Effect of pH and Recombinant Barley (Hordeum vulgare L.) Endoprotease B2 on Degradation of Proteins in Soaked Barley

Nonfermented soaking of barley feedstuff has been established as an in vitro procedure prior to the feeding of pigs as it can increase protein digestibility. In the current study, two feed cultivars of barley (Finlissa and Zephyr) were soaked in vitro either nonbuffered or buffered at pH 3.6 and 4.3. Solubilized and degraded proteins evaluated by biuret, SDS-PAGE, and differential proteomics revealed that pH 4.3 had the greatest impact on both solubilization and degradation. In order to boost proteolysis, the recombinant barley endoprotease B2 (rec-HvEP-B2) was included after 8 h using the pH 4.3 regime. Proteolysis evaluated by SDS-PAGE and differential proteomics confirmed a powerful effect of adding rec-HvEP-B2 to the soaked barley, regardless of the genotype. Our study addresses the use of rec-HvEP-B2 as an effective feed enzyme protease. HvEP-B2 has the potential to increase the digestibility of protein in the pig, either supplied as recombinant additive or as possible new selection criterion in barley breeding

Changes in serum phosphate in malnourished piglets refed with either CSB+ (n = 9), CSB+/wp (n = 9) or CSB++ (n = 10) or continuously malnourished (REF, n = 8) for 3 weeks.

<p>Values are mean (95% CI). Repeated measurement analysis was used to calculate the effects of diet (P diet), time (P time) and their interaction (P diet-time). The diet-time interaction was significant (P <0.01).</p

Body composition after refeeding period of malnourished piglets with CSB+, CSB+/wp or CSB++ or continuously malnourished (REF) for 3 weeks.¹^,³.

<p>Body composition after refeeding period of malnourished piglets with CSB+, CSB+/wp or CSB++ or continuously malnourished (REF) for 3 weeks.<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0170043#t002fn001" target="_blank">¹</a>^,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0170043#t002fn003" target="_blank">³</a>.</p

Corn-Soy-Blend Fortified with Phosphorus to Prevent Refeeding Hypophosphatemia in Undernourished Piglets - Fig 1

<p>Changes in body weight (A) and supine length (B) in malnourished piglets refed with either CSB+ (n = 9), CSB+/wp (n = 9) or CSB++ (n = 10) or continuously malnourished (REF, n = 8) for 3 weeks. Values are mean (95% CI). Repeated measurement analysis was used to calculate the effects of diet (P diet), time (P time) and their interaction (P diet-time). The diet-time interaction was significant (P<0.001) for the weight increment. There was an effect of time and diet on the increment in supine length (P diet <0.01, P time <0.001). The data were log-transformed prior to analysis.</p

Compositions of reference and the 3 refeeding diets¹.

<p>Compositions of reference and the 3 refeeding diets<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0170043#t001fn001" target="_blank">¹</a>.</p