by Justin Waggoner, extension beef systems specialist, Garden City
Although it may seem a little too early to think about weaning. Early weaning may be one of the management tools that beef cattle producers may need to consider using this fall. The recent winter weather conditions have resulted in cows and replacement females that may be lacking body condition coming into the grazing and breeding season.
Yes, cows will likely pick up some body condition over the upcoming grazing season. However, it can be very difficult to put condition on lactating cows, especially higher producing females, even under ideal grazing conditions. Therefore, it is possible that some cows will still be lacking condition during the later months of the grazing season. One of the easiest ways to manage cow nutrient demands is by weaning the calf. This reduces the energy requirements of the cow by 25-30%. This effectively means that the nutrients consumed by the cow that were being used to sustain lactation 
may now be used to improve cow condition. A study designed to evaluate preconditioning duration conducted at K-State documented that cow body condition scores improved as calf age at weaning decreased. The cows on this study remained on native grass pastures following weaning and the observed increase in body condition score in this study occurred over a 60 day period. Therefore, the results of this study suggest that early weaning calves may improve body condition of cows grazing native pastures late in the grazing season.
Early weaning is a valuable management tool that is most often associated with drought. However, it may be an even more valuable management strategy to manage the nutrient demands associated with lactation and improve cow condition, especially on young cows. Additionally, early weaned calves may be managed to target a number of different value-added preconditioning programs or special sales.
Table 1: Effect of calf age at weaning on cow body condition score (BCS; Bolte et al., 2007)
| Calf Age, days | |||||||
| Item | 160 | 145 | 130 | 115 | 100 | SEM | P-value |
| BCSa | |||||||
| Initialb | 5.46 | 5.41 | 5.48 | 5.50 | 5.46 | 0.091 | 0.87 |
| Finalc | 5.46 | 5.67 | 5.85 | 5.99 | 5.90 | 0.091 | 0.01 |
| Change | 0.02 | 0.25 | 0.37 | 0.50 | 0.43 | 0.118 | 0.01 |
aBody condition score (scale = 1 to 9; 1 = emaciated, 9 = obese)
bInitial BCS was measured 60 d before calves were shipped to feedlot (d -60 weaning)
cFinal BCS was measured 60 d after calves were shipped to feedlot
