A yearling heifer consumes 907 kg as fed of feed and excrete

A yearling heifer consumes 9.07 kg (as fed) of feed and excretes 6.11 kg of wet feces daily. The feed is 90% dry matter and the feces are 20% dry matter. The composition of the ration and the digestion coefficient of each diet component are as follows Calculate the Digestible Dry Matter content of this diet

Solution

The net dry matter of the feed is = 9.07 x 90/100 = 8.16Kg [because the feed has 90% dry matter]

Ash is 3.6% of total dry matter of feed 8.16 Kg, therefore Ash weight is = 8.16 x [3.6 /100] = 0.29Kg

The digestibility coefficient is 52% so total digested weight = 0.29 x 52/100 = 0.15 Kg

For neutral detergent fiber 45% is = 8.16x 45% = 3.67 Kg

And the digestibility coefficient is 45% so total digested weight = 3.67 x 45/100 = 1.65 Kg

Now by doing same procedure for others

Non – fiber carbohydrates = 2.93 Kg and 2.7 Kg

Ether Extract = 0.2Kg and 0.18 Kg

Crude protein = 1.06 Kg and 0.82Kg

So the digestible content of the feed is = 0.15 + 1.65+2.7+0.18+0.82 = 5.5Kg. This digestible content is for dry matter of the feed. The faces has 20% dry matter so, the rest of the dry matter [100-20 = 80%] would be account for the dry matter of diet.

That is = 5.5 x 80% = 4.4Kg.