The planting of thornless prickly pear as livestock feed is becoming increasingly popular, especially in arid and semi-arid areas where water resources and livestock feed requirements are a constant challenge. Thornless prickly pear (Opuntia spp.) offers a sustainable and cost-effective solution, as it adapts well to various climatic conditions and requires little water to grow.

The plants are not only nutritious for livestock, but also have the potential to benefit the agricultural ecosystem by preventing soil erosion and promoting biodiversity. This article explores the benefits of planting thornless prickly
pear as livestock feed, as well as the practical aspects of this approach for sustainable agriculture.

Using prickly pear as livestock feed

The thornless prickly pear has the potential to radically change the landscape of livestock feed production in South Africa. Farmers in the drier regions of the country can plant this crop to significantly increase the carrying capacity of their fields or to act as a buffer against droughts, depending on the extent of the plantings on a particular farm.
According to various studies, up to about 25 tonnes of fresh fruit can be produced per hectare, while the production of leaves can be up to 140 tonnes of wet matter per hectare (or 14 tonnes of dry matter per hectare) per year, based on a density of 1 000 plants per hectare.

Nutritional value

Prickly pear is mainly a source of energy, but has a low protein content. When fertilised, the protein content of prickly pear can increase to about 8% on a dry basis. This makes prickly pear a valuable ingredient in maintenance rations.

For prickly pears grown specifically for feed and properly fertilised, the typical nutritional value is as follows:

• Dry matter: 9 to 10%
• Protein on a dry basis: 8%
• Energy on a dry basis: 6,6 MJ/kg (compared to maize which contains around 12 to 13 MJ/kg)
• Crude fibre on a dry basis: 15%

When the diet of sheep includes a large percentage of prickly pears, their manure can be very wet, making it appear as if the animals are suffering from diarrhoea. However, research has shown that the mucilage in the leaves is the cause of the wet manure. This mucilage is not broken down by the digestive system, and it binds water in a way that makes it impossible for it to be absorbed into the intestinal tract to form the typical dry sheep manure. The wet manure does not have the characteristic smell of skatole, indicating that it is not caused by pathogens or a malfunction of the digestive system.

Methods of using prickly pear as animal feed

For sheep, the leaves should be cut off and spread out. It is not necessary to carve the leaves, as the sheep can fully utilise them without the need to carve them. Trials conducted with sheep grazing directly on the plants showed that the sheep eat the bark of the plants from below and cannot reach high enough to graze the plant evenly, which rules out sheep grazing as an option. In a later trial, cattle were used to graze the plants directly, which was very promising. However, the plants should be at least three years old to have strong frames with tougher stems that cannot be torn off by the cattle. It is also extremely important to graze the plants only once and then give them a minimum of one year to recover.

Although the trials are still in their early stages, it seems that the best method would be to graze the plants in small blocks and then give them a rest period of 12 to 24 months before grazing them again. A major advantage of the prickly pear is that the plant maintains the same shape throughout the year, meaning that the farmer has a constant source of feed 365 days a year. There is no need to cut off leaves and store them for later – the leaves can remain on the plants and be cut as needed.

Some important notes

According to research, farmers who plant prickly pears will not be successful unless they are prepared to follow the following steps. Without these actions, it is a failed attempt and a waste of money:

Plant protection: It is important to fence plantations well, as livestock and game such as kudu, duiker and steenbok can destroy the entire plantation in one night. If fencing is not possible, the farmer must be prepared  to control problem animals. However when the plants are older than two years, the damage caused by smaller animals such as steenbok and duiker will be very limited.

Regular orchard inspection: It is crucial that the orchards are inspected at least once a month (or even more frequently) by well-trained personnel to identify any signs of cochineal or prickly pear fly (cactoblastis). Cochineal should be killed on the leaves, and infected leaves that have prickly pear fly as a cause should be cut off immediately and fed to livestock. It is also extremely important to remove cut material from the orchard immediately.

Orchard management: Every prospective producer should realise that prickly pear orchards require the same attention and care as any other orchard or crop. Although prickly pears can be planted without irrigation in many of South Africa’s drier regions, it is still necessary to fertilise, prune and keep the orchards free of disease annually.

Frost damage: If there are signs of frost damage, all leaves showing visible damage or rot should be cut off immediately and fed to the livestock. Again, it is essential to remove the cut material from the orchard immediately.

Fertilisation: Annual fertilisation is essential, because without it the plant will not reach its full production potential and it will cost the farmer a significant percentage of production. In winter the plant may turn yellow due to nitrogen deficiency, making it more susceptible to frost damage. Nitrogen also has a positive effect on the protein content of the leaves.

Irrigation: This is not always necessary, but in areas where rainfall is less than 300 mm per year, irrigation is recommended to ensure adequate production. The planting and use of thornless prickly pears as animal feed offers
exciting possibilities for sustainable agriculture in South Africa, especially in the drier regions. With the necessary care and management measures, farmers cannot only increase the carrying capacity of their farms, but also reduce the impact of droughts and ensure a constant feed source for their animals.

It is important to follow all the steps mentioned in this article carefully to guarantee the success of prickly pear as animal feed. In the next section, we look at the choice of cultivars, which plays an important role in optimising production and the sustainability of this crop.

For any other queries, visit the Witkraal Boerdery website at www.witkraal.co.za.

Source reference

Witkraal. (2022, March). Prickly pears as animal feed [PDF]. Witkraal Farm.