List the strengths and limitations of the two analytical met

List the strengths and limitations of the two analytical methods for evaluating feedstuff: Proximate Analysis and Van Soest detergent method. Feel free to use outside resources besides your textbook and lecture material but properly cite the resources used.

Solution

Two methods of evaluating feedstuffs are given. These are \"Proximate Analysis\" and \"Van Soest detergent method\".

Proximate Analysis:

This method is a quantitative method for determining the amount of macronutrients in feedstuffs. The compounds present in feed are partitioned into six categories. These categories are based on the chemical properties of the compounds. The method is a fast analysis. But the limitation is that it is just a partitioning technique. It partitions compounds on the basis of similar chemical characteristics that they have. So, it determines not the nutrients present in feedstuffs; infact it determines moisture, ash, crude protein, crude lipid, crude fiber etc. by partitioning nutrients from non-nutrients.

This method has been replaced by “Van Soest detergent method”. In this method, analysis of fiber present in the feedstuff is done. Plants cells have more and less digestible cell walls. The more digestible walls are those which contain starch and sugars. The less digestible are those cellulose, hemicellulose and lignin. These two types of fibers are separated using acid and neutral detergent respectively. The acid detergent fiber is an indicator of digestibility and energy intake. On the other hand, neutral detergent fiber is an indicator of feed intake.

So, Van Soest detergent method is useful in determining the feed intake and digestible feed intake in ruminants. It is a good method in comparison to Proximate Analysis. However, some limitations of the method include: