The one production number that any wean-to-finish or finisher manager easily collects is the number of deads. But don't forget to routinely assess the full impact of attrition — the number of culls, lights and deads.
The disconnect between grow-finish staff and marketing results means the significance of culls and lights on the bottom line can be easily overlooked. The entire production team needs to focus on producing full-value pigs and to understand three factors:
First, high mortality alerts everyone. Owners see dollars down the drain and frustrated workers as they remove dead pigs. However, it's important to realize a gradual increase in dead pigs or an above-average number of culls and lights may go undetected.
Second, records systems aren't uniform in assessing culls, lights and deads. It's important to know what the numbers reflect. Does the farm's full-value pigs calculation include mortality? Are weights of pigs recorded for accurate calculation of the costs associated with attrition?
Third, numerous causes of attrition can increase the complexity of the problem. Many noninfectious causes such as nutrition, environmental factors and genetics can be involved. Infectious causes can include porcine reproductive and respiratory syndrome (PRRS), ileitis, Mycoplasmal pneumonia, circovirus and salmonellosis.
Case Study No. 1
A Midwest farm had good closeout records in 2006, producing 94.4% full-value pigs from feeder to finish. This number included 1.9% death loss and 3.7% lights and culls. The farm was PRRS-naïve, and pigs were vaccinated only for mycoplasma.
With the dramatic appearance of porcine circovirus type 2 (PCV2) in 2007, the farm staff was watching for any obvious clinical signs, and we were happy none were evident (high mortality, skin lesions, wasting pigs).
However, the farm did note a gradual increase in mortalities, culls and lights in 2007. Samples were collected from some fall-behind pigs and the diagnosis for PCV2 was met. Due to cost and vaccine availability, it was decided to only vaccinate the sow herd. By the end of 2007, the percentage of full-value pigs decreased to 91.5%, with 3.2% mortality and 5.3% culls/lights.
As pig groups from PCV2-vaccinated sows closed out, the number of full-value pigs increased, but there was more value to be gained from PCV2 control. Diagnostics indicated PCV2 was still affecting pigs.
During mid-2008, some pigs were vaccinated and compared with unvaccinated groups. The results convinced the farm to initiate a pig vaccination program for PCV2 in the fall of 2008. The closeout summary for 2008 (sows vaccinated) did show improvement over 2007, with 94.3% full-value pigs compared to 2007's 91.5%. There was a reduction in the percentage of both deads (2008, 2.3%) and culls/lights (2008, 3.4%) compared to the group of unvaccinated sows in 2007.
The numbers for 2009 will be evaluated for cost-effectiveness. This case demonstrates the value of good records and diagnostics in establishing health protocols to increase the number of full-value pigs.
Case Study No. 2
A 900-sow, breed-to-wean herd in Indiana produces pigs for off-site, wean-to-finish barns. This herd is PRRS-naïve and pigs are vaccinated for mycoplasma. Farm closeouts had acceptable numbers of cull pigs until one group closed out with 5% culls. The next group was back to normal at less than 1.5%, so the producer was not overly concerned.
However the next two closeouts had 3.5% and then 7.5% culls and lights. Examination revealed several pigs with multiple swollen joints, stiff gait and arched back. These pigs were obviously gaining very poorly. Erysipelas was cultured from the joints of affected pigs at our lab and confirmed at the diagnostic laboratory.
Pigs with the typical “diamond-shaped” skin lesions had never been observed in this finisher. The sow herd was routinely vaccinated for erysipelas; skin lesions were never observed. Water-based vaccination of 11-to 12-week-old pigs was initiated, and nine closeouts averaged only 1.7% culls and lights. Before vaccination, nine closeouts averaged 3.6% culls.
This case demonstrates the insidious nature of some disease problems that can cause an increase in cull and light pigs. It also points out the need to closely review closeouts for trends in conjunction with the clinical pattern in the pigs.
It is well accepted that disease problems can increase mortality and, thus, profitability in swine production systems. What may be overlooked are the opportunities to increase the number of full-value pigs by reducing culls and lights. It is important to investigate management factors and health problems. Good records and diagnostics are essential to instituting health protocols with a high probability for increasing the number of full-value pigs sold.