Preference, Yield, and Forage Nutritive Value of Annual Grasses under Horse Grazing

Abstract

Core Ideas Horses preferred winter wheat, annual ryegrass, and spring wheat. Annual ryegrass, spring oat, and winter barley were the highest yielding species. Spring oat, spring barley, and spring wheat had little to no regrowth. Winter wheat and winter rye consistently had higher forage nutritive values. Annual ryegrass can extend the grazing season or provide emergency forage for horses. Annual grasses such as oat (Avena sativa L.), wheat (Tricum aestivum L.), and barley (Hordeum vulgare L.) can serve as alternative forage but little research exists under horse (Equus caballus) grazing. The objectives were to evaluate annual cool‐season grasses for preference, yield, and forage nutritive value under horse grazing during the summer and fall in Minnesota. Spring‐planted grasses included spring barley, spring oat, spring wheat, winter wheat, and annual ryegrass (Lolium multiflorum L.). Summer‐planted grasses included the same five species plus spring forage oat, winter barley, and winter rye (Secale cereal L.). Beginning in June and September of each year, horses grazed grasses at a vegetative stage. Plots were mowed, allowed to regrow, and grazed again. Although spring oat, spring forage oat, and winter barley were often among the highest yielding grasses (≥3.0 Mg ha−1), they were also among the least preferred grasses (≤32% removal). Annual ryegrass, winter wheat, and spring wheat were among the most preferred grasses (≥35% removal). Among these highly preferred grasses, annual ryegrass was typically higher yielding (≥2.7 Mg ha−1), while winter wheat and spring wheat were among the lowest yielding species (≤4.7 Mg ha−1). All grasses contained ≥130 g kg−1 crude protein (CP), ≤610 g kg−1 neutral detergent fiber (NDF), ≤220 g kg−1 nonstructural carbohydrates (NSC), and ≥2.02 Mcal kg−1 equine digestible energy (DE). Annual ryegrass appears to be a viable forage alternative to maximize yield, preference and forage nutritive concentration in horse pastures.

Yield, nutritional quality, and fatty acid content of organic winter rye (Secale cereale) and winter wheat (Triticum aestivum) forages under cattle (Bos taurus) grazing conditions

“…Previous studies agree with greater CP for WW than WR [21,26,27] and a general decrease in CP over the growing period [15,25–28,32]. The CP values are consistent with previous studies performed in the Midwest region of the USA, which reported CP of 12 – 20% DM for WR [21, 26] and 11 – 34% DM for WW [22,25,26].…”

“…Forage yield for WR was greater ( P < 0.05) than WW (Table 2), which is consistent with results of previous studies [21–24]. However, the actual yield values are inconsistent with previous studies [21–25]. Variation in yield is mainly due to factors, like year, location, and environment, which differ between studies and affect the yield of small grain forages [21,24,26,27].…”

“…The WR had greater ( P < 0.05) NDF and ADF compared to WW (Table 2), and forages increased in NDF and ADF over the grazing period. Previous studies reported greater fiber for WR compared to WW [21, 27] and an increase in NDF and ADF with plant maturity [15,25,27,28]. Similar studies performed in the Midwest region of the USA [21, 25] reported NDF of 53 – 67% DM for WR and 38 – 61% DM for WW, and ADF of 28 – 42% DM for WR and 24 – 31% DM for WW.…”

“…Previous studies reported greater fiber for WR compared to WW [21, 27] and an increase in NDF and ADF with plant maturity [15,25,27,28]. Similar studies performed in the Midwest region of the USA [21, 25] reported NDF of 53 – 67% DM for WR and 38 – 61% DM for WW, and ADF of 28 – 42% DM for WR and 24 – 31% DM for WW. Low precipitation during the current study may have slowed maturation and decreased fiber production [28].…”

Yield, Forage Nutritive Value, and Preference of Legumes under Horse Grazing

“…In a pasture setting, legumes tend to be highly preferred by both sheep and cattle compared with cool‐season grasses (Boland et al, 2011, 2012; Rutter, 2006). Horses are known to be selective grazers (Allen et al, 2013; Archer, 1973a, 1973b; Hunt and Hay, 1990); yet, most research has focused on examining preference among grass pasture species (Allen et al, 2013; DeBoer et al, 2017; Grev et al, 2017). In separate experiments, horses were found to prefer Kentucky bluegrass ( Poa pratensis L.) and meadow fescue [( Festuca pratensis (Huds.)…”