Effects of Dietary Inclusion of β-Hydroxy-β-Methylbutyrate on Growth Performance, Fat Deposition, Bile Acid Metabolism, and Gut Microbiota Function in High-Fat and High-Cholesterol Diet-Challenged Layer Chickens

Abstract

Excessive lipid deposition in layer chickens due to inappropriate feeding adversely affects egg production; however, nutritional manipulation methods to deal with this issue are still limited. β-hydroxy-β-methylbutyrate (HMB), a metabolite of L-leucine, was recently reported as a lipid-lowering nutrient in mice and pigs, although its role in layers had not been investigated. Here, we employed high-fat and high-cholesterol diet (HFHCD)−challenged growing layers as an obese model to explore HMB function in the regulation of lipid metabolism and the potential mechanisms involved. We found that dietary supplementation with (0.05% or 0.10%) HMB significantly reduced HFHCD−induced bodyweight growth in layers, mainly due to reduction in abdominal fat deposition. Mechanistically, HMB supplementation enhanced hepatic bile acid synthesis from cholesterol through elevating expression of Cyp7a1, a gene coding a key enzyme in bile acid synthesis. Furthermore, 16S rRNA gene sequencing revealed that HMB supplementation remodeled the diversity and composition of the layers’ cecal microbiota, and the abundance of Bacteroidetes at the phylum level were especially affected. Correlation analysis further indicated a strong negative association between Bacteroidetes abundance and lipid metabolism−related parameters. Taken together, these data suggest that dietary HMB supplementation could improve abdominal fat deposition in layers, probably through modulating hepatic bile acid synthesis and gut microbiota function.

Beta‐hydroxy‐β‐methyl butyrate‐supplemented diet for broiler chickens is more conducive to dietary protein reduction than a leucine‐supplemented diet until 21 days old

“…This result confirmed that the reduced broiler performance was also related to the lower serum IGF‐1 level 8 . These observations support the idea that the low‐protein diet supplemented with HMB positively affects overall performance 19,20,34,36 . In the present study, the diet with HMB had similar muscle yields and meat quality to those from broilers fed with SPD by increasing the development of early gut and small intestine morphology.…”

“…8 These observations support the idea that the low-protein diet supplemented with HMB positively affects overall performance. 19,20,34,36 In the present study, the diet with HMB had similar muscle yields and meat quality to those from broilers fed with SPD by increasing the development of early gut and small intestine morphology. This result did not confirm that the breast muscle is more sensitive to HMB than the leg muscle with different fiber types.…”

“…The results on serum TC levels indicate that broilers fed with each diet represent a relatively balanced lipid metabolism and a liver function unaffected by the protein levels 21 . Our results show that dietary leucine and HMB may not be a precursor of cholesterol synthesis and mitigate fat deposition in broiler chickens 15,36 . However, the results on both breast and leg muscles did not confirm that HMB may be a proper feed additive to produce poultry meat with functional consumer properties 20 …”

“…21 Our results show that dietary leucine and HMB may not be a precursor of cholesterol synthesis and mitigate fat deposition in broiler chickens. 15,36 However, the results on both breast and leg muscles did not confirm that HMB may be a proper feed additive to produce poultry meat with functional consumer properties. 20…”

Editorial for the Special Issue “Bioactive Compounds of Natural Products on Metabolic Disorders and Complications”

“…Inappropriate feeding in layer chickens results in excessive fat deposition and metabolic disorders, thereby affecting egg production. Considering the poultry industry, Liao et al found that dietary supplementation with β-hydroxy-β-methylbutyrate could reduce abdominal lipid deposition in layer chickens through enhancing hepatic bile acid synthesis and gut microbiota function [8].…”