To cull or not to cull (III) (continued from April 2014 issue)
During and after a major (dairy) expansion, it may be particularly difficult to control proportionsof involuntary and voluntary culls. In an analysis of 186 Wisconsin herds that expanded significantly between 1994 and 1998, Weigel etal, (2003) noted that cows in the bottom 20% for production in these herds prior to expansion were 4.2 times more likely than the average production cow to be culled, while after the expansion,they were only 2.55 times more likely to be culled than the average cow. In contrast, cows in the top 20% for production inthese herds prior to expansion were only half (0.5) as likely to be culled as the average cow, while after the expansion, they were 0.68 times as likely to be culled than the average cow. These results indicate that following an expansion, voluntary culling decreases and involuntary culling increases.