Monitor nutrient status of cows
January 27, 2016
Managing cows through the winter presents unique challenges – especially when snow covers most of South Dakota, explained Adele Harty, SDSU Extension Cow/Calf Field Specialist.
"Cows oftentimes receive supplemental feed to meet their nutrient requirements during late gestation and into calving season because forage available for grazing is limited," Harty said.
She explained that supplemental feeds can range from hay, to cake, to distillers grains or lick barrels.
Whatever the preferred method of supplementation, Harty said to ensure that cows' nutrient requirements are being met, there are two simple tools cattle producers should use on a regular basis.
The first is to monitor body condition score and the second is to monitor manure consistency.
"By monitoring body condition score (BCS) on a regular basis you are evaluating trends in nutritional status through time, and can make appropriate management decisions," she said. "The most important question to ask is, 'what condition are my cows in, and are they gaining, maintaining or losing condition?"'
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Harty reminded producers that on a 1-9 scale, the goal is to have cows in a BCS of 5 at calving. "A cow with a BCS of 5 is described as one whose "overall appearance is generally good,"' Harty said.
She explained that the fat cover over the ribs feels spongy. Palpable fat cover is present on either side of the tail head. Supplemental feeds need to be added to the nutrition program if cows are losing condition and will drop below a BCS of 5 before calving.
If the cows are in adequate condition of BCS 5 and maintaining, no immediate changes are likely needed. However, Harty said if cows are in poor condition, a BCS less than 5, or losing condition, management changes need to be made immediately. "If the cows are in BCS greater than 5, the nutrition program is more than adequate, but one may need to evaluate the feed costs associated with this excess condition."
Manure consistency can serve as an indicator of forage quality and animal performance. The primary question this indicator can help answer is, "Do the cows need a protein supplement? If they are receiving a protein supplement, is it enough?"
Photos accompanying this article show manure from animals with excess protein (Photo 1), sufficient protein (Photo 2), and deficient in protein (Photo 3) in their diet.
Excess Protein: Manure patties similar to Photo 1 indicate a diet with crude protein greater than 10 percent. The center of the patty has a crater-like appearance. If there are small folds present around the edges of the patty, the crude protein content will be in the 10-13 percent range. No additional supplementation is needed for mature cows with manure of this consistency.
Sufficient Protein: Manure patties similar to Photo 2 indicate diet crude protein is between 6 and 9 percent. This manure will have flat folds. As forage quality increases the folds become smaller. This manure indicates forage quality adequate to meet maintenance requirements for mature cows. Depending on the stage of production, additional protein supplementation may be required particularly during late gestation or early lactation.
Deficient Protein: The manure in Photo 3 indicates diets with crude protein of 5 percent or less. These droppings have very distinct rings at the lower portion which tend to be firm. Manure from this forage quality tends to stack, but the rings are a true indicator of lower forage quality. This manure type indicates the forage is below maintenance requirements for all classes of beef cattle and that protein supplementation is necessary to increase digestibility and utilization of the low quality forage.
"This is a simple tool to evaluate whether or not cows need to be supplemented or if your current supplementation program is working," Harty said.
If cows are still grazing dormant range, it is challenging to collect a representative sample of the forage to determine quality. However, Harty added that if the manure is indicating protein deficiency on low-quality forages, adding or increasing a protein supplement will increase the utilization of those low-quality forages, especially this time of year. "Adding a protein supplement to low-quality forages will be beneficial to maintain body condition score and cow meet nutrient requirements," she said.
If the cows are being fed supplemental hay, Harty reminded producers to have the hay analyzed for protein, energy and mineral content. "Hay quality varies from year to year, so what has worked in the past isn't going to work the same every year," she said. "Beyond that, because they are probably consuming a mixture of hay and forage grazed from pasture, monitoring BCS and manure consistency can ensure that nutrient needs are being met."
For more information on body condition scoring cows or monitoring manure consistency to determine supplementation needs, contact Adele Harty at 605-394-1722 or firstname.lastname@example.org.