Two years ago, the industry first became widely aware of what appeared to be an increase in mobility problems in finished cattle and higher death loss late in the feeding period. In response, Elanco formed an Animal Welfare Advisory Board, in part to develop research programs to compile data on feedyard mobility, mortality and disease state.
During the recent Academy of Veterinary Consultants meeting in Denver, Michael Genho, MS, MA, MBA and Gary Vogel, PhD, both with Elanco, summarized some observations from the ongoing research.
Since August 2013, auditors under contract with Elanco have evaluated 2.6 million head of cattle at packing plants, using a four-point mobility-scoring system from the North American Meat Institute. In analyzing the data, Elanco scientists found a low level of lameness, with less than 1 percent of cattle rating 3 or 4 mobility scores. They found that cattle from mixed-sex pens had higher rates of mobility scores 2 and 3 compared with pens of steers or heifers. Pens of Holsteins had a somewhat higher frequency of mobility score 2, but otherwise the data did not show differences between breeds.
The data showed a higher incidence of mobility scores 3 and 4 during periods of hot summer temperatures and a small increase in scores 2 and 3 in longer-haul cattle.
Previous reports have suggested that feeding cattle to heavier weights could be associated with a higher incidence of lameness, but the Elanco data did not show an increase in heavier cattle. In fact, the odds of lameness scores 3 and 4 actually decreased as live weight increased in the data set.
Looking at mortality trends, Vogel cited Benchmark data on 78 million head of cattle finished between 2005 and May 2015. The data show mortality rates were generally flat from 2005 through 2010, but began to creep upward since 2010 and over the last few years. Death loss across all feedyards in the data set averaged 1.3 percent in 2005, 1.56 percent in 2014 and 1.69 percent year-to-date in 2015.
The data show a strong seasonal effect, with death loss highest in April, May and June and lowest in the fall. The increase in mortality rates was distributed across all feeding stages, rather than concentrated in heavyweight cattle as some suspected.
Drought conditions across much of the country over the past five years have been implicated in higher death loss in feedyards, based on an assumption that cattle from drought-stressed areas likely shipped to feedyards with compromised immune systems. Vogel notes that out weights, daily gains and days on feed have increased in recent years, possibly contributing to higher death loss.