Nutrition management of your cow herd is very important during late pregnancy and early lactation. What happens during this time can not only affect your current calf crop but your future one as well. Having the cow’s nutrition needs met can reduce dystocia for the cow and improve the overall performance of the calf.
During this time you can have problems from 2 different directions. First off her nutritional requirements spike as compared to other times of the year. Second, the overall quality of your forage is lower because we have not got to the “spring green up” yet.
It is very critical that you get the nutrition right during this time because if she is lacking it will affect not only the health of the calf but the probability of her getting bred come breeding season.
Nutrition requirements during late pregnancy
Entering the late gestation period the fetus experiences it’s most rapid growth. It is during this time that 70% of the calf’s growth occurs. If that is not enough she is also beginning to prepare for producing the milk needed for that calf.
Studies have shown that the crude protein needed increases 10% and her energy requirements go up about 25% from mid to late gestation.
What this can mean is that the minimum nutrient density at this stage should be 8% CP and around 54% TDN (total digestible nutrients). The usual spike in forage quality usually doesn’t occur until some time in March.
Now you may be thinking that you do not have to worry about that because you baled some high quality hay during the summer. The problem with that is depending on how hay is stored it can lose anywhere from 10% to 50% of it’s quality over time. I discuss some ideas on how to properly store hay here.
Body Condition Score is Key
One good indicator that you can go with is making sure that your cows are in proper BCS at calving time. A general rule of thumb is that cows should be in a 5 condition at this time. Your 1st calf heifers should be at a 6 due to their needs for still growing themselves.
Studies have shown that when she is at the optimal BCS the calf generally stands up in about a 1/3 of the time. The calf will also be healthier because she will be better able to provide the colostrum needed to boost it’s immune system.
It is a good idea when you are tagging and weighing your calves to write down the mother’s BCS. You can then use the numbers to figure out the running average of your herd.
I will say that it can be difficult to get a good BCS during this time of year because of the cow’s winter coat and the bulge of the growing fetus. There are many resources available help you with this such as your local county extension office or online like the one with the Texas AgriLife extension.
Monitor BCS Over Time
Now I will tell you that during this time of year you do not want to just check the BCS of your cows once. It is important that you monitor it overtime between calving and breeding season.
Keeping an eye on this say every week will let you now if your nutrition plan may be lacking in anything. If you cow’s average is decreasing over time your herd may be in a negative energy balance.
Let’s say that when you first check them the running average is say a 6.0, then the next week the average may be more like 5.5, then the week after that they are at 5.0. This could mean that either your forages or supplements are not providing all that they need and you need to make adjustments.
They may look to be in “good” condition now but they will need to be at least a 5 in order to start estrus again when it comes to breeding season. The trouble is the running average says that they will not be.
Improving plane of nutrition
Many producers believe that they can increase energy intake with low quality forages by simply feeding corn, though this can backfire on them. This is due to the fact that on a forage based diet the starches in corn will decrease both forage intake and digestibility.
If you are needing to supplement a forage based diet then you will need to provide for crude protein. Protein supplements can improve forage digestibility and intake of low quality forages. These supplements can also improve the nutrient flow from the rumen to the intestines.
