84 Pasture production in integrated warm- and cool-season grass equine rotational pasture systems
Authors: Weinert J.R., Meyer W.A., Williams C.A.
Journal: Journal of Equine Veterinary Science
Summary
# Editorial Summary: Integrated Warm- and Cool-Season Grazing Systems for Horses Researchers at Rutgers University compared traditional cool-season grass pastures with an integrated system combining cool-season grasses and warm-season crabgrass to determine whether this approach could sustain equine grazing throughout the season whilst maintaining forage quality and horse condition. Over a full grazing season (May to November), three horses grazed two 1.5 hectare rotational systems, with herbage mass, nutritional composition (including water-soluble and non-structural carbohydrates), and body condition monitored monthly across three seasonal periods. The integrated system dramatically increased total forage availability from 6,335 kg to 9,125 kg and extended carrying capacity from 276 to 390 horse-days, with crabgrass sections proving particularly valuable during the mid-summer slump period (July to September) when cool-season grasses typically decline. However, advantages diminished in late autumn, and crucially, integrated grazing offered no benefit in reducing dietary non-structural carbohydrates (NSC remained 7.05–7.65% across all sections), which may disappoint practitioners seeking to manage metabolic concerns such as laminitis risk. Both systems maintained acceptable horse body condition scores (5.78–6.11), suggesting that integrated rotational systems can increase stocking density and extend grazing availability without compromising nutritional adequacy, though refinement of late-season production remains necessary for year-round application.
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Practical Takeaways
- •Integrating warm-season grasses like crabgrass into rotational systems can significantly increase available forage during the summer production slump, allowing more horses to graze the same acreage
- •This integrated approach maintains horse body condition without requiring supplemental feeding during peak grazing months, reducing feed costs
- •Late-season forage production remains a challenge in integrated systems; cool-season only sections perform better in fall, so rotational planning should account for seasonal strengths of each grass type
Key Findings
- •Integrated warm- and cool-season grass systems produced 9,125 kg forage versus 6,335 kg in cool-season only, increasing carrying capacity from 276 to 390 horse days
- •Crabgrass sections yielded 4,758 kg/ha during summer slump period versus 1,086 kg/ha for cool-season grass in same period
- •Both integrated and control systems maintained adequate horse body condition scores (5.78 and 6.11 respectively) throughout grazing season
- •Water-soluble carbohydrates were lower in crabgrass (4.46%) during summer slump compared to cool-season control (7.92%), but non-structural carbohydrates remained similar across all sections