There are a lot of misconceptions about how beef is raised and what kind of ranching practices are sustainable. One of the big debates is whether grass-finished or grain-finished beef is more environmentally sustainable. In a previous blog post, I shared some research on the nutritional differences between the two, which you can find here.
First, let’s talk about the differences between these two operational models. There are three different phases in grass-finishing cattle. The first phase is a cow-calf operation, then a pre-grass finishing phase, then the grass finishing phase. The cow-calf model is typically similar to conventional cow-calf models, but the calves are not shipped to a feedlot in the fall. They are backgrounded on forages such as grass, alfalfa hay, grass hay, and wheat straw during fall and winter. What they are fed depends on availability and weather, but they are not fed grain. They typically enter the finishing program when they are 12 months old, which coincides with grass growing in the spring. They typically finish at 1070 pounds when they are almost two years old.
Cattle raised in a conventional operation start their lives in the same way. The calves typically summer on grass, then when weaned in the fall they are shipped to a feedlot or backgrounder operation. When they are ready, they are finished on grain-based rations in the feedlot. There are a lot of things that might be a part of a ration, including, corn silage, haylage, dry hay, supplements, sugar beets, distiller’s grains, soy meal, and corn. The average finishing weight is 1254 pounds at 1.2 years old. Conventionally finished animals are also often implanted to increase their rate of weight gain and given ionophores, which increase feed efficiency.
Looking at the weights that they finish at and how long it takes to finish them, we can see that the conventionally raised cattle are the most efficient. But that’s not what we’re looking at. This discussion is evaluating the carbon footprint of these two different groups. The short answer, conventionally finished beef has a lower carbon footprint. In fact, “the combination of consumer a higher-energy, lower forage diet, shorting time spent on feed during finishing and having heavier carcass weights translate into an 18.5 to 67.5 percent carbon footprint for grain-finished beef as compared to grass-finished beef.” That is a big difference! There are multiple factors that go into this, which is why there is such a big difference in how much of a benefit there is to conventionally finishing the animals.
One of the big reasons that grass-finished cattle are not as efficient is because forage diets produce more methane emissions than grain-based diets do. However, there are some benefits to grass-finished cattle. They spend their entire lives on forages that humans can’t eat, so they are turning these inedible forages into high-quality protein. Two-thirds of rangeland is “marginal land” that isn’t suitable for anything but grazing animals.
However, most of grain finished cattle’s diet is also forages and byproducts that humans cannot eat. In most conventional operations, the land that cannot be used for crops isn’t left empty, instead, ranchers use it to run more cows so that they can raise more beef on less land than if they were going to finish all their animals on grass.
I don’t write this to say that there is anything at all wrong with grass-finished beef. It’s leaner and does have a different flavor than grain-finished beef, and there are a lot of people who prefer their beef to be grass-finished. There is room for diversity in how we do things within agriculture, and I believe that diversity makes our industry stronger. However, I don’t like seeing lies spread about how conventional beef is raised.