HRM and cell grazing: a review of the evidence base
The HRM and cell grazing: a review of the evidence base project examined comparisons of stocking methods including continuous grazing and intensive rotational methods described as Cell Grazing or something similar.
There is widespread interest in Cell Grazing and debate over the relative merits of Cell Grazing, other rotational methods and continuous grazing. In this review we examine comparisons of stocking methods that include continuous grazing and intensive rotational methods described as Cell Grazing or something similar.
We first examined previous reviews of continuous and rotational grazing and then conducted a computer-based survey of peer-reviewed scientific papers that compared grazing methods. For this study, we included reports which compared continuous grazing and a rotational method that mentioned cell grazing, short duration grazing, time-controlled grazing, high intensity; had many paddocks; or had short grazing periods and long rest periods. The focus was on rotational systems involving one group of stock moving between many paddocks. Both Australian and overseas studies were included. Summaries of the papers are provided in the appendix.
Tables were prepared showing where results for different stocking methods were the same or different for various measurements. For these comparisons the studies were divided into groups where both methods used the same stocking rate, and those studies where the stocking rate used was higher for Cell Grazing. Previous reviews (including Wheeler 1962; O’Reagain and Turner 1992; Briske et al. 2008) of continuous stocking with various forms of rotational stocking have concluded that animal production from continuously grazed pasture is similar or greater than that achieved with rotational stocking. In this current review, a total of 29 papers were assessed, 6 from Australia and 23 from overseas.
Only one of the 11 studies that reported animal production found LWG/head was higher for Cell Grazing when stocking methods were compared at the same stocking rate. For measures of diet quality and intake, stocking methods were similar or continuous grazing was superior. Three studies compared animal production when the Cell Grazing was grazed at a higher stocking rate. In two short term studies, LWG/head was the same for both methods; in the other study (Pitts and Bryant 1987) LWG/head was the same for both methods in two years but lower for Cell Grazing in another year. The combination of similar LWG/head and higher stocking rates gave higher LWG/ha for Cell Grazing. However, as there was no continuously grazed treatment at the higher stocking rate, any impact of Cell Grazing per se is uncertain. For comparisons of diet quality and intake, Cell Grazing was better in three studies, poorer in one, and there were no differences in the other four.
When: 20 July 2013 to 30 August 2013
Contact: John McIvor
For more information, please read the final report summary and download the final report (B.NBP.0788) (PDF, 570.9KB) from the Meat & Livestock Australia website.