26 Defining a robust sow: How increases in sow productivity impact the biology of reproduction lactation and body composition

摘要

Considerable emphasis has been placed on genetic selection for increased litter size, number of pigs weaned and quality and size of piglets weaned. Concurrently, selection goals have also focused on improved GF and kg of pork produced. Productivity of sows and the total U.S. pork production system has continued to improve annually. Data from USDA-ERS and summarized by the National Pork Board (2018) for the years 2001 to 2017 showed an annual linear increase of 0.12 pigs born (R2 = 0.95), pigs slaughtered per breeding animal increased 0.29 head annually (R2 = 0.92) and kg of pork produced per breeding animal showed an annual linear increase of 37.5 kg (R2 = 0.96). It has also been shown that overtime genetic selection, feeding programs and management have resulted in increased ADG, gain:feed and lean efficiency while changes in ADFI were not reported (Fix et al., 2010). Genetic improvement has increased the metabolic demand on sows requiring an increased focus on the management of sow weight and condition. These competing demands require today’s sow to be more robust, as an individual sow’s increased productivity can negatively influence body weight loss, body composition, follicle and oocyte development, and lactation yield.