Are Your Cows Too Large?
Research suggests large cows are more susceptible to climatic changes.
From the 2012 Ag Census to the 2017 Ag Census, the number of beef farms decreased by 3.9%, but cow numbers slightly increased. The consolidation was from a 5% reduction in small ranches (1-100 cows), but a 6% increase in medium ranches with 100-500 cows and a 1% increase in large ranches with 500 or more cows. We will get to see what effect the recent droughts had on consolidation of cattle farms with the release of the 2022 Ag Census in mid-February.
There are several barriers for young or new farmers entering beef cattle operations, including high cost of land and equipment and relatively low returns on investment. The average annual cost per breeding female increased to more than $1,000 dollars per cow in 2022 and have remained at that level. The recent good calf prices have resulted in positive returns over cash costs for the last few years for cow-calf producers.
These numbers should grab your attention, because I don’t believe the costs and returns can be much different across the regions where beef cows are produced. The costs of maintaining a beef cow and the unit cost of production of weaned calves have increased tremendously during the past five years. Variable costs such as fuel, fertilizer and herbicides have been blamed as the primary culprits. However, fixed costs such as equipment, hired labor and land have increased, as well. When cattle numbers rebound, and they always do, will these high calf prices remain stable enough to cover these high costs of production?
Additionally, cow carrying costs have increased because of a 30% increase in cow size — from 1,047 pounds (lb.) in the mid-1970s to 1,369 lb. in the mid-2000s — during the last 30 years. This trend appears to have continued. A 30% larger cow requires 22% more energy per day for maintenance and will consume 20%-30% more forage per day, decreasing cow carrying capacity of the farm or increasing input costs associated with pasture management, supplementation and stored forages. Smaller cows also have been shown to have greater weaning efficiency (pounds of calf weaned per pound of cow body weight).
The increased cow mature weight equates to an increase in stocking rate, if cow numbers are not adjusted. As stocking rate increases, we know that weaning weights and rebreeding rates decrease. This has been linked to reductions in forage allowance (pounds of forage available per pound of animal body weight) limiting diet selectivity, diet quality, dry-matter intake and forage regrowth rate. Total weaning weight per acre has been shown to increase up to a point, even though individual animal weight is decreased; until animal performance is reduced to such an extent that weaning weight per acre begins to decrease.
In research on introduced warm-season grasses in the southeastern United States (Beck and others, 2016; doi:10.2527/jas2015-0049), cow-calf pairs were separated into heavy (weighing 1,220 lb.) and light (weighing 970 lb.) cow size groups and stocked on pastures 2.5, 1.7, 1.2 and 1 acre(s) per cow unit during four years. These pastures were fertilized with 100 lb. of nitrogen per acre during the summer.
Heavy cows weaned heavier calves than light cows, but the increase was only 19 lb. heavier weaning weight for every 100-lb. increase in cow mature weight. Larger cows also lost more weight and body condition than smaller cows. Weaning efficiency ratios of smaller cows were higher (0.49 lb. of calf weaned per 1 lb. of cow for small cows vs. 0.42 lb. for large cows). As stocking rate increased, pounds of calf weaned per acre increased from 130 lb. at the lightest stocking rate to 411 at the heaviest stocking rate.
The increase in weight and condition loss with larger cows is a concern. This could lead to reduction in fertility and increases in rebreeding interval for large cows, especially those with higher stocking rates. Because hay was fed when needed and cows were supplemented to maintain appropriate body condition, rebreeding rates were not affected. But, as cow mature weight and stocking rate increased, the amount of hay and annual cow costs increased, as well. Increasing stocking rate reduces individual calf body weight gain, but increases total calf gain per acre.
For the larger cows, any advantage in calf weaning weight was diminished during a two-year drought while this research was conducted, but was enhanced during periods of normal rainfall. These responses to drought indicate production systems with higher stocking rates and larger cows are more affected by climatic stressors, and thus less resilient to harsh environments.
Editor’s note: Paul Beck is a state extension beef cattle nutrition specialist for Oklahoma State University. This article is reprinted with permission from the Jan. 29, 2024, OSU Cow-Calf Corner newsletter.
