Classification of feeding standards

A. Comparative type feeding standard:

1. Hay standard:

• In 1810 German Scientist Albert Thaer gave a concept of “ hay equivalent” as a measure of relative value based on determining the materials in feed extractable with water or other solvents.
• This standard provided that 100 lbs. of meadow hay was equal in nutritive value to 91 lbs. of clover hay 200 lbs. of potatoes, and 625 lbs. of mangels.
• This standard Only compared the value of hay and potatoes for milking cows, but did no analysis.
• Nothing was known about the chemical value of these feeds and the physiological requirements of animals and gave the practical feeding experience only.

2. Scandinavian “feed unit” standard:

• Given by Professor Fjord in 1884.
• Only the feed unit was taken into account.
• According to this standard, one feed unit is required for every 150 lbs. of body weight and an additional feed unit for every three pounds of milk production.
• Was based upon the actual milk production record of the farm animals.

B. Digestible Nutrient type feeding standard:

1. Grouven’s feeding standard:

• Given by Grouven, a German chemist in 1859.
• According to this standard, a cow weighing 1,000 lbs should be fed 28.7 lbs. of dry matter containing 2.67 lbs. of crude protein, 0.6 lbs. of crude fat, and 14.55 lbs. of crude carbohydrate.
• Now abandoned as the proportion of digestible parts varied with different feeds.

2. Wolff’s feeding standard:

• Given by Dr. Emil Von Wolff in 1864.
• Standard is based on digestible protein, digestible carbohydrates, and digestible fats contained in feedstuffs.
• He calculated the ratio of digestible protein to digestive carbohydrate, called the Albuminoid ratio.
• Later the albuminoidration developed as nutritive ratio which is the sum of digestible carbohydrate, digestible protein, and 2.25 x digestive fat, divided by digestive protein.
• This standard doesn’t consider the quantity and quality of milk produced.

3. Haecker’s feeding standard:

• Recognized that the food requirements must vary by the composition of the product.
• Separate requirements for maintenance from the requirements of production.
• Took into account the allowance for the percentage of fat in the milk in addition to the requirement for maintenance, production, and total milk yield.
• Includes digestible crude protein, carbohydrates, and fats which later were expressed in digestible crude protein and total digestible nutrients.

4. Savage feeding standard:

• Developed as Haecker’s standard was too low, especially in protein.
• He expressed his standard in terms of DCP and TDN and further showed that about 2/3 requirement of the dry matter should be met by feeding roughages and the remaining 1/3 from concentrates.
• He suggested that in the case of milking cows, at least 24 lbs. of dry matter should be provided for an average cow. The nutritive ratio should not be wider than 1:6 or narrow than 1:4.5.

5. Morrison feeding standard:

• B. Morrison observed that stockmen are spending large sums of money for entirely unnecessary amounts on protein supplements, thus considerably reducing their profits.
• He, therefore, combined nutrient requirements in one set of standards later known as the “Morrison feeding standard”.
• Standards include Dry matter (DM), Digestible protein (DP), and total digestible Nutrients (TDN).
• He indicated the nutrient requirement of animals in a range rather than in one figure.

C. Production value type feeding standard:

1. Kellner feeding standard:

• Given by Kellner, a German Scientist in 1907.
• Takes into account not only the digestibility of the feeds as calculated from the amount lost in feces and urine but also the entire loss from the body including energy expended in digestion and passing the food inside the body( Chewing).
• To measure the heat loss from the body, Kellner devised a respiratory apparatus.
• Heat is determined indirectly by finding the amount of CO₂ liberated or by oxygen gas used in oxidation.
• According to this system, a 1,000 lbs. animal needs 0.6 lb. of digestible protein and 6.35 lbs. of starch equivalent.

2. Armsby feeding standard:

• Given by Armsby in 1917 and is based on true protein and net energy values.
• Using the respiration calorimeter, Armsby determined the net energy required for mastication, digestion, assimilation, and also the amount of heat and gases given off through the excretory channel.
• After considering losses of energy such as in urine, feces, gases, and in the work of digestion, he was able to estimate the amount of net energy available for productive processes
• A common criticism of the Armsby standard is that the expense of determining the requirements of the animals and the net energy in the various feeds is excessively high.

Merits of feeding standards

• Consists of the quantity of nutrients required by an animal to remain healthy and highly productive.
• Are by productivity, composition of the product, and physiological condition.
• Serves as guides in feeding animals and in estimating adequacy of feed intake and feed supplies for groups of animals.

Limitations of feeding standards

• Is not a complete guide to feeding because other factors such as palatability and the physical nature of the ration are not taken into account.
• The environment may change nutrient requirements.
• Doesn’t consider the economics of livestock production.
• It is misleading when unconventional feed resources are used.