Selection of feeding areas by cattle in a spatially heterogeneous environment: selection between two tropical grasses

Abstract

A herd of 28-33 Japanese Black cows (Bos taurus) were allowed to graze on an experimental plot comprising monoculture swards of centipedegrass (Eremochloa ophiuroides) and bahiagrass (Paspalum notatum) (0.39 and 0.61 ha, respectively) for 3-5 days each month (from 0850 to 1600 hours) between May (late spring) and October (mid-autumn). On a monthly basis, the animals showed an increasing trend to select centipedegrass in preference to bahiagrass as the relative crude protein (CP) concentration of the former increased relative to the latter. On a daily basis, the animals showed a decreased selectivity for centipedegrass with the progression of grazing days, as centipedegrass sward lost both quantity and quality faster than bahiagrass sward under higher degrees of defoliation. Animals maintained similar bite rates on the two swards by modifying feeding station behavior as soon as they switched between the swards, i.e., they increased the number of bites per feeding station and decreased the number of feeding stations selected per unit grazing time soon after switching to centipedegrass, with the reverse process occurring soon after the switch to bahiagrass. The results show CP concentration to be a partial forage factor influencing animals' choice between tropical grasses growing as patches. The results also demonstrate that animals have an ability to adapt their foraging behavior flexibly and rapidly to varying types of vegetation.

Seasonal and interannual variations in feeding station behavior of cattle: effects of sward and meteorological conditions

“…These two variables were negatively related ( Figure 2a) and received opposite effects of the three predictors (equations (1) and (2)). The present results agree with previous observations in that step is generally a minor component of feeding station behavior compared with bite in terms of the number (Murray, 1991;Lazo and Soriguer, 1993;Hirata et al, 2008), with the majority of feeding station-to-feeding station movements as single-step moves (Roguet et al, 1998b;Ogura et al, 2004;Shingu et al, 2010). The bite/step ratio in animals is likely to decrease as vegetation becomes scarce and discretely distributed (Murray, 1991).…”

“…For 2013, the number of steps and step rate between feeding stations were also computed as N step /N FS and N step /T move , respectively. Bite rate quantified in this study may also be termed 'bite rate across feeding stations' (Hirata et al, 2008), because the rate is based on foraging time, including moving time between feeding stations as well as residence time within feeding stations and is discriminated from 'bite rate within feeding stations' defined as N bite /T residence . However, this paper uses the term 'bite rate' for simplicity.…”

“…The animal is considered to move to a new feeding station at the cost of taking steps when intake rate from the current feeding station falls below the threshold level under repeated bites (Searle et al, 2005;Gregorini et al, 2011). Bite number, residence time and intake per feeding station, feeding station number per unit foraging time and step number between feeding stations are major feeding station behavior variables, which reflect profitability or unprofitability of feeding stations (Ruyle and Dwyer, 1985;El Aich et al, 1989;Roguet et al, 1998b;Gregorini et al, 2007Gregorini et al, , 2009Gregorini et al, and 2011Hirata et al, 2008;Shingu et al, 2010). The cost-benefit concept of the feeding station behavior is useful for a better understanding of foraging behavior of animals (Roguet et al, 1998b) and adjusting management strategies of various grazing systems ranging from an intensively managed small paddock of a sown pasture to an extensive rangeland across a landscape (e.g.…”

“…Ruyle and Dwyer, 1985;El Aich et al, 1989;Gregorini et al, 2011). However, previous studies have focused mainly on relatively short-term (<1 day to about 30 days) variations in feeding station behavior in order to investigate the effects of forage availability (Ruyle and Dwyer, 1985;Roguet et al, 1998b), sward structure (Gregorini et al, 2009), plant species (Hirata et al, 2008), grazing management (Gregorini et al, 2011), animal species (Shingu et al, 2010) and rumen fill (Gregorini et al, 2007). Relatively little information has been reported on how grazing animals modify feeding station behavior seasonally and interannually in response to varying environmental conditions (El Aich et al, 1989;Jiang and Hudson, 1993).…”

<b>Grazing behavior and spatial distribution of feces of Young bulls in silvopastoral systems and Marandu monoculture in the Pre-Amazon region

“…The distribution of cattle on pastures and the selection of sites for grazing, resting, or ruminating are determined by complex interactions between biotic and abiotic factors (Hirata, Yamamoto, & Tobisa, 2010). Among them, stand out the climate, soil characteristics, topography, availability of water, botanical composition, quantity and quality of forage, shading, and factors related to animal behavior and human activity.…”