Brassica carinata, a new resource to feed animals

Brassica carinata is an oilseed plant of the same genus as ‘Rapeseed’ (Brassica napus), ‘Indian mustard’ (Brassica juncea), ‘Turnip’ (Brassica rapa) and the group of cabbages in general (Brassica oleracea). Unlike some of this species, B. carinata oil cannot be used for human consumption (see below), but it has other uses that make a particularly interesting crop.

⇒ In Uruguay, the area planted with this crop has increased in response to the growth of the biofuel industry. It is being promoted by the forestry company UPM and accepted among producers, mainly because it fits very well within the crop rotation system. In contrast to other winter crops, such as wheat and barley, B. carinata is harvested early, by the first days in November. This means that the fields are vacant sooner.

Morphological characteristics

The structure of the plant is prepared to resist marginal growing environments. However, to obtain good yields, it is recommended to maintain adequate levels of nitrogen, phosphorus, potassium, and sulphur in the soil. Brassica Carinata grows best in well-drained soils with a pH of 5.5 to 6.5.

During the rosette state of the plant, the development of green matter is amazingly fast. At maturity, the plant may reach between 1.20 to 1.50 m. The yellow flowers are formed by four petals in the shape of a cross. The fruit has a high resistance to dehiscence, minimizing seed loss during harvest.

Commercial importance

Although Brassica carinata has a high oil content in its seed, it is not suitable for human consumption. This is because it has a high level of erucic acid, which is toxic and produces myocardial lipidosis, among other conditions. However, due to the characteristics of its fatty acids, with more than 90% of them as unsaturated, it is an ideal raw material to produce biofuels. These biofuels, in contrast to fossil fuels, produce 70% less greenhouse gas emissions. The product remaining as a residue after oil extraction is a high-protein, low-fibre meal, suitable to be included in animal rations.

Use of Brassica carinata in animal feeding

As mentioned above, the meal obtained after oil extraction from B. carinata is a good source of protein. It contains 40 to 42% of good quality crude protein, and it could be fed to all livestock species. However, it is advisable to use it together with other ingredients, due to its high content in glucosinolates.

The toxicity of glucosinolates, for livestock and humans, is associated with the formation of thiocyanate. This compound interferes with iodine trapping in the thyroid gland and the synthesis of thyroid hormones (T3 and T4). Consequently, anomalies will appear in all tissues, including reproductive organs.

Among the most common symptoms of intoxication by glucosinolates, we find:

• drop in male and female fertility
• growth delay
• impaired productive performance.

Since Brassica carinata is of the same family as canola, these symptoms can be similar to the ones observed in animals ingesting feeds with high inclusion of Canola meal.

However, the inclusion of B.carinata meal the ration according to the recommendations per species (Table 1), can be a good alternative to the use of other oilseeds, such as soya and sunflower, especially when they are out of season.

Conclusions

This oilseed is a winter crop. It represents an alternative to other oilseeds, such as soya and sunflower, due to:  

• its high oil production for the distillation of biofuels.
• the production of meal as a by-product of biofuel distillation, which can be used as a source of good quality protein to feed poultry, pigs, and ruminants.
• the possibility of using it in crop rotations.
• the high adaptability of the plant to adverse climates, especially dry season.
• the promotion of the utilisation of non-fossil fuels, reducing the greenhouse gasses emissions.

This article was originally pubished in nutriNews Spain, under the title Brassica carinata, un nuevo recurso para la alimentación animal