Leader Follower Grazing System
A multi-species, leader follower grazing system has recently been implemented here at the Permaculture Research Institute (PRI). Multi-species grazing has been shown to improve pasture quality, control weed growth, and enhance pasture utilization (getting the most out of every blade of grass). All of these are achieved while increasing the carrying capacity, enabling more animals to thrive off the same plot of land, continuing the cycle of land restoration. This style has been added into the already productive rotational grazing system currently thriving at PRI. The rotational method was originally employed to prevent a common problem for most farmers known as overgrazing while maintaining the property. The overgrazing of animals is one of the biggest challenges we face in animal agriculture.
Overgrazing can be caused by the overstocking of animals, too many, or under-stocking, too few. Overstocking usually extracts too much from the land and prevents proper regeneration of pasture before the feeding animals return. Under-stocking works differently, and takes a longer period of time generally. The process is pretty simple, the grazing animal eats its favorite food for as long as it can. If too few animals are on a paddock, only the favorite food will be consumed until ultimately it is reduced to a insignificant portion of the pasture. As nature does, this favorite is replaced by a less appealing plant based on selection pressure from the cows, sheep, goats, whatever your animal may be. Eventually the plants not eaten by the grazing animal will be the only ones left. The pasture diversity and health have now been significantly reduced without ever being consumed at an extravagant rate. A very easy way to avoid the understocked problem is to finish mow an area whenever the grazing period has ended. Overgrazing can and will ultimately lead to desertification as the end result of continual land degradation. This all too common problem can be avoided simply by the proper management of animal systems.
The term Multi-species is self explanatory, but a leader follower system usually means that the leader species has a higher nutrient requirement than the follower. Therefore, to effectively implement this system, the nutritional requirements of the animals involved must be evaluated. Then a plan starting from the species with the highest nutrient demands down to the species with the lowest can be successionally put in place to capture the most energy from your pastures while getting it to the appropriate animal. The highest quality pasture is the tip of each blade of grass. According to the “first bite” theory, cows will naturally select the best available pasture as their primary food source within a paddock and then move on to the secondary only when necessary. To figure out how long a pasture can sustain your herd, multiply the average weight by the total number and “Daily utilization rate”. A 3-4% daily utilization rate is commonly calculated from agriculture studies and is based on a 2.5 % forage intake, and a 0.5% trampling loss. The range comes from whether of not specific studies included a 1% buffer. (Blanchet et al., 2003). Your pasture should roughly support one hundred pounds per inch per acre. This allows for easy approximations followed by keen observations.
Pastures that support multiple species and are properly rotated will yield higher total animal mass per consumed pasture than unrestricted grazing. Single species will not be as “productive” in weight gain, but in total, your animal population will prosper. Rotational multi-species grazing has many positive aspects. “Dairy cows in early lactation, produced the same amount of milk as cows that remained indoors until, with a lower fat content (38.6 versus 41.6 g kg-1) and higher protein content (33.6 versus 30.7 g kg-1). The improvement is attributed to a higher total dry matter intake, energy and protein intake provided by excellent grass utilization conditions,” (Kennedy et al. 2005).
Other beneficial effects of a multi-species, leader follower grazing systems make it more and more appealing. An underrated aspect of animal welfare is their natural behavior. Other than normal needs like food and water: appropriate rest, movement, and social behavior are aspects included within this rotational method that help create the happiest and healthiest cows possible. “Grazing reduces the risk of mastitis because the infection pressure of bacteria within the immediate environment is lower due to unrestricted space. On balance, grazing generally has a positive influence on udder health. Grazing also benefits the claw health of dairy cows. Infectious diseases like foot rot and the disease of Mortellaro are more common in the cowshed, because the infection pressure is higher. The relatively hard floor in conventional cubicles can result in wounds and pressure sores on knee and heel joints,” (Van den Pol-van Dasselaar A., 2008). The Agriculture & Horticulture Development Board (AHDB) in the United Kingdom, found Mastitis is most often transmitted by contact with the milking machine, and through contaminated hands or other materials, in housing, bedding and other equipment. Mastitis treatment and control is one of the largest costs to the dairy industry in the UK, and is also a significant factor in dairy cow welfare. By reducing the exposure frequency of your cows to confined spaces, naturally healthy cows are easier to achieve and maintain.
Different species may require different parasite control, fencing, mineral supplements, and management practices. On our farm, the dairy cows can be held in their paddock cells with a single or double lined electric fence attached to our main lane way. Cows are the leader in our system and spend one week in a cell eating the best forage they can find. To prevent overgrazing problems caused by under-stocking, we then cut our pasture down. This is also a major benefit to our biosphere. Perennial grasses are the best way to sequester carbon on dry land. After the grass is cut, the growth recovery period will capture more carbon from the atmosphere while using the nitrogen supplied by the cows. The dairy cows are moved on to their next pasture to continue their leisurely life. While eating to their hearts content, the cows are fertilizing our pastures and setting the table for our chickens.
As you may have previously read in other articles, we employ chicken tractors routinely on this farm. The mobility aspect enables us to utilize chickens for all sorts of wonderful tasks. After the grass has been mowed, a 200 meter electric fence is put up around the cell the cattle have just vacated. This allows sixty-five chickens to eat insects, seeds, and residuals left behind by the cows. Their scratching and clawing at the soil mixes and spreads the manure left by the cows in a more even distribution across the fenced area. Again, the ultimate goal is to achieved, these chickens are living as wildly as possible. They engage in all their natural social behaviors, get the same movement and rest periods that nature would allow without the predatory dangers. Water access must be supplied to both the cows and chickens, but daily maintenance is significantly reduced when allowing a natural lifestyle. Here at PRI, we do provide the chickens with sulphur, shell grit, and some high quality grain feed to ensure healthy and happy chickens.
Our system is very basic, but with only two species involved we are getting exceptional results. Our pastures are recovering faster and with a healthier composition of plant species. The process will continue, with more animals involved in a system, mimicry of our natural world can be imitated at a higher and higher level. Our multi-species, leader follower grazing system is still in its infancy, but already yielding positive results for the animals involved, us as consumers, and the environment.
Maritime Pasture Manual
Blanchet, K., H. Moechnig, and J. DeJong-Hughes. (2003) Grazing Systems Planning Guide. St. Paul: University of Minnesota Extension Service.
Kennedy E., O’Donovan M., Murphy J.P., Delaby L. and O’Mara F.P. (2005) Effects of grass pasture and concentrate-based feeding systems for spring-calving dairy cows in early spring on performance during lactation. Grass and Forage Science , 60, 310-318.
Mayne C.S., Newberry R.D. and Woodcock S.C.F. (1988) The effect of a flexible grazing management strategy and leader/follower grazing on the milk production of grazing dairy cows and on sward characteristics. Grass and Forage Science , 43, 137-150.
Smits M.C.J, Frankena K., Metz J.H.M. and Noordhuizen J.P.T.M. (1992) Prevalence of digital disorders in zero-grazing dairy cows. Livestock Production Science , 32, 231-244.
Somers J.G.C.J., Schouten W.G.P., Frankena K., Noordhuizen-Stassen E.N. and Metz J.H.M. (2005) Development of claw traits and claw lesions in dairy cows kept on different floor systems. Journal of Dairy Science , 88, 110-120.
Van den Pol-van Dasselaar A., Vellinga T.V., Johansen A. and Kennedy E. (2008) To graze or not to graze, that’s the question. Grassland Sci. Eur. 13: 706-716