Bull selection and management when done right will contribute to more than fifty percent of the positive improvement in your beef cattle herd or negatively if done wrong. The herd bull in any given beef cattle herd is responsible for fifty percent of each years production. This is not the place to economize when it comes to purchasing replacement animals. Think about it, if cows are $1000 each and a good bull can service at least 25 cows. Does it sound like a good management decision if you limited the amount to pay for a herd bull to the same $1000 price.
Prospective herd bulls should be evaluated for breeding soundness to see that they meet minimum standards both for physical condition and semen quality.
This evaluation should include the bull’s general physical condition, legs, feet, age, teeth and eyes. Also the reproductive organs should be examined and any infectious disease or physical defects ruled out. If posible it would be good to observe him mounting, ejaculating and dismounting a cow. A good herd bull will need to be in top physical condition, especially at the start of breeding season.
His semen should be examined under a microsope by a qualified professional. Percentage of live sperm, movement, numbers, structure and shape must all be evaluated with accuracy if a good estimate of the bulls fertility and ability to get cows settled is to be obtained.
Always remember to gine a bull plenty of extra feed 30 to 40 days before expecting him to perform heavy breeding service. Be sure his feet are sound and cared for properly. Control of all external and internal parasites is also important, remember he is half the production for each breeding season.
Young bulls should not be expected to perform heavy service because they are still growing and developing. Heavy service too early might cause infertility. Approximately 15 cows for a yearling plus bull is usually about all he needs to service. A two year old bull might service as many as 25 cows, especially if hand mated and a mature bull should be able to service 35 to 50 cows. Rough or hilly terrain might be a contributing factor to these numbers.
Good management of your bulls after they have been fertility tested will improve your chances for good conception rates. Tests have proven that one bull with 25 cows will always get more calves than four bulls with 100 cows. When four bulls are in one pasture they will spend a lot of their time fighting and a bull may be inclined to spend too much time with one cow. Production seems to decrease in multiple sire programs when there are more than 15 to 18 cows per bull.
A practice of rotating bulls has proven to increase calving rates as much as 15 to 18 percent. This practice allows the bulls to rest and it keeps fresh bulls with the cows at all times. Using four bulls in a 100 cow herd. Put one bull with the entire group for 15 days, take him out and put another one in for 15 days. After this second 15 day period all the bulls may be turned in to serve any cows not yet in calf.