Summary: In this article, Attica Veterinary Associates' Sam Leadley compares the nutrient needs of three sizes of heifers. He advises that for a 170-pound heifer to gain one pound a day in warm weather, she'll need to be eating between 3.5 and 4 pounds daily.
Because this article was so popular, we asked Sam Leadley a follow-up question:
Q: Why do you think this topic was of interest to producers in 2011?
A: I believe most of us have fallen into the trap of “same old, same old” when it comes to feeding grain to weaned calves. What we were doing in the ’90s we kept doing the next decade as well. Why change? Heifers were alive, reasonably healthy. And who is checking on rates of gain?
Underfeeding weaned heifers, primarily grain, is a silent thief. Letting these young heifers stand still or gain at a slow rate when their maintenance needs are low sets us up for having to pay for much more expensive gains later in life.
When farm managers become aware of the potential profits that can be claimed by a small change in management they often want to know the details. How will size of heifer determine feeding rate? Will weather make a difference? These are down-to-earth questions that managers want answered by practical articles in Progressive Dairyman.
—Sam Leadley, Calf Management Consultant, Attica Veterinary Associates
For ages and ages, many farms weaned calves based on their age. Little or no consideration was given to rumen maturity or level of grain consumption. This procedure works well for some calves and not so well for others.
More recently the industry has informally adopted the standard, “As soon as she is regularly eating two pounds of grain daily, she is ready to wean.” The term weaning here means to go off milk entirely. In volume, depending on the pellet used, this comes to about 1.7 to 2 quarts.
How much growth in a 170-pound heifer will two pounds of starter grain support?
A. None. Even in warm weather she will not even maintain her weight when she is eating only two pounds grain a day.
Remember, the energy and protein in her ration is divided between maintenance and growth. As heifers get larger and live in colder environments, maintenance needs go up. That leaves less for growth if the amount fed is fixed.
How much more grain does the 170-pound heifer need to eat to grow to gain one pound a day in warm weather?
A. We estimate she needs to eat between 3.5 and 4 pounds daily. Recall this is to gain one pound a day.
Let’s compare nutrient needs of three sizes of heifers at different seasons of the year (Table 1) . That will allow us to see how inadequate two pounds of starter is for meeting both maintenance and growth needs.
It is easy to see that none of the values in the table are anywhere near two pounds of grain.
What does this tell me about the amount of grain I want my heifers to be eating when I pull them fully off milk?
1. When they are eating two pounds of grain daily, that is a good time to reduce the amount of milk they are receiving. I feel this is a good time to cut back on milk. My recommendation for a farm feeding twice daily is to cut off one of the two feedings. That is, cut the milk ration in half. When the milk ration is cut in half, the experience of many calf raisers is that grain intake grows dramatically the next three to five days. Often grain consumption will go from two pounds to four or more pounds daily.
2. Keep in mind the season of the year. Note in the table above, in the winter column all the values are greater than five pounds. And, you recall, these amounts will only meet maintenance needs and provide for one pound average daily gain.
3. If you are weaning calves around 150 pounds compared to heavier heifers, remember these lighter heifers need to be observed more carefully for pneumonia symptoms than heavier animals. The extra 20 or 40 pounds gives the larger calves more reserves to deal with weaning stresses.
4. Are you really serious about getting gains around two pounds a day? Then your 170-pound calf will need to consume in the neighborhood of seven to eight pounds of grain daily. Small amounts of hay will complement the grain ration for these eight-week-old to 12-week-old animals. PD
—Excerpts from Calving Ease , October 2010