Assessing cow nutrition during late gestation
It can be tempting to try to save some money by letting dry cows rough it on low-quality forage with little to no supplement, but this is not the time to skimp on nutrition. As a cow moves from mid- to late-gestation, her energy requirement increases 25 percent and her protein requirement increases by 10 percent.
During the last month prior to calving, the fetus is gaining approximately one pound per day. Research has shown cows who are in a body condition score (BCS) of four or less at calving have decreased concentration of immunoglobulins in the colostrum compared to cows in a BCS of five to six.
Calves born to thin cows may be weak and slow to nurse, resulting in reduced consumption of colostrum making them more susceptible to disease. Additionally, providing proper nutrition during late gestation helps prepare the cow for lactation and rebreeding.
There are several points for producers to consider regarding late gestation nutrition.
A calving BCS of five to six is optimal.
It is more economical to put condition on a cow during late gestation than after calving due to the increased nutrient demand for lactation.
A cow must gain 75 pounds of body weight to increase one full BCS, but during late gestation, this number increases to account for fetal growth and placental weight.
Cows in good condition can maintain or slightly increase BCS with protein supplementation on low-quality forage.
If cows are thin, both protein and energy supplementation is needed to increase BCS.
Supplementing corn alone to cows on a forage-based diet can reduce forage intake and digestibility, as well as result in weight loss if the cows’ protein requirement is not met.
Consider separating and feeding thin cows from cows in good condition.
At the end of the day, cow condition is essentially an insurance policy. Staying ahead of the game and maintaining cow condition rather than letting cows slip and get behind can really pay down the road.
For more information, see the NebGuide, “Supplementation Needs for Gestating and Lactating Beef Cows and Comparing the Prices of Supplement Sources” at extensionpublications.unl.edu/assets/pdf/g2268.pdf.
For assistance with ration development for a herd, contact your local Beef Extension personnel.
Erin Laborie is a Beef Systems Extension Educator at the University of Nebraska-Lincoln and is based in Beaver City, Neb. She can be reached at firstname.lastname@example.org.