Fodder beet roots
Description and recommendations
Fodder beet root, forage beet, betterave fourragère, mangold, mangel, würzel
The classification of both the wild and cultivated forms of Beta vulgaris is confusing. It is generally accepted that all cultivated beets belong to the Beta vulgaris subsp. vulgaris subspecies. This subspecies is divided into the following groups : root beets Crassa (fodder beets), Altissima (sugar beets) and Conditiva (garden beets), and leaf beets Flavescens (Swiss chard) and Cicla (spinach beets) (Oyen, 2004).
In British English, the name "fodder beet" refers to varieties with smaller roots and high DM content, while types with broader roots that sit high in the soil are called "mangels" or "mangolds". In Germany, "mangolds" refers to white varieties of leaf beets (Henry, 2010).
The fodder beet (Beta vulgaris subsp. vulgaris L.) is a biennial plant grown for it fleshy, swollen root. The size, shape and colour of the root are extremely variable and depend on the variety. Roots from fodder varieties tend to be less deeply buried (up to 2/3 above ground) than those of sugar and intermediate fodder-sugar varieties (ADBFM, 2009). The vegetative part develops mainly during the first year of growth. The dark green, heart-shaped leaves are borne in a rosette, lying horizontally to catch as much light as possible. After the first year, if the root is not harvested and after cold exposure, the rosette turns into a 50-80 cm tall flower stalk that bears small, green, bisexual petal-less flowers (Henry, 2010). Fodder beet crops that are intended for fodder (rather than for seed production) are cultivated as annual crops and the roots must be harvested before winter since they do not withstand frost (ADBFM, 2009).
In Northern Europe, fodder beet roots have been used as fodder since the Middle Ages. They became a major winter feed for cattle in the 1800s. Traditional fodder beets had multigerm seeds (resulting in clusters of 2 or 3 plants) that required the manual separation (thinning) of the young plants. This labour-intensive aspect of fodder beet cropping led to its decline after World War II and fodder beets were replaced by maize in ruminant diets. The development of monogerm varieties in the 1970s allowed full mechanization and higher yields, resulting in a renewed interest in fodder beets (Henry, 2010). Three types of fodder beet varieties have been defined depending on their DM content: fodder (< 12 % DM), fodder-sugar (12-16 % DM) and sugar-fodder (16-20 %) (ADBFM, 2009; Limagrain, 2011). As a rule, beet varieties are only accepted as sugar beet if the DM is higher than 20 % and the beet is white (Højland et al., 1994 cited by OECD, 2001).
The main use of fodder beets is ruminant feeding, though they can also be fed to pigs (Henry, 2010; Rees et al., 1956). Their high sugar content makes them palatable and a valuable energy source (Draycott et al., 2003). They are also a potential crop for biofuel production (Henry, 2010).
Fodder beet originated from Middle East and was already used as cattle feed in the ancient Greece in 500 BC (Henry, 2010). Beta vulgaris L. ssp. maritima, is regarded as the parent species of the cultivated beets (fodder beet, sugar beet, beetroot, yellow beet, Swiss chard) (OECD, 2001). The crop spread to Europe, was introduced into the USA in 1800 and is now cultivated worldwide in the cooler climates (Northern America, New Zealand and the higher parts (above 600-1000 m) of the tropics (Oyen, 2004; OECD, 2001). Sugar beets were derived from fodder beets in Continental Europe during the 1800s as sugar cane was subjected to English blockade. In 2008, France was the main producer of fodder beets (13,000 ha) followed by the United Kingdom (10,000 ha) and Belarus (8,000–10,000 ha) (Henry, 2010).
Fodder beet can grow between 8°C and 25°C (ADBFM, 2009; Oyen, 2004). Frost below -3°C can damage the plant. Soil pH should be higher than 6.5 since fodder beet is susceptible to acid soils that cause physiological yellowing. Soil liming is recommended but boron availability should be respected to prevent black heart disease (ADBFM, 2009). Fodder beet crop are moderately tolerant of soil salinity and can withstand irrigation with saline water (Oyen, 2004). Fodder beet roots is a drought tolerant crop that can provide fodder at the end of summer when other plants have disappeared (ADBFM, 2009).
Fodder beets are particularly productive and are the highest yielding crop grown under temperate climates. Yields of 50-75 t of fresh roots / ha are common and up to 100 t fresh roots / ha can be obtained. The crop also produces 10-20 t / ha of leaf material (Draycott et al., 2003)
Fodder beet roots and foliage can be grazed. Strip grazing is recommended: cattle enter the stand and each animal is allowed to graze 3 linear meters of fodder beet during 2 hours a day. Grazing saves many harvesting and distribution operations (ADBFM, 2009). Strip grazing is also possible with pigs (Limagrain, 2011).
Harvest and storage
Fodder beet roots can be harvested when physiological maturity is reached, i.e. when basal leaves are dried. However, as roots do not spoil in soil, early harvest is not necessary and roots can remain in the soil as long as no damaging frost (- 5°C) occurs. If the roots are removed from the soil they can be stored in large outdoor clamps (covered with straw to protect from frost) during 4-5 months provided they were healthy and had not been damaged during harvest. Frozen beets can be left to unfreeze and must then be fed to animals as soon as possible. Harvesting diseased beets should be avoided except when the symptoms are mild. In that case the roots should be kept separate from the healthy ones and fed quickly to the animals (ADBFM, 2009).
In cooler parts of the tropics the roots can be stored in the ground for use during the dry season (Göhl, 1982).
Fodder beet roots that have been previously cleaned (stones and soil removal using rotating drums) can be fed whole to animals or can be chopped to facilitate intake (ADBFM, 2009; Miserque et al., 2003).
Root crops cause soil losses during harvest (Ruysschaert et al., 2003). Sugar beet roots harvesting may result in 17 t earth losses/ha (Boardman et al., 2006). Fodder beet roots which are not as groovy as sugar beet roots are less deleterious to soil than sugar beet roots because they lift less soil when they are harvested (Boardman et al., 2006).
Greenhouse gas consumer
Fodder beet crops are amongst the higher CO2 consumers; they also release the highest O2 (Kerten, 2003).
Genetically modified fodder beets
GM (Roundup Ready) fodder beets have been developed but in 2011 no such variety had been released in Europe (GMO Register, 2011). Field trials were authorized in Denmark in 2005 for a 4-year period. Digestibility and feeding values of Roundup Ready fodder beet were similar to those of conventional varieties (Hartnell et al., 2005). Milk yields obtained with GM fodder beet fell between those of conventional beets. Fodder beet type did not affect the concentration of hormones and growth factors in whey (Weisbjerg et al., 2001).
Cases of poisoning have been reported in cows fed on fodder beets. The symptoms described were similar to those of milk fever and were alleviated by calcium injections (Price, 1954). Leaves contain high amount of oxalic acid (calcium oxalates) and should not be fed in large quantities to livestosk as it has deleterious effect on Ca status. Oxalates bind circulating Ca and may result in milk fever (Duncan et al., 1997). However, levels of between 3.0-6.0 g/kg DM have been observed in the roots, far below the 100 g/kg level that is considered to be dangerous (Boyd et al., 1991).
Freshly harvested fodder beet roots can contain high levels of nitrates, that are known to cause scouring in farm animals. Scouring was observed on pigs fed fodder beet containing high levels of nitrates and the digestive disturbance ceased within two days when fodder beet with very low nitrate levels was substituted. It has been suggested that nitrates rather than oxalates were the cause of the scouring observed in other experiemens (Boyd, 1991). In sows, Cases of abortion in herds fed on high nitrate/nitrite fodder beet roots have been reported (Bouska, 1991).
Fodder beets have a relatively low DM content, from less than 12 % to 20 %. They are mainly an energy feed due to their high content of watersoluble carbohydrates (55 to 70 % DM, mostly sucrose). There is a positive relationship between DM content and sugar content and intermediate fodder-sugar types contain both more sugar (up to 80 %) and DM (up to 20 %) than types used only for fodder. NDF is about 20 % DM and crude fibre content is rather low (5-8 % DM). Fodder-only types are richer in fibre. Protein content is about 6-10 % and thus also fairly low. Mineral content (for clean roots) is 8-10 % DM for low-DM beets but only of 4-6 % for high-DM roots. Ca and P are low (Dulphy et al., 2000).
Tables of chemical composition and nutritional value
Fodder beets are well appreciated for their palatability and are often used to replace cereal grains as a source of energy. It is a fresh forage, highly valuable for winter feeding, with a positive effect on the health status of the animals (Chenais, 1994a; Dulphy et al., 2000; ADBFM, 2009).
Risk of acidosis
Due to the high amount of fermentable carbohydrates and low contents of fibre, protein and mineral matter (which results in a weak buffering power), feeding fodder beets may cause acidosis though the risk is rather low. DM intake should not exceed 0.8 % LW (Dulphy et al., 2000; Enemark et al., 2002). They should be included progressively in the diet in order to prepare rumen flora to the high amount of sucrose. A fodder beet-based should be balanced with fibrous forages such as hay (ADBFM, 2009). Ketosis can also result from feeding excessive amounts of fodder beets (Dulphy et al., 2000).
The fill value of a low-DM fodder beets is lower or comparable to that of fresh grass, silage or hay, while the fill value of high-DM fodder beets is even lower and comparable to that of concentrate feeds (INRA, 2007).
Digestibility and energy value
Fodder beets are highly digestible: OM digestibilities are in the 87-90 % range (Dulphy et al., 2000) and a value of 96 % has been reported (Sabri et al., 1988). NE (lactation) values are about 7.9-8.2 MJ/kg DM (INRA, 2007; Donosa et al., 2010), similar or higher than those of cereal grains. However, a DM intake higher than 0.5 % LW slightly depresses digestibility and the energy value, down to NE (lactation) 7.1 MJ/kg DM. Roots that have been unsufficiently cleaned contain large amounts of mineral matter that decrease their energy value (Dulphy et al., 2000).
An in vitro study concluded that the larger amounts of substrate fermented with fodder beets have a potential to supply more energy for microbial synthesis than a barley/oat grain mixture or raw potatoes. The replacement of barley/oat grain by fodder beets did not result in a decreased supply of glucogenic substrates and fodder beets facilitated microbial growth (Eriksson et al., 2004b; Eriksson et al., 2004c).
The protein content of fodder beets is low and beet protein is quite soluble (N effective degradability of 85 % ; INRA, 2007). Nitrogen supplementation is therefore necessary (Dulphy et al., 2000). Fodder beet can help to control an excess of dietary protein. Supplementing dairy cows fed an alfalfa/grass silage with fodder beets resulted in a lower concentration of milk urea and in a lower urinary ratio urea/creatinine (Eriksson et al., 2009).
Fodder beets are valuable for dairy cows. Lactating dairy cows can be fed with 20 kg/d of fresh fodder beets (about 3-4 kg DM). A 1-week transition with 1 kg (DM) of fodder beets is recommended (ADBFM, 2009). Diets with 3 or 6 kg (DM) of fodder beets can support a milk production of 30 kg/d (Dulphy et al., 2000).
Many studies have reported that the inclusion of fodder beets increases the fat and the protein contents of milk. This effect is particularly notable with diets based on forages such as grass silage and hay that tend to give low milk fat and protein. The effect is small when fodder beets are included at less than 0.8 % LW (DM basis) in the diet, and insignificant when fodder beets supplement maize silage (Dulphy et al., 2000). In lactating cows, the inclusion of fodder beet in the diet reduced silage DM intake but resulted in an increase in total DM intake and estimated ME intake. It had no significant effect on milk yield, though it increased milk protein content and milk energy output. However, milk energy output expressed as a proportion of ME intake was significantly reduced (Ferris et al., 2003). Fodder beets tended to decrease the milk yield and the energy corrected milk yield was lower whereas the composition of the milk was unaffected compared to a total mixed ration with barley (Mogensen et al., 2003). In dairy cows fed a control diet comprised of hay ad libitum and 15 kg fodder beet, supplementation with either 1 kg ground rapeseed, or 1.4 kg ground linseed, or 1 or 1.4 kg ground sunflower-seed allowed to control milk fat content and milk fatty acid composition (Collomb et al., 2004).
Fodder beet can be associated with potatoes: in lactating cows, compared with barley, a mix of fodder beets and potatoes (80/20) appeared to have a greater effect of substitution on silage intake and this decreased milk production by a magnitude corresponding to the lower intake of ME (Eriksson et al., 2004a).
Suckler cows can be given 30-40 kg/d of fresh fodder beets (4-6 kg DM) but the amount should not exceeed 10 % LW (ADBFM, 2009).
Lactating ewes can eat 4-7 kg/d of fresh roots (0.6-1 kg DM) though the precise amount depends on the animal requirements. A 4-week adaptation period (with 1 root per day) is recommended. Older ewes should be fed chopped roots (ADBFM, 2009).
Lactating goats can be fed 4-5 kg/d of fresh fodder beets (0.6-0.75 kg DM). Gestating animals can eat 1 kg/d of fresh roots (ADBFM, 2009).
Fodder beets in organic farming
Like other root crops, fodder beets might be of good value in organic dairy farming as they could help to improve energy supply as well as nitrogen balance. They could be beneficial by reducing the amount of potential human food in animal feeding (Eriksson, 2000).
Fodder beets in the tropics
Fodder beet is a relatively uncommon crop in tropical and subtropical countries, but it could be useful in periods of food shortage. In Sudan, a trial comparing fodder beets (a mixture roots and tops) and sorghum forage concluded that fodder beets had a higher nutritive value (lower crude fibre, higher protein and ME), which was reflected in the lower DM intake and equal or superior milk yields by cows fed on beet roots without any adverse effects on milk. Feeding cost was also much lower (Khogali et al., 2011).
Fodder beet roots are a palatable energy feed for growing pigs. They can be fed fresh, dried or ensiled. However, while the fibre content is low, it is still higher than that of wheat and maize grain and substituting fodder beet for cereals may cause a reduction in the value of other dietary ingredients. Lysine (2.3 to 4.3 % of protein) is likely to be the first limiting amino acid in fodder beet. Estimates for the DE value of fodder beets for growing pigs are in the 13.2-14.4 MJ/kg DM range, i.e. slightly lower than for cereal grains. Drying the roots had no effect on the DE or ME. Feeding fodder beets to pigs is safe though some cases of scouring and abortion have been reported in animal fed roots containing high levels of nitrates (see Caution above) (Boyd, 1991).
Fresh fodder beets are bulky due to their high water content and pigs fed fresh fodder beet consume slightly lower levels of the root crop than pigs fed the dried material. However, the water content of fodder beet seems to be quickly reduced following ingestion, and growing pigs can consume large quantities of fresh fodder beet. For instance, in pigs fed 70 % (DM basis) of fresh roots, DM intake were only 12 % less than for pigs fed the control compound feed (Boyd, 1991). In sows, fodder beet roots increase eating time, reducing feeding rate by 20 % with the positive effect of decreasing aggressive behaviour (Appleby et al., 1987 cited by Love, 2008).
In unbalanced diets, the use of high amounts of fodder beets in growing pigs usually depresses the performance of growing pigs, due to the lower protein content of the roots. Direct substitution of fresh fodder beet for increasing amounts of a balanced compound diet impaired growth performance, lean and fat deposition and killing out proportion, resulting in degraded economic performance in spite of the lower feed cost. In balanced diets containing 15 to 40 % (DM basis) of fresh or dried fodder beet roots, growth performance (daily liveweight gain and feed conversion ratio), fat deposition and killing out decreased significantly as fodder beet supplied increasing proportions of the total diet (Boyd, 1991).
Ensiled fodder beet root gave good results in finisher pigs as it increased daily weight gain by 15.7 %, improved feed conversion ratio and lean to fat ratio (Schichter, 1993).
Sows receiving diets where fodder beet roots partially (25 %) replaced concentrates had poorer scores at mating (55% vs 85%) and their litter had lower birthweights (Makaganchuk et al., 1974). Silages containing limited proportion of fodder beet roots (23 %) could be fed to pregnant and lactating sows without affecting fertility (Moshkutelo et al., 1988).
Horses and donkeys
Horse can consume 0.5 kg/100 kg LW of fresh fodder beets. Chopping the roots is not necessary (ADBFM, 2009).
Tables of chemical composition and nutritional value
|Dry matter||% as fed||17.9||13.4||22.3||2|
|Crude protein||% DM||16.7||1.4||15.2||17.9||3|
|Crude fibre||% DM||12.3||4.1||7.6||14.8||3|
|Ether extract||% DM||4.5||2.8||6.2||2|
|Gross energy||MJ/kg DM||15.6||*|
The asterisk * indicates that the average value was obtained by an equation.
Last updated on 24/10/2012 00:43:44
|Dry matter||% as fed||16.3||2.2||12.6||19.4||17|
|Crude protein||% DM||6.7||1.1||5.1||9.0||18|
|Crude fibre||% DM||5.8||0.8||4.3||7.4||19|
|Ether extract||% DM||0.5||0.7||0.1||2.8||13|
|Starch (enzymatic)||% DM||0.1||1|
|Total sugars||% DM||72.5||68.6||76.5||2|
|Water-soluble carbohydrates||% DM||66.0||7.6||54.7||81.9||10|
|Gross energy||MJ/kg DM||16.7||0.4||15.6||16.7||10||*|
|Ruminant nutritive values||Unit||Avg||SD||Min||Max||Nb|
|OM digestibility, Ruminant||%||89.2||4.1||77.6||93.0||11|
|Energy digestibility, ruminants||%||84.6||1.6||84.6||90.0||10||*|
|DE ruminants||MJ/kg DM||14.2||0.3||13.6||14.6||10||*|
|ME ruminants||MJ/kg DM||11.9||0.3||11.6||12.4||10||*|
|Nitrogen digestibility, ruminants||%||52.1||12.2||36.0||80.6||11|
|Pig nutritive values||Unit||Avg||SD||Min||Max||Nb|
|Energy digestibility, growing pig||%||81.0||*|
|DE growing pig||MJ/kg DM||13.6||*|
The asterisk * indicates that the average value was obtained by an equation.
Last updated on 02/05/2013 17:05:30