A researcher dried a feedstuff and determined that it contained 10 percent moisture. he took 1 gram (dry) of it and combusted it in the bomb calorimeter. the calorimeter contains 1 kg of water. The temperature was raised 2.7 degrees centigrade. Two kilograms (2000 grams) of dry matter of the material was fed to a pig each day for several days. the fecal collections of the pig averaged 200 grams dried per day for the last few days. the feedstuff analyzed 2.41 percent nitrogen (dry basis); the feces (dry basis) analyzed 4.6 percent nitrogen. (hint: the feedstuff contained _ grams protein, the feces contained _ grams protein.)

The objective of the information given is to calculate the apparent digestible dry matter present in the feedstuff(%) and the apparent digestibility of the protein?

From the given information:

The apparent digestible dry matter present is:

[tex]=\dfrac{ (\text{Dry matter fed to the pig} - \text{Fecal matter of the pig} )}{\text{Dry matter fed to the pig}} \times 100 \%[/tex]

where;

Dry matter fed to the pig = 2kg = 2000 g

Fecal matter of the pig = 200

∴

The apparent digestible dry matter present = [tex]\dfrac{2000-200}{2000}\times 100\%[/tex]

[tex]=\dfrac{1800}{2000}\times 100\%[/tex]

= 90

Amount of Nitrogen(i.e. the protein) content present in the feedstuff = 2.41%

i.e.

2.41 g/100 g OR 48.2 g/2000 g feed

Amount of protein present in feces = 4.6% (4.6 g/100 g OR 9.2g/200g of feed)

∴

apparent digestibility of the protein is:[tex]=\dfrac{\text{Amount in feed }- \text{Amount in feces}}{\text{Amount in feed }}\times 100[/tex]

[tex]= \dfrac{(48.2 - 9.2)}{48.2}\times 100[/tex]

[tex]= \dfrac{39}{48.2}\times 100[/tex]

= 81%