Studies of grazing behaviour in relation to grassland management: III. Rotational compared with continuous grazing

Abstract

1. A series of observations on the grazing behaviour of identical twin cattle on two contrasting systems of pasture management—rotationally and continuously grazed—is described.2. The rotationally grazed cows averaged only 11 min. (day/cow) shorter feeding time and 18 min. shorter ruminating time than their continuously grazed co-twins. The total time they spent in work was thus 29 min. shorter.3. While the average differences in total work over the whole trial was not great, the continuously grazed cows worked for appreciably longer daily periods at the time of seasonal feed shortage during which time the rotationally grazed cows were buffered by their pasture diet being supplemented with silage.4. The differences in grazing behaviour between the cows of the two treatments, together with the magnitude of the seasonal variations which occurred in both groups, indicated that dairy cows attempt to maintain a stable production in the face of adverse pasture conditions by increasing their feeding time.5. Previous conclusions based on observations of uniformly treated twins regarding the importance of heredity in the determination of grazing behaviour were fully confirmed.

Enhancing pasture productivity with alfalfa: A review

“…Differences in consumption rates appeared to be related to bite size and biting rate, the former being controlled primarily by herbage availability and form (Stobbs 1974;Hodgson 1981). Factors that reduce bite size will also reduce intake rate (Dougherty et al 1989c), which in turn results in increased grazing time and energy expenditure during grazing, which affects cattle performance negatively (Hancock and McMeekan 1954;Stobbs 1974;Hodgson 1981;Popp et al 1997b). When herbage availability increases, intake rate also increases, even when pastures are of similar digestibility and protein content (Dougherty et al 1988).…”

Effect of grazing system, stocking rate and season of use on herbage intake and grazing behaviour of stocker cattle grazing alfalfa-grass pastures

“…These observations were not unexpected. The suggestion has been made in several studies that grazing time increases only in response to reduced herbage availability (Hancock and McMeekan 1954;Hodgson 1981). Herbage availability was not affected by grazing system, but it was reduced by higher stocking rates (Popp et al 1997).…”

“…Intake of forage was depressed by modifying biting rate and bite size (Hodgson 1981) and bite size was found to be the primary factory limiting intake (Stobbs 1974). A reduction in available herbage, resulted in increased grazing time (Hancock and McMeekan 1954;Hodgson 1981) as intake rate was reduced (Dougherty et al 1989b). However, Walker et al (1989) found stocking rate and grazing system did not affect time spent grazing.…”

Studies on the habits of Zebu cattle V. Night paddocking and its effect on the animal

“…At the Ruakura Research Station in New Zealand the effects of rotational and continuous grazing on the animal have been studied (Hancock & McMeekan, 1954). In this case the difference in total working time was less than half an hour.…”

“…Allowing for any differences there may be in the ruminating process, differences in food consumption could be inferred from differences in the time spent ruminating. At the same time, on similar pastures, the actual time spent grazing may indicate the availability of the herbage (Hancock, 1954 a). Thus, if the type of herbage remains relatively constant over a number of observation periods, the ruminating times should give an indication of the food consumed, and the relationship between ruminating time and grazing time should give an indication of the availability of the herbage.…”