Nine lactating crossbred Friesian cows were used just after the lactation
peak along with the "Swing Over" method, to examine the effect of replacing maize
silage with ears (MS) by water hyacinth silage (WHS) in3 rations on nutrierit
digestibility and milk production. Cows averaged 472 kg live body weight, at 2^nd to 4th
parities. Cows were fed for 140 days according to allowances of NRC for dairy cattle
(1989). Tested rations consisted of: concentrate feed mixture (CFM)+ (100% MS) as
Control ration (CR), CFM + (75% MS + 25% WHS) as tested ration 1 (TR1), CFM +
(50% MS + 50% WHS) asTR2. The results obtained didn't reveal any significant differences between CR
and TR1 in the digestion coefficients of CP , EE , CF , NFE and feeding value as TDN
& DCP. All values of CR and TR1 were significantly (P<0.05) higher than those of
TR2. Total DM, TDN, DCP intake were in the following order: CR>TR1>TR2. The
daily milk yield, FCM and fat% were significantly (P<0.05) higher for CR and TR 1 than
that obtained with TR2. Only fat percentage, among milk constituents showed
significantly (P<0.05) higher values for cows fed CR and TR1 than those of TR2.
Cows fed TR1 attained the best feed conversion, economic efficiency and feed cost/
kg milk as compared with those fed CR or TR2. It could be recommended to use WH
silage along with MS, in a proportion of 1:3 beside CFM, in dairy ration to improve
considerably milk productivity and decrease cost of milk production I kg than that
obtained by using ration contained 100% MS with CFM.