Abstract :

 

T

his study was conducted to investigate the effect of different feeding levels on productive and reproductive performance and some body measurements of growing buffalo heifers during the period from first services up to ninetieth days of pregnancy. Eighteen buffalo heifers at the first services were divided into three treated groups (6 heifers each) and received their feeding allowance according to Kearl, (1982) in which animals in group one (R1) fed 100% of their allowances up to the end of the experiment (control) and those in group two (R2) fed 80% of the allowances until heifers grow up to  300 kg, and then fed 100% of the allowances up to the end of the experiment, while those in the third group (R3) fed 80% of the allowances during the whole experimental period. Average age of heifers at first service was 517.3, 571.7 and 594.7 days old and live body weight were 347.8, 339.3 and 349.0 kg for R1, R2 and R3, respectively. Results indicated that heifers fed 80% of the allowance (R3) recorded the lowest values in most of nutrient digestion coefficients and feeding values (TDN and CP%) in comparison with the other experimental groups, while CF digestibility had the inverse trend. Also, animals in R3 recorded the lowest (P<0.05) blood constituents and oldest ages at first service and conception than those in other experimental groups. Heifers fed 100% of the allowance (R1) recorded the higher body condition score than those in the experimental groups. There were significant differences between heifers in both R1and R2 in comparison with those in R3 respecting the most of growth performance parameters and animals in both groups (R1 and R2) were significantly better than those in R2. However, Heifers fed 80% of the allowance (R3) had a better (P<0.05) feed conversion ratio expressed as the amount of intake of DM, TDN or CP than those in R1 and R2 groups. Interval from puberty to the first service or to conception was significantly shorter for heifers in R2 than those in R1 and R3 groups. Number of oestrous cycles from Puberty to the first service or to the conception was significantly the lowest with heifers in R1 followed by those in R2 then the highest values were recorded with those in R3 group. It could be concluded that feeding growing buffalo heifers at first service on (R2) had more beneficial effect on heifers’ reproductive performance, indicating positive reflection on the subsequent first lactation season of primiparous cows under Egyptian condition.

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