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Objective: To evaluate the effects of mixing piglets prior to weaning on growth and behavioral and physiological stress markers during the preweaning and postweaning periods in the face of an outbreak of Escherichia coli diarrhea.
Materials and methods:This experiment was conducted on 144 Large White × (Large White × Landrace) piglets in a large commercial piggery in the southeast of Spain, beginning in October 2007 and concluding in December 2007. Animals from 24 litters from two adjacent rooms (A and B) were used, with 12 litters per room. Piglets were individually identified by eartags. A random number generator was used to select six focus piglets (three males and three females) from each litter for data collection. Each room was divided into two sides by a central corridor, with six farrowing pens (2.1 m × 2 m) per side. Pigs were weaned on Day 28. Growth performance, behavioral stress markers, and physiological stress markers (neutrophil:lymphocyte ratio and acute phase proteins [APPs]) were measured from birth to Day 58. Day 0 was defined as the day of birth and pigs were weaned on Day 28 (at 4 weeks of age as required by EU legislation8). Ten days before weaning (Day 18), dividers separating pairs of neighboring pens were removed on one side of each room (12 litters total), thus allowing two litters to mix (Mixed group; six focus piglets per litter, 72 focus piglets total). On the other side of each room, litters were not mixed and the piglets remained in the same pen with their siblings until weaning (Control group;12 litters total, six focus piglets per litter, 72 focus piglets total).
Results: When colibacillosis occurred in Room B, there was a detrimental effect on growth performance, especially highlighted when piglets were mixed prior to weaning. Concentrations of APPs 2 days after weaning were higher in Room B. Mixed piglets spent more time fighting immediately after mixing; however, after weaning, mixed piglets spent less time fighting than the controls.
Implications: Mixing piglets affected by E coli diarrhea may have a detrimental effect on growth rate. Animals with colibacillosis may have higher APP concentrations. After weaning, pigs mixed pre-weaning spend less time fighting than controls, which might help them cope with the stress of weaning.
Quiñonero J, Ramis G, Lopes E, et al. Effect of mixing piglets affected by Escherichia coli diarrhea on growth and welfare responses. J Swine Health Prod. 2012;20(5):216–222.