Reducing Pre-weaning Mortality in Loose-Housed Farrowing Systems

Project Overview

Project Type: Graduate Student
Funds awarded in 2009: $9,980.00
Projected End Date: 12/31/2010
Grant Recipient: University of Minnesota
Region: North Central
State: Minnesota
Graduate Student:
Faculty Advisor:
Dr. Yuzhi Li
University of Minnesota

Annual Reports


  • Animals: swine


  • Animal Production: housing


    Pork producers using alternative housing and production systems have been seeking ways to decrease pre-weaning mortality of piglets, thereby increasing their profits and increasing the standard of welfare on their farms. The major objectives of this research project were to identify the major factors associated with non-infectious pre-weaning mortality, to develop a management protocol to manage these factors, and to implement this protocol on farms using alternative housing and production systems.

    A survey was developed and given to alternative swine producers in Minnesota and Iowa to identify the major factors associated with pre-weaning mortality on their farms. A management protocol to decrease pre-weaning mortality was developed based on the responses to this survey, and previous research completed by the authors. From those producers that completed the survey, 6 farms were chosen based on size and location to participate in the study. Producers agreed to follow as closely as possible the developed management protocol based on their time available and economic considerations.

    Producers collected farrowing performance data (total born, number born alive, stillborns, litter size within the first 24 h of farrowing after crossfostering, and litter size 10 d post-farrowing). Performance data were collected from November, 2010 to May, 2011 from 255 farrowings on 4 alternative swine farms. Two farms were omitted due to lost or incomplete records. Average piglet mortality in the first 10 d post-farrowing on these 4 farms was 21.1% and ranged from 15.2% to 29.9%. Number born alive ranged from 7.5 to 10.8 piglets/litter and number of piglets that died per litter within 10 d post-farrowing ranged from 1.1 to 1.7 piglets/litter. Additionally, total born (P < 0.01), number born alive (P < 0.01), litter size 24 h post-farrowing (P < 0.01), and number of piglets alive/litter 10 d post-farrowing (P < 0.01) were greater in the spring compared to the winter.

    Pre-weaning mortality on these farms was affected by a combination of factors including season, genetics, housing, and management practices. Management recommendations to decrease pre-weaning mortality based on the findings on each farm included increasing biosecurity, providing supplemental heat for piglets, proper semen storage, providing additional bedding in muddy conditions, and reviewing sow and boar environmental and nutritional management needs. The results of this study provided key focus areas on each farm aimed at decreasing pre-weaning mortality. Pre-weaning mortality is higher on alternative farms because they do not use as much proven technology as on confinement farms.


    Pre-weaning mortality of piglets is a major cause of reduced efficiency in alternative swine production. Marchant et al. (2000) reported that 20 to33% of piglets may die before weaning in farrowing facilities of alternative production systems. In the Midwest U.S., average pre-weaning mortality of piglets in alternative systems is 26% (Kliebenstein et al., 2007), which is about two-fold of that (10 to 13%) in confinement systems. The majority of the pre-weaning piglet deaths are not caused by diseases, but by crushing and starvation (Edwards et al., 2002). On average, piglet crushing accounts for 75% of total pre-weaning mortality in alternative production systems (Dunn, 2005). Early piglet death not only represents economic loss, but causes welfare concerns because 70% of piglets crushed are potentially healthy and viable (Spicer et al., 1987). By reducing non-infectious pre-weaning mortality while maintaining litter size born alive, litter size weaned can be increased thereby improving production efficiency and enhancing piglet welfare.

    Previous studies have indicated that pre-weaning mortality is related negatively to litter size (Lund et al., 2002) and birth weight (Quiniou, et al. 2002), and related positively to variation in birth weight and parity of sows (Hellbrugge et al., 2008b). Maternal behavior (Damn et al., 2005) is associated with piglet crushing and has been claimed as the major cause of pre-weaning mortality in both confinement and alternative farrowing systems. Andersen (2005) reported that piglet mortality mainly depends on mothering ability of sows, which tends to be consistent among individual sows across parities (Jarvis et al., 2005).

    Our previous research conducted at the West Central Research and Outreach Center (WCROC), University of Minnesota indicated that by improving management practices in a loose housing system, pre-weaning mortality can be reduced from 27% to 19% (Li et al., 2010). The purpose of this project was to ask pork producers using alternative production systems to implement a management protocol specifically developed to manage the major risk factors to piglet survival while maintaining litter size at birth to increase the number of piglets weaned.

    Project objectives:

    The major objectives of this research project are to develop a model to identify the major factors associated with non-infectious pre-weaning mortality, to develop a management protocol to manage these factors, and to validate this protocol on farms using alternative housing and production systems. The anticipated goal is to wean 1 more pig per litter than the average number of pigs weaned on each farm.

    Producers will be provided with essential information on ways to improve piglet welfare by identifying the factors that contribute to piglet mortality. In general, increased profit and improved welfare conditions for the pigs in alternative systems will contribute to the long-term viability of farmers using alternative production systems, the local economy, and the environment.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.