256 Rye with or without purple top turnips for stocker calf grazing as part of a Southeastern U.S. integrated crop-livestock system

• Published in: Journal of animal science 2019-12, Vol.97 (Supplement_3), p.91-92
• Main Authors: Cox - O’Neill, Jordan L, Ott, Grace C, Harmon, Deidre D, Poore, Matt H, Eisemann, Joan H, Pickworth, Carrie L
• Format: Article
• Language: English
• Subjects: ORAL PRESENTATIONS
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/skz258.189

The objective was to evaluate stocker calf performance and grazing potential of double-crop annual forages during the winter as a diversified crop-livestock system. Angus crossbred steers (n = 56) were stratified by BW (275 ± 1.3 kg) and hip-height (118.3 ± 0.66 cm) into 12 groups (n = 4 to 6/group) and randomly assigned to graze either monoculture rye (RYE) or rye and turnip mixture (MIX). The study was conducted at two locations in eastern North Carolina. Each treatment had 3 replicate pastures (6 to 9 ha) per location with a stocking rate of 0.6 ha/steer. Winter annual treatments were planted following corn grain harvest in early October, with the MIX producing 64% ± 2.9% rye and 36% ± 2.0% turnip (leaf and root) on a DM basis. Two-day consecutive weights of steers were taken at initiation and completion of the grazing period. Mineral and water were available ad libitum. Data were analyzed using Mixed Procedure of SAS and differences were declared at P < 0.05, with tendencies declared between P = 0.05 and 0.10. Initial forage mass was greater (P < 0.05) for MIX (1889 kg DM/ha; 9.4% turnip root) than RYE (1568 kg DM/ha). All steers at a location were removed from grazing when forage mass was estimated at 1200 kg DM/ha. The grazing period was 45 days for location 1 and 77 days for location 2. Values for steers grazing RYE and MIX, respectively, for the following variables did not differ (P > 0.10): free choice mineral intake, 201 g/d and 216 g/d; ADG 0.99 kg/d and 1.05 kg/d; gain per hectare 104 kg/ha and 110 kg/ha; and hip-height growth 8.9 cm and 8.1 cm. The increased forage availability for the MIX did not result in greater ADG or gain per hectare when stocking rate and grazing period remained constant.