Long-Term Impacts of Livestock Grazing on Chihuahuan Desert Rangelands

Abstract Use of adapted beef cattle biotypes is gaining momentum as a novel management strategy for limiting the environmental footprint of ranching and adapting to climate change in the southwest. We compared supplement intake (SI), calf birthweights, cow weights, and body condition scores (BCS) of desert-adapted Brangus (BR; n = 15) vs. Raramuri Criollo (RC; n = 28) cows in four adjacent pastures (1098±85 ha) for three months (Mar 7 – Jun 9, 2020) using ANOVA for a RCBD (significance at P < 0.05). Cows had ad libitum access to 18% crude protein lick tubs in all pastures, which were weighed weekly to determine SI. Brangus cows had greater SI than RC, both overall (BR: 0.21±0.04 vs. RC: 0.08±0.03 kg×cow×d-1) and on a metabolic bodyweight basis (BR: 2.31±0.09 vs. RC: 0.95±0.09 g×kg0.75). All cows were bred to Brangus bulls and calf birth weights were not different between biotypes (BR: 31.5 ± 1.0; RC: 29.6±0.9 kg). Brangus cows weighed more at the beginning (535.0±14.8 kg) and end (582.2±14.5 kg) of the study compared to RC (beginning: 345.5±11.8 kg; end: 357.0±12.0 kg). Percent of bodyweight change was not different between biotypes (BR: 8.51±2.35; RC: 2.85±1.81 %). On a 1 to 5 scale, BCS of Brangus (4.06±0.09) was greater than RC (3.18 ± 0.07) at the onset of the study, but biotypes had similar BCS at the end of the trial (BR: 4.09 ± 0.09; RC: 3.89±0.08). Our preliminary results indicate that lighter RC cows were capable of gaining bodyweight and improving BCS with reduced SI, both overall and on a metabolic bodyweight basis. This finding may reflect lower nutrient requirements, better relative efficiencies and lesser grazing impacts on desert rangelands by RC cattle. Future studies will seek to replicate these breed-comparison trials over multiple years, research sites, and supply chains, with an emphasis on overall systems production efficiency and sustainability.

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Managing Tallgrass Prairies for Productivity and Ecological Function: A Long-Term Grazing Experiment in the Southern Great Plains, USA

Agronomy ◽

10.3390/agronomy9110699 ◽

2019 ◽

Vol 9 (11) ◽

pp. 699 ◽

Cited By ~ 5

Author(s):

Steiner ◽

Starks ◽

Neel ◽

Northup ◽

Turner ◽

...

Keyword(s):

Great Plains ◽

Tallgrass Prairie ◽

Production Efficiency ◽

Nutritive Value ◽

Plant Biomass ◽

Continuous System ◽

Livestock Grazing ◽

Long Term Study ◽

Wide Range

The Great Plains of the USA is one of largest expanses of prairie ecosystems in the world. Prairies have been extensively converted to other land uses. The remaining prairie ecosystems are important for livestock grazing and provide benefits including habitat for avian, terrestrial, and aquatic species, carbon regulation, and hydrologic function. While producers, land management agencies, and some researchers have promoted livestock management using rotational stocking for increased production efficiency and enhanced ecosystem function, scientific literature has not provided a consensus on whether rotational stocking results in increased plant biomass or animal productivity. To address this research need, we established long-term grazing research using an adaptive management framework to encompass a wide range of production and ecological interactions on native grassland pastures. This paper describes objectives, design, and implementation of the long-term study to evaluate productivity and ecological effects of beef cow–calf management and production under continuous system (CS) or rotational system (RS) on native tallgrass prairie. Findings from 2009 to 2015 indicate that plant biomass and animal productivity were similar in the two grazing management systems. There were some indicators that forage nutritive value of standing biomass and soil nutrient content were enhanced in the RS system compared with the CS, yet individual calf body weight (BW) at weaning was greater in the CS. This prepares us to engage with producers to help determine the focus for the next phase of the research.

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Impact of Climate Change on Livestock Returns and Rangeland Ecosystem Sustainability in the Southwest

Agricultural and Resource Economics Review ◽

10.1017/age.2018.13 ◽

2018 ◽

Vol 47 (2) ◽

pp. 336-356 ◽

Cited By ~ 1

Author(s):

Gregory L. Torell ◽

Katherine D. Lee

Keyword(s):

Climate Change ◽

Current Method ◽

Adaptive Methods ◽

Livestock Grazing ◽

Climate Projections ◽

Stocking Rate ◽

Forage Production ◽

Temperature And Precipitation ◽

Stocking Rates

Climate change will increase variability in temperature and precipitation on rangelands, impacting ecosystem services including livestock grazing. Facing uncertainty about future climate, managers must know if current practices will maintain rangeland sustainability. Herein, the future density of an invasive species, broom snakeweed, is estimated using a long-term ecological dataset and climate projections. We find that livestock stocking rates determined using a current method result in lower forage production, allowable stocking rate, and grazing value than an economically efficient stocking rate. Results indicate that using ecology and adaptive methods in management are critical to the sustainability of rangelands.

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