Virginia Extension livestock budgets show winter feed costs make up 60 percent of total expenses for the typical fall calving cow/calf producer who feeds hay.  

One way to lower feed costs is by stockpiling forages for winter grazing.

Stockpiling is a process of allowing forage to accumulate growth during the late summer and fall to be grazed by cattle instead of the normal practice of feeding hay after the growing season has ended.  

In Virginia, cow/calf producers who stockpile, make the last hay cutting or remove cattle from pastures in early to mid-August to allow these fields sufficient time for regrowth before growth stops in the fall.  

Tall fescue is a common cool season grass found on most farms throughout the state and is ideal for stockpiling. It produces both higher yields and forage quality when compared to other cool season grasses used for stockpiled winter grazing.

A 3-year Virginia study showed that stockpiled tall fescue contained 23 percent more energy and 36 percent more crude protein compared to average grass hay in Virginia. For example, stockpiled fescue fields that received 40 pounds of nitrogen per acre averaged 13.9 percent crude protein and 68.1 percent total digestible nutrients.

Although there was a slight increase of 0.7 percent crude protein when the nitrogen rate was increased from zero to 120 pounds per acre, the range was small and likely biologically insignificant. Furthermore, the stockpiled fescue will meet the nutritional requirements of all classes of beef cattle.

The yield of stockpiled fields is dependent upon rainfall and nitrogen application rates.

The 3-year Virginia study compared nitrogen rates and source effect on the yield of stockpiled fescue. Stockpiled fields that did not receive nitrogen produced ~2,500 pounds of dry matter per acre. Yields increased linearly for each source of nitrogen. However, rates of yield increase varied between nitrogen sources.

Ammonium sulfate, broiler litter and urea are the most common nitrogen (N) sources used to fertilize pastures in Virginia.

The 3-year Virginia study determined the increase in yield of pounds of dry matter (DM) for each pound of nitrogen applied from the following products: ammonium sulfate (11.08), broiler litter (9.29), and urea (7.10).

Many producers apply 40 -50 pounds of nitrogen per acre to stockpile fescue for winter grazing.

Table 1 shows the response rate in pounds of dry matter and grass per acre using an application rate of 50 pounds nitrogen per acre and assuming that a pound of grass is 80 percent water and 20 percent dry matter:

Table 1: Dry Mater Response Rate to Nitrogen

Nitrogen Source

lb. N/lb. DM

lb. N/acre

lb. DM/acre

lb. grass/acre

Ammonium Sulfate

11.08

50

554

2,770

Broiler Litter

9.29

50

465

2,325

Urea

7.10

50

355

1,775

 

Clearly rainfall is one of the most important factors influencing pasture yields. It is recommended that nitrogen be applied when there is a high probability of rainfall in the weather forecast to maximize yields. 

June 2013 nitrogen prices are listed in Table 2. The broiler litter prices are based on a minimum of 45 pounds of nitrogen per ton.

Table 2: Nitrogen prices and costs per acre to apply 50 lbs of N

Nitrogen Source

$ /lb. N

lb. N/acre

$ /acre

Ammonium Sulfate

.77

50

$38.50

Broiler Litter

.77

50

$38.50

Urea

.67

50

$33.50

 

 

Due to the volatility of fertilizer prices in recent years, producers should check fertilizer prices in order to determine the most inexpensive source of nitrogen.