Mean temperatures keeping cows lean

Some cows I’ve seen lately look thinner than normal for this time of year. With more than a month of winter remaining, it could mean trouble for producers as calving time approaches.

We’ve had colder than normal temperatures, combined with a longer than normal continuous cold spell in our part of the state and this has increased the nutrient needs of all classes of livestock for farm operators.

Not the answer

In conditions like these, livestock need high quality feed to maintain their body condition. Hay may lack enough energy to meet the cow’s nutrient needs and just feeding more hay may not solve the problem.

In fact, laboratory analysis of several hay samples I’ve seen indicate much of the hay made last summer was not high quality forage.

Wet conditions pushed hay harvest dates far past the ideal plant maturity stages last spring, resulting in lower quality hay being rolled up by many producers, compared to what they are accustomed to making.

That means the producer may have to supplement with protein or energy or both to meet the animals nutrient requirements. Some may think the animal can just eat more of a low quality hay to get what they need, but the opposite is actually true.

Can’t eat as much

When the quality of forage is low, the animal physically cannot eat as much in a given time period because the feed does not pass through the rumen as quickly as high quality hay. If not as many nutrients are available and the pass through is slower, the result is loss of body condition even though the animal may have a full stomach.

Livestock consuming low to medium quality feed for periods through the winter months in a normal year may maintain their weight, but with the additional demand from the cold temperatures we’ve seen this year, it is almost a given they are losing some fat reserves.

This problem, unless proper nutrients are supplied through concentrates or higher quality hay, could get progressively worse after calving when the nutrient demand on the cow becomes even greater.

Requirements

The National Research Council, Nutrient Requirements of Beef Cattle (7th edition), lists the following requirements for a 1,200 pound dry, mature cow in the last third of pregnancy: crude protein 7.7 percent, and total digestible nutrients at 52.3 percent on a dry matter basis.

The same cow, but after calving and producing milk (20 lbs./day), requires 10.1 percent crude protein and total digestible nutrients of 58.7 percent on a dry matter basis.

Also, keep in mind adjustments to these numbers must be made to account for cold temperatures or wet/muddy conditions.

Laboratory analysis of different hay lots provides critical information for the producer to reduce guesswork and make wise decisions. Forage tests provide percent protein figures, total digestible nutrient percentages and much more information so managers can feed their different hay lots to the class livestock and or the body condition score livestock it is best suited to be fed to.

Keeping score

Body condition score (BCS) is a way to describe the degree of fatness as we look at cows in a herd. The numerical range of 1 to 9 identifies the different degrees with 1 being very thin and 9 being excessively fat.

Don’t make the mistake of using live weight as your determining factor of fat reserves and body condition. Producers should look at the covering over the ribs, back, tail head, hooks and pins to determine the body condition score number for each animal.

Pictures and explanations of scores may be found at http://ohioline.osu.edu/l292/index.html.

Grouping animals using BSC score numbers and livestock class allows the farm manager to feed corrected diets to the different groups. Doing this can keep managers from wasting nutrients due to over feeding, but supply more nutrients for lesser conditioned livestock or growing animals.

Calving

Research has consistently shown that the body condition of a cow influences days to first estrus after calving. Beef cows should maintain a minimum body condition score of 5 after calving to consistently maintain a 12-month calving interval.

Longer calving intervals greatly reduce profitability for the cow/calf operator. Data from Virginia Tech indicates that 91 percent of the beef cows with BCS >5 at calving showed signs of estrus by 60 days post-calving, whereas only 61 percent of beef cows with BCS 4, and only 46 percent of beef cows with BCS <3 showed estrus.

Some cattle producers believe that by limiting the feed a cow gets prior to calving will reduce the calves birth weight and calving difficulty.

Difficulty

Research at the U.S. Meat Animal Research Center in Nebraska, has shown that birth weights can be reduced when limiting cow nutrition, but calving difficulty is actually increased in underfed cows even when they have lighter weight calves.

Also, data from three different studies involving several thousand cows showed that calves which experience calving difficulty are about four times more likely to be born dead or die within 24 hours of birth than those born without difficulty.

So, one can see that proper nutrition of the cow herd is very important and how it can be tied directly to profitability.

Providing the right nutrients during cold weather and using each lot of hay strategically in the feeding program will help make you money.

Guessing costs you

Guessing can be expensive if you are purchasing nutrients you don’t need, but it may even be more expensive if you are not providing enough nutrients to keep your cows in a 12-month calving interval.

About the Author

The author is an Ohio State University Extension Agriculture and Natural Resources Extension Educator in Monroe County, Ohio. More Stories by Mark Landefeld

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