The patterns of causes of death in feedlot cattle are changing. In the past, death losses were usually related to bovine respiratory disease (BRD) which occurred shortly after the feeder cattle arrived at a feedlot. Following the best practices, weaning and vaccinating calves 45 to 60 days before they left the ranch of origin prevented most cattle from getting sick. Reports from the field are now indicating that something strange has started happening. Cattle that are properly pre-conditioned and vaccinated remain healthy during the initial period after entry into a feedlot. Now, some of them start getting sick after 60 days on feed. In the past, most cattle remained healthy after the high-risk arrival period.
My speculation is that both post-arrival sickness and death losses of heavy cattle near the end of the feeding period are related to excessive genetic selection for increased meat production. There is a point where the animal’s system starts to break down. It is good to have high producing animals but overdoing selection for meat may take away from other vital systems, such as immune function and building strong bone structure. Could it be possible, that the immune system becomes compromised if most of the animal’s production resources are put into meat?
If an animal was a country
A visual analogy may help people understand my concept for a possible explanation. Pretend that an animal is a country that has a national budget. If most of the budget is put into the economy (meat) there is little money left for the military (immune system) or infrastructure (heart and skeleton). Fortunately, the beef industry is starting to recognize the problem. The American Angus Association now has an EPD (expected progeny difference) for both good leg conformation and PAP scores. EPDs help producers select for the best cattle. PAP scores predict a beef animal’s susceptibility to brisket disease (high altitude sickness).
Recently, the Western Livestock Journal did several articles on brisket disease that featured Tim Holt, DVM, from Colorado State Univ. Brisket disease is now occurring at lower elevations in Nebraska. Another name for brisket disease is congestive heart failure. Holt recommends that producers should genetically select against brisket disease. He suggests that the problem may be similar to poultry. Holt was quoted in the Western Livestock Journal saying, “The chickens were growing so big and fast that they were dying from heart failure.”
The new EPDs for both leg conformation and PAP may help reduce deaths in cattle late in the feeding period. There is so much muscle mass that the heart is overworked. Packers need to report back to feedlots if fed cattle die or go down in either the truck or the plant stockyard. Problems with downers and fat cattle deaths are a relatively new phenomenon. Twenty years ago, dead or downed fully finished cattle was a very rare occurrence. The problems that are occurring today have to be fixed back at the ranch and at the feedlot.
Other factors that can contribute are feeding programs that border on irresponsible. One ration I saw had only 4 percent roughage and the rest was corn and distiller’s grains. Another area that needs study is examining the effects of the small particle size of distiller’s grain on the rumen. People who handle feedlot cattle at the packing plant have identified certain feedlots that have increased problems with either lameness or deaths. Breeders need to select for optimum performance and not the maximum. The broiler industry has fixed many of their problems. They now grow a productive broiler chicken with much stronger thicker legs. The beef industry needs to learn from them.