Typically in the Holden Farms' 30,000-sow production system, keeping sows slightly on the heavier side and with a slightly higher backfat of 3/4-in. (18-19 mm) has been the approach to optimizing genetic potential, says Nick Holden of Northfield, MN.
But subpar reproductive performance and 15% sow mortality forced the family-owned pork production company to take a different tact in October 2003, Holden reported at last fall's Leman Swine Conference in St. Paul, MN.
The sow gestation-feeding program was aggressively altered, dropping from an average daily feed intake of 5.5 lb. to 4.2 lb., and reducing backfat to 0.60-.68 in. (15-17 mm).
“This was accomplished by reducing (feed intake for) many sows that were at 4.5 to 5.5 lb./day during the first 12 weeks of gestation, down to 4 lb., and some as low as 3.5 lb.,” explains Holden.
Now, instead of feeding 6 lb. three and four weeks before farrowing, then 8 lb. the last two weeks before farrowing, then workers simply feed 6 lb. two weeks before farrowing.
“Any sows still over-conditioned were kept at 4.0-4.5 lb. until farrowing,” he adds.
“After a three- to four-month transition period, performance has been very encouraging,” reports Holden. “After 14 months of reducing gestation intake, 80% of the herd (a 2,200-sow farm called Triagra) was considered in good condition,” (Table 1).
Concerned that sows would get too thin, the base level for gestation feeding was gradually raised 0.3 lb., bringing it up to 4.5 lb. by December 2004.
“Today a majority of the herd is at a 4.5-lb./day average setting, and holding condition well,” says Holden.
The changes in gestation feeding levels have also resulted in substantial improvements in lactation feed intake, from 11.9 lb. to 13.9 lb./sow/day, on average, he notes.
In turn, breed-back and subsequent born-alive numbers have improved, and weaning weights have increased by more than 0.5 lb./pig during this time period.
While the feeding program is working well for most sows, due to genetic differences within the herd, not all animals respond the same to the different feeding levels, explains Holden.
“Thus, some lines must be reduced to 4 lb. for a substantially longer time than other lines, and some down to 3.5 lb. for shorter periods of time,” he says.
Holden also notes that adjustments in average gestation feeding levels alone don't account for improvements in sow performance.
“We have worked hard on improving the quality of gilt entered, along with improvements in our boar stud, to help improve feet and leg issues and conformation,” he says.
|Parameter||October 2003||April 2005|
|Farrowing rate, %||77.3||90.4|
|Percent bred by Day 7||77.5||94.0|
|Wean-to-estrus interval, days||7.7||5.2|
|Sow death, %||15.3||9.4|