How many.....?

[63DH8]

How many cows and bulls are needed to have a selfsupporting herd and avoid inbreeding?

 

[backhoeboogie]

You are going to have to define inbreeding. Then you are going to have to define a time frame. (e.g. no inbreeding for 20 years and then do the math)

Most all humans go back to what is known as "The 17 Daughters of Eve", based on DNA studies. At one time it was "The 14 Daughters of Eve."

Cattle are likely all related in some fashion unless DNA has mutated. That happens in human's about every 10,000 years.

 

[Brandonm2]

How many cows and bulls are needed to have a selfsupporting herd and avoid inbreeding?

I think a lot of that would depend on how related they were when you bought them. Obviously if I bought all Angus cows they would be more closely related then if I had bought individuals from 30 different breeds. On the other hand if you bought 30 bred 2006 heifers from farmer Bob up the road who has been in business raising his cows for as long as anybody can remember and who runs a closed herd (on the female side), his cows are probably ~80% sisters (or better). IF you held bulls back from THAT group you would probably be running into inbreeding depression almost immediately. This is a really hard question to answer. I think a master cattleman who had 100 cows and who maintained 4 distinct unrelated cow family groups with an available bull battery of 10 or more COULD with clever management and a good crossfencing and outcrossing program could avoid any serious inbreeding problems indefinitely.

 

[63DH8]

Hmmm.... This IS going to require some thought. At what point is there degrading of the animal?

What I plan is to buy same breed cows from different breeders. Staying with-in the breed, I want to buy bulls from outside those breeders. Doing this, I'm wondering how many bulls and cows will I need to prevent any genetic degradation.