Grazing Behavior and Diet Preference of Beef Steers Grazing Adjacent Monocultures of Tall Fescue and Alfalfa: I. Spatial Allocation

Abstract

Adjacent forage monocultures are a valuable tool to study the diet preference of grazing animals. Previous research has suggested that cattle will exhibit a partial preference for a legume over a grass regardless of forage species. The objective of this study was to determine if beef steers have a partial preference for alfalfa (Medicago sativa L. subsp. sativa) over tall fescue (Festuca arundinacea Schreb.). These forages have not been evaluated previously as adjacent monocultures. Behavior data recorders, global positioning system (GPS), and pedometers were used to evaluate grazing behavior and diet preference of beef steers grazing tall fescue monocultures or adjacent monocultures of tall fescue and alfalfa at proportions (by ground area) of 50:50, 25:75, and 75:25. Steers exhibited a partial preference for alfalfa, grazing it for 61 to 65% of the time regardless of the proportion offered. A diurnal pattern of preference was not observed. Steers grazing tall fescue monocultures spent more time ruminating (p = 0.02) and tended to graze less time (p = 0.06) than steers in adjacent monoculture treatments. Time spent idling, number of prehensions and mastications, and bite rate were similar (p > 0.05) among treatments. Steers grazing tall fescue monocultures spent less time standing, more time lying, were less active, and took fewer steps (p ≤ 0.05) than steers in adjacent monoculture treatments. These results support the proposal that cattle have a partial preference for legumes over grasses.

Dietary Nutritive Value, Dung Quality, Decomposition, and Nutrient Movement into Soil in Smooth Bromegrass Pastures

“…Cattle exhibit a partial preference for legumes relative to grasses (Boland et al, 2011;Villalba et al, 2015), and in mixed grass-legume swards, they select legumes at greater proportions than offered (Wen et al, 2004). Cattle exhibit a partial preference for legumes relative to grasses (Boland et al, 2011;Villalba et al, 2015), and in mixed grass-legume swards, they select legumes at greater proportions than offered (Wen et al, 2004).…”

“…To better understand cattle dung dynamics on pastures, accounting of how pasture management affects dietary nutritive value, dung quality, decomposition, and nutrient movement needs further investigation. Cattle exhibit a partial preference for legumes relative to grasses (Boland et al, 2011;Villalba et al, 2015), and in mixed grass-legume swards, they select legumes at greater proportions than offered (Wen et al, 2004). Few studies, though, have investigated whether cattle grazing legume-interseeded pastures select diets with greater nutritive value (Popp et al, 1999;Ullerich et al, 2002) and whether changing dietary nutritive value in pastures impacts dung quality and decomposition (Kyvsgaard et al, 2000;Bosker et al, 2002;van Vliet et al, 2007;Jost et al, 2013;Lima et al, 2016).…”

Spatial Arrangement of Forages Affects Grazing Behavior of Beef Heifers Continuously Stocked at Low Stocking Rate

“…In the present experiment, there were no differences in fiber (NDF or ADF) content between treatments (Table 1), so this may not be the explanation for these differences. Boland et al (2011b) also reported that NFC and starch concentrations were greater in alfalfa than tall fescue at both the morning and afternoon sampling time (322 and 360 g kg -1 DM for alfalfa and 172 and 200 g kg -1 DM for tall fescue, in the morning and afternoon, respectively). Justifying the importance of nonstructural carbohydrates as a factor influencing grazing behavior, Ciavarella et al (2000) reported that sheep grazing shaded and unshaded areas of canarygrass (Phalaris aquatica L.) selected 2.6 times more forage in the unshaded area and that forages from this area were greater in both WSC and starch.…”

“…Time spent grazing on a patch (s -1 ) and bite rate (bites min -1 ) during three periods of visual observation (A-C) by beef heifers grazing annual ryegrass alone (RG), a mixed sward of annual ryegrass and clover mix of berseem, white, and red clover, clover mix alone (CL), and adjacent pastures of RG and CL. Boland et al (2011b) observed that steers grazing tall fescue and alfalfa as adjacent pastures spent an average of 28.2% of their time in the morning grazing tall fescue compared with 23.3% in the afternoon. Heifers grazing the ADJ pastures had the choice to eat grass or legume.…”

“…Boland et al (2011b) observed that steers grazing tall fescue and alfalfa as adjacent pastures spent an average of 28.2% of their time in the morning grazing tall fescue compared with 23.3% in the afternoon. Boland et al (2011b) indicated that WSC concentration in alfalfa and tall fescue was not different during the morning or afternoon hours (107 and 114 g kg -1 DM for alfalfa and 97 and 113 g kg -1 DM for tall fescue, in the morning and afternoon, respectively) and thus would not have been a factor influencing preference. Grazing fiber-rich forages with slow passage rates in the afternoon helps maintain gut fill and decrease the need to graze at night (Rutter, 2006), when animals would be more at risk to predation (Gluesing and Balph, 1980).…”