Select Sires

Energy Balance and Dry Matter Intake
(Part One)
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired Oct. 27, 2005
With Ray Nebel,
Extension Specialist and Professor of Reproductive Management,
Virginia Tech

This week’s Reproductive Moment is with Ray Nebel, Extension Specialist and Professor of Reproductive Management at Virginia Tech. This is the first in a two part series, Ray, where we are talking about Energy Balance and Dry Matter Intake and its effects on reproductive performance.

Yes, Bill. One of the real keys to reproductive performance is nutrition. In nutrition the main thing that we look at is energy balance and dry matter intake. What I mean is the amount of energy that she actually eats or intakes is partitioned into maintenance of her body, to milk production, and to reproduction.

You mentioned body condition scoring as a method of monitoring this.

Yes. In a good milk cow, one with a high milk production, she is going to peak in milk production about seven weeks after calving. So, her negative energy balance is early in lactation where her dry matter intake cannot keep up with the demands of the energy that she is going to expend, because now she has teat milk production and maintenance. So her energy balance actually goes negative in that early lactation period. Therefore, what we want to do is to monitor when we turn that corner, and the way to do that is with body condition scoring.

Tell us more about body condition scoring.

The body condition scoring was actually set up many years ago. It is a way of looking at the cow as far as the condition or the amount of fat covering that she has across strategic parts of her body, mainly the hips and pins across the short ribs and around the tail head area. The scale goes from one to five. A cow that is over conditions, or is very fat, is a five, and a cow that is thin is a one. So one, two, three, four, and five, and we also go half numbers.

What should the score be? What is the ideal score?

Well, the ideal score depends on the stage of lactation. In a cow that is dry and getting ready to calve, we are looking at about three and a quarter to three and a half. In a cow that is getting ready to calve, a four would be over-conditioned, and a cow that is a two and a half would be too thin. She has to have a certain amount of energy, as we mentioned. Because she is going to take that fat reserve and use it up as energy, her intake won’t be great enough to meet the energy demands.

It is important to monitor this body condition scoring throughout, isn’t it?

Right, if they calve at three and a quarter or three and a half, then, when there is time to breed them, they are going to be somewhere around a two and a half. Therefore, it is not uncommon for a cow to lose one body condition score from calving to breeding. What we really want to monitor is if the cows are losing more than one body condition score, because that says that their dry matter intake doesn’t meet their demand. They are losing too much body weight and it is going to delay cycling activity. By doing body condition scoring, we can get a rough estimate of whether our cow is cycling, and whether we need to put them back onto a reproductive program or need to delay the reproductive cycle so that we can get them in good condition before we start breeding.

Thanks, Ray. We will continue our discussion next week with Ray Nebel, Extension Specialist and Profession of Reproductive Management at Virginia Tech.

Select Sires Inc., 11740 U.S. 42 North, Plain City, Ohio 43064 / Phone: (614) 873-4683 Fax: (614) 873-5751