Methane from agriculture, especially livestock, represents a significant portion of global methane emissions. Agriculture overall is responsible for 40%‑50% of anthropogenic methane emissions, with ruminants accounting for roughly 56%‑70% of methane from this figure. Other agricultural activities like manure management and rice paddies also contribute. Mitigating emissions from cattle production is one of the important aspects to reduce the environmental impact of agriculture.
Feeding corn to cows
Lactating dairy cows consume on average 40‑60 pounds of corn silage daily on an as‑fed basis, and about 10‑15 pounds of corn grain. As a result, over a year, a single dairy cow can consume around 15,000 pounds of corn silage and 3,600 pounds of corn grain, depending on productivity and feeding practices.
To estimate how many acres of corn a dairy cow needs in a confinement system, we can use those figures and compare them to typical corn yields. Corn silage yields vary, but a common estimate is 20‑25 tons per acre. If we use a mid‑range yield of 22.5 tons (45,000 pounds) of silage per acre, each cow requires about 0.33 acres of corn silage per year, as shown in Figure 1 (page 60). Corn grain yields also vary, but let us use a conservative 150‑200 bushels per acre. Taking a mid‑range yield of 175 bushels per acre, it would be about 9,800 pounds of corn, resulting in about 0.37 acres of corn grain required per cow in confinement, also shown in Figure 1.
Combining both corn silage and grain, each cow requires 0.7 acres for both feedstuffs. For ease of calculation, let’s say each cow requires 1 acre of corn planted yearly. This would account for both feedstuffs, allowing for some variation in yields, consumption and feed management practices.
Continue reading this article published in Progressive Dairy.
