Culling is a fact of life in the dairy business. Cows become ill or get injured and must be removed from the producing herd. Low-producing and unprofitable animals are also routinely culled. It is important for dairy producers to understand the circumstances behind their culling decisions and the events that lead to having to make that decision. With proper understanding of the factors that lead to culling, managers can change or adjust their production practices so unnecessary culling is avoided as much as possible.

Culling can be divided into two categories: voluntary and involuntary. Voluntary culling occurs when the manager decides to remove a cow from the herd, usually due to low production. Involuntary culling, on the other hand, is forced upon the manager by the occurrence of illness, injury or infertility. Producers need to work to manage culling so involuntary culling is minimized to the greatest extent possible.

Three researchers from the University of Wisconsin investigated the culling issue as it pertained to expanding farms in Wisconsin. Potential culling variables were put into one of three categories: facilities, management practices or labor situation. Then the risk for low-producing and high-producing being culled versus their average herdmates was estimated.

The researchers found that from 1981 to 2000, the risk of low-producing cows being culled relative to average-producing cows decreased from 4.2 times more likely (between 1981 and 1989) to 2.55 times more likely (between 1996 and 2000). On the other hand, the risk of high-producing cows being culled compared to average-producing cows increased from 0.5 times likely (1981 to 1989) to 0.68 times likely (1996 to 2000).

Using statistical analysis, the authors studied the culling variables on farms that had expanded by at least 40 or 50 percent (40 percent if original herd size was greater than 100 cows and 50 percent if herd size was 60 to 100 cows) between 1994 and 1998. Culling was analyzed between 1996 and 2000. Variables that significantly increased the risk of high-producing cows being culled were:

•herd size greater than 150
•rolling herd average greater than 25,000 pounds
•more than 30 cows per full-time employee
•less than 80 percent family labor
•3X-milking heifers being custom raised
•using a clean-up bull in addition to artificial insemination (A.I.)
•no cooling fans or sprinklers
•having a pit-parlor milking system
•not having self-locking manger stalls or palpation rails

Among low-producing cows, variables that increased their risk of being culled compared to their average-producing herdmates included:

•a calving interval of greater than 15 months
•family labor making up more than 50 percent of total labor
•100 percent A.I. breeding
•pasture or dry lot being the primary calving location
•having a loose housing system
•using sand for bedding in freestalls

The main conclusion from the study was that in expanding herds, involuntary culling increased. What does this mean for producers considering expansion? Producers should focus on improving health care practices and cow comfort. Also, cows should receive more personal attention, as evidenced by the fact that fewer cows per full-time employee decreased culling risk.

It is reasonable to conclude from this study that family members providing farm labor have a greater stake in seeing cows are well cared for and, therefore, spend more time looking out for animals that may be stressed in some fashion. If producers can adjust their management practices, labor situation and facilities to decrease involuntary culling of high-producing cows, one should expect that profitability will increase. And, for the expanding dairy farm, profitability is extremely important.  PD

References omitted due to space but are available upon request.

—From Penn State Dairy Publications website

Sarah Roth, Extension Associate, Penn State