Performance of Stocker Cattle Managed On Pastures Over-Seeded With Annual Forages

The goal of this study was to determine the performance of stocker calves managed on permanent pastures over-seeded with winter and summer annuals. Twenty-one 7-month-old Angus calves (BW = 263 ± 24 kg) sourced from the university farm, were randomly assigned to three treatments. The treatments were: i) Grass Hay Only (GHO; Control; 5 calves), ii) Permanent Pasture Only (PPO; 8 calves), or iii) Permanent Pasture + Winter Annual (PPW; 8 calves). The same calves were later randomly assigned to the summer treatments: i) Grass Hay Only (GHO; Control; 5 calves), ii) Permanent Pasture Only (PPO; 8 calves), and iii) Permanent Pasture + Summer Annual (PPS; 8 calves). The annual forages used in this study were: Barley (Hordeum vulgare L.) in winter and pearl millet (Pennisetum glaucum L.) in summer. The winter trial lasted for 58 days whereas the summer trial lasted for 42 days. The GHO calves had better (p=0.02) average daily gain (ADG; 0.69 kg/day) compared to the PPO (0.47 kg/day) and PPW calves (0.44 kg/day). There was no statistical difference (p=0.24) between the PPO and PPW calves. The PPS calves had better (p=0.01) ADG followed by the GHO and PPO calves (1.20, 1.15, 0.38 kg/day, respectively). In conclusion, over-seeding summer annuals onto existing permanent pastures is likely a good management practice for stocker cattle vs. conventional hay feeding. Whereas Over-seeding winter annuals on to permanent pastures may be beneficial, the timing of grazing should match optimal forage growth. The lack of effect seen in the winter trial can be attributed to grazing the annual forage at a mature growth stage typically accompanied by reduced nutrient availability. Future studies may determine the economic benefits of Over-seeding permanent pastures with annual forages in southern California, a region with similar weather conditions to tropical or mediterranean climate.