The two trains of thought regarding the selection of replacement animals are “everything stays as a replacement” or “only the best of the best stay.” Unfortunately, there has been a trend in multipliers to go the “everything gets sold as a replacement” route in recent years, and it has not ended well for the operations purchasing groups of replacement gilts.
You can walk through a sow farm and find the ugliest old girl, who is often the most productive sow on the place. She doesn’t have to be a beauty, but she must be functional. Regarding production animals, “beauty is as beauty does.” The information below is a bit tongue-in-cheek, yet the frustration is real in the field.
Criteria to select for:
Feet and Leg Soundness
Faults We Are Not Selecting Against:
Feet and Leg Soundness
In particular, some of the faults we’ve seen in the field include standability (i.e., any issues with leg and foot conformation), number of teats, and micro vulvas. A birds-eye view of how bad things are can be illustrated by the following story: a farm that was having issues with their replacement gilts. They were supposed to be traditional white maternal “Purebred” gilts, yet there were quite a few blue butt and spotted pigs in the group. Somehow terminal semen was used, yet these animals were sold as purebred white sows.
It’s common that soundness issues necessitate culling low parity sows from the herd. The issue with culling low parity sows is they have not yet paid for themselves! The “Pocket Guide for the Evaluation of Structural, Feet, Leg, and Reproductive Soundness in Replacement Gilts” produced by the National Pork Board is an older yet excellent resource for selection characteristics.
What to look for in replacement gilts:
Feet and leg soundness
• Toes that are big, evenly sized, and spread apart provide better weight distribution
• Other issues to watch for: Cracked hooves, foot pad abrasions, injuries, swollen joints
• Width of chest and rear, length of body, proper set of pasterns on front and rear legs (pasterns)
*Soundness can also be affected by disease, floor surface, and nutritional deficiencies
• Seven or more well-spaced, well-developed, functional teats on each side
• Well-developed, non-tipped vulva
It is all too easy to take the shortcut of not actively selecting replacement females to go into the herd. Yet, who doesn’t want to save time and money by doing it right the first time?