Influence of Chlorella vulgaris on growth, digestibility and gut morphology and microbiota of weaned piglet

Abstract

The purpose of this study was to evaluate the impact of Chlorella vulgaris (5% in the diet), supplemented or not with two exogenous carbohydrase mixtures on piglets’ performance, nutrient digestibility and gut morphology, fermentation products and microbiota. Forty-four male piglets weaned at 28 days of age, with 11.2 ± 0.46 kg of live weight, were used and assigned to 1 of 4 dietary treatments: cereal and soybean meal based-diet (control, n = 11), control diet with 5% of C. vulgaris (CH, n = 10), CH diet supplemented with 0.005% of Rovabio® Excel AP (CH + R, n = 10) and CH diet supplemented with 0.01% of a recombinant 4-carbohydrase mixture (CH + M, n = 11). Growth performance was not changed by the of C. vulgaris inclusion during 21 days of trial. However, total tract apparent digestibility of nutritional fractions was negatively impacted by the inclusion. In addition, the viscosity of duodenum plus jejunum contents slightly increased in all groups fed with the microalga. In contrast, dietary microalga increased duodenum villus height and promoted a healthier gut microbiota, with higher abundance of some specific bacterial taxa (Colidextribacter, Oscillospira and Lactobacillus). This study indicates that the dietary inclusion of 5% C. vulgaris improves piglets’ gut health without impairing performance. Data also indicate that C. vulgaris reduces nutrient digestibility but promotes compensatory developments of gut mucosa and prebiotic effects. Dietary supplementation with exogenous carbohydrases does not seem to be necessary for this inclusion level. Therefore, the incorporation of CH as a sustainable feed ingredient in piglets’ nutrition is a viable alternative approach.

Integrated Omics analysis of pig muscle metabolism under the effects of dietary Chlorella vulgaris and exogenous enzymes

“…It was positively correlated with actinin-1 (ACTN1), NDUFS3, CAMK2A and TUBA4A. These proteins have been mentioned to reflect higher energy production/nutrient utilisation rates of the tissue from pigs fed a control diet, coherent with the higher nutrient availability mentioned in an analogous piglet trial 38 .…”

“… 65 have found that pigs fed with reduced protein diets (13% as fed) have higher intramuscular fat (IMF) accumulation. Accordingly, we found that diets with high levels of CV have lower crude protein digestibility in weaned piglets 38 . In addition, CV accumulated significantly higher levels of PUFA (18:3 n -3, 18:4 n -3 and 20:5 n -3) in the muscle 34 , supporting the aforementioned hypothesis.…”

“…Instead of reflecting higher muscle development, this could reflect the higher nutrient availability of the control diet. The CV + R diet had detrimental effects in the digestibility of several nutrient fractions, including crude protein, when fed to weaned piglets 38 . The same could occur in the finishing pigs of this study, thereby comparatively increasing protein synthesis rates and overall anabolism in control piglets.…”

“…Thus, we hypothesised that the animals fed with diets containing C. vulgaris alone and supplemented with Rovabio® Excel AP were less able to digest C. vulgaris cell wall when compared to pigs fed the diet supplemented with four-CAZyme mixture, which allowed the digestion of the cell wall polysaccharide matrix into structurally simpler oligosaccharides 23 . Therefore, without an efficient disruption of C. vulgaris cell wall, the digestion of this biomass in the gastro-intestinal tract of pigs is compromised, blocking the access to valuable intracellular nutrients 36 – 38 . Although these dietary treatments did not influence zootechnical performance and meat quality traits in finishing pigs 34 , they led to significant changes in the muscle transcriptomic profile, triggering the expression of genes involved in energy homeostasis biological processes, such as lipid metabolism and mitochondrial function, functioning as a compensatory system.…”

Rumen-protected glucose stimulates the secretion of reproductive hormones and the mTOR/AKT signaling pathway in the ovaries of early postpartum

“…Plasma was separated via centrifugation (3000 × g, 15 min) and stored at -80°C. The cows approximately on d 14 during the post-partum period were slaughtered using electrical stunning followed by exsanguination according to the usual practices of the China beef industry 34 . The ovaries (bilateral) were collected from cows within 20 min after slaughter, then cleaned up fat and connective tissue, rinsed in RNase-free phosphate buffer, and the wet weight of the ovaries were measured.…”