5 benefits of using Biolys in swine diets

Biolys supports growth and carcass performance of pigs as effectively as L-lysine HCl. Sponsored by Evonik.


Lysine is the first limiting amino acid in swine diets regardless of the phase of growth. Balancing diets with crystalline L-lysine is a well-established practice around the world. Nutritionists have two lysine sources available in the market, L-lysine HCl and L-lysine sulfate. Biolys®, in the form of lysine sulfate, contains 60% L-lysine and is produced by fermentation.  The co-products of the fermentation are inactivated and preserved in the final product, referred to as biomass. The biomass provides an extra source of energy and nutrients. Utilization of Biolys in the formulation of swine feed can easily be adopted when understanding the following properties.

  1. Same bioavailability compared to lysine HCl

Determination of the nutritional value of an ingredient relative to the standard is necessary for feed formulation. Several studies have compared L-lysine sulfate to L-lysine HCl at different growth stages in pigs. For instance, Smiricky-Tharder et al. (2004), Liu et al. (2007), and Palencia et al. (2018) conducted studies in the nursery phase, while Htoo et al. (2016) and Li et al. (2019) conducted studies in the growing-finishing phases. A summary of the results of available literature is shown in Table 1. On average, the relative bioavailability of L-lysine sulfate (Biolys) to L-lysine HCl was 107% when optimizing ADG, and 103% when optimizing feed efficiency. However, in all supporting studies, the relative bioavailability was not statistically different from 100% and concluding that both lysine sources are bioequivalent to optimize pig performance.



  1. Extra energy and nutrient content

Aside from its high content of lysine, Biolys also contains biomass which contains lipids, amino acids, and minerals. Biolys provides 20% more energy compared to L-lysine HCl to achieve the same content of lysine in a diet formulation. For instance, Biolys contains

3,058 kcal/kg of net energy, from which 2,545 kcal/kg is from it’s lysine content and 513 kcal/kg is from it’s biomass. Other nutrients like phosphorus, methionine, threonine, tryptophan, arginine, valine, etc. can be found in Biolys in smaller proportions, and average values are reported in the nutrient matrix that can be added in the nutrient loadings.

  1. Cost savings in feed formulation

Feed cost can represent up to 70% of the costs at a swine operation. Looking for ingredients that can generate savings is always an ongoing task.  A simple way to evaluate an ingredient is by optimizing several diets at the same time to determine the difference in cost that the new ingredient can provide.  A more accurate method is by assigning the feed volume or feed budget per pig for each of the feed formulations to determine the overall savings or the savings per pig. In a simple exercise, four diets for growing-finishing pigs were optimized to cover the following bodyweight ranges 25-50 kg, 50-75 kg, 75-100 kg, and 100-130 kg, and feed budgets 24, 29, 36, and 54 kg, respectively. Table 2 shows the cost per diet for different lysine sources. Based on this feed program, savings up to $0.51 per MT and $0.14 per growing-finishing pig were estimated when using Biolys in the feed formulation. The savings are mainly due to the extra energy and nutrient content.


  1. Similar carcass trait performance compared to lysine HCl

A study conducted at Iowa State University evaluated the use of L-lysine HCl and Biolys in the finishing period and measured carcass characteristics at the end of the trial (Li et al., 2019). Pigs were fed the two lysine sources at three incremental levels plus a basal diet (no added lysine). The basal diet and the three incremental levels of lysine were formulated to achieve 65%, 75%, 85%, and 95% of the SID lysine requirements based on the NRC (2012) recommendations for pigs in the bodyweight range of 67 to 98 kg and 98 to 112 kg for phase 3 and 4, respectively. Parameters measured were hot carcass weight, carcass yield, back fat, loin depth, and lean percent. Table 3 shows the results of the carcass characteristic of the seven dietary treatments. No differences were observed in carcass traits due to lysine sources. The results suggest that both lysine sources are equivalent to optimize the carcass performance of market pigs.



  1. Easy on sulfur content

Sulfur is the eighth-most abundant element in the body. Sulfur has low toxicity (Boone et al., 2017). However, sulfur-containing molecules can be converted to hydrogen sulfide. Only microorganisms can convert sulfur into hydrogen sulfide. The National Research Council in its special edition for Mineral Tolerance of Animals (NRC, 2005) recommended sulfur levels not to exceed 0.4% in the diets of poultry and swine. Dale et al. (1973) reported that pigs fed a diet containing 0.42% of sulfur for 130 days did not experience reduced growth.  Similarly, Kerr et al. (2011) reported that pigs fed diets containing up to 0.5% of sulfur did not experience a reduction in growth.  However, when pigs were fed diets containing 0.82 and 1.21% sulfur, growth was reduced by 5% (Kerr et al., 2011). In a typical swine diet, Biolys inclusion rates range between 0.1 and 0.8%. Biolys contains up to 7% sulfur. Therefore, the contribution of sulfur by Biolys is in the range of 0.007 to 0.06 % in the diet.  A study was conducted to determine the apparent total tract digestibility of sulfur in diets formulated with L-lysine HCl or Biolys (Li et al., 2019). Pigs were fed diets containing 0.27% L-lysine HCl and 0.38% Biolys to achieve 0.60% SID lysine for pigs 68 to 101 kg body weight. Results of this trial showed sulfur digestibility of 74.2% and 71.8% in pigs fed L-lysine HCl and Biolys, respectively. No statistical difference in the digestibility of sulfur was observed between the two lysine sources.


Biolys supports the growth and carcass performance of pigs as effectively as L-lysine HCl. Biolys provides 20% more energy compared to L-lysine HCl to achieve the same content of L-lysine in a diet formulation. The extra energy and nutrient contents generate savings in feed formulation up to $0.22/MT of feed and $0.06 per pig under the current price ingredient conditions.

Dr. Maria Mendoza, Technical Service Manager, Evonik Corporation


Boone, C., C. Bond, A. Cross, J. Jenkins. 2017. Sulfur General Fact Sheet. National Pesticide Information Center, Oregon State University Extension Services. npic.orst.edu/factsheets/sulfurgen.html.

Dale, S. E., R. Ruminant susceptibility relies on the capacity of the microorganism in the rumen to convert sulfur into H2S.  C. Ewan, V. C. Speer, and D. R. Zimmerman. 1973. Copper, Molybdenum and Sulfate Interaction in Young Swine. J. Anim. Sci. 37:913–917.

Htoo, J. K., J. P. Oliveira, L. F. T. Albino, M. I. Hannas, N. A. A. Barbosa, and H. S. Rostagno. 2016. Bioavailability of l-lysine HCl and l-lysine sulfate as lysine sources for growing pigs. J. Anim. Sci. 94:253–256. doi:10.2527/jas2015-9797.

Kerr, B. J., T. E. Weber, C. J. Ziemer, C. Spence, M. A. Cotta, and T. R. Whitehead. 2011. Effect of dietary inorganic sulfur level on growth performance, fecal composition, and measures of inflammation and sulfate-reducing bacteria in the intestine of growing pigs. J. Anim. Sci. 89:426–437. doi:10.2527/jas.2010-3228.

Li, Q., S. a. Gould, J. K. Htoo, J. C. Gonzalez-Vega, and J. F. Patience. Bioavailability of l-lysine sulfate relative to l-lysine HCl for growing-finishing pigs. Translational Animal Science, 3:1254–1262. doi: 10.1093/tas/txz094.

Liu, M., S. Y. Qiao, X. Wang, J. M. You, and X. S. Piao. 2007. Bioefficacy of Lysine from L-Lysine Sulfate and L-lysine HCl for 10 to 20 kg Pigs. Asian-Aust. J. Anim. Sci. 20:1580–1586.

National Research Council. 2005. Mineral Tolerance of Animals: Second Revised Edition, 2005. Washington, DC: The National Academies Press. https://doi.org/10.17226/11309.

Palencia, J. Y. P., M. Resende, M. A. G. Lemes, M. F. S. A. Mendes, S. R. Silva Junior, A. P. Schinckel, M. L. T. Abreu, and V. S. Cantarelli. 2018. Relative bioavailability of L-Lysine sulfate is equivalent to that of L-Lysine HCl for nursery pigs. J. Anim. Sci. 1–32.