Canadian researchers have learned that the productivity in electronic sow feeding (ESF) systems is comparable to sows housed in stalls, provided proper management practices are followed.

Dynamic groups that did not add or subtract animals more often than every five weeks did not affect sow productivity.

Sow productivity equal to stalls can be obtained in an ESF system, but only if animals were past embryo implantation when the group was formed.

In the study at the Prairie Swine Centre Elstow Research Farm, over 800 breedings were compared, with females ranging in age from gilts to Parity 5. New animals were added each reproductive cycle.

Within the ESF systems, small groups of about 35 sows were all added to the pen at the same time (static) vs. larger, dynamic groups of 120 sows, where about 35 sows were removed for farrowing and others added at five-week intervals, and not added weekly as in several other studies.

Researchers also considered two stages of gestation at which to place the animals. Animals were either moved to the ESF 8-10 days post-breeding, or approximately 45 days post-breeding, by which time embryonic implantation should have occurred.

Data was also maintained for sows housed in stalls for their entire gestation period.

Farrowing rate measured combined farrowing rate and litter size (Table 1). Females were classified by parity as gilts, first, second and mature, and included calculation of an adjusted performance assuming a standard distribution of ages in each system.

The farrowing rate of the animals differed with parity, lowest for gilts and not different among the older animals. This difference is common in commercial herds, but was more pronounced in the ESF system. Once gilts were housed individually, the difference was eliminated. There were no differences between the static and dynamic groups for farrowing rate.

Litter size was smaller for gilts than for other parities. The total number of live piglets per 100 sows bred was higher for the post-implant group than for the pre-implant treatment, with stalled animals in the intermediate group.

Researchers: H.W. Gonyou, Y. Z. Li and M.L. Strawford, all of the Prairie Swine Centre. Contact Ken Engele, assistant manager, Information Services, by phone (306) 373-9922, fax (306) 955-2510 or e-mail Ken.Engele@usask.ca.

Table 1. Farrowing Rate of Gilts and Sows in Stalls and Various Management Programs within an Electronic Sow Feeder
System 1
Pre-Implant Post-Implant
Stalls Static Dynamic Static Dynamic
Gilt 793 678 681 734 763
1st Parity 898 874 865 929 910
2nd Parity 922 879 956 896 1,008
Mature 948 896 896 982 980
Adjusted2 895 834 845 894 917
Adjusted Sows3 929 886 898 948 968
1Results of five reproductive cycles with new gilts added each cycle.
2Based on a theoretical herd demographic of 25% gilts, 20% 1st parity, 18% 2nd parity and 37% mature(approximates a 15% culling rate per cycle to a maximum sixth parity).
3Based on a theoretical sow herd run without gilts, as we have done for three cycles, with 27% 1st parity, 23%2nd parity and 50% mature (approximates a 15% culling rate to a maximum of six parities).

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