Sow Reproductive Performance, Lifetime Performance, Their Risk Factors, Predictors and Farm-Level Factors in Farm Data Analysis

Abstract

The objectives of this review are 1) to describe a productivity tree for the number of pigs weaned per sow per year (PSY), 2) to explain a lifetime performance tree for annualized piglets weaned and 3) to summarize sow-level risk factors, predictors and farm-level factors for high lifetime performance of sows in farm data analysis. First, the PSY is an integrated measurement of sows for breeding farms which has two branches in the tree: one is the number of pigs weaned per litter farrowed which is related to prolificacy, and another is the number of litters per sow per year is associated with fertility. Also, the lifetime performance tree consists of four components: sow longevity, fertility, prolificacy and lifetime reproductive efficiency which are measured by sow life days, lifetime nonproductive days, lifetime pigs born alive and annualized lifetime piglets weaned, respectively. The number of annualized lifetime piglets weaned includes the three other components. Sow-level risk factors for decreasing sow reproductive performance are low or high parity, increased outdoor temperature in summer, decreased lactation feed intake, single insemination, decreased lactation length, prolonged weaning-to-first-mating interval, returning to service, low birth weight or low preweaning growth rate and high age at first-mating. Also, there are predictors for lifetime reproductive performance of sows. An example of the predictors is that gilts with lower age at first-mating are associated with higher lifetime performance in all four components. Other examples are that no re-service in parities 0 and 1 and weaning-to-first-mating interval 4 or 5 days in parity 1 are associated with higher fertility, whereas more piglets born in parity 1 is associated with higher prolificacy. Farm-level factors includes farm size, high-performing farms, standard operating procedures, insemination timing, within-herd variability of number of serviced sows, numbers of farrowing spaces and parity structure in farms. Increased knowledge of relationships between components of the trees, risk factors for low reproductive performance, predictors for sow lifetime performance and farm-level factors should help producers and veterinarians maximize a sow’s potential and optimize her lifetime productivity on breeding farms.