Managing for milk level in your cow herd is kind-of like determining whether the porridge is too cold, too hot, or just right. Too little milk in the cow herd equates to lighter weaning weights which impacts dollars generated in the cow/calf enterprise. However, low milk level in a cow herd should result in lower feed costs. High milk level equates to heavier weaning weights, but also has the potential to increase feed inputs and therefore cow costs. As milk potential increases so does nutrient needs. Cows that have a high milk level have a greater need for pounds of protein, pounds of energy (TDN), ounces mineral, etc. to be consumed daily to meet those needs compared to cows with a low level of milk potential. A number of years ago at the University of Nebraska, three groups of cows were developed that were similar in weight, but differed in level of milk produced. The cow in the moderate level of milk group gave 28% more milk than the cows in the low level of milk group. Likewise, the cows in the high milk level gave 46% more milk than cows in the low milk level group. As one would expect, the feed for lactation between the three groups differed, with cows in the moderate and high level milk groups needing more feed to stay in similar weight and body condition as compared to cows in the low level of milk group. Even more interesting is that feed during gestation was greater for cows in the moderate and high level of milk groups compared to cows in the low level of milk group. Indicating that even when the cows with different milk producing abilities were not lactating, milk potential increased nutrient needs. In addition, feed needed in the feedlot was greater for the offspring from dams that had higher milk potential. Data from the U.S. Meat Animal Research Center in Clay Center, NE indicates that cows with greater potential to produce milk also have a greater percent of their body weight as heart, liver, and lungs. So the greater nutrient need for non-lactating cows and for their offspring in the feedlot may be a result of having to maintain more heart, liver, and lungs that are highly active tissues.

If cattle are asked to produce in a lush environment, then cow mature weight and level of milk is less of a concern, however, carrying capacity will be reduced. If feed resources are limited, cow weight and milk production need to be carefully scrutinized. Cow weight and milk level impact not only nutrient requirements but also impact feed intake. Cows bred for a high level of milk production have higher nutrient requirements even when not lactating. So how big should my cows be and how much milk should they give? It depends!! Match cow size and milk level to your feed resources. From an economic standpoint, the greater number of cows that can be grazed on a given forage base and meet their nutrient needs from the grazed resource base, the greater the profit potential of the enterprise.