EFFECT OF FEEDING LEVEL REGIMES ON: 3- PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF PREGNANT BUFFALO HEIFERS AT FIRST SEASON MILK

This objective of this experiment was to study the effect of plane nutrition with reference to the compensatory growth as well as productive and reproductive performance of buffalo heifers. Eighteen growing buffalo heifers averaged 156 days and 110 kg body weight were allotted randomly into three similar groups of six each at the beginning of the first part of experiment as published Shahin et al., (2016). The live body weight at the beginning of the second part of experimental period (at first service) was 347.83, 339.33 and 349.0 kg and age of 517.25, 571.69 and 594.66 days for groups R1, R2 and R3, respectively, as published (Mona et al., 2016). The live body weight at the beginning of the third part of experimental period (present one) of the experiment (at 3 mo of gestation) was 408, 398.4 and 399.9 kg and age of 624, 676 and 693 days for groups R1, R2 and R3, respectively. All nutritional allowance of all groups were calculated according to the standard of Kearl, (1982) where group R1 fed 100% of their allowances up to the end of the experiment (control), R2: fed 80% of their allowances until heifers grow up to 300 kg, and then switched on 100% up to the end of the experiment, while R3 fed 80% of the allowances over the whole experimental period that extended up to 105d lactation season. Results indicated that nonsignificant differences among dietary treatments were found respectively all nutrient digestibilities and feeding values (TDN and DCP). Despite CF digestibility was somewhat higher with 80% treatment (R3) than the others (R1 and R2). Also, digestibility of DM, CP and EE were slightly improved with R2 compared to those of the other treatments. Regarding growth performance, results showed that weights at 3, 6 and 9 months of gestation as well as just before calving were almost similar among dietary treatments. However, heifers fed R2 recorded significant higher total gain and daily gain at most growth phases in comparison with the other two feeding regimes (R1 and R3).  Feed conversion ratio was better with heifers fed R3 followed by those fed R2, while those on R1 had the poorest values. The BSC at all measuring times were higher significantly with R1 than those of  R2 and R3 treatments and as well as the values of R2 were significant higher than those of R3. Calf birth weight were not influenced by dietary treatments or BSC at calving, however R2 (feed restriction at 80%) had the highest calf birth weight. Also, heifers fed R2 recorded significant lower time required for closure of the cervix, position of the uterus and uterine horns symmetry city and the lowest values of the NS/C after the 2^nd service (1.33) compared with the other treatments.  Milk yield was significant higher with R2 (restricted feed group) than that of the other treatments (R1 and R3), while milk composition (fat, protein, lactose, TS, SNF and ash) were not significant.  It could be concluded that feeding growing buffalo heifers at 80% of feeding allowances according Kearl (1982) up to 300 kg live body weight and the fed on 100 of allowance along the successive stages (puberty and gestation and up to 105-d lactation season) were more suitable for productive and reproductive performance of heifers.