Introduction

Split marketing is a strategy that commercial swine producers often practise when marketing finishing hogs. The split marketing strategy encompasses the concept that the heaviest 25 to 50 per cent of pigs in respective pens are marketed one to two weeks earlier than their remaining pen mates.

Weight variation among market pigs within respective pens may prevent producers from marketing all pigs at the same time. Split marketing is employed in an effort to maximise premiums paid by processors for uniformity of animals marketed, and at the same time decrease the opportunity for producers to take full advantage of the benefits (decreased risk of disease transmission, reduced incidence of animal fighting and the cleaning and disinfecting of facilities) of the ‘all in – all out’ systems.

The amount of research data on this subject is somewhat limited. However, the scientific work that has been conducted has evaluated performance characteristics and more recently, the effects on the social dynamics of remaining pen mates of marketed pigs.

Performance

Several studies have evaluated performance of pen mates of removed market ready pigs. Early work on this subject (Bates and Newcomb, 1997) reported that weight gain and feed intake increased of remaining pigs when the heaviest 50 per cent of the pigs were marketed two weeks earlier than their pen mates.

Additionally, a study conducted by Woodworth and coworkers (2000) utilised 1,272 pigs and three treatments (zero sort = no pigs marketed before prior to close–out, one sort = four pigs marketed 21 days prior to close–out, or two sorts = two pigs marketed at 27 days prior to close–out and three additional pigs marketed 14 days prior to close–out of market ready pigs) demonstrated that Average Daily Gain (ADG) was lower for pigs in the zero–sort pens versus one–sort pens. Furthermore, carcass characteristics were not influenced by marketing strategy. However, sort discount was greater for pigs in the zero–sort pens than from the one– and two–sort pens.

In contrast, Knauer et al. (2004) evaluated 649 barrows and gilts to investigate the effect of removing 25 or 50 per cent of market–ready pigs and the performance of their remaining pen mates. Results of this study suggest that producers will not gain or lose performance of pen mates when removing of 25 per cent or 50 per cent of market ready pigs two weeks prior to the final marketing date if pigs are allotted eight square feet of space per pig.

DeDecker and colleagues (2005) also evaluated performance of finishing as a proportion of pigs were marketed. This study involved 1,456 crossbred pigs and four treatments which included: 1) zero per cent removed, 2) 25 per cent removed, 3) 50 per cent removed and 4) 50 per cent removed with reduced space. One aspect of this study evaluated these marketing strategies in terms of the overall live weight of pigs produced. The total live weight produced for the control and the 25 per cent removed group was greater than that of the 50 per cent removed treatments. Additionally, total feed consumption for the 25 per cent removed and 50 per cent removed treatment was les than that of the zero per cent removed treatment.

This study suggest that in terms of total live weight produced, there is no benefit from removing 25 per cent of the heaviest pigs and a disadvantage for removing 50 per cent of the heaviest pigs. Furthermore, based on the findings of this study, it appears that removing 25 per cent of the heaviest pigs in the pen to be marketed may create an economic edge for producers when taking into account total weight of pigs produced and total feed consumption.

Social Dynamics

Research reports have documented that mixing pigs will increase fighting behaviour and decrease growth performance. However, there is very limited research that has been conducted on the effect of removing pigs from an established group as it relates to split marketing strategies.

Scroggs and coworkers (2002) evaluated aggression and immune responses in small groups of six pigs per group, pre– and post–removal. Results of this study indicated that post–removal aggression and measures of immune response were similar for groups with pigs removed and those that remained undisturbed (no pigs removed) in their respective pen settings.

Conte and co–workers (2012) conducted a study involving the aspect of the effect of split marketing on the welfare of finishing pigs. As there appears to be a growing concern about the welfare of male pigs that are castrated, this study utilised non-castrated (intact) male pigs and female pigs for a total of 392 pigs. Pigs in this study were assigned to one of four different treatments with 14 pigs per pen. Treatments included:

• 1) male split marketing (three heaviest were removed 14 days prior to the harvest of the 11 remaining pigs)
• 2) male, all–out
• 3) female, split marketing and
• 4) female, all–out.

Results of this study suggest that intact males in the split marketing groups spent more time engaged in aggressive behaviour than those intact males of the all-out pen treatments. In the intact male groups, reduced aggression was reported only on the day of split marketing. Skin lesion scores and severity were similar in pigs in the split marketing groups and all–out treatment groups. The male groups showed a greater number of aggressive behaviours; however, the female pig groups in general had greater lesion scores (more severe) than those of the male groups. Moreover, the removal of the three heaviest pigs from the groups of 14 pigs did not have any effect on growth performance for either the female or intact male groups.

Key Points

Removing pigs from an established pen increases the access to resources (floor space and feed resources) and may also change the social dynamics of the remaining pigs.

In general, it appears from the documented research referenced in this article that split marketing of finishing pigs can be utilised by producers with minimal negative impact on pig performance, carcass characteristics or social dynamics of the pigs. However, marketing strategy will be dependent upon multiple factors (biosecurity protocols, pig flow, floor space, feed resources, market outlets, packer buying matrix, etc.) within a production system and it is apparent that all factors must be carefully evaluated.

Resources

Bates, R.O. and M.D. Newcomb. 1997. Removal of market ready pen mates improved growth of remaining pigs. J. Anim. Sci. 75(Suppl. 1):247 (Abstr.).

Conte, S., P.G. Lawlor, N.O’Connell and L.A. Boyle. 2012. Effect of split marketing on the welfare, performance, and carcass traits of finishing pigs. J. Anim. Sci. 90:373-380.

DeDecker, J.M., M. Ellis, B.F. Wolter, B.P. Corrigan, S.E. Curtis, E.N. Parr and D.M. Webel. 2005. Effects of proportion of pigs removed from a group and subsequent floor space on growth performance of finishing pigs. J. Anim. Sci. 83:449-454.

Knauer, M., Stalder, K.J., Baas, T.J., Newcom, D.W., Mabry, J.W., Hentges, D. and H.G. Kattesh. 2004. Effect of removing market ready pigs on performance of their pen mates. Iowa State University Animal Industry report: A. S. Leaflet R1969.

Scroggs, L.V., H.G. Kattesh, J.L. Morrow, K.J. Stalder, J.W. Dailey, M.P. Roberts, J.F. Schneider and A.M. Saxton. 2002. The effects of split marketing on the physiology, behavior and performance of finishing swine. J. Anim. Sci. 80:338-345.

Woodworth, J.C., S.S. Dritz, M.D. Tokach, R.D. Goodband and J.L. Nelssen. 2000. Examination of the interactive effects of stocking densities and marketing strategies in a commercial production environment. J. Anim. Sci. 78 (Suppl. 2):56 (Abstr.).

April 2012