PHOTO: CANVA


have to be up grazing when they would be more at risk for predation. Pastures with both forage species would then meet such requirements through grass feeding while taking the other nutritional advantages of legumes.


Response to air temperature Air temperature is one of the most important factors impact- ing animal behaviour and is most commonly associated with cattle site-use preference. In temperate climate areas, the air temperature in summer can rise above the upper critical tem- perature limit and cause heat stress in livestock. Cattle need shade to ease thermoregulation under this condition, which can determine their location within the field. Therefore, shade is an important factor in determining the spatial patterns of grazing animals, particularly in summer.


Water source The distance from water to a favoured site for grazing will in- fluence the use of pasture. Animals will not only overuse a site near water but will also utilise less desirable kinds of plants rather than walk excessive distances to better feed. As a result, the area near the water location will be used more heavily than sites farther removed. The degree of use around a water source should not, therefore, be used as the key criteria in judging the condition or current degree of use of a pasture.


Feed supplement Animal distribution in pasture can be altered by placing re- wards such as supplements (e.g. feed or salt licks) in locations where greater utilisation is desired. This can modify livestock preference for particular zones and change habitat-use pat- terns or distance travelled to increase the uniformity of foraging and restore grasslands.


Behavioural response to fly attacks Acute behavioral responses such as tail flicking, leg stomping, subcutaneous skin twitches and horizontal and vertical head movements may serve to temporarily relieve animals under heavy biting fly infestations. These acute responses can dis- rupt normal grazing activities and are often implicated as a source of decreased animal performance due to increased en- ergy expenditure and deterred energy intake. When fly insec- ticidal control methods are implemented, fly populations fall significantly and cattle tend to visit fewer feeding stations, likely due to reduced irritation and decreased time spent walking. Painting cows with zebra-like striping may also be an effec- tive means of controlling fly attacks. In a study conducted at Kyoto University, Japan, the total number of biting flies on the legs and body of zebra-like striped cows were almost half those on cows with black or white surfaces, as indicated by the fly-repelling behaviours per 30 min (39.8 versus 53.0). It was assumed that the odour of the painting lacquers might


affect the landing behaviour of biting flies or that the motion detection systems flies use to control their approach and landing might be confused.


Fertilisation of pastures Sodium fertiliser has been observed to increase the grazing time of dairy cows kept on pastures of restricted availability. Cows on pastures with sodium fertiliser also ruminated for longer, chewed faster, spent longer standing and less time ly- ing and had longer drinking bouts compared to cows on pasture without sodium. Further, the proportion of herbage that was rejected by the cows also decreased with sodium fertiliser. Similar responses were observed, but to a lesser extent, with potassium fertil- iser. The changes in herbage composition with sodium or potassium fertiliser increase feeding and drinking by dairy cows grazing on low-quality herbage. The increase in feed- ing is achieved by increased bout number but reduced bout length, and the increase in drinking is achieved by increased bout length.


Conclusions To optimise animal production under grazing conditions, ani- mals should be able to graze the pasture effectively and effi- ciently. Having a good basic understanding of cattle grazing behaviour will help anticipate their interaction with the pas- ture and ultimately help improve grazing management skills.


References are available from the author upon request. ▶ DAIRY GLOBAL | Volume 9, No. 3, 2022 15


Air temperature is one of the most important factors impact- ing animal be- haviour and is most commonly associated with cattle site-use preference.


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