BEEF SPECIES SYMPOSIUM: Beef production without mature cows.

摘要: Nutrients in animal feed get partitioned to growth, lactation, pregnancy, fat accretion, and/or maintenance. For mature beef cows, >80% of nutrients consumed annually go unproductive Integrated over the entire U.S. cattle production system, nearly one-half maintenance cow herds. This accounts for much inefficiency and can be minimized by single-calf heifer which heifers are fattened slaughtered after having their first calf. We propose a modification, use sexed semen, so that most replace themselves with greatly decreases size inherently inefficient herd required increases efficiency terms waste produced, such as methane, increasing ratio used growth those Additional management is including AI, early weaning, attention when calving 2-yr-old heifers. Low conception rates semen less efficient females than males also must considered. However, these issues seem outweighed benefits increased from decreasing while eliminating need breeding back lactating first-calf heifers, castration, health problems inherent older cows mastitis lameness. Moreover, decreased generation interval accelerate genetic progress.