Evaluation of Performance and Costs of Two Heifer Development Systems

Early weaned (EW) heifers must be developed for a longer period of time usually resulting in increased development costs. Developing EW heifers on native range may reduce these costs. Dried distillers grains plus solubles (DDGS) offers protein and energy that compliment native forages for developing heifers. The objective of this study was to evaluate the performance and costs of two heifer development systems in northwest South Dakota. Sixty-five nulliparous crossbred beef heifers were randomly allotted to one of two systems: 1) heifers (n=33) weaned at 132 d of age (461 lb) and developed on range with a DDGS supplement (1.8 to 6.4 lb/hd/d) from Sept. 25 to May 18 (Range); 2) heifers (n=32) weaned at 218 days of age (605 lb) and developed in a drylot with grass hay and a conventional supplement (2.6 to 3.6 lb/hd/d) from Dec. 2 to May 18 (Normal). Supplement levels were established to result in both groups of heifers reaching 65% of mature weight at breeding (863 lb). All heifers were managed similarly after May 18. Heifers were synchronized with a shot of PGF2α and bred natural service beginning June 14. As necessary for target weights to be reached, ADG through the feeding period was greater (P \u3c 0.05) for Range (1.68 lb/d) than (Normal 1.34 lb/d). Range heifers tended (P = 0.12) to be heavier on May 18 (859 and 830 lb, respectively) and were heavier (P \u3c 0.05) at breeding (915 and 834 lb, respectively). Weight differences in May were a result of higher than expected gains by the Range heifers in the spring. From May 18 to June 14, Range heifers gained more (P \u3c 0.05) than Normal (2.07 and 0.32 lb/d, respectively). Synchronized conception and overall pregnancy rates were similar (P \u3e 0.25) between the Range and Normal heifers (58% vs. 50% and 91% vs. 88%, respectively). Supplement and forage costs for the Range system was similar ($122/hd) to the Normal ($117/hd). Range development provides an alternative method for developing early-weaned heifers that reduces daily costs