Nursery Pig Behavior and Performance
Livestock Update, January 2003
Tom O'Hare and C. M. Wood, VA Tech
The nursery phase is a critical stage in pig production. Small pigs coming out of the nursery will usually be the tail enders all the way to market. A common management practice is to sort pigs at weaning to give pigs equal opportunity in the nursery (Friend et al., 1983). This often requires mixing litters, which causes an increase in fighting because pigs fight as they establish a dominance order (McGlone et al., 1987). The problem with aggression is that it can lead to an increase in wounds that can cause infection and sometimes a decrease in weight gain. Temperature and pen space are easy to optimize with proper management. Aggression among mixed piglets is still a problem that needs attention.
In an article by Friend et al. (1983), pigs were grouped by three different methods and exposed to an odor masking agent (OMA) in an attempt to reduce fighting. The groups included eight pigs from one litter, four pigs from two litters, and one pig from eight litters. Half of the pens in each group were sprayed with OMA 20 minutes after they were moved into the nursery. The pigs sprayed with the OMA stopped their normal activity, which included fighting, only for two to five minutes while their attention was focused on the OMA agent. This research indicated that an OMA does not help behavior in a positive way but only in a temporary way.
McConnell et al. (1987) researched the effects of weaning weight, co-mingling, group size, and room temperature on pig performance. The first experiment tested piglets that were allotted to four weight groups. As expected, heavier weaning weights resulted in greater daily gains. The second experiment consisted of pens with eight, 16, or 24 pigs. Pen space, waterer space, and feeder space were held constant per pig. Increasing the number of pigs per pen did not affect gains or intakes of feed. This lack of any effects may have been due to standardization of area per pig. The third experiment included pigs that were either co-mingled or reared as littermates. Results indicated that co-mingling has an effect on performance in a dense arrangement, when pigs are limit fed, but in a small group that is full fed there is little effect on performance. The fourth experiment, conducted in the winter so there was no outdoor effect on temperature, included two temperature regimens. Pigs in the cooler environment had a 24% reduction in daily gain, consumed less feed, and were less efficient in converting feed to gain.
Recently, studies in environmental enrichment have included toys to decrease aggression. An abstract by Jolly et al. (2002) reported on toys given to nursery pigs. There was a positive association between the piglets with toys and their behavior, namely fewer aggressive actions. Environmental enrichment shows promise as a possible option to decrease aggressive behavior and increase positive behaviors. The swine industry is always faced with increased costs, and pressures from animal rights activists have been increasing. The addition of toys will increase costs and labor for producers, but if toys help decrease aggressive behaviors and possibly increase gain (Wood et al., 2003), they may be of some interest to producers. Plus, enriched environments may alleviate some of the pressures from animal rights activists.
Friend, T. H., D. A. Knabe, and T. D. Tanksley, Jr. 1983. Behavior and performance of pigs grouped by three different methods at weaning. J. Anim. Sci. 57:1406-1411.
Jolly, E. S., J. B. Gaughan, and A. K. King. 2002. Environmental enrichment for neonatal pigs and its influence on post weaning agression. J. Anim. Sci. 80(Suppl. 1):25-26.
McConnell, J. C., J. C. Eargle, and R. C. Waldorf. 1987. Effects of weaning weight, co-mingling, group size and room temperature on pig performance. J. Anim. Sci. 65:1201-1206.
McGlone, J. J., W. F. Stanbury, and L. F. Tribble. 1987. Effects of heat and social stressors and within-pen weight variation on young pig performance and agonistic behavior. J. Anim. Sci. 65:456-462.
Wood, C. M., B. Osborne, S. Meder, A. Young, A. Damon, J. Joseph, M. Ashby, T. O'Hare, and L. A. Kuehn. 2003. The effect of toys on performance and behavior of weanling pigs housed in littermate or mixed groups. J. Anim. Sci. (abstr.). Accepted.