PLANTAIN AND FESCUE IN PASTURES FOR DAIRY COWS IN THE SOUTHERN CAPE.

Among the problems experienced by pasture-based dairy farmers in the southern Cape are required high stocking rates, poor persistence of pastures, an increase in weed ingression in no-till pastures, and increasing input costs associated with irrigation and fertilisation. Research should thus focus on strategies that can improve the resilience and efficiency of pasture systems. The inclusion of forage herbs, such as Plantain, into pastures, may have various potential advantages, whereas In terms of an alternative grass component, Tall Fescue may be a species that can be included due to its improved drought tolerance, the resultant ability to more effectively utilize soil water and rainfall due to its deep root systems. The aim, therefore, of the study of the authors cited below was thus to determine the whole system production potential and efficiency of three pasture systems based on the current system (Kikuyu-ryegrass), monocultures of alternative species (Tall fescue and plantain) and a pasture mixture that includes alternative species (Tall fescue, plantain and red clover). The preliminary data collected during year one of the planned three year study are presented here.

The project is evaluating the three pasture systems. The first system is based on kikuyu-ryegrass pasture, and is aimed at representing a typical long term no-till pasture in the region. The second system, or “Monoculture”, consists of two separate areas, one planted to a monoculture of plantain (Plantago lanceolata) and the other to Tall Fescue (Festuca arundinacea). The third system is based on a diverse pasture mixture consisting of Tall Fescue, plantain and red clover. The trial is being conducted in the form of a full farmlet study over a three year period. The premise behind a farmlet study is to apply systems to a large enough area and in such a manner that it resembles a practical farming unit. Each system was allocated its own “mini-herd” of 24 cows in milk, selected to maintain approximately 150 days in milk and which provides a constant flow of animals into and out of the system. Milk yield and milk composition from the previous lactation were used to block animals.

The mixture system yielded higher than the other two systems from July to April. Compared to the kikuyu-ryegrass system, the monoculture system had a higher or similar yield from July to October. Thus, both alternative systems have the potential to compete favourably with the kikuyu-ryegrass system during winter and spring in terms of pasture yield. The total annual pasture yield for the three systems was: kikuyu-ryegrass 14.3 ton DM per ha, monoculture 15 8 ton DM per ha, and mixture 18.0 ton DM per ha. The respective milk yields were 27126 kg per ha, 29834 kg per ha, and 31592 kg per ha. The higher milk yield was the result of a combined effect of higher grazing capacity and milk yield per cow achieved by the mixture system, particularly during spring and summer. The higher milk yield per ha in the monoculture system compared to the kikuyu-ryegrass system was primarily driven by grazing capacity and not milk yield per cow.

Although the results are still very preliminary, they do indicate that the inclusion of plantain and Tall Fescue, whether in a mixture or as a monoculture, hold the potential to yield similar or even higher pasture and milk per ha when compared to kikuyu-ryegrass. When all parameters for pasture, milk and fodder flow are considered, the mixture system performed the best. However, it is likely that a combination of the systems on a whole farm scale will be the most effective at spreading risk for the producer. In this way the producer can use a kikuyu-ryegrass (or ryegrass) system for winter fodder flow, the mixture system for its superior milk and pasture yielding ability in spring and summer and the monoculture swards to reduce the need to re-establish pastures during autumn and thereby improving fodder flow in this season.               

Reference:

J. van der Colf, S. Ammann & R. Meeske, 2020. Farm system study: Development of dairy systems based on forage herb pastures in the southern Cape. In: Proc. of the 2020 Information Day on Milk production from planted pastures, Outeniqua Research Farm: Directorates Plant and Animal Sciences, WCDA, Booklet page 46.