From the Editor
I would like to begin by thanking Drs. Hank and Isabel Harris for submitting the thought-provoking letter (Swine Health Prod. 1999;7(3):101-102) about the nomenclature of production systems. It would certainly help the industry, including the readers of Swine Health and Production, to have a standardized vocabulary. Although I believe that the Drs. Harris have identified the pertinent issues, I do not agree with their choice of nomenclature. The following is my opinion laced with a spattering of fact.
"Isowean" was registered as a trademark term by PIC. As it was originally described by Harris, the Isowean system was a very successful management tool to eliminate diseases. The term "Isowean" became synonymous with a very strict protocol of management that included medicating the sow and the piglets, an early weaning age, movement of pigs to an offsite nursery, and maintaining a strict all-in-all-out (AIAO) protocol in the nursery barns. At times, Isowean also included identifying older sows with a high degree of immunity and isolating these sows offsite prior to farrowing. The significance of Isowean was that it virtually guaranteed the elimination of a specific pathogen from the weaned pigs. Isowean was the ultimate set of standards to be used when disease elimination was required.
The swine industry in North America has bastardized both the protocol and the intent of Isowean. I disagree with the Drs. Harris in their comment that MEW, MMEW, and SEW are synonymous with Isowean or indeed with one another. The philosophy of SEW was "it is the segregation, not the medication, that makes the system work." As we all know, many producers had problems with the early-weaning system. They either couldn't maintain the growth or health of the very young pig or couldn't maximize the production of the sow with a short lactation length. As weaning ages increased from 8 to 21 days, the industry persisted in using the term SEW. However, the only part of the Isowean system that they had maintained intact was the offsite rearing of the weaned pig.
The relationship between "Isowean" and current management techniques is analogous to the relationship between sterile, surgical techniques taught at a veterinary college and on-farm repairs in pigs.
There are other issues that make an all-inclusive nomenclature difficult. Many producers populate nurseries from multiple sow units or fill grower barns from multiple nurseries. Therefore the group integrity is not intact. Some producers have one barn per geographic location whereas others have multiple barns per site. Many nursery units are no longer managed AIAO. Very definitely, this system of offsite rearing of weaned pigs does not eliminate disease.
I suppose a word becomes the "correct" term when an industry adopts the term. This can be crudely measured by looking at the use of the terms "Isowean," "MEW," "MMEW," "SEW," and "multisite production" in the proceedings of the AASP Annual Meeting, Leman Conference, and IPVS over the past 9 years. "SEW," "Isowean," and "MEW" are used most frequently and in approximately equal frequencies. "Multisite production," "early weaning," and "MMEW" are used less often. However, in North America, "Isowean" is rarely used and there is a trend, over time, toward the increased use of "SEW" and "multisite" or "offsite production."
Perhaps the real problem is that the use of a standardized word or set of nomenclature to describe such a wide variety of management systems will not convey the truth. Therefore the use of "SEW" to describe all systems with offsite rearing of weaned pigs is inaccurate. Each system does need to be described in terms of the number of sites and sources, number of barns per site, ages on each site, weaning age, whether AIAO management is practiced, and pig density. Our industry has moved a long way from the original Isowean concept. Each time we change one of the mandates of disease control, we move further from the intended use of "Isowean."
I also have some concerns about using alphanumeric notation to denote complex management systems. Firstly, the precision of detail required to fully describe the system is lost or trivialized with the coding. Secondly, swine veterinarians in North America frequently use acronyms in regular conversation with one another. This terminology is subsequently used in both oral and written communication in proceedings papers and ultimately in the scientific press. This insulates us from persons working on other continents where the acronym is not understood or widely known. We need to aim for universal rather than exclusionary language.
As editor, I would encourage our authors to use precise language to fully and accurately describe the management system used in their study to convey a clear picture to the readership. Our industry is too diverse to adopt "one" standardized set of nomenclature.