Sensory evaluation, physical examination, water stability test and palatability test are alternative methods for evaluating the quality of feeds without the use of laboratory equipment as following:

Feed quality problems indicators include:

-        Minimal   or no improvement after drug or antibiotic treatment.

-        Signs   of   rancidity.

-        Disease occurrence that is associated with a particular feed batch.

Smell and taste

-        Depends on experience, can spot major formulation changes as, fresh feeds have  a  pleasant  odor, high protein (> 30%) diets possess a strong odor of animal meal, old  feeds  has weak odor, spoiled  feeds have  a musty smell due to fat rancidity and fungal growth, and spoiled feeds taste sour, bitter, or rancid.

Moisture and hardness

-        Moist feeds are quite soft and easily compressed. When placed in a bottle/bag and shaken, the sound is muffled and does not move freely.

Color

-        Feed color reflects the type of raw, cooking temperature, degree of cooking.   Feed deterioration also affects the color.