Effects of spring and fall stockpile grazing management system on performance of fall-calving beef cows, preweaning calf performance, forage characteristics, and economics

Objective

The objective of this study was to compare the effects of tall fescue grazing systems using either rotational grazing only or rotational grazing and spring and fall stockpiling on beef cow body condition and reproductive performance, calf preweaning performance, forage characteristics, and system economics.

Materials and Methods

Over 2 yr, multiparous, fallcalving cows (n = 360 cows per year; 6 groups per year; BW = 600 ± 64 kg; gestation = 113 ± 9 d) were randomly assigned to 1 of 2 treatments: (1) rotational grazing only (CON) or (2) rotational grazing and spring and fall stockpile grazing (SP). Treatments were initiated in late April and terminated in late December each year. Pastures were 48.4 ha/replicate. Control pastures were divided into 8 (6.1 ha; rotated every 5 d) paddocks. Twenty-five percent of SP pastures (12.1 ha) were stockpiled for the initial 120 d, with the remaining 75% rotationally grazed (36.3 ha; rotated every 6–7 d). Starting in early August, 50% (24.2 ha) of the pasture was stockpiled. Strip-grazing (cows moved every 2–3 d) was used when grazing stockpiled forage in SP pastures. Cow BW and BCS were determined every 28 d, and forage characteristics were evaluated every 2 wk.

Results and Discussion

Cows grazed for 25 more days in SP compared with CON, resulting in a subsequent reduction of hay fed per cow in SP compared with CON (59 vs. 347 kg, respectively). Cow BW did not differ at trial end; however, BCS was greater in CON than in SP (5.3 vs. 5.1, respectively). No differences were observed in AI conception rate or overall pregnancy rate between treatments. There were no differences in calf birth BW or weaning BW between SP and CON. With an average hay price of $150/907 kg, breakeven urea price between treatments was $586.8/907 kg.

Implications and Applications

Grazing system type had minimal to no effects on cow and calf performance. Use of a spring and fall stockpiling system increased grazing days, reduced stored feed use, and could reduce winter feed costs.