Researchers find no difference in pig performance between wean-to-finish systems and conventional, nursery and grow-finish combinations.
Pig performance of the two management alternatives was rated by average daily gain, average daily feed intake and feed-to-gain ratio.
"From the day the pigs are weaned to the day they are slaughtered, overall pig performance is a wash," says Mike Brumm, University of Nebraska animal scientist. The results are based on three trials at the university's Haskell Ag Lab, Concord, NE.
The caveat to pig performance in wean-to-finish barns, of course, is proper management during the critical first weeks after weaning.
"Pig performance in wean-to-finish is indeed as good as nursery and finishers," Brumm notes. "That housing system appears to meet the needs of the weaned pig when done correctly."
Materials and Methods The research used three groups of 17-day-old, PIC crossbred barrows, 240 pigs/group. The three treatments included:
- Wean-to-finish at 7.5 sq. ft./pig and 15 pigs/pen;
- Wean-to-finish double stocked (DS) at 3.75 sq. ft./pig for eight weeks (30 pigs/pen), then randomly divided to stock two pens with 15 pigs/pen, 7.5 sq. ft./pig; and
- Nursery for eight weeks at 3.75 sq. ft./pig with 15 pigs/pen and then moved to grow-finish pens at 7.5 sq. ft./pig.
The facilities used included a double-curtain sided, totally slotted grow-finish barn and a nursery with woven wire flooring and open mesh partitions. All pigs had access to one, two-hole, wean-to-finish feeder/15 pigs and one cup drinker/15 pigs.
Temperature in the nursery started at 84 to 86 F. and declined 3 to 4 each week, down to 70 F. Temperatures in the wean-to-finish barn were from 73 to 76 F. with one or two, 250-watt heat lamps for supplemental heat.
The researchers found that pigs started on feed after weaning just as well in wean-to-finish barns as conventional nursery systems.
"Our data would suggest no difference in the pig's ability, as long as you furnish that heat zone with mats and heat lamps," he says. "There is no difference in ability to get pigs started in terms of daily gain, feed intake or feed conversion."
Eight-Week Performance After eight weeks, pigs in wean-to-finish barns were 2 to 4 lb. heavier than the nursery-housed pigs and wean-to-finish (W-F) double stocked pigs.
Again, Brumm says, proper temperature makes the difference. Pigs in the nursery may be heat stressed toward the end of their stay and, consequently, may not eat as much feed, he says.
In many nurseries, managers often focus on preventing chilling, even when pigs weigh 60 lb. and could benefit from lower temperatures.
Meanwhile, W-F pigs could choose their temperature because the pig zone offers a range of temperatures.
"Wean-to-finish pigs were in a cooler temperature, closer to their thermo-neutral zone. As a result, they ate more feed and grew faster," he explains.
The weight advantage for the W-F pigs disappeared in the grow-finish stage, however. In fact, differences in ADG, ADFI and feed:gain between the groups was deemed not significant during the grow-finish period.
"The pig that was slightly heavier coming out of the nursery did not do any better when we housed them in the same grow-finish facility," Brumm says.
The researchers also found that moving one-half of the pigs from the double-stocked pens had no effect on their performance.
Debate Continues So the question remains: Is wean-to-finish better than conventional nursery and grow-finish systems?
"Perhaps," says Brumm.
"Our data would suggest that wean-to-finish is probably minimally better, if the nurseries deal with the needs of the pig in terms of temperature and feeder and drinker requirements," he concludes.