Differentiate between Feed Conversion Ratio and Feed Efficiency Ratio. Explain how to calculate them.

Feed Conversion Ratio (FCR) and Feed Efficiency Ratio (FER) are both metrics used in animal agriculture to assess the efficiency of feed utilization, but they measure slightly different aspects of the process.

Feed Conversion Ratio (FCR):
FCR is a measure of how efficiently an animal converts feed into body mass or product. It is calculated by dividing the total amount of feed consumed by the animal by the weight gain or product output during a specific period. The formula for FCR is:

[ FCR = \frac{{Total\,Feed\,Consumed}}{{Weight\,Gain\,or\,Product\,Output}} ]

A lower FCR indicates better feed efficiency, as it means the animal is gaining weight or producing more product using less feed.

Feed Efficiency Ratio (FER):
FER is similar to FCR but takes into account the energy content of the feed. It measures the amount of energy in the feed relative to the energy in the animal's output, such as weight gain or product production. The formula for FER is:

[ FER = \frac{{Energy\,in\,Output}}{{Energy\,in\,Feed}} ]

Like FCR, a higher FER indicates better feed efficiency, as it means the animal is producing more output per unit of feed energy consumed.

Calculation:

1. Feed Conversion Ratio (FCR):

   • Determine the total amount of feed consumed by the animal during a specific period (e.g., kilograms or pounds).
   • Measure the weight gain or product output of the animal during the same period (e.g., kilograms or pounds).
   • Divide the total feed consumed by the weight gain or product output to calculate FCR.

2. Feed Efficiency Ratio (FER):

   • Calculate the energy content of the feed consumed by the animal.
   • Measure the energy content of the animal's output (e.g., weight gain or product production).
   • Divide the energy content of the output by the energy content of the feed to calculate FER.

Both FCR and FER are important indicators of efficiency in animal production systems and are used by producers to optimize feed formulations, management practices, and overall profitability.