Day of Mixing Effect on Gestating Sows' Well-being and Reproduction19 August 2014
This Pork Checkoff-sponsored study by Dr Robert Knox of the University of Illinois evaluated the effects of the day of mixing gestation sows into groups using reproductive and sow welfare measures.
Treatments were applied during the summer months to obtain greater sensitivity to stress.
Sows were assigned to housing treatment in:
- stalls from weaning through gestation (Stall)
- stalls from weaning until mixed at day 3-7 (D3 Mix)
- stalls from weaning until mixed at day 13-17 (D14 Mix) and
- stalls from weaning until mixed after day 35 (D35 Mix).
All mixed sows were placed into pens in groups of 58 animals. Each pen provided adequate floor space and had one electronic sow feeding station.
Recorded reproductive measures included pregnancy rate at day 30, farrowing rate, litter size and longevity.
Well-being measures were obtained and included early effects (Period 1) and later effects (Period 2). Period 1 recorded fighting events, lesions and lameness, as well as cortisol change and body condition in the first 12 days after mixing or moving into the sow's permanent stall. Period 2 recorded lesions, lameness and body condition from day 13 until farrowing.
These results suggest that optimal reproduction and well-being can be achieved with use of stalls and that day of mixing can reduce all measures.
When mixing sows, short-term well-being responses, as well as long-term reproduction and well-being measures, must be considered in sow-housing management evaluation.
Mixing during the first week after weaning results in reduced farrowing and well-being measures compared with mixing after the fifth week. Mixing after the second week shows intermediate effects.
Using the stall strategically appears to be helpful in improving sow reproduction and well-being. However, data suggest that problems associated with day of mixing could have minimal impact in well-managed farms.
You can view the full report by clicking here.