In May I wrote about choosing a cow size and type that fits the environment. The summary I presented was that given our abundant and high-quality forage base, larger cows were biologically and therefore more economically efficient. This runs contrary to common wisdom, as I often hear beef producers talk about wanting to have smaller cows. I thought it useful to revisit this topic again as it was brought up on a recent beef tour to West Virginia.
Two commercial herds in New York were used to evaluate the profitability of individual cows to the cow/calf, feedlot and whole system enterprise. The energy required by the cow and her steer calf through weaning was estimated using the approach of Fox et al, 1999 and Tedeschi et al, 2006. The estimate was based on the chemical composition of the feed delivered during the winter, the chemical composition of the pasture, the body weight and body condition score (BCS) of the cow, and the weaning weight of the calf. Based on the feedstuffs fed during the
winter and an estimated cost of pasture, an economic value was assigned to the energy required. Other costs, such as vet and medicine, minerals, supplies, building and machinery repair, taxes and depreciation, were added to the cost of estimated feed required. Steer calves were priced based on the New York Beef Producer’s Tele-Auction. The profit of the individual cow was calculated by subtracting the cost from conception to weaning from the value of the steer calf at the time of sale.
These calves were then placed into the Cornell Feedlot and Value Discovery Program, which was designed to provide complete feedlot, carcass and economic data on weaned calves that otherwise was not available to producers with a small number of cows. Feedlot profit was defined as the receipts of the sale of cattle minus all expenses related to feeding and marketing.
Finally, the economics of the entire system was calculated as total receipts from the sale of finished cattle minus the expense of the cow/calf and feedlot operations.
This data was collected in 1997, so the economics have drastically changed; however, the concept remains the same. The range in body weight of the cows was 266 pounds, with a 219-pound difference in weaning weight of the calves (Table 1). A ratio that is often noted is the proportion of a cow’s weight to the weaning weight of her calf. The goal is that she wean at least 50 percent of her body weight. In this data set, the range was 45 to 60 percent. Surprisingly, there wasn’t a large difference in the cost of energy (TDN) to feed cows of differing weights. Unlike today, there was not much profit in any segment of the beef industry.
We wanted to evaluate the relationship between each of the variables. Table 2 provides the result of the evaluation. Using an analysis of the R2 between variables, we can estimate how much of one variable is explained by a second variable. For example, an R2 of 1 indicates that 100 percent of the variation of variable A is explained by variable B.
For emphasis, I have highlighted the R2 with a value greater than 50 percent.
Reading across the top row of Table 2, the TDN/cow in pounds has an R2 of 1 with the TDN per cow in pounds (the same variable in the left-hand column). Reading across the rows, the TDN per cow in pounds has an R2 of 18 percent with the adjusted 205-day weight of the calf. This means that the amount of TDN consumed by the cow explains only 18 percent of the variation in the adjusted 205-day weight of the calf. This makes sense when you see that the adjusted cow weight explains 68 percent of the variation in TDN consumed and 74 percent of the cost of that TDN consumed. This is intuitive, as heavier cows eat more and, therefore, the cost to feed her should be higher. However, even as the cost increases with increased body weight of the cow, variation in profit does not follow. Only 2 percent of variation in the profit of the cow is explained by the amount or cost of the energy (TDN) she consumed.
Using the analysis of the data presented in the table, what information becomes available to direct selection of cow size? Use the far right column titled “C/C profit.” The factors that explain more than 50 percent of the variation in profit of the cow are TDN consumed by the calf (87 percent), the ratio of adjusted 205-day calf weight to adjusted cow weight (82 percent), and the adjusted 205-day calf weight (59 percent).
When we look at the variation in the profit of the cow, her steer in the feedlot or the entire system, the adjusted cow weight explains very little of the variation (R2 = 6 percent, 10 percent and 6 percent, respectively).
While the R2 would indicate that cow size does not have a positive or negative influence on profitability of the cow, if we look at the data in another manner, we see more evidence that cow weight, at least in our environment, may be positively related to profit. By ranking the profitability of each cow and graphing this against her weight, Figure 1 shows a trend line that as a cow gets heavier, she is more profitable compared to her lighter herd mates.
Why does this data run counter to the notion that smaller cows are more profitable than larger cows? The predominant reason is that you have to evaluate cows in the environment where they will be producing. Of the total energy consumed by a cow, 70 percent goes to maintenance, which is essentially nonproductive.
This is true in the range pasture of Montana or the highly productive pasture of the Northeast U.S. The quicker she meets her maintenance requirement, the quicker she can convert the extra energy to production. In our environment with abundant forage, our cows can meet their maintenance requirements without much effort, leaving the remaining energy available to gain weight for rebreeding and meet milk production to wean a heavier calf.
There are limits and exceptions. Producers selling cattle into the grass-finished market will likely want a small frame size and hence lighter weight cow so her progeny finish before 24 months of age. Getting cows too large is also a problem as the beef won’t “fit the box.”
- Cows that wean greater adjusted 205-day weaning weight compared to their body weight (BCS = 5) are more profitable. This is one variable that can be a useful selection criteria.
- The greater the energy intake of the calf, the greater the profit. This intake is in the form of both milk and forage.
- Do we need 1,600-pound cows? Probably not, but we can certainly handle the profitability of 1,300- to 1,400-pound cows.