Recent disruption in the global supply chain and pressure from international carbon neutral policies have significantly reduced the supply of inorganic phosphorus (P) to the Asia-Pacific region. Simple survey results investigating current and last year's inorganic P prices from several feed mills are presented in Figure 1. If we look at the extreme cases, the MCP price in Vietnam has increased from $460 to $780, the MDCP price in Malaysia has increased from $570 to $800, and the DCP price in Malaysia has increased from $330 to $650. Overall, the average end-user prices for MCP, MDCP and DCP in the South East Asian countries have increased by 171%, 135% and 169%, respectively. This increase in inorganic P price exacerbates already skyrocketing feed costs due to an increase in energy and protein sources.

Figure 1. Increase in inorganic phosphorus price in major South-East Asia region (End-user price surveyed in November 2021).

One of the strategies to mitigate the inorganic-P driven increase in formulation cost is to use an effective phytase with the application of mineral matrix. This strategy is best understood by sharing a recent swine trial experience than with a wordy explanation. In this US research facility trial, we used 120 pigs weighing 25kg and allocated them to three dietary treatments with eight replicated pens and five mixed-sex pigs per pen. Pigs were fed a single-phase grower diet for 41 days (25-64 kg), and one pig per pen was sacrificed to collect the 3rd metacarpal bone for measurement of bone mineral density and bone-breaking strength. The diets were corn-soybean meal-based diets with 3339 kcal ME and 1.03% SID lysine/kg. The three treatments were:

1. Positive control diet with 0.32% avP and 0.65% Ca

2. Negative control diet with 0.17% avP and 0.65% Ca (-0.15% avP)

3. Negative control diet with 500 FTU phytase (Quantum Blue^®, AB Vista)

Table 1. Ingredients and nutrients composition of the experimental diets

As evident in the formulation, the application of 0.15% avP matrix reduced MCP inclusion from 11.3kg to 4.1kg/MT of feed, which is a 7.2kg MCP savings per MT of feed. As a simple calculation, 7.2 kg MCP savings at the current end-user price of MCP at $0.78/kg would reduce formulation cost by $5.62/MT of feed. In a feed mill producing 10,000 MT of feed per month, the annual formulation cost saving would be $674,400 (10,000 MT x $5.62 x 12 months). In addition to the formulation cost savings, this strategy reduces phosphorus release into the environment, reduces carbon footprint and hence is a responsible strategy for sustainable swine production. Nutritionists can achieve even further savings if a higher dose of 1000 or even 1500 FTU were applied which will replace 0.195% and 0.222% av Prespectively, depending on phytate content in the diet.

Growth performance and metacarpal bone characteristics are presented in Figure 2. Reducing avP content from 0.32 to 0.17% decreased average daily gain by 8.4%, final weight by 3 kg, bone-breaking strength by 11% and metacarpal bone ash content by 3%. However, the application of Quantum Blue at 500 FTU brought the growth rate and metacarpal bone ash content back to the positive control levels, indicating that the 0.15 avP matrix application with 500 FTU dose of Quantum Blue was justified.

Figure 2. Growth performance (Left) and metacarpal bone characteristics (Right) of grower pigs fed the experimental diets

Another grower pig study used a corn/wheat/soybean meal-based diet containing 0.23% phytate P, but this time we applied 0.21% avP and 0.22% Ca matrix to test the full mineral matrix application. The average body weight at the start of the trial was 20 kg and pigs were fed the experimental diet for 42 days. Diet formulation is presented in Table 2. The dietary treatments were Positive Control, Negative Control (-0.21% avP and -0.22% Ca) and Negative Control + 1200 FTU Quantum Blue.

Table 2. Ingredients and nutrients composition of the experimental diets

As full mineral matrix was applied, MCP inclusion was decreased from 10.9 kg to no inclusion, which is a saving of $7.87/MT of feed by simply accounting for the reduction of inorganic P inclusion. This will lead to $954,883 annual savings for the feed mill with a 10,000 MT/month production capacity. The performance and bone characteristics are presented in Figure 3. Reducing 0.21% avP and 0.22% Ca decreased average daily gain by 24%, increased FCR by 15%, and decreased bone-breaking strength and bone ash content by 55% and 29%, respectively. However, the application of Quantum Blue at 1200 FTU brought the growth rate and metacarpal bone ash content back to the positive control levels, indicating that the 0.21% avP matrix application with 1200 FTU dose of Quantum Blue was justified.

Figure 3. Growth performance (Left) and metacarpal bone characteristics (Right) of grower pigs fed the experimental diets

The scope of this article is to discuss mitigation strategies for increased inorganic P price, however, in many countries (particularly in Europe and America) energy and amino acid matrices with high dose phytase strategy are also applied along with mineral matrix to extract maximum values from the feed. Application of energy and amino acid matrix will further reduce feed cost by 5-10 dollars depending on the cost of the energy and protein source in the diet.

To be able to implement such a nutritional strategy, nutritionists need confidence in three major contributing factors for successful implementation.

• Phytate-P content in the ingredients and diet

• Variation in phytate-P content in the ingredients and diet

• Trust in the mineral matrix values for the phytase used in the diet

A typical corn-soybean meal-based diet contains around 0.24% phytate-P content, which is sufficient to apply a phytase matrix up to 1500 FTU of Quantum Blue. However, due to the variation in phytateP content in the ingredients, some diets may end up with only 0.21% phytate-P content in the diet. In that case, applying too high a matrix would lead to a phosphorus deficiency and loss of performance. This, however, is highly unlikely in South-East Asia where high phytate-P ingredients such as rice bran (typically more than 1 % phytate-P) are commonly used. Quantifying a new batch of ingredients for phytate-P content and hence estimating total phytate-P content in the final diet more accurately would provide important information for decision making. To help this process, AB Vista provides a cloudbased online NIR service (Feed Quality Service) for accurate quantification of phytate-P content in ingredients and final feed. With this service, it is possible to ensure sufficient phytate-P is in the diet to allow the phytase to liberate the required phosphorus.

The other contributing factor is the trust in the mineral matrix values provided by phytase manufacturers. There is confusion and distrust on phytase matrix values in the market as some phytases drive their matrix values from calculation/modelling or simply reproducing without in vivo validation. Therefore, for successful implementation of this nutritional strategy, nutritionists should make sure that the matrix they are using with a phytase was validated with multiple in vivo experiments. To make sure of this, the derivation of the Quantum Blue matrix used the holo analysis approach for validation. The holo analysis is a statistical technique that analyses the data with consideration of multiple factors that could affect the animal's response such as genetic, management, dietary ingredient and nutrient independent variables. It is a much more complicated and better technique than meta-analysis which analyses trial data based on several selection constraints. A total of 29 swine trial data with 201 data points (=treatment groups, not individual pens) were used for Quantum Blue swine holo analysis and the analysis was done with the application of 85% confidence limits on the derived matrices, indicating that the matrix was validated with a safety margin. The results indicated that 445 FTU of Quantum Blue releases 0.15% avP and 640 FTU released 0.175% avP. With this in vivo data-driven matrix, nutritionists can confidently implement the recommended mineral matrix with Quantum Blue.

In conclusion, rising feed cost is driven by increased ingredients costs and the recent spike of inorganic P cost exacerbates increasing feed cost in the region. One of the nutritional strategies nutritionists can use to reduce formulation cost is using an efficient phytase with mineral matrix application. For successful implementation of the strategy though, a nutritionist needs to be able to accurately quantify phytate-P content in the ingredients and diets and select an efficient phytase with matrix values that have a safety margin derived from multiple in vivo evaluations.

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Article made possible through the contribution of AB Vista

Rising inorganic phosphorus price: Strategy to tackle the increasing formulation cost