Deferred rate of gain effects on growth, body composition, and concomitant blood metabolites in yearling Angus and Brangus heifers

Deferred supplementation of subtropical forage diets may be a viable nutritional strategy to elicit compensatory growth of growing heifers. This experiment evaluated delayed BW gain on body composition of yearling heifers fed bermudagrass round bale silage (RBS) and dried distillers grains (DDG) for 140 d. Angus (n = 30; 273 ± 24 kg) and Brangus (n = 30; 277 ± 30 kg) heifers, mean age of 277 ± 25 d, were allocated to 1 of 12 pastures. On d 0, heifers were assigned to either (1) RBS + DDG fed to gain 0.84 kg/d from d 0 to 140 (control) or (2) RBS offered ad libitum from d 0 to 70 and RBS + DDG fed to gain 1.4 kg/d from d 70 to 140 (DL). On d 70, control heifers were heavier (P < 0.05) and had greater (P < 0.05) BCS, ultrasound rib fat, rump fat, and LM area (LMA) than DL heifers, whereas intramuscular fat (IMF) was not different (P > 0.05). On d 140, BW tended to be (P = 0.06), and LMA, BCS, and rump fat were, greater (P < 0.05) for control than DL, and rib fat, IMF, and LMA as a percentage of BW were not different (P > 0.05). Irrespective of treatment, hip height, pelvic area, and IMF increased (P < 0.05) over time. Delayed BW gain affected BCS, LMA, and blood metabolites but did not affect skeletal measurements, IMF, and LMA as a percentage of BW during realimentation. Deferred supplementation and delayed growth can be a viable management practice for developing heifers on forage systems.