Genetic and economic analyses of sow replacement rates in the commercial tier of a hierarchical swine breeding structure

Abstract

Commercial-level sow replacement rates were investigated for a 10-yr planning horizon using a stochastic life-cycle swine production model. A three-tiered breeding structure was modeled for the production of market hogs in a three-breed static crossing scheme. Growth and reproductive traits of individual pigs were simulated using genetic, environmental, and economic parameters. Culling was after a maximum of 1, 5, or 10 parities in commercial levels within 1- and 5-parity nucleus and 1-, 5-, and 10-parity multiplier combinations. Yearly changes and average phenotypic levels were computed for pig and sow performance and economic measures. For growth traits, greater commercial level response was for systems with higher sow replacement rates, 110 to 115% of lowest response. Phenotypic changes in net returns ranged from $.85 to 1.01 x pig-1 x yr-1. Average growth performances were highest for systems with greatest genetic trend. Highest kilograms.sow-1 x year-1 finished was for 10-parity commercial alternatives. System differences in total costs and returns per pig resulted primarily from differences in replacement costs. Removal of the gilt system from analyses often reduced ranges among systems for economic measures by more than 70%. Systems with the lowest commercial replacement rates were most profitable. Within these systems, those with higher genetic change had highest net returns. For high replacement rates, no more than 175% of market value could be paid for gilts, but with lower sow replacement rates commercial units could justify as much as 450%.

Sow removal in Swedish commercial herds

“…Other studies have estimated the optimal economic lifespan at five parities (Scholman and Dijkhuizen, 1989;Lucia et al, 2000a;Rasmussen, 2004). Production systems with low replacement rates are the most profitable, as has been shown by Faust et al (1993) in a simulation study. Longevity is also important from an animal welfare point of view.…”

The impact of season, parity and breed on selected reproductive performance parameters of sows

“…Therefore, in our methodology we adopted just such a scope of parities. In the early 1990s it had been proved that a low degree of culling and basing production on sows with a large number of litters is the most profitable, because young gilts/sows are most vulnerable to various types of dysfunctions (Faust et al, 1993).…”

Genomic Analysis of IgG Antibody Response to Common Pathogens in Commercial Sows in Health-Challenged Herds

“…A common limitation for genetic selection of improved host response to infectious pathogens is that these traits are not expected to be expressed in the nucleus, where selection is performed, because of high biosecurity (Faust et al, 1993). Disease traits are usually expressed at the commercial level, such as during the acclimation or introduction period of gilts into a commercial herd, when they are exposed to several pathogens (Serão et al, 2016).…”