According to my math you will get 75% carriers. 50% will have 1 TH gene. 25% will be double carriers with 2 TH genes, also known as DEAD calves. 25% will be free of TH.
If you breed a TH clean animal to a TH carrier, then you will get 50% with 1 TH gene. 50% will be TH free.
If you have the theory that only TH carriers will make great show prospects, then all you are doing by breeding double carriers is eliminating 25% of your calf crop that could have been culls sent to the sale barn and exchanging them for 25% of your calf crop born dead. The only positive I would see is that your creep feed bill would be less, due to less calves alive to eat it. I would think that more calves (even if they go the sale barn) would make up for any added expense related to feeding the sale barn calves.
If you breed a TH clean animal to a TH carrier, then you will get 50% with 1 TH gene. 50% will be TH free.
If you have the theory that only TH carriers will make great show prospects, then all you are doing by breeding double carriers is eliminating 25% of your calf crop that could have been culls sent to the sale barn and exchanging them for 25% of your calf crop born dead. The only positive I would see is that your creep feed bill would be less, due to less calves alive to eat it. I would think that more calves (even if they go the sale barn) would make up for any added expense related to feeding the sale barn calves.