Hog farmers could be in for a big swing!

If the preliminary results hold true, within five years, a majority of breeders will buy replacement females at weights of 66 lb. or less. This idea has been coined the junior gilt concept.

The production practice is already catching on in Europe. In the United Kingdom (U.K.) and Sweden, 20-30% of replacement females are purchased at 55-66 lb. (junior gilts).

The junior gilt concept offers a variety of advantages.

1) Junior gilts are cheaper --In Europe, before the recent price slump, a 200-lb. conventional gilt from a breeding company sells for about $280.50.

Junior gilts, from different European breeding companies, sell for $85-100. After adding the additional rearing expenses, there is still a 9% savings over the 200-lb. gilt (see Table 1).

Newsham Hybrids (U.K.) recently reported savings of $33-42 at 209 lb., which is a 12-15% savings on its average standard gilt price.

2) Improved sow performance --Apart from an increase in the death rate of piglets (number born alive mortalities to weaning), the results are improved (see Table 2).

In a comparison of 49 herds using standard gilts and 16 herds buying junior gilts, the junior gilt herds showed a:

* 5.9% advantage in farrowing rate,

* 0.07 increase in litters/ sow/year,

* 17 less open days/sow/ year,

* 0.5 more pigs born alive per litter,

* 0.28 more pigs reared per litter,

* 1.39 more pigs weaned/ sow/year on 132 lb. less feed required/sow/year for the earlier purchased replacements (see Table 2).

3) Better offspring performance --A very important difference hidden in the published figures is the higher weaning weight per ton of sow and piglet feed. At 257 lb. for conventional gilts and 314 lb. for junior gilts, this is a 22% improvement. In European economics that's equal to a 9% reduction per tonne (2,205 lb.) in the price of all breeding and piglet feed.

But do the advantages of the junior gilt system at weaning continue through postweaning? The 'acceleration phase' of lean growth deposition per day usually starts to ease off around 77-88 lb.

Daily gain (15-82 lb.) was 1.29 lb./day in the junior gilts' offspring vs. 1.21 lb./day for conventional gilts' offspring. That's a 0.08 lb./day difference.

There was a marked difference in feed conversion ratio (FCR); 1.8 junior gilts to 2.23 conventional gilts. This in itself would suggest the junior gilts' offspring could cope better with disease challenges at this critical stage of growth. Because of this massive feed conversion advantage, the liveweight produced per ton of feed used through this stage was heavily in favor of the junior gilt sourced herds, 1,539 lb. vs. 1,232 lb., a difference of 307 lb. or 25%. Even more dramatic, the figures on 1997 PIC costings reveal a reduction of 70% on the cost/lb. gain to this weight.

4) Longer acclimatization period --A much longer acclimatization period (see Figure 1) should result in less disturbance to the herd's current health status. Current junior gilt herd owners feel that breeding herd health is better and there are fewer re-occurring health problems.

Further evidence on the overall disease incidence is needed, but in the PIC report, sow mortality was 0.3% lower. However, the death rate at birth was higher in the junior gilt herds, 12.66% per litter vs. 11.18% per litter in conventional gilt herds. The absolute mortality figure (AMF) per litter was 1.19 piglets from conventional gilts vs. 1.41 piglets from junior gilts, but the junior gilts' piglets were weaned 2.5 days later.

5) Earlier artificial insemination service dates --Better gilt lactation feeds and feeding programs allow for gilts to be inseminated at 230 lb. vs. 275 lb. This is a 10-18% savings on breeding cost for a six-year production cycle.

Further Study Newsham Hybrids has a program which shows a breeder how to change progressively from buying standard gilts to junior gilts using grandparent gilts from the same source.

The process takes 40 months before 100% of slaughter pigs (at 210 lb.) are sourced from sows which are home-bred from grandparent sows or the offspring of sows bought as junior gilts.

Note: Many breeding companies have a program to supply junior gilts. Contact your salesperson for details and availability.