MILK PRODUCTION, SOME RUMEN PARAMETERS AND FEED UTILIZATION EFFICIENCY OF LACTATING GOATS FED RATIONS CONTAINING BERSEEM SILAGE AND THEIR MIXTURE WITH BARELY OR MILLET X NAPIER GRASS HYBRID.

The effect of using berseem silage and its mixtures with barely or millet x napier grass hybrid in diets of lactating goats on their performance for milk production and feed conversion efficiency was studied. Eighteen Zaraibi does with average body weight of 40.0 kg were divided randomly into three equal groups (6 in each group). All animals were fed concentrate feed mixture  (CFM) to cover 40% of requirements recommended by NRC (1981). Besides ad libitum silage supplement, where berseem silage offered to group 1(G₁), silage made of 50% berseem – 50% barley to group 2 (G₂) and silage made of 50% berseem – 50% millet x Napier grass hybrid to group 3 G₃. The feeding trails lasted 14 weeks. The obtained results showed that the crude protein (CP) and ash of berseem silage were higher (14.61 and 12.31%, respectively) than the other silages. But, the crude fiber (CF), ether extract (EE) and nitrogen free extract (NFE) were lower in berseem silage (28.84, 2.29 and 41.95%, respectively) compared with their mixtures with barely or millet x napier grass hybrid. The daily feed intake as g/h, %BW and g/h w^0.75 was increased with mixture silage (G₂ and G₃) compared with berseem silage alone (G₁). The effect of the experimental rations on daily water consumption was not noticeable.
                As for ruminal parameters, ammonia-N concentration was significantly (P< 0.05) higher with berseem silage (G₁) compared with G₂ and G₃. But, ruminal total VFA's concentrations and microbial protein were significantly (P< 0.05) lower with G₁ compared with G₂ and G₃ during 2 and 4 hrs post-feeding. The effect of the tested rations on most blood parameters was not significant (P< 0.05).
                As for milk production, the obtained data showed that milk yield of dairy goats was significantly (P< 0.05) decreased  with G₁ (1.339 kg/h/d) compared with G₂ (1.601 kg/h/d) and G₃ (1.550 kg/h/d).  Milk composition as fat, protein, lactose, total solids, solids non fat and ash for the three treatments were fluctuated without significances. Accordingly, the feed conversion efficiency based on DM and CP, was better with G₂ (0.901 and 0.125, respectively) and G₃ (0.911 and 0.123, respectively) compared with berseem silage alone, G₁(1.01 and 0.145, respectively).