense. Take a look at your first-calf heifers and assess their overall condition. Keep in mind thin heifers will not breed back quickly, if at all. The later she breeds back, the longer it will take for her to get back on track with the rest of the herd.
   You may want to consider the following to ensure that first-calf heifers are able to grow, milk and wean a bigger calf.
   1. Graze first-calf heifers either with three-year olds or virgin replacement heifers and always give heifers the best-quality pasture available. Thus, graze first-calf heifers and mature cows separately.
   2. Supplement first-calf heifers with grains (energy) like corn, corn silage, or barley before they lose body condition. In many situations, the energy needs are not met and the first-calf female loses weight and body condition from the time of calving to the start of the breeding season.
   The pounds of protein or energy needed by the first-calf female compared to a mature cow at the same stage of gestation or lactation are not all that different. However, the percent of the diet that needs to be protein or energy between these two groups of females is different. The difference is because of the amount of feed/forage that they can eat. The mature cow can eat more feed compared to the younger female.
   For this reason, beginning at least three weeks before calving, first-calvers need to be managed and fed separate from the mature cows. Research indicates that a first-calf-heifer within three weeks of calving experiences a 17% decrease in daily feed intake. These data further illustrate the need to separate first-calf-heifers from mature cows beginning at least three weeks before the start of the calving season and illustrate that nutrient density of the diet has to be high because intake is restricted. Intake is re-established to more "normal" levels by about one week post-calving.
   3. Control internal and external parasites. 
   4. If heifers are thin at calving and calves may need to be weaned at 5-6 months of age.
   5. As with you cows, provide a high-quality, complete mineral available at all times.
   First-calf heifers usually steal all the headlines, but remember cows continue to grow until they are 4-5 years old. Many 3-year-olds come up open and should also be managed with as much zeal as your 2-year-olds. It may prove profitable to manage 2- and 3-year-olds together as a single unit. Managing 2- and 3-year-olds together is better than mixing 3-year-olds with the mature cows because the younger cows frequently get pushed away from feed, and that keeps them from earning their keep.
   First-calf heifers are unique management group in your cow operation. Remember once they get behind, it’s hard for them to catch up on profitability. Thus the best policy is to make sure they never fall behind! They are very susceptible to calving and reproductive failure unless properly fed and managed. ∆ 
   DR. TERESA L. STECKLER: Extension Specialist, Animal Systems/Beef, Dixon Springs Agricultural Center, University of Illinois