Brand Insights from Evonik
Regardless of the phase of growth, lysine is the first limiting amino acid for swine and balancing diets with crystalline L-lysine is a well-established practice around the world. There are two lysine sources available to nutritionists: 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 average daily gain (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.
2. 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 its lysine content and 513 kcal/kg is from its 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.
3. 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 an on-going 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 to assign 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 $0.22 per MT and $0.06 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.
4. 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 achieved 65%, 75%, 85%, and 95% of the SID lysine requirements based on the NRC (2012) recommendations for pigs in the bodyweight rage 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 on carcass traits due to lysine sources. The results suggest that both lysine sources are equivalent to optimize carcass performance of market pigs.
5. 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.
Conclusions
Biolys supports 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.
References available on request.
Maria Mendoza, Ph.D., Technical Service Manager, Evonik
