Dietary Ulva lactuca and CAZyme supplementation improve serum biochemical profile and hepatic composition of weaned piglets

Abstract

Ulva lactuca is a seaweed with antinutritional cell wall for monogastrics. Carbohydrate-Active enZymes (CAZymes) supplementation can potentially cause its disruption. This study evaluates four diets: Ctrl—control diet; UL—control + 7% U. lactuca (wild caught, powdered form); ULR—UL + 0.005% Rovabio® Excel AP; ULU—UL + 0.01% ulvan lyase on piglets’ haematologic and serologic profiles, hepatic lipids and minerals. White blood cells and lymphocytes reached the highest values in piglets fed UL compared to control, and to control and ULR; respectively (P < 0.05). IgG levels were boosted by seaweed incorporation compared to control (P = 0.015). The glycaemic homeostasis was assured by the seaweed inclusion. Dietary seaweed decreased serum lipids (P < 0.001), with the exception of ULU, due to HDL-cholesterol increase (P < 0.001). Cortisol was decreased in ULR and ULU (P < 0.001). No systemic inflammation was observed (P > 0.05). While hepatic n-3 PUFA increased in piglets fed with seaweed diets due to increment of beneficial 22:5n-3 and 22:6n-3 fatty acids (P < 0.05), the opposite occurred for n-6 PUFA, PUFA/SFA and n-6/n-3 ratios (P < 0.05). Hepatic pigments were unchanged (P > 0.05). ULR reduced α-tocopherol levels (P = 0.036) and increased serum potassium levels (P < 0.001) compared to control. Seaweed contributed to overcome piglets’ weaning stress, with some benefits of including CAZyme supplementation.

Integrated transcriptomics and proteomics analysis reveals muscle metabolism effects of dietary Ulva lactuca and ulvan lyase supplementation in weaned piglets

“…Seaweeds are generally known to have a beneficial n-3 PUFA content 6 . In our study, we found that 18:4n-3 (stearidonic acid) was virtually absent in the control diet, as shown in our companion paper 19 . Corominas et al 33 have reported that tissue PUFA has an inverse relationship with lipogenic gene expression, like SCD , which could help explain the differences we found.…”

“…These results have been previously published in companion papers and are briefly mentioned to provide context 19 , 26 . Diets had no statistically significant effect on the growth performance of piglets.…”

“…However, in a recent study by our research team, we found that feeding piglets with a different seaweed, Laminaria digitata , maintained the circulating levels of electrolytes within reference values for swine 42 . The same happened when feeding piglets with U. lactuca 19 . Therefore, the exact reason for the apparent disruption of muscle osmotic homeostasis is unclear in the current study.…”

“…The live animal trial took place at the experimental facilities of the Animal Production Department of the School of Agriculture (Instituto Superior de Agronomia) of the University of Lisbon, Portugal. The experimental conditions have already been described elsewhere and are briefly mentioned here for contextual purposes, including the chemical composition of the diets 19 . Briefly, thirty male piglets (Large White × Duroc, aged 28 days) were randomly distributed into three experimental diets (n = 10): control (standard wheat, maize, soybean meal diet), UL (7% Ulva lactuca replacing the control diet) and ULU (UL + 0.01% ulvan lyase).…”

“…However, to the best of our knowledge, the use of whole Ulva sp. biomass as a feed ingredient (> 3% dietary incorporation) in piglet diets is scarcely studied 19 , possibly because of the antinutritional effects that can occur due to their highly complex cell wall polysaccharides 13 . This is partly caused in turn by the highly complex, cross-linked ulvan, a sulphated polysaccharide made up of rhamnose, glucuronic acid and xylose monomers 11 .…”