What are Beef Twinners?
Beef twinners are a composite line of cattle developed at the U.S. Meat Animal Research Centre (MARC) in Nebraska. This project started in 1981 by selecting cattle based on their ability to produce twins. This was based on selection on both twinning history and recorded ovulation rates over several cycles in heifers. Bulls were selected which had high predicted breeding values for twinning, based on their daughters having twins and high ovulation rates. These were mated to cows which had high predicted breeding values for twinning. This has resulted in a herd with a twinning rate of around 60%, compared with an average twinning rate among all breeds of cattle not selected for twinning of two per cent. Breeds represented in this population are: Holstein, Simmental, Charolais, Brown Swiss, Pinzgauer, Gelbvieh, Swedish Friesian, Norwegian Red, Shorthorn, Hereford, Angus, Swedish Red and White.
Cattle produced in this project are large framed, growthy, and muscular with desirable beef characteristics. Maternal ability in this population is excellent. Carcass data from steers fed high energy density diets have shown high cutability with relatively high levels of marbling.
In the longer term, it is important to remember that in both beef herds and sheep flocks the vast majority (more than 70 per cent of the total) of the feed requirement is required to simply maintain the breeders. This means that high calving and lambing percentages reduce the proportion of feed going to maintenance. This will reduce the amount of greenhouse gases produced per unit of meat on the butchers’ shelves. Successful adoption of technology to get lambing and calving rates over 150 per cent should be better for the environment and more profitable for the farmers.