Responses of beef heifers developed with compensatory growth during gestation

Objectives were to determine responses of an imposed compensatory growth pattern during gestation in beef heifers on subsequent lactation potential and to define effects of compensatory growth on maternal and calf performance more clearly. In experiment one, gestating beef heifers were assigned to one of two dietary treatments: (1) conventional (CON) or (2) stair-step (SS) compensatory growth nutrition regimen. Treatments were imposed at d 90 of gestation for 180 d. The CON diet was formulated for a constant gain of 0.49 kg/d throughout the feeding period. The SS diet was formulated to provide 65% of the metabolizable energy intake of CON heifers for 90 d, followed by 25% more metabolizable energy in the last 90 d of gestation. The compensatory growth nutrition regimen did not adversely affect maternal or calf performance at parturition or during the calf nursing period. The stair-step nutrition regimen with 90 d energy restriction and 90 d re-feeding of energy did not affect lactation yield or calf weight compared to CON heifers. In experiment two, gestating beef heifers were assigned to one of two dietary treatments: (1) CON or (2) SS compensatory growth nutrition regimen. Treatments were imposed at d 90 of gestation for 180 d. The conventional diet was formulated for a constant gain of 0.68 kg/d throughout feeding period. The SS diet was formulated to provide 65% of the metabolizable energy intake of CON heifers for 120 d, followed by 25% more metabolizable energy in the last 60 d of gestation. Neither maternal or calf performance was adversely affected by imposed compensatory growth in the last 60 d of gestation. Although a compensatory growth response was observed in SS heifers, lactation yield was not affected by dietary treatment in experiment two. The results of this research suggest that compensatory growth can be imposed during gestation without impaired performance of beef heifers or their nursing calf.