How much grass does a cow eat to gain a pound?

Answer 1

It all depends on how big she is, how much milk she is producing, what stage of lactation she is in, what body condition she's in (fat, thin, or moderate), breed, age, and nutritional quality of the grass (as determined by growth stage and species that make up the pasture fodder). For this question, we can only use an example.

Say we have a 1200 lb Angus cow in her 3rd month of lactation and she's consuming around 4% of her bodyweight in dry-matter forage (in this case, grass) per day. This calculates out to this cow eating around 48 pounds (1200 x 0.04) of dry-matter forage per day. For as-fed, let's assume that the grass is good quality and at 65% moisture. This means that she is expected to eat around 6% of her bodyweight per day, or 72 pounds of grass per day.

Answer 2

There are way too many factors at play here to be able to give an accurate answer to this question. Cow size, age, breed, stage of lactation, stage of reproduction, maintenance requirements (as per size/weight, age and breed), environmental stressors, body condition score, among others are all at play at determining how much feed or grass it takes for a cow (assuming this is a full-grown mature cow [female bovine] we are referring to here) to gain a pound.

Other factors at play are the nutrient quality of the grass. We would need to know all the energy information of the particular samples of grass collected, including digestible energy (DE), metabolic energy (ME), and net energy for maintenance and gain or growth, and possibly lactation and reproduction if this cow is lactating and/or pregnant. Until then, this question cannot be answered, even in any estimated calculations.

Answer 3

As a general rule, a bovine (cow or not) will eat, on average, around 2.0% of their body weight in dry matter per day. Depending on the moisture quantity of the grass that the cattle-beast is on and the body-weight of the bovine in question, this can translate to an average daily consumption of 30 to at least 70 lbs of forage per day. Grasses that are more mature or have already seeded out will have a lower moisture content than grasses that are still growing. Hay has a much lower moisture content than either stage of grasses: Grass-hay is often at a moisture content of around 10 to 20% (80 to 90% dry matter), whereas grass that has reached maturity has a moisture content of around 40% (60% dry matter), and growing grass (grass that is around 12 inches in height) can have a moisture content between 50 to 70% (dry matter of 50 to 30%).

To Calculate:When you have a forage test done on your pasture and have an approximate value of moisture content of the grass, you need to convert this into dry matter content. All you have to do is take the moisture content and subtract by 100%. Then divide by 100. Next, using the weight of your cattle-beast, you take the animal's daily intake percentage and multiply that number by the animal's weight to get the approximate amount of feed/forage the animal will consume (on a dry matter basis) per day. Then, taking the dry matter content (not in percent) you calculated previously, divide the amount of feed the animal consumes per day with the dry matter content number, and this will give you the as-fed value of how much your cattle-beast will eat per day. An Example:One 1200 lb cow is on excellent quality pasture in late spring, with the forage content analysis telling you it has an approximate moisture content value of 75 percent (25 percent DM). Your cow is in her second month of lactation, which means her nutrient requirements and daily intake is higher than when she would be dry (not lactating). That being said, she has an approximate daily rate of intake of 3.0 percent of her body weight. Calculate the amount of grass she needs/is consuming as-fed on a daily basis.

First find the DM (dry matter) content:

Moisture content = 75%

Dry matter content = 100% - 75% = 25% ÷ 100 = 0.25

Then find the daily consumption of the animal DM:

Amount of forage consumed per day (lb) on a DM basis = 1200 lb x 3.0% = 1200 x 0.03 = 36 lb/day

Now find the as-fed daily consumption value:

Amount of forage consumed per day (lb) on an As-Fed basis = 36 lb/day ÷ 0.25 DM = 144 lb per day.

Note, as mentioned above, the amount a bovine will consume on a daily basis depends on the body weight of the animal, pasture quality and moisture content of the grass. In a perfect world, these are the only three variables that one has to contend with. However, since this is NOT a perfect world, there are other variables to consider that affects an animal's rate of intake: weather, ambient air temperature, wind, time of day the animal is eating, animal's health status, whether the animal is going through a period of compensatory gain or not, body condition score of the animal, the terrain and topography of the pasture, competition from other animals, types of grasses in question, physiological stressors of an animal, how much gain you wish to expect from your animals per day, etc.

So please take this with a grain of salt, as you can never get an accurate number when it comes to judging how much a bovine will eat on a daily basis.

Here's another example taken from another question merged to this one answered by someone else:Cows will eat about 2.0 to 2.5% of their body weight in dry matter (take all the water out) grass if that is all that they consume.

Lets use an example:

1000 lb cow x 2.0% = 20 lbs of Dry Matter (DM)

20 lbs of dry matter / 15% dry matter in grass = 133 lbs of grass per day

Grass is generally about 85% water - thus use 100-85=15% [Note: this is not always true, as it depends on the stage of growth the grass is in--growing grass will always have a higher moisture content than grass that has reached maturity and goes into dormancy.]

There are several factors that affect this amount. As you can see by the equation, the biggest factor affecting intake is body weight, followed by nutrient value, then moisture content.

Answer 4

More information, please. Dairy? Beef? Lactating? Check out the related answers below.

Answer 5

Any kind of grass that is palatable (tastes good, easy to chew, etc.)