Within the last decade, research in swine nutrition has continued to fine-tune nutrient requirements within each stage of production to feed pigs to achieve optimal performance at minimal feed cost. In most systems, these phases include two to three nursery diets, three to five finishing diets, and sow diets for gestation and lactation. 

Although there are periods of the production cycle where the diet being fed may over- or under-supply nutrients, current “phase-feeding” standards are generally bottlenecked by feed mill efficiencies and bin management which limit commercial farms from achieving more precision. 

Though this approach has helped define the modern pork production system, the advent of commercially available diet blending technologies, such as Gestal EVO, allows for a re-think as they provide the ability to mix and deliver two or more diets in proportionate ratios according to needs.

Nursery to finish
Blending diets to increase dietary phases has been tested in commercial environments. The biggest payback delivered is diet cost savings by reducing times when nutrients are over-supplied. Furthermore, diet blending minimizes excretion of nitrogen and phosphorus.

Future opportunities to use diet blending to increase production efficiencies in growing pigs include: 1) Applying different phase budgets to separate groups of pigs (e.g. skipping nursery stage one diets for the bigger/older pigs), 2) Implementing split-sex feeding, or 3) Using diet blending technologies for real-time notifications of bin outages and problem pens. 

Gilt development
Gilt developer barns represent an immediate opportunity for diet blending. Gilt groups of various ages are often housed within the same barn and in many cases, providing the ideal number of phases is not economical due to feed system constraints. This results in compromises in the number of diets fed and feed system limitations exacerbate problems with developing gilts becoming over-conditioned, leading to increased maintenance costs and decreased lifetime performance. A dual feed line blending two extreme diets on a per-pen basis can deliver any intermediate diets and may be able to manage feed intake at critical times, with diet cost savings and gilt retention rates among the benefits. As shown by Holtkamp (2019), a 10% reduction in annual gilt replacement rate on a 2,400 head sow farm resulted in 829 additional marketed pigs and 222,310 additional pounds of pork produced per year.

Sows
Although many factors influence the nutrient requirements of lactating sows, most systems currently feed a common diet throughout lactation. Recent preliminary data indicates the daily standardized ideal digestible lysine requirement can range from 0.85% to 1.35% depending on parity and stage of lactation. This data indicate that if two diets could be blended in lactation, considerable diet cost savings could be realized while minimizing sow body weight loss which negatively affects subsequent reproductive performance.

In gestation, feed adjustments based on body condition are common. Since requirements vary by parity and stage of pregnancy, the ability to reliably deliver different nutrient concentrations individually would offer further diet cost advantages. Sows in mid-gestation and older parity females represent examples where nutrients are commonly supplied in excess today. Furthermore, diet blending provides the capability to alter late-gestation diets or implement transition feeding.  

The proposal to add diet blending capabilities to commercial farms represents a paradigm shift from the way we feed pigs today. Of course, these changes require initial investment and understanding in order to exploit long-term benefits. While change is difficult, we should remember other major structural shifts, such as the use of artificial insemination and multi-site production, and their impact on the way pork production looks today. Historically, feed system limitations have limited nutritionists from realizing the pigs’ full potential. Now, with diet blending, we can take advantage of the known benefits of precision feeding.