Tall Fescue Online Monograph

Some dairy producers, when first using tall fescue, have struggled to prevent rank growth and observed poor intake from the resulting low-quality forage. Especially under irrigation, growth of tall fescue is fast from mid spring to autumn. Experience has shown that a 10- to 14-d grazing frequency is needed to keep tall fescue pastures in a high-quality forage condition. The recommended grazing management for tall fescue on dairy farms during warm weather is summarized in Table 7-2. To maintain forage quality, grazing frequency must be more frequent than that used for ryegrass. As the number of hectares planted to tall fescue increases, the number of stock grazing tall fescue must be increased.

When soil moisture is adequate for good growth, tall fescue should be grazed every 10 to 12 d. In Victoria and New Zealand, usually this means a 10- to 12-d rotation from 25 September to 20 November. Commencement of stem elongation and flowering will be slightly later farther north. Rotational grazing in mid spring requires short rest periods (10-20 d) between grazings so that grass is kept between 5 and 7 cm tall. Six to 8 wk after the start of heading most new growth will be leaf rather than stem, so maintaining quality is easier from then on.

Management during winter and early spring, before 20 September, is similar to that followed for perennial ryegrass, but different later in the year. During the heading phase in spring (20 Sept.-20 Nov. in Victoria for Advance, 25 Aug.-20 Nov. for early cultivars), grazing needs to be frequent (10-12 d) to reduce stem production. If grazing pressure is not sufficient, ungrazed clumps will appear; then mowing before or after grazing may be needed occasionally to reduce the number of stems. It often is convenient to cut tall fescue paddocks for silage during this period. If reproductive stems have been reduced by grazing or removed by mowing, Advance tall fescue regrowth from December on will be predominantly leafy.

Between December and May, tall fescue should be grazed when it is at the 2- to 3-leaf stage (~2800 kg DM/ha standing crop). Where pastures are irrigated, a grazing frequency of 12 to 14 d is needed for tall fescue, in contrast to the 14 to 25 d used for perennial ryegrass, requiring a heavier stocking rate for the fescue. On dryland farms, grazing frequency will be determined by rainfall and may need to follow a 20- to 40-d rotation cycle. If tall fescue is grazed at the same frequency as ryegrass, a common error, there will be more standing crop left each time that cows leave the paddock because feed allocation will have exceeded the demand. A faster grazing frequency solves this problem.

When there has been a drought, even irrigated tall fescue pastures that are intensively grazed by dairy cows may need a rest period in autumn to ensure long-term persistence. Where there is only one tall fescue paddock on a farm, there is strong temptation to graze it frequently during dry summers despite slow recovery because other paddocks on the farm are not providing any green feed. This results in decreased tall fescue population and increased winter weeds. As dryland farms increase the proportion of the farm in tall fescue, the need to overgraze in dry summers will decrease because there will be more paddocks available with green feed.

Sometimes pasture clumps are larger and more noticeable in tall fescue than in perennial ryegrass pastures because dung patches take 3 to 20 wk to decompose to the point where grass growing on them becomes acceptable to grazing cows. Since dairy cows graze tall fescue every 14 d rather than the 20 to 30 d used with perennial ryegrass, an increasing number of dung patches will be unacceptable at each successive tall fescue grazing. Cows eventually consume the grass at the dung patches; however, more grazing pressure is placed on the plants between the dung patches, which may reduce tall fescue persistence.