The maternal line is invaluable for obvious reasons (see the Maschhoff Memo in the June issue, page 16), but you can’t make a profitable market pig without a worthy sire. The terminal line is much simpler to explain than the maternal line. However, the terminal line is what can change our system value the fastest.
With the maternal line, all the progeny are meant to be a maternal animal to stay within the system to improve our sow herd. On the flip side, the primary intention of the terminal boar line is to leverage genes for the wean-to-market value drivers.
When we select animals in terminal lines, we see the improvement that results from upgrading the herd quickly because the genes are expressed faster (i.e. in the very next generation). For example, if we were to make a change in a maternal trait, a boar and a sow have to first make a purebred daughter, then grandparent stock and then parent stock and so on. The female has to get into the system before it affects the litter, and it’s a three to four year timespan before a value change in a purebred is realized in the commercial breed-to-wean system. With the terminal line, we see the value from the sire in roughly 10 months when the terminal pig goes to market.
How We Select
We’re able to use a simplified selection index in the terminal line, which ultimately helps us make progress faster. This comes from the fact that there are fewer traits to consider when selecting a terminal line because wean-to-market value driver traits are the only traits expressed in their progeny.
Today, our terminal boar inventory is a blend of proprietary lines developed by the company along with some purchased from external suppliers.
We look for characteristics such as survival, carcass feed conversion, carcass average daily gain, back fat, loin depth and meat quality. These are the items that impact company profit and specifically the traits that help get pigs to market faster and more efficiently from a production standpoint. Ultimately, it helps us create pork products desired by consumers.