The fastest way of increasing the herd size of high milk-yielding cows is  

Multiple Ovulation Embryo Transfer Technology (MOET) is one programme for herd improvement. High milk-yielding breeds of females and high quality (lean meat with less lipid) meat-yielding bulls have been bred successfully to increase herd size in a short time. 

MTP (Medical Termination of Pregnancy) is induced abortion. 

Outcrossing is the practice of mating of unrelated animals within the same breed. 

Inbreeding is the practice of mating closely related animals within the same breed. It usually reduces fertility.