Fiber Analysis (NDF and ADF)
📌 Fansus analysis involves two main components: Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF), which are crucial for determining feed digestibility in ruminants and non-ruminants.
⚖️ This analysis categorizes feed components into cell contents (soluble in acid/base solvents) and cell walls (insoluble).
💧 NDF represents the cell wall fraction, consisting of lignin, cellulose, hemicellulose, and associated protein; it is the portion insoluble in Neutral Detergent Solution (NDS).
🔬 ADF represents the residue remaining after treating NDF with Acid Detergent Solution (ADS), primarily comprising cellulose and lignin.

Relationship Between NDF and ADF Components
➡️ Netral Detergent Soluble (NDS) represents cell contents like lipids, starch, protein, and sugars, which dissolve in the neutral detergent solution.
🌲 Hemicellulose is determined by the difference: Hemicellulose = NDF - ADF, confirming that NDF values must always be higher than ADF values.
🧪 Acid Detergent Soluble (ADS), which dissolves out of the NDF fraction, is primarily hemicellulose, while ADF is the residue (cellulose + lignin + silica).

Determination of Lignin and Cellulose
🔥 Lignin is determined by treating ADF with concentrated $\text{H}_2\text{SO}_4$ (72-75%), which dissolves cellulose, leaving lignin and silica; subsequent ashing (burning) isolates the lignin by measuring the weight loss (ash/silica remains).
🔴 Alternatively, lignin can be oxidized using $\text{KMnO}_4$, leaving cellulose and insoluble ash.
☣️ The $\text{H}_2\text{SO}_4$ method is corrosive and requires a fume hood, while the $\text{KMnO}_4$ method is safer but longer; however, $\text{H}_2\text{SO}_4$ is often used because the reagent is readily available.

Comparison with Proximate Analysis
📊 Components like crude protein, crude lipid, and NFE (Non-Fiber Carbohydrates) generally fall under Neutral Detergent Soluble (NDS) in the Fansus system.
🔗 Some proteins and nitrogen-containing compounds may be insoluble protein bound to fiber, potentially dissolving in the acid step ($\text{ADS}$), unlike the simple partitioning in proximate analysis.
📈 The NDF method is best suited for analyzing feeds with high fiber content and can be biased if used on feeds with high crude protein ($\text{CP}$) or very low fiber.

Key Points & Insights
➡️ Digestibility is directly impacted by the ADF and NDF fractions of the feed material.
➡️ Hemicellulose can be calculated as the difference between NDF and ADF (NDF - ADF), where NDF contains hemicellulose, cellulose, lignin, and silica.
➡️ When using $\text{KMnO}_4$ to analyze lignin, the weight loss from burning after oxidation determines the amount of lignin present, leaving behind cellulose and insoluble ash/silica.
➡️ The $\text{H}_2\text{SO}_4$ method for lignin determination necessitates strict safety protocols due to the corrosive nature of the acid and the need for a fume hood.

📸 Video summarized with SummaryTube.com on Nov 19, 2025, 07:22 UTC