Influence of varying levels of rumen degradable to undegradable protein on milk yield, composition and some blood parameters of Karadi ewes

الملخص EN

Twenty-four lactating Karadi ewes, 3-5 years old and 54±0.69 kg in body weight were used to study the effect of rumen degradable protein (RDP) to rumen undegradable protein (RUP) ratio on milk yield, composition and some blood metabolites.

Ewes with their lambs were placed in individual pens and fed ad libitum on three rations containing different levels of RDP:RUP namely 68:32 (T1), 56:44 (T2) and 50:50 (T3).

Milk yield was recorded in two successive days at biweekly intervals commencing at 2nd week post lambing by using hand milking and lamb suckling technique.

Also, blood samples were withdrawn at start, mid and at the end of the experimental period (84 days).

Daily milk yield and total milk yield averaged 1.16±0.038 and 98.31±4.44 kg, respectively.

Feeding ewes protected soybean meal (SBM) resulted in a nonsignificant increase in milk yield in T3 (15.22 %), and 12.06% in fat corrected milk (FCM) in T2 as compared to control.

A significant (P < 0.05) effect of treatment on both percentage and yield of fat and protein was observed.

However, the highest fat percent and yield was recorded in T2, whereas, the highest percent and yield of protein was noticed in T2 and T3, respectively.

Cholesterol and urea levels was significantly (P<0.05) lower in T1 as compared to other groups.