Hay Quality Determines Supplementation Needs

Jeff Fisher, Chris Bruynis, Jeff Moore, and Steve Boyles, Ohio State University Extension (this article first appeared in the January issue of The Ohio Farmer Magazine)

Rain in the late spring through early summer delayed hay harvest in some areas of the state. Additionally there were some high temperatures that caused an increase in the rate of maturity of forages. For example alfalfa grown at 63°F may take 52 days to reach early bloom but only 21 days at 90°F. As forages mature, there is an increase in cell wall content and a decrease in the digestibility of the cell wall. So for some producers, all these factors came together to create the perfect storm and significantly lowered forage quality.

A group of agents in Pike, Ross and Gallia counties worked with forty-seven livestock producers in obtaining hay sample for nutritional analysis this fall. There were a total of eighty-one hay samples collected. The following are a subset of those samples with example diets to meet beef cow dietary requirements for late pregnancy and lactation.

The following diets are for a 1300-pound cow in the last trimester of pregnancy. The table includes Crude Protein (CP) and Total Digestible Nutrients (TDN) which can be an estimate of energy needs. Soybean meal (SBM) and Corn were made available as supplemental protein and energy if needed.

HayTable1

The following table is for a 1300-pound cow for lactation. There were various levels of lactation. The hay samples are the same ones as above.

HayTable2

Forage quality is always important to cattle nutrition and can greatly affect the cost of supplementation. These are computer generated diets. Computer cows do not waste feed but we know their live counter parts do. Additional supplementation is necessary during cold and/or wet weather. Consideration needs to be given to the hay delivery system. Higher levels of grain also slightly change mineral requirements. Some of the diet above would benefit from calcium supplementation since grains like corn are relatively low in calcium. Cattle genetics can also affect nutritional cost. If a producer constantly needs to supplement cows with energy and protein, even in a good year, there needs to be attention to bull selection. Milk production should be closely aligned to the forage quality that can be produced.