Beef cow nutrition from calving to breeding
Many producers are now in full swing of calving season or soon will be in the Northern Plains. Although late winter has been relatively mild with above average temperatures the last few weeks, we had snow and cold temperatures in December and Jan...
Many producers are now in full swing of calving season or soon will be in the Northern Plains. Although late winter has been relatively mild with above average temperatures the last few weeks, we had snow and cold temperatures in December and January that challenged the nutritional status of cows this winter. Additionally, we are likely to have cold temperatures and snow again before spring is truly upon us. Managing cow nutritional status from now until adequate green grass will become very important to ensure cows will be cycling and fertile when the breeding season starts.
Managing Body Condition Scores (BCS) It all comes down to managing body condition score (BCS) of cows. There is strong evidence that cows with a moderate BCS of 5 (on a scale of 1 to 9) will be more likely to restart estrous cycles before breeding and more likely to get pregnant than cows in thinner BCS (less than 5). Most beef cow nutritionists will recommend that a producer should score body condition on their cows at calving. I suggest taking this very literal. If a producer is tagging and weighing calves as they are born, take a look at the cow and write down her BCS along with the calf data. As calving season progresses, keep track of the running average of the BCS of the cows. If the running average is 5 or better, the cows are in great shape and it will be a simple matter of feeding them adequately to maintain BCS. If the running average is less than 5, then the feeding program should be modified to give them the opportunity to gain BCS before breeding begins.
Monitoring BCS Over Time A second important aspect of managing cow BCS between calving and breeding is whether it is increasing or decreasing over time. If the running average is decreasing as time goes on, the cows are in a negative energy balance and pulling fat off their bodies (losing BCS). For example, let’s say the running average after the first week of calving is 5.2, but at the end of the second week it is a 5.1, and by the end of the third week it is 4.9. In this example, there is evidence that BCS is slipping. An average BCS of 4.9 seems close enough to 5 to consider the herd to be at the status you want, but the problem is that it needs to remain there until breeding and the fact that the running average is declining suggests that it will not. Therefore, this is an indicator that your feeding program should be adjusted to provide the nutrients to gain body weight and therefore body condition.
Now if we consider that we could be looking at a cooler spring with a late green-up (think about the last two years), it may be an unwise choice to continue feeding them the same under the assumption that they will pick up weight and condition when grass greens-up. That green-up may come too late to get them ready for breeding. Thus, if the average BCS is less than 5 or is moving lower as calving proceeds, it would be wise to consider improving the nutritional value of the diet for cows to ensure that they will be ready for breeding season regardless of what the spring weather turns out to be.
What about first-calf heifers? Another caveat to consider is that first-calf heifers are the group that is most likely to lose BCS after calving. They are young and still growing while lactating for the first time. This creates greater nutritional challenges for them than mature cows and makes them more likely to fail to have adequate nutritional status to be reproductively sound when breeding begins. I recommend that it is even more important to keep records on them of BCS status over time and make appropriate adjustments. Abundant research suggests that first-calf heifers should be at a BCS of 6 (rather than the BCS of 5 suggested for mature cows) and that they should gain BCS after calving, even if they were at 6 at calving. Keeping them separate from the mature cows is an important step in this process. They cannot compete at the feed bunk with larger, older cows and will get cheated out of their share of feed and supplements. Additionally, keeping them separate will allow the opportunity to adjust their diet if needed, and not have to provide additional, unneeded feed to the mature cows.
Feeding Considerations There are an abundance of feedstuffs that can be used to improve nutrient intake if needed. These include distiller’s grains, wheat midds, and a large variety of other byproducts and commodities. Good to high quality hay can also be used as a supplement to improve nutrition. Fortunately, the prices on almost all of these feedstuffs have dropped dramatically in recent years. Wise shopping can lead to improved nutrition at the best possible price. Nutritionists can play a critical role in determining which feedstuff provides the needed nutrients at the best price.