Before making the final decision to keep a gilt as a herd replacement, it’s important to conduct a thorough visual inspection, recommends Todd See of North Carolina State University.
“While genetics is of prime importance,” he says, “so are body structure and reproductive fitness. With thorough checking, you can often detect a shortcoming or flaw that would reduce the gilt’s performance in your breeding herd and, in some cases, shorten her reproductive life span.”
He offers these useful tips and guidelines for visually inspecting and evaluating a gilt:
Pay special attention to feet and legs. They are critically important because today’s sows are expected to spend their entire life on concrete or wire floors. At the same time, a sow is expected to farrow more than two litters a year, nurse each litter for two or three weeks and breed back in seven days or less.
An ideal gilt’s feet are large compared to her legs, with both toes the same size.
The pasterns should be relatively soft, not rigid or erect. Rear hocks and front knees should be angled to prevent extreme pressure on knee joints.
Bottoms of feet should be perfectly flat so that the gilt’s weight is evenly distributed. Otherwise, sores can develop due to uneven pressure.
The gilt’s skeleton is extremely important because it affects her longevity and function. An ideal frame is long, wide and deep to allow ample space for the litter to gestate. It also allows the animal to get up and down, and move without difficulty.
A replacement gilt must have at least six functional nipples on each side, evenly spaced and prominent. Her underline should be free of undeveloped “pin” nipples and inverted nipples. Pin nipples never function, while an inverted nipple may pop out at farrowing. But this often does not occur, so it’s preferable to pass up a gilt with one or more inverted nipples.
Appearance of the vulva is important for reproductive performance, so watch for two faults:
1. A vulva that is small and not fully developed, which may indicate an immature internal reproductive tract.
2. A vulva tipped up on the end, which may cause breeding difficulty.
In the case of purchased gilts, See adds, you should visually inspect them for mange, lice or signs of an unhealthy condition. By doing this before the animals are placed in the breeding herd, you can administer any necessary treatment. If a problem is not treatable, the animal can be kept out of the breeding herd.