A single bull named Jackson (pictured above) has sired many of the calves born in the United States in the past decade, and scientists say new bloodlines are needed to avoid future inbreeding among his many progeny.
It isn't like horses. You can breed a mare to a brother or a sire to a daughter and get good results if you know your blood strains, but in people it just doesn't work.
But so have I seen little Miriam and Martha, laughing-eyed elves, heedlessly gambol around their old sire; sporting with the circle of singed locks which grew on the marge of that burnt-out crater of his brain.
But before they had time to feel really awkward one of the leopards approached Aslan and said, " Sire, there is a messenger from the enemy who craves audience."
I was quite surprised by my results because they were contrasting to so many other species, where the oldest males sire the most offspring or the males with the largest territories.