A often overlooked option might lie in selection for Stayability. Stayability is a trait that is defined as “given that female offspring are retained in the herd, what is the relative probability she will survive to 6 years of age”. Stayability includes a variety of factors, but in essence it is a description of the potential for a cow to calf and breed back on a repeated basis. Let’s walk our example cowherd through this… We will not change the weaning rate, although there is an argument that calf survival is better from cows than heifers, but for simplification purposes we will assume that we wean 95 calves from our 100 cows. Our initial replacement rate is 20%. This means that if we sell open cows, cows that don’t wean a calf and a few other cows for age or other reasons, of our 95 calves, we will need to keep 20 for replacement heifers to maintain our 100 cow number. This is quite a realistic or even low replacement rate for most cow herds. It also means that in an average year we have 75 calves to sell. (47.5 steers on average and 27.5 heifers on average). This amounts to 24225 pounds of steers + 13475 of heifers = 37700 pounds of Saleable Weaning Weight.
At a 5% increase in stayability is shown in the table below
What if we could increase our stayability by only 1%? Or stated another way, what if we could reduce our replacement rate by 1% while still maintaining a 95% weaning rate? Immediately we know we can sell 1 more heifer since we don’t need to keep 20 heifers anymore. At 490 pounds we have boosted our weaning sale weight by 4.9 pounds per cow, but if we keep digging a bit deeper, it also means we have one less calf from a first calf heifer and one more from a mature cow. Remember earlier when we mentioned that first calf heifer calves are 50 pounds lighter than those from mature cows? This means we also added another 50 pounds of average weaning weight to our cow herd or 0.5 pounds per cow. Also, if we follow the logic, we are somewhat likely to have 1 less calf from the second calvers, and one more from the mature cows adding another 25 pounds to our herd total. We have added 565 pounds of weaning weight to our herd total through a 1% improvement in stayability. This process did not incur extra cost, in fact it eliminated the cost of developing 1 replacement female. 565 pounds is more than our average weaning weight of 500 pounds, so in essence we have added the equivalent of more than 1 calf to our total sale weight and seen more than a 1% improvement in average weaning weight. The math in every cow herd will be different, however this example serves to illustrate the importance and potentially outsized multiplier effect of matching a cowherd to the environment. The next time you are selecting for performance, keep in mind that performance can travel many paths and sometimes the one less travelled leads to the desired destination.
Gelbvieh guide • Summer 2022 • Page 51
