This study aimed to evaluate the effect of the inclusion of Sesbania sesban hay (SH) at rates of 10, 20, and 30% in the rations on the expense of berseem hay (BH) on milk yield and composition, reproductive performance of Ossimi ewes, and the growth performance of their offspring. Thirty-six Ossimi ewes with the initial average body weight of 38.31 ± 0.91 kg were chosen prior to 30 d of lambing and used in a randomized complete block design with four experimental rations. Rations were formulated as follow: R1 (60% concentrate feed mixture (CFM) and 40% BH) and served as control, while the tested rations R2 (60% CFM + 30% BH + 10% SH), R3 (60% CFM + 20% BH + 20% SH) and R4 (60% CFM + 10% BH + 30% SH). The feeding trial was started at the last month of gestation, through the delivery, and lasted along the lactation period.
Results demonstrated that feed conversion was somewhat lower with the inclusion of rations by SH. The inclusion of the SH in all tested rations significantly increased blood serum urea-N concentrations. In addition, serum total protein, albumin, cholesterol, ALT, and glucose concentrations were significantly increased (P<0.05) with R4 compared with those of control one. The inclusion of SH at 20% (R3) and 30% (R4) resulted in a decrease (P<0.05) in milk yield. Substitution of BH by SH at 30% (R4) led to a reduction (P<0.05) in milk fat compared to the rest of the other groups. In contrast, milk protein values followed the opposite trend for milk fat values. Otherwise, concentrations of lactose, total solids, and SNF didn't significantly change by dietary treatments. The interval from lambing to first estrus (d) for ewes fed on SH was longer than ewes fed on control. Comparably, estrus duration (hour) showed an increasing trend as increasing SH level in the rations. While SH supplementation in ewe's rations decreased both P4 and E2 concentrations (P<0.05) compared to those of control one. The economic efficiency was noticeably higher with the inclusion of SH in ewes' rations. Accordingly, it could be concluded that substitutions up to 30% of BH by SH for ewes' rations have not left any adverse effects on productive and reproductive performance, as well as the favorable metabolic parameters reflected in the high economic efficiency of the experimental rations that provisionary depending on the cost and the availability of berseem hay.