Variation in Sow Farm Output
Both underproduction and overproduction create undue costs in an operation.
By John Deen and Sukumarannair S. Anil
One of the major determinants of the value of sow farm output is the level of production and the variation of that production. Underproduction results in downstream underutilization of growing pig capacity. It also results in more mixing of pigs as other sources of pigs are often used to fill in the gap created by a low-producing sow herd. Not only is there an on-farm component of underproduction, but there is also seasonal underproduction that results in higher prices available during the times when most sow farms underperform.
Conversely, overproduction has its own costs. The first one is that it is often closely related to underproduction where an accumulation of open sows has occurred, and this accumulation suddenly becomes productive. Think of seasonal infertility as not only a problem of underproduction, but there is also a concomitant overproduction that occurs afterwards. While there is obviously a direct effect upon the number of pigs produced, it appears that the quality of the pigs produced during overproduction is compromised. In many farms we see a reduction of weaning age of at least two days when overproduction occurs. This reduction is quite understandable as the farrowing room manager is trying to fit too many sows through his or her facilities.
Explanation of the Model
An analytic model on variation in sow farm output was made to monitor the weekly number of pigs born alive. We made the unit a week as it creates a visible and discrete unit, and there is little transport of pigs during the weekend. However, we have found problems when we define sow farm output by the number of pigs weaned. The number of pigs weaned can be manipulated by changing the weaning age, and this manipulation of the weaning age usually reduces the amount of variation in output. However, this manipulation is actually one of the costs of variation. Therefore, instead of weaned pig output, we monitor the number of pigs born alive in a week. This has a low likelihood of manipulation and allows us to avoid the noise of the manipulation of weaning age.
Figure 1 is an example of the variation in production across 10 identical sow herds that have an average production of over 1,100 pigs per week. However, the range of output is very wide. Much of this variation is due to seasonal infertility and subsequent overproduction, but there are also other causes such as disease outbreaks and breakdowns in production methods (there still is a Christmas infertility syndrome).
Management a Three-Step Process
To manage this variation I believe there is a three-step process. The first is to put a price on the relative value of pigs if they are underproduced or overproduced. For underproduction, this entails a recognition that money is left on the table and that poor practices of disease containment can occur. Though it is subjective, the relative value of pigs based on level of production needs to be described throughout the whole production system.
Discus Methods of Control
The second step is to discuss methods of control of these variables. Plan on seasonal infertility and subsequent improvements in fertility. Extraordinary resources can be put into play during the summer months to improve reproductive performance. Feed quality, labor quality and cooling methods must be emphasized.
The third step is to start analyzing the robustness of sows under different insults. We can blame environmental insults and disease for much of the problem, but there are real differences among genotypes in their ability to handle such insults. Selection for maximum performance may, in fact, reduce the ability to respond to adverse conditions. I often compare a sow unit to a feed mill. Both are expected to provide a high quality product on a consistent basis. Overproduction should not be rewarded, but underproduction should not be tolerated. Empty feed crops are of course intolerable, but empty barns may create similar economic problems.
Editor’s Note:John Deen DVM PhD, is an Associate Professor at the University of Minnesota, and Sukumarannair S. Anil DVM PhD, is a Research Asssociate at the University of Minnesota.