Low-Intensity, High-Frequency Grazing Strategy Increases Herbage Production and Beef Cattle Performance on Sorghum Pastures

Abstract

We assessed the effects of high-intensity and low-frequency (HILF) vs. low-intensity and high-frequency (LIHF) grazing on herbage production and performance of beef cattle grazing sorghum pastures. The experimental design was a complete randomized block with two treatments and four replicates (paddocks), carried out in 2014/15. The management target of 50 and 30 cm for pre- and post-grazing, respectively, a LIHF grazing management strategy oriented to maximize beef cattle herbage intake per unit time, was compared with a HILF grazing management strategy of 80 and 20 cm for pre- and post-grazing, respectively, aiming to maximize herbage accumulation and harvest efficiency. Sixteen Brangus steers of 15-month-old and 265 ± 21 kg of live weight (LW) were randomly distributed to paddocks (experimental units). The LIHF resulted in shorter rest periods when compared with the HILF. The greater leaf lamina mass in LIHF allowed greater sward light interception at post-grazing, resulting in greater total herbage production than HILF (7581 and 4154 kg DM/ha, respectively). The average daily gain (ADG) of steers was greater for the LIHF than for the HILF treatment (0.950 and 0.702 kg/animal, respectively); however, even with a greater stocking rate in the HILF, there was no difference for LW gain per ha, with an average of 4 kg LW/ha/day. Our findings demonstrated that the LIHF strategy that is based on offering to the animals an optimal sward structure to favor the maximum herbage intake rate fosters greater herbage production, harvesting efficiency, and ADG without compromising LW gain per area of beef steers, despite the lower herbage harvested per stocking cycle.

Convergence points of optimal herbage accumulation and intake rate by sheep grazing tall fescue

“…We hypothesize that growth rate will be maintained in the exponential phase of the curve, thus promoting a higher frequency of grazing events. Studies by Savian et al (2018), Savian et al (2020), Schons et al (2021) and Portugal et al (2022) support this idea. In a long‐term study, Savian et al (2020) and Schons et al (2021) applied this concept comparing “Rotatinuous stocking” (RN – SSH pre‐grazing of 18 cm and SSH post‐grazing of 11 cm) to traditional rotational stocking (RT – SSH pre‐grazing of 25 cm and SSH post‐grazing of 5 cm) of sheep grazing Lolium multiflorum .…”

“…,Savian et al (2020),Schons et al (2021) andPortugal et al (2022) support this idea.In a long-term study,Savian et al (2020) andSchons et al (2021) applied this concept comparing "Rotatinuous stocking" (RN -SSH pre-grazing of 18 cm and SSH post-grazing of 11 cm) to traditional rotational stocking (RT -SSH pre-grazing of 25 cm and SSH post-grazing of 5 cm) of sheep grazing Lolium multiflorum. Greater total herbage production (RN = 8714 and RT = 6822 kg DM ha À1 ) and herbage accumulation rate (RN = 52.1 and RT = 33.2 kg DM ha À1 day À1 ) and greater individual performance of the animals (RN = 0.12 and RT = 0.05 kg animal-À1 day À1 ) were documented in the "Rotatinuous stocking" treatment, in which the animals began grazing a paddock at the SSH predicted for STIR -max and removed from the paddock when the SSH had been reduced by 40%.…”

Stocking method effects on forage accumulation, canopy attributes, and nutritive value of grazed Mulato II brachiariagrass pastures

“…Forage from pastures under RSL and RSM showed greater NDF concentration, but similar IVDOM compared to CS at average canopy height of 20 cm, although the IVDOM was less at the taller mean canopy height when managed at RSL and RSM (Table 5). The difference in IVDOM between average canopy height for pastures under RS suggests that the canopy target adopted may impact animal performance due its effect on forage nutritive value (Euclides et al, 2016; Portugal et al, 2022). It has been suggested that animal behaviour may be affected by canopy height, and it may impact animal performance (Herling et al, 2011).…”

“…and Sorghum sudanense (Piper) Stapf cv. EMBRAPA BRS 802 mixture] favoured both FA and animal performance (Portugal et al, 2022).…”