Dr Tom Gillespie, a swine veterinarian from Rensselaer, Indiana replied to my blog on Crop Progress and Hog Barns from earlier this summer. He asked that I comment on the possible differences in performance between wean-finish barns and nursery moved to finisher combinations of facilities. In his reply he stated that one production system claims a 4% advantage to nursery moved to finisher vs. wean-to finish.
The first research I did on wean-finish funded with check-off dollars investigated this possible difference and the results have been published (J. Anim. Sci. 2002. 80:309-315). In these trials there was no difference in performance from weaning to slaughter for pigs weaned in a nursery for 8 weeks and then moved to a fully slatted finisher versus single stocked or double stocked wean-finish finish pigs sorted down at 8 weeks post wean grown to slaughter in the same fully slatted finisher.
In these trials I used the same wean-finish feeder in the nursery as I think many of the early claims on improvements in performance for wean-finish were actually comparisons between feeders in the late nursery phase. I continue to think some of the limits to late nursery performance are associated with incorrectly dimensioned feeders.
More recently, MetaFarms released a summary of pig closeouts from January 1, 2009 thru December 31, 2012. Pig weaning weights and final weights were similar. Wean to finish closeouts were 1.52 lb/d adg and 2.67 feed conversion. This compares to a combined nursery moved to finisher average of 1.51 lb/d adg and 2.73 feed conversion. Wean-finish closeouts had 2 less days on feed and approximately 1% lower overall mortality.
Some of this difference would be reflective of possible health differences between flows with some systems targeting their health challenged flows to nurseries while pigs from flows with more stable health would go to wean-finish sites. Also, wean-finish would tend to be newer facilities.
Murphy-Brown is aggressively converting all of their Midwest production to single-stock wean-finish and closing down nursery sites. The new Cargill contract facilities in SE Iowa, Western Illinois and NE Missouri are all designed as wean-finish.
On the other hand, I’ve reviewed more nursery plans this past 6 months than I have in total for the previous 6 years. In many cases the nurseries are intended for flows that have known health challenges that have proven difficult to control on a consistent basis due to siting of the sow unit, location of gilt multipliers, etc.
All of this suggests that there is no correct way of housing/flowing pigs. For some production systems wean-finish may present obstacles that are tough to overcome, either in terms of reliable labor to start pigs once every 6 months or because of long standing health challenges such as PRRS.
Other production systems have made the decision that wean-finish is the only production option they will pursue in the future and deem the challenges this poses as solvable.