Effect of dietary energy level on nutrient utilization, rumen fermentation, productive and some reproductive performance of pregnant buffalo heifers [electronic resource].

Includes references.

Twenty-Two pregnant buffalo heifers were divided into three groups (G2, Gland G3) fed different dietary energy levels. Iso-nitrogenous rations with three levels of dietary energy (80, 100, 120 %TDN of allowances), respectively. Feeding experiment was started from the first 3 months of gestation till the first 120 days of lactation. Ages and live body weight at the beginning of experimental were (658.75,715.13 and 653.13 days old and 450.88, 428.43 and 467.25 kg body weight, for GI, G2 and G3, respectively). Animals received normal and high energy level (G I or G3) during pre and postpartum period recorded the highest digestibility values ofDM, OM, CP, EE and NFE as will as feeding values (roN and DCP) compared to those fed on 80 % TDN (G2), differences were significant and highly significant, respectively. While, CF digestibility was high significantly (P<0.05) improved for low energy level (G2). Daily gain, body condition score of heifers fed nonnal or high energy levels were significantly (P<O.05) better than those fed low energy level. Feed conversion (kg DMI and DCPI I kg gain) was poorer in G2 and G3 than those in GI at 9 months of gestation. The differences were significant only between GI and G2. While, feed conversion as TONI kg I kg gain was better (P<O.05) in G2 than in Oland 03 at 9 months ofgestation. Also, animals received normal and high energy level (G I and G3) recorded (P<0.05) average live body weight, live body weight changes, relative' change to initial body weight and body condition score at first lit month after calving, at first 4 month after calving and least number of services per conception, however, treatment (02) showed the poorest (P<O.05) mean values. Dietary energy level did not affect ruminal pH value. Concentration of ruminal NHrN and VFA'S were significantly higher for heifers fed nonnal and high energy level groups (G I and G3) Ihan that of the low energy level (G2) group. Also, animals received (100 or 120 % TDN) GI and G3 recorded higher mean body (P<0.05) weight just before calving, calf birth weight, placenta weight and fetus liquid weight than those of02 group (80% TDN). While, those fed (80% TDN) G2 recorded higher mean age at first calving and drop of fetal membrane than those 0 I and G3 groups. A shorter interval to the first postpartum estrus, service period and days open were recorded for buffaloes dam of G1 and 03 compared to those fed G2 treatment. At the same time animals fed normal level (GI) recorded higher (P<0.05) average daily milk, 7 % FCM, fat, protein, lactose, TS, SNF and Ash yields than those ofG2 or G3 treatments (80 % and 120 % TDN) but, milk.

Summary in Arabic.

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