Dietary Supplement Boosts Health and Metabolism in Older Laying Birds
Image Source: Natural Science News, 2024
Key Findings
- Researchers from Hunan Agricultural University found that silymarin supplementation helps maintain consistent egg production in late-stage laying hens
- Hens receiving 500 mg/kg and 750 mg/kg of silymarin had higher average egg weights and better feed efficiency
- Silymarin improved liver health by reducing liver damage markers and enhancing lipid metabolism in the hens
Liver lipid dysregulation is a significant issue in late-stage laying hens, leading to a decline in egg production performance. To address this, researchers from Hunan Agricultural University conducted a study to evaluate the effects of silymarin (SIL), a natural compound known for its liver-protective and lipid-lowering properties in humans, on the liver health and egg production in late-stage laying hens[1].
In this study, 480 Lohmann Pink laying hens, aged 68 weeks, were divided into five groups. Each group received a basal diet with varying concentrations of silymarin (0, 250, 500, 750, or 1,000 mg/kg) over a 12-week period. The results were promising: hens supplemented with silymarin maintained consistent laying rates throughout the study, unlike the control group, which saw a significant decline in laying rates from weeks 9 to 12.
Notably, the groups receiving 500 mg/kg and 750 mg/kg of SIL showed higher average egg weights during weeks 5 to 8 compared to the control group. The 750 mg/kg SIL group also had a higher average daily feed intake, while the 500 mg/kg SIL group exhibited a lower feed-to-egg ratio during the same period. These findings suggest that silymarin supplementation can improve both egg production and feed efficiency in late-stage laying hens.
The study also examined the biochemical and molecular effects of silymarin on the hens. The group receiving 500 mg/kg of SIL showed significant reductions in serum levels of ALT and AST, enzymes that indicate liver damage. Additionally, there was a marked decrease in serum triglycerides and total cholesterol levels, indicating improved lipid metabolism.
Further analysis revealed that silymarin positively influenced the expression of several liver enzymes involved in lipid metabolism, such as FASN, ACC, Apo-VLDL II, FXR, and CYP7A1. Apo-VLDL II is particularly noteworthy because it plays a crucial role in transporting triglycerides to growing oocytes in laying hens[2]. By enhancing the expression of these enzymes, silymarin helps regulate lipid metabolism more effectively.
The study also explored the impact of silymarin on the cecal microbiota, the community of microorganisms in the gut. Silymarin supplementation altered the composition of the cecal microbiota, increasing the abundance of species associated with secondary bile acid synthesis. This change in microbiota composition could further support improved lipid metabolism and overall liver health.
Targeted metabolomics identified nine metabolites, primarily involved in thiamin metabolism, that were significantly different in the silymarin-supplemented groups. These metabolites could play a role in the observed improvements in liver function and egg production.
The findings of this study align with previous research on liver lipid metabolism in poultry. For instance, earlier studies have shown that the liver is a major site of lipid synthesis and metabolism in chickens, particularly in laying hens[3]. The presence of specific lipoproteins like Apo-VLDL II ensures efficient delivery of triglycerides to the oocyte, which is essential for egg production[2]. Moreover, factors such as restricted movement and increased production in different housing systems can influence hepatic lipid metabolism and predispose hens to conditions like fatty liver hemorrhagic syndrome (FLHS)[4].
In conclusion, the study from Hunan Agricultural University demonstrates that dietary supplementation with silymarin can significantly improve egg production rates in late-stage laying hens by enhancing hepatic lipid metabolism and cecal microbiota function. Among the different concentrations tested, 500 mg/kg of silymarin showed the best overall effects, making it a promising feed additive for regulating liver lipid dysregulation in poultry.
NutritionHealthAnimal Science
References
Main Study
1) Dietary silymarin improves performance by altering hepatic lipid metabolism and cecal microbiota function and its metabolites in late laying hens.
Published 13th July, 2024
Journal: Journal of animal science and biotechnology
Issue: Vol 15, Issue 1, Jul 2024
Related Studies
2) Apolipoprotein VLDL-II inhibits lipolysis of triglyceride-rich lipoproteins in the laying hen.
Journal: Journal of lipid research, Issue: Vol 31, Issue 3, Mar 1990
Related Articles
25th May, 2024 | Jim Crocker