Recommended Forages: unlocking the potential of legumes

Forage legumes, include amongst others, Lucerne, Desmodium, Lablab bean, Cow peas, Vetch, Sunhemp, Lupins and agro-forestry trees like Calliandra, Leucaena, and Sesbania. Forage legumes possess attributes that set them apart from other forage categories. Let us take a closer look at some key characteristics that make forage legumes a valuable addition to ruminant diets.

Leguminous crops have the ability to engage in a symbiotic relationship with nitrogen-fixing bacteria. Plants of the family of legumes establish a mutually beneficial relationship with nitrogen-fixing bacteria called rhizobia, which reside in specialized root nodules. Through this symbiosis, legumes can convert atmospheric nitrogen into a usable form for plant growth. This remarkable feature allows legumes to enhance soil fertility and reduce the reliance on synthetic nitrogen fertilizers.

Some of the most notable advantages of including forage legumes in cattle diets are their high protein and energy content and lower fibre content compared to tropical grasses. Incorporating legumes into dairy and beef diets, therefore, can increase the protein, energy density of the diet and lowering the fibre content of the ration can contribute to a higher feed intake which results in healthier and more productive cattle.

Legumes, if soils are fertile and soil health is well maintained, often contain high concentrations of minerals, especially Calcium and vitamins (A and D), providing additional nutritional benefits for livestock. 

In cultivated pastures and grasslands in the tropics, perennial legume species can play a vital role in improving persistence and longevity. Legumes like Centrosema, Stylo Butterfly pea and Lucerne are renowned for their ability to withstand grazing pressure and persist under various environmental conditions. However, it is crucial to consider climate and soil conditions such as acidity, available phosphorus, the correct inoculant and the root penetrating ability in the soil when utilizing forage legumes in Kenya. Soil analysis should be conducted before applying any corrective measures (farmyard manure, lime, phosphorous) to ensure the right fertilizers are used to achieve optimal growth of the leguminous forage crop. 

The yield potential of legumes varies depending on climatic and soil conditions and management practices. Some legume species have higher yields than others and irrigation can contribute to year-round availability and increased yield. Careful management of an intensively cultivated forage crop like Lucerne is necessary to maximize productivity and achieve desired results. 

Also note that the nutritional characteristics of different forage legumes can vary depending on factors such as species, variety, agronomic practices, stage of maturity at harvest, and part of the plant used. Ruminant nutritionists and farmers must carefully evaluate the nutritional composition, imbalances, and suitability of different feed options when including forage legumes in the diet to ensure the specific requirements of their cows are met. 

There is the risk of bloating when legume forages are fed in excess. Care should be taken when feeding and an animal nutritionist should be involved to advise on inclusion levels. For ruminant nutritionists in East Africa, the Rumen8 software application can be a valuable tool when formulating balanced diets that make optimal use of leguminous forages discussed in this article. This software application provides a comprehensive solution when formulating rations for ruminants, considering the specific nutritional needs of the animals and available feed resources. 

As we conclude the first category of the NEADAP Forage Finder series, we have explored the unique characteristics and advantages of forage legumes in ruminant nutrition. By harnessing the potential of these legumes in intensified sustainable livestock farming systems farmers can optimize milk production, improve the health status of the herd, and maximize margins above feed costs. An added advantage is that enteric methane emission intensity will reduce on diets that have a lower fiber content. Stay tuned for the upcoming releases in this series, where we will delve into whole-plant grain crops (maize, oats, pearl millet), tropical grasses, and root and tuber crops, further enriching your understanding of forages for the benefit of farmers in East Africa and their livestock.

Read More about Selected Legume Forages:

1. Pigeon pea (Cajanus cajan)
2. Cowpea Forage
3. Lablab (Lablab purpureus)
4. Alfalfa (Medicago sativa)
5. Pea forage
   
6. Sunn Hemp (Crotalaria jungea)
7. Hairy vetch (Vicia villosa)