Effects of early management system and subsequent diet on growth and conception in maiden buffalo heifers

The aim in the present study was to determine the relative effects and interactions between long term and short term nutritional management on live weight (LW), conception and pregnancy rate at first mating in buffalo heifers. Heifers had experienced two management systems from the time of weaning and, at the start of the study, heifers from management system A (n = 19) and management system B (n = 34) had a similar LW (308 +/- 39 kg) but differed substantially in age (456 +/- 38 and 693 +/- 114 days, respectively). During a 5-month mating period, heifers were randomly assigned to two dietary treatments that differed in CP/NSC ratio (0.84, n = 27 and 0.51, n = 26). The two dietary treatments had no apparent effects on daily weight gain (DWG), age at conception or LW at conception, and results are therefore considered for management system. Heifers from management system B had a higher (P < 0.01) DWG than heifers from management system A (696 +/- 26 and 446 +/- 34 g/day, respectively), However, heifers from management system A conceived at a younger age (P < 0.05) and lower LW (P < 0.01) compared with heifers from management system B (age, 543 +/- 16 and 844 +/- 11 days; LW, 364 +/- 10 and 391 +/- 7 kg). Pregnancy rates after the 5-month mating period were similar for heifers from management system A (47.4%) and management system B (52.9%). The outstanding advantage of management system A. therefore, was that heifers conceived at a younger age. It is concluded that nutritional management and growth from the time of weaning and during the pre-pubertal period has a major influence on age and LW at first conception in buffalo heifers. Also, the negative effects of early nutritional deficiency on reproductive function are not overcome by a relatively short term period of dietary supplementation. (C) 2001 Elsevier Science B.V. All rights reserved