The present study was designed to investigate the effect of three energy levels on the performance of Egyptian buffaloes. Eighteen pregnant buffalo cows six years old in the 3rd season of lactation and weighing on the average 561.06 ± 20.96 kg (at the last three months of pregnancy) were divided randomly into three similar groups. The experimental rations were isonitrogenous with three levels of energy (100, 80 and 120% TDN). The first group served as control and animals were fed ration (R1) containing CFM 45.22%, yellow corn 27.82% and berseem hay 26.96%. The second group was fed ration (R2) containing CFM 45.73%, yellow corn 25.12% and berseem hay. The third group was fed ration (R3) containing CFM 41.84%, yellow corn 31.59% and berseem hay 26.57%. Digestibility trial was conducted at the end of the experiment using three animals from each group.
The results showed that:
Buffaloes fed 80% dietary energy level recorded lower digestibility values of DM, OM, CP, CF, EE and NFE than those fed 100 and 120 % levels. The nutritive values as TDN or DCP for all groups were quite similar. Animal fed 120 % dietary energy level recorded heavier calf birth weight than those fed 100 and 80 % energy levels with no significant differences. Animals fed 120 % energy level recorded lower (P < 0.01) time lapsed to placenta expulsion (h), interval from calving to uterine horns symmetry and cervical closure (days), as well as number of cervices per conception than those fed 100 and 80 % energy levels. Interval from calving to complete uterine involution, to the first estrus and calving intervals (days) for animals fed 120 % energy level were significantly (P < 0.01) shorter than that fed 80 and 100% energy levels. Buffaloes fed 120 % energy level conceived 26.2 and 62.17 days earlier than those fed 80 % and 100% energy level, respectively. The differences in days open were significant (P < 0.01).Milk yield and fat, protein, lactose, total solids, solid not fat and ash as a percent for buffaloes fed 120 % energy level were significantly higher (P < 0.01) than those fed100 and 80% dietary energy levels. The animals received 120 % dietary energy level recorded highest (P < 0.01) progesterone (ng/ml) and 17-estradiol (pg/ml) than those fed 100 and 80% energy levels. Progesterone concentration increased slightly up to 15 days postpartum and decreased at 20 days then it increased up to 35 days postpartum. However, 17-estradiol concentration (pg/ml) behaved in an opposite trend,