A:   Open cows are usually due to mis-management of the nutrition program. Minerals are important, but I rarely see large reductions in reproductive performance due to minerals alone, especially in Nebraska.

Here's a check list for you to help evaluate the reproductive performance of the herd>

1. Separate non-pregnant cows by age. Are the majority of the opens in young cows, females trying to become pregnant for the second calf. If this is the case, then more often than not, it is due the nutrition program. Calf 1st-calf-females in a body condition score or 6 (on 1 to 9 scale). A lot of the diets that I see for these females after calving is often deficient in energy. Grass hay and alfalfa don't not have enough energy, so you will need to added some corn, distillers, gluten, silage, etc to the diet. If there are a lot of "running" age cows (4 through 12 year olds), then this is a concern because if you have paid close attention to the genetic make-up of you herd, these cows should be of the weight and milk out0put that fit the resources on you operation. If the majority of the opens are old cows.......then you kept them to long.

2. Bull to cow ratio. For young bulls, 1:12 to 1:15; older bulls 1:25 to 1:30. Did you have any breeding pastures that had only one bull for the entire breeding season? May be the bull was good early and got hurt or sick later in the breeding season. Did you run 2 yearling bulls in one breeding pasture? Probably not the best management strategy.

3. What was the length of the breeding season? 60 to 65 days is common. A shorter breeding season, especially in drought conditions, could result in more open females.

4. Vaccination program for the cows. Consult your vet to make sure the reproductive diseases are covered.

5. Did you notice any other bulls in your pasture? Trichomonisis is not common in Nebraska, but it is in some boardering states. Consult your vet to make sure this was not the cause. If you observed very few cows cycling towards the end of the breeding season, then observed cows cycling after the breeding season ended, may indicate early abortions.

6. Did you have a lot of calving difficulty in the heifers? This will cause an increase in the post-partum interval and result in more opens young females.

Again, minerals are important and it sounds like you have this area covered.