PSXIII-18 - Effects of Spring and Fall Stockpile Grazing Management System on Performance of Fall-calving Beef Cows, Pre-weaning Calf Performance, and Forage Characteristics

Abstract: The objective was to compare the effects of tall fescue grazing systems utilizing either rotational grazing only or rotational grazing and spring and fall stockpiling on beef cow body condition and reproductive performance, calf pre-weaning performance, and forage characteristics. Over 2 years, multiparous, fall-calving cows (n = 360/year; BW = 600 ± 64 kg; gestation = 113 ± 8.5 d) were randomly assigned to 1 of 2 treatments (3 reps/treatment/year); 1) rotational grazing and spring and fall stockpile grazing (SP) and 2) rotational grazing only (CON). Treatments were initiated in late April and terminated in late December each year. Pastures were 48.4 ha/replicate. The CON pastures were divided into eight (6.05 ha) paddocks and cows rotated every 5 days. Twenty-five percent of SP pastures (12.1 ha) were stockpiled for initial 112 days with remaining 75% rotationally grazed (6 paddocks; rotated weekly). An additional 50% (24.2 ha) was stockpiled for 95 days starting early August. Strip-grazing was utilized when grazing stockpiled forage. Forage availability into new paddock was greater in SP than CON during grazing rounds 4, 5, and 6 (P ≤ 0.01), coinciding with grazing of stockpiled forage. Grazing days were increased 24 days for SP versus CON (P ≤ 0.01). Hay fed per cow was reduced in SP compared to CON (59 kg vs. 347 kg, respectively; P ≤ 0.01). Cow BW did not differ at trial end (P = 0.13) however, BCS was greater for CON than SP (5.3 vs. 5.1, respectively; P ≤ 0.01). No differences (P ≥ 0.14) were observed in AI or overall pregnancy rate between treatments. There were no differences in calf birth or weaning BW (P = 0.30) between treatments. Overall, utilization of spring and fall stockpiling system had little impact on cow and calf performance but increased grazing days.