1. The Interaction of Microalgae Dietary Inclusion and Forage-to-Concentrate Ratio on the Lipid Metabolism-Related Gene Expression in Subcutaneous Adipose Tissue of Dairy Goats.
- Author
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Kyriakaki, Panagiota, Mavrommatis, Alexandros, and Tsiplakou, Eleni
- Subjects
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UNSATURATED fatty acids , *GOATS , *LIPID metabolism , *GENE regulatory networks , *ADIPOSE tissues - Abstract
Simple Summary: Polyunsaturated fatty acids (PUFAs), especially those obtained from microalgae, are an efficient and sustainable strategy to enrich ruminant products with biofunctional molecules. However, the high dietary inclusion needed to substantially affect product quality can also bring negative effects on lipid metabolism. The dietary forage-to-concentrate ratio (F:C) is also a lever to drive metabolic functions, including lipid metabolism, with the advantage of its easy manipulation. To address this hypothesis, we conducted an experiment assessing the interaction of two inclusion levels of Schizochytrium spp. (20 or 40 g/day), a microalga rich in PUFA, and two F:C ratios (60/40 or 40/60) on regulating gene networks involved in lipid metabolism in goats' tail fat. Results showed a decreasing gene expression under the effect of high microalgae levels or the high-grain diet. However, when the diet was based on forages, the negative effect of high microalgae levels on lipogenic gene expression was more attenuated. Long-chain polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) have been shown to be effective in enhancing the quality of ruminant products, including meat and milk. However, under these dietary conditions, the de novo lipogenesis could be influenced, too. On the other hand, even if the forage-to-concentrate ratio (F:C) is also a key factor affecting lipid metabolism in small ruminants, there is scarce information about its interaction with dietary PUFA. This study investigates the potential of the F:C ratio as a lever to manipulate lipid metabolism in dairy goats under high dietary PUFA supplementation. For this purpose, twenty-two crossbred dairy goats [Alpine × Local (Greek) breeds] (BW = 50.6 ± 6.1 kg) at early lactation (70 ± 10 days in milk) during the age of 3–4 years old, were separated into two homogeneous subgroups (n = 11). In the first phase, each goat was fed 20 g Schizochytrium spp./day followed by either a high-forage (20 HF) or a high-grain (20 HG) diet, while in the second phase, each goat was fed 40 g Schizochytrium spp./day followed once again either a high-forage (40 HF) or a high-grain (40 HG) diet. The F:C ratio of a high-forage and high-grain diet was 60:40 and 40:60, respectively. Tail fat tissue samples were collected by biopsy on the 42nd day of each experimental phase (last day). Significant decreases (p < 0.05) in the gene expression of ACACA, CBR2, COX4I1, ELOVL5, ELOVL7, LEP, and SCD were presented in goats fed 40 g compared to those fed 20 g Schizochytrium spp., while the gene expression of ACACA, AGPAT2, AGPAT3, ELOVL5, ELOVL6, EPHX2, FASN, and SCD was decreased in high grain compared to high-forage diets. This study also indicated that with the aim to enrich goat products with PUFA by increasing their levels in the diet, lipid metabolism is negatively affected. However, a diet with higher forage inclusion can partially attenuate this condition. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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