By Beth Hall
Beef producers ask experts lots of questions designed to improve production, so to help them start 2018 with the best practices, University of Tennessee Extension Beef Cattle Specialist Jason Smith answers the four most frequently asked questions of 2017. According to Smith, “These topics are not more important than others, but the frequency of these questions suggests there is quite a bit of confusion or inconsistent information available to beef producers.”
Smith hopes these answers assist beef producers in having the information they need to start 2018 in the right direction. Here are the top four questions of 2017, in no particular order:
Q: Why are first-calf heifers so hard to get bred back?
A: First-calf heifers are still growing, so they are going to be a bit different than the other, more mature cows in the herd. First-calf heifers have protein and energy requirements about 10-15 percent higher than mature cows, and so should be managed separately from the mature cowherd. To ensure reproduction doesn’t suffer, make sure to feed first-calf heifers enough to meet their needs, with either 10-15 percent more feed overall, or with feed that’s 10-15 percent higher in protein and energy.
Q: Is it true that you shouldn’t feed pregnant cows very much during late gestation? Won’t this cause the calf to get too big?
A: No, or at least not to the extent that it will decrease calving difficulty. Restricting a cow’s nutritional intake restricts the developing fetus, but not the birthweight. Birthweight is a resilient metric, so restricting nutrition simply inhibits the calf’s immune system and potential for growth, efficiency and reproduction. It will also set the cow up for failure during the upcoming breeding season, as she is likely to go into it at a nutritional disadvantage. Don’t be afraid to feed cows to meet their requirements and calve in an adequate state of body condition—just don’t make them obese. Ideally, cows should be managed to go into the breeding season at a body condition score of 5 to 6 to maximize the chance that calving and the following breeding season will be successful.
Q: Do I really need to feed high-magnesium mineral?
A: Yes, at least for a portion of the year, which is generally early in the spring and late in the fall when we see green-ups and rapidly growing forages. Some could benefit from supplementing an elevated level of magnesium year-round, but intake must also be considered. Cows need a balance of minerals, and producers should note that feeding a low-consumption traditional high-mag mineral year-round may lead to sub-clinical deficiencies of other important minerals during times of need.
Q: When cows are eating too much mineral, can I cut it with white salt to decrease consumption?
A: Yes, but it is not recommended unless a nutritionist has suggested to do so, or the label specifically states to provide an additional source of salt. To a small degree, cattle do adjust their mineral consumption in order to meet their demands for certain minerals. When provided with a complete free-choice supplement, their intake will change as the demands of their bodies change (dry vs. lactating) and as forages mature (growing vs. dormant). When salt is added to an already salt-limited mineral supplement, we limit the animal’s natural ability to regulate consumption and we change the formula of the mineral. The simplest solution to mitigate over-consumption is to move the mineral feeder farther away from areas where cattle are spending a considerable amount of time. If cattle are under-consuming, just move the mineral feeder closer to these areas.