Explanation:

Let's decode the pattern used in the given examples:

 DONKEY = 88

Assign numbers to each letter and change to opposite letter

D(4)------------->W(23)

O(15)------------>L(12)

N(14)------------>M(13)

K(11)------------>P(16)

E(5)------------>V(22)

Y(25)----------->B(2)

Now adding positional value of opposite letters.(W,L,M,P,V,B)= 88

Similarly 

SPARROW is coded as =79

and So on 

PEIGON is coded as 96.