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When is the right time to start supplementing?

I get the above question a lot, and it’s usually followed up or preceded by, “okay, what should I supplement or what would you recommend.”  The question actually leads to more questions, and is also a good reason to evaluate why we supplement our cattle and what are the benefits.

August is now here and fall is only about 6 weeks away (officially).  People don’t often think of supplementing cows with energy or protein this time of year.  There is normally ample grass, and summer activities like haying and other farming enterprises usually are more of a priority than wondering about supplementing the cow herd.  In addition, supplementation is an added cost and conventional wisdom often states that cows don’t need supplement until Mother Nature dictates (drought, cold weather, short feeds supply, etc...).

What are the Reasons and Benefits of Supplementation Now?

Late breeding season

For May and June calving herds, breeding season is now.  Heat stress in August can be a challenge for breeding (both for bulls and cows) and forage quality is declining, especially for cool season grasses.  Numerous studies have shown what forage protein, energy and mineral content does as pastures mature.  If breeding is a challenge already due to heat stress, subtle mineral imbalances, and declining pasture conditions will only further aggravate.  Certain rotational grazing practices can help by keeping cows on better grass but don’t overlook the values of a small amount of protein supplementation; like that offered with CRYSTALYX®.

Declining Forage Quality

Grass conditions can be deceptive and highly variable from one year to the next.  A colleague of mine shared some graduate study work done in Wyoming where lbs. of forage per acre, protein content and digestibility of native range varied greatly in the month of July in back-to-back years.  Much of the variability had to do with precipitation and the timing thereof.  In the end, the more favorable year in regards to forage production, resulted in poorer quality forage.  Similar work has been done in Nebraska by other industry Colleagues – see charts below.


Wyoming Rangeland Grass

Year one

Year two

Forage lbs./acre

277 lbs./acre

490 lbs./acre

Crude protein content



InVitro dry matter digestibility




Nebraska Brome Grass observations – 4 year averages

Crude Protein

Phosphorus levels

June 1st



July 1st



August 1st



September 1st




Maintaining Body Condition Score

It is very well understood that poor cow body condition results in poor reproductive efficiency.  The net result is fewer pounds of beef weaned.  Beef cows are susceptible to body condition loss at this time of year, especially with nursing calves at side and declining forage quality.  Supplementation can reduce this loss of body condition, and it is much less costly to maintain body condition now or in early fall with a supplement like CRYSTALYX® vs. trying to add 50-80 lbs. or more to a cow during cold weather and when she if further along in gestation.

Benefits of Fetal Programming

Numerous studies in the Animal Science community have centered around Fetal Programming or developmental programming.  In beef cattle, this simply means that if we supplement a pregnant cow in early and mid-gestation, that supplementation effect can improve the next generations’ calf survivability and weaning weight (Stalker et al., 2006), reproductive efficiency in heifer calves (Martin et al., 2007), and feed efficiency and carcass merit in finished feedlot calves (Larson et al., 2009).  All the above are an opportunity to improve profitability in a beef enterprise.

What’s next?

The take home message is to evaluate your forages and your cow condition now.  It may or may not be the best time to start supplementing but the benefits of early supplementation outweigh waiting too long and playing catch up.  Playing catch up is hard to do, expensive, and is normally not cost effective.  Start planning your supplementation strategies now.

Larson, D.M., J.L. Martin, D.C. Adams and R.N. Funston.  Winter grazing system and supplementation during late gestation influence performance of beef cows and steer progeny. J. Anim. Sci. 2009, 87:1147-1155.

Martin, J.L., K.A. Vonnahme, D.C. Adams, G.P. Lardy, and R.N. Funston. Effects of Dam Nutrition on Growth and Reproductive Performance of Heifer Calves.  J. Anim. Sci. 2007, 85:841-847.

Stalker, L.A., D.C. Adams, T.J. Klopfenstein, D.M. Fuez, and R.N. Funston.  Effects of Pre and postpartum nutrition on reproduction in spring calving cows and calf feedlot performance.  J. Anim. Sci. 2006, 84:2582-2589.