By Charlotte Westwood BVSc MANZCVS (Animal Nutrition) PhD, Veterinary Nutritionist
“Chicory or bulb turnips - which is the better feed for cows?” As for any cropping decision, there’s not a single answer. Consideration needs to be given to a range of factors that influence the value of summer crops to your business.
Both crops support similar milksolids responses
Chicory and bulb turnips both deliver high quality feed well suited for lactating dairy cows. Research in the 1990s1 showed similar milksolids responses to chicory and turnips (grams of milksolids/kg of dry matter; DM of crop consumed by cows).
Summer crop selection is more about when you need high quality milking feed and less about which crop will support the best milk response.
Feed supply curves differ for chicory and turnips
Chicory supports multiple grazings of a lesser quantity of feed over a longer time period. Crops are rotationally grazed for 100-120 days between December and March. Chicory behaves like a high quality, taprooted pasture delivering better daily DM growth rates and higher quality feed than summer pasture. When summers are hot and dry, chicory regrowth may not match herd demand.
Turnips deliver a single grazing of bulk high-quality feed over a shorter time period. Turnips accumulate most high quality leaf and bulb DM before late December. Pushed forward as a ‘feedbank’ into summer, turnip grazing starts in January, lasting between 40 and 60 days as a high quality feed to supplement poor quality summer pasture.
More crop ground is required for chicory than for turnips
Referring to Figure 1, the ‘flatter’ DM supply feed wedge of chicory means less mid-summer feed is supplied by chicory compared with the peak mid-summer feed supply from turnips. Relatively larger areas of chicory are needed to supply the same amount of mid-summer feed as delivered by turnips1. Chicory requires 4-5ha/100 cows to supply 4-5kgDM/cow on a 21-day rotation2 compared to Turnips which only require 2-2.5 ha/100cows for 4-5kgDM/cow for 60 days feed3. When comparing costs to grow either chicory or turnips, include regrassing costs in the final cents per kgDM costs for each crop type; larger areas of chicory require greater investment in regrassing than costs associated with returning relatively smaller turnip areas to pasture.
To achieve 60 days of turnip feed it is important to consider using two bulb turnip cultivars with differing maturities. For example, Cleancrop™ Toto summer turnip has a 55-90 day maturity whereas Cleancrop™ bulb turnip has a later maturity of 80-110 days. When planted on the same day, farmers can achieve a larger window where the turnips maintain quality.
Weed species present in crop paddocks
Limited herbicide options exist to control summer broadleaf weeds and thistles in chicory crops. A greater range of selective herbicide options exist for weed control in turnip than chicory crops, particularly for Cleancrop Toto and Cleancrop bulb turnip. If this year’s summer crop paddocks were full of weeds, consider a brassica for this 2020/21 summer crop. Select next summer’s chicory paddocks now and plan to plant annual ryegrass in autumn 2021 followed by chicory in spring 2021. You’ll have two chances to control weed species before chicory is planted later next year.
Summer chicory and turnips – a new dairy grazing study
To help further understand the strengths and weaknesses of chicory and turnips, PGG Wrightson Seeds commissioned a large chicory and turnip dairy grazing study during summer 2019/20.
This study has delivered insights and information around use of chicory or bulb turnips as summer feeds for dairy cows. Run on a commercial dairy farm near Huntly, the study collected information about chicory and turnips, and responses by lactating cows to the crops. Data included tonnage of crops consumed per hectare (ha), cow body condition score (BCS) and milk responses by cows to the crops. These results are currently being analysed and will be fully available to view in the coming weeks.
1Waugh CD, Clark DA, Harris SL, Thom ER, Copeman PJA, Napper AR (1998) Chicory for milk production. Proceedings of the New Zealand Grasslands Association 60: 33-37
2DairyNZ Chicory management (1-72b) https://www.dairynz.co.nz/media/840469/1-72b-chicory-management.pdf
3DairyNZ Turnips – Growing a high yielding crop (1-62) https://www.dairynz.co.nz/media/253747/1-62_Turnips_Growing_a_high_yielding_crop.pdf