Early Lactation Nutrition in the First-Calf Beef Heifer


Hi. This is Beth Doran, ISU Extension Beef Field Specialist in Northwest Iowa. Today, I’d like to talk with you a little bit about heifer development and specifically nutrition post-calving. When you look at this, you’ll see that post-partum heifers are really very fragile. That’s because they’re continuing to grow, they’re trying to milk and feed a calf, they’re trying to resume their estrous and then couple that all with the weather and if it’s inclement whether there’s cold, rain, or mud, you’ll see that that’s going to greatly increase the nutritional demands on this first calf heifer. We know that the economic losses in the cow-calf enterprise is usually the biggest due to the failure to rebreed. Post-calving nutrition is very very critical. When you think about it, you look at the energy, the protein, the mineral, and vitamin requirements, they’re all increased because milk production is increasing. We also know that it’s difficult to add body condition to a heifer that is lactating. The good news is, though, there’s less growth than pre-calving and that heifer’s intake will increase compared to pre-calving. One of the things that we need to keep in mind in terms of post-calving nutrition is how we’re going to transition them from grass so that they can graze. Looking at growth after calving, there’s two cardinal rules to kind of remember, one is that eighty-five percent of the mature body weight is what that heifer needs to achieve at her first calving. By the time she reaches her second calving, she needs to be at ninety-two percent of her body weight. You look at the example down at the bottom you’ll notice that we have a heifer here that at ninety-two percent, she’ll have to weigh twelve hundred and fifty pounds. Take that first calf heifer, she has to weigh eleven hundred and fifty pounds. So you figure in that next year, from the time that she calves until she becomes a three-year-old, she’ll have to gain a hundred pounds. That’s a little over a quarter of a pound per day. Looking at the energy requirements for milk production, I want to take you through a little bit on this chart. Looking at the energy requirements for milk production, you’ll notice that as the pounds of milk increase, that the energy that’s required by that animal increases. That’s regardless of whether they’re a first calf, second calf or mature animal. Now if you go in and you start to look at this heifer that’s at 20 pounds in terms of her milk production, you’ll notice that that’s about 4 mega Cals of energy she has to have. That’s equivalent to five pounds of corn to provide that. You’ll also notice as you go through there, in terms of the first calf versus the second calf versus mature, that there’s an increasing energy requirement as that animal matures. When you look at the energy requirement and the dry matter change from late pregnancy to lactation, we’re going to be looking at a heifer that’s 270 days pregnant versus one that’s lactating. You’ll notice that the heifer that’s 270 days into her pregnancy has to gain nine-tenths of a pound versus only three tenths of a pound average daily gain for that one that’s lactating. However when you look at the total energy requirements on those two animals, you’ll notice that they really aren’t all that terribly different from the top of this line to the top of that line, but there is a repartitioning of the energy depending on whether that animal is going to be lactating, whether it’s pregnancy, whether it’s growth or maintenance and you’ll see that basically the pregnancy and the growth are reduced while the energy that has to go to lactation is increased. When we look at the protein requirement change from late pregnancy to lactation on a high milking British breed heifer, you can see that there’s a substantial increase in the amount of protein that needs to be supplied to that heifer. Most of that is because of the milk production and when you figure milk, one of the major components in it is going to be protein. Also looking at protein requirements and relative to how many pounds of milk are produced, you’ll see that there’s an increasing requirement, as more milk is produced the protein requirement goes up and we have the same relationship in terms of the first calf, second calf, versus mature animal with the mature animal having the greatest protein requirements at any given stage of production. When you look at that middle line and you’re looking at the 20 pounds of milk that’s produced, you’ll see that that’s about 400 grams. Contrast that with basically the 700 grams that’s needed if she’s in a high milking stage. When you look at 400 grams that are required, that is equivalent to about 8 pounds of hay, six pounds of corn. When you go up to the 700 grams that are required of metabolizable protein over here, you’ll see that those energy, those amounts of feeds, are basically doubled. Number one to take in looking at some nutrition post-calving, we’re going to look at a heifer that’s 270 days pregnant versus one that has just calved and it’s lactating versus a mature cow. In this particular set of examples, you’ll see that we’re going to be feeding hay and corn and what I really want you to think about is what are these costs across the bottom per day and we’re going to focus specifically on that lactating animal. Notice that this is a dollar and ninety two cents, that’s with hay priced at one hundred dollars a ton and corn at 3.75 a bushel. Now I want you to contrast this with ration two. Same kind of scenario in terms of the heifer, the mature cow, and the lactating heifer, but we change the feed stuffs a little. We’re still feeding some corn and some hay, but we’ve added some corn stalks and distillers grains and in doing that, you can see that we have dropped this cost by 54 cents compared to the previous slide. We’re still feeding some hay and corn, but we’re taking advantage of those alternative feed stuffs. And last if we go to the last set of rations and looking at ration three, same type of scenario, you can see now that we have dropped out the corn, we’ve dropped out the hay, we’re still going to feed those corn stalks and distillers grains, but we decided to come back in some corn silage and in doing this, we’re still able to reduce that cost another six cents versus what it was with the ration just before this one. So you can see there’s a number of different ways that you can formulate those rations to reduce the cost, the important point though is to make sure that you’re going to meet the needs of that heifer. In summary on post-calving, we recognize that the nutritional requirements are going to increase, but at the same time intake is increasing, so the ration doesn’t have to be quite as nutritionally dense per pound of feed. Two cardinal rules: first calvers need to be eighty-five percent of their mature body weight, second calvers need to be ninety-two percent of their body weight. Regardless of whether it’s the first calf heifer or second calf heifer, the body condition score needs to be that five and a half to six at calving. I realize there’s no one ideal ration. Nutrition is both a science, and the science of it is you need to meet the energy needs and the protein needs and the vitamin and mineral requirements for that animal, but there’s also an art. You’re going to have to consider what feeds stuffs do you have, what kind of equipment do you have, what are the facilities, what’s the animal that you’re feeding, and how are you going to be grouping those animals together. So in conclusion I would say if you want more information about calving and you want more information about developing your heifer, I’d encourage you to go to our Iowa Beef Center website. We have a nice website there with a number of materials. I want to thank you for your attention today and I want to wish you good luck!