**2. Beef cattle management in the United States**

To better understand the manner in which alternative intensive animal farming tactics can minimize negative effects on animal health, it is important to understand the multiple ways beef cattle and calves are managed and marketed after weaning.

Initially, beef cattle producers are faced with the marketing decision of when to sell calves. The decision comes down to whether calves will be sold immediately after weaning, preconditioned for a period of 42-days before selling, or ownership retained for a longer period of time. Before the backgrounding period begins, the producer must determine that there is sufficient feed available to feed the calves and when the projected backgrounding period will end. The next questions the producer must answer are: 1) do I sell the calves at the end of the backgrounding period, or 2) keep the calves and put them on spring and summer pasture for summer grazing. The market timing decision is important, because dietary energy level during the growing period effects future performance, especially cattle destined for summer grazing. Steers and heifers destined to go to the feedlot after the growing period can be fed dietary energy levels that support average daily gain (ADG) of 1.14 to 1.36 kg/hd/day (2.5 to 3.0 lb/hd/day). However, if steers and/or heifers are destined for summer grazing of perennial and annual forages, then (ADG) of 0.59 kg/hd/day (1.30 lb/hd/day) is a more appropriate confinement pre-grazing growth rate, because although early spring vegetative pasture grasses are highly nutritious, high water content (≥80%) of early spring vegetative grasses and the quantity of available forage can restrict the animals' ability to consume a sufficient quantity of dry matter for maintenance and growth [8–10]. Steers and heifers fed higher energy diets for more rapid growth during the drylot wintering period, in the Northern Great Plains, will have greater body fat that cannot be maintained when transitioned to a grazing environment. Therefore, a high energy pre-grazing dietary regimen is inappropriate for animals destined for a grazing environment, because body condition will decline until a grazing growth equilibrium is attained. The amount of time for equilibrium to occur depends on the degree of fatness and forage quality. In addition to appropriate pre-grazing body condition, beef cattle heifers placed on grass that are not intended for breeding purposes will experience reduced ADG due to physical activity associated with estrus activity. Estrus activity is easily alleviated with ovariectomy conducted by a licensed veterinarian. At the end of the summer/fall grazing period, the producer determines whether to continue grazing late into the fall period, sell, or retain ownership and place the yearlings in the feedlot. Grazing late into the fall and early winter period in the Northern Great Plains region of the United States results in slower than desired ADG due to declining forage quality. When retaining ownership late into the fall/ early winter period, an alternative to grazing low quality pastures is to feed harvested round baled hay in a free-ranging environment using a technique referred to as "bale grazing". In this situation, the animals are not confined to feedlot pens, but are

allowed to range freely while being fed high quality baled hay. For intensified animal agriculture, feeding areas might range from 65.0 to 135.0 ha in size; however, the feeding areas can be sized to fit a given number of feeder cattle. Upon completion of the bale grazing period, the producer decides whether to continue retaining ownership by placing the feeder cattle in a feedlot or to sell. Assuming the decision is to retain ownership, another decision needs to be made that will affect how the animals are to be fed. That decision is whether the cattle will be forage finished using a foragebased diet and non-starch finishing supplement [11] or fed a high-caloric grain-based feedlot energy diet designed for 2.15 to 2.27 kg/hd/day (4.75 to 5.0 lb/hd/day).
