With the high price of pig feed these days, anything that lowers your cost is easy to swallow. Science is constantly seeking new ways to do that, and a recent study found that pulses, especially faba bean, could help trim the expense.

Pulse power

In a bid to diversify energy and protein for pig diets, University of Alberta researchers have been looking at increasing the inclusion of locally grown pulses in feed. Apart from reducing feed cost, there are a number of agronomic and sustainability benefits to growing pulses. In addition to fixing atmospheric nitrogen (N) in symbiosis with root bacteria, pulses aid in diversifying soil microbial populations and nutrient uptake. If that’s not enough, they also break pest and disease cycles in yearly crop rotation with cereal grains and oilseeds.

This study looked at the potential for faba beans, which offer greater yield compared to field peas, fewer inputs in relation to other crops, and a lower carbon footprint than sourcing animal forms of protein.

However, the inclusion of faba beans in swine diets has been limited by its content of antinutritional factors like tannins and vicine and covicine. Antinutritional factors are components in food that can reduce nutrient use or feed intake. In response, researchers have found solutions through this study by identifying more suitable faba bean cultivars for producers.

Faba takes flight

When faba beans were first introduced to Western Canada about 20 years ago, their high tannin content served as a double-edged sword. The tannins helped guard the crop from early frost damage in the fall, but they gave the beans a bitter taste, rendering them of limited value for inclusion in pig diets. To improve their feed potential, a new white-flowered cultivar named Snowbird was introduced. While its lower tannin level improved feed potential, that came at the expense of reduced protection against early frost.

In a nutshell (or bean pod), the dilemma was this: How could science achieve the best of both worlds for producers, rendering the beans effective as a crop and a feed source? For a solution, crop researchers have reduced the level of tannin to retain frost protection while enhancing digestibility of the bean. Though producers also receive low tannin levels with Snowbird, they lose frost protection in the process. In the course of this study, University of Alberta researchers found that faba bean cultivars with moderate amounts of tannin could still be included in pig diets, provided that the cultivar was also low in vicine and covicine – the anti-nutritional factors. This was a notable breakthrough for producers, as it meant they could reduce their risk of frost damage while growing faba bean for both food and feed without harmful effects.

It pays to be picky

To maximize the benefit of adding faba beans to a rotation, it’s important to do your homework before choosing the best variety for your farm. Among faba bean cultivars with moderate tannin content, researchers found Fabelle to be a top choice for feed intake and weight gain. Across cultivars, variations in dietary fiber and starch content contribute to differences in dry matter, energy digestibility and growth performance of pigs – which can all impact the bottom line. On the other hand, while ensuring that a cultivar will benefit your pigs is obviously paramount, this also needs to be weighed against yield impacts from reduced frost protection.

Having established the viability of faba beans in reducing feed cost, scientists on this study feel that getting that message to the end user is critical. For the findings to be adopted, pig producers must be convinced that pulse grains like faba bean are cost effective.  By replacing expensive soybean meal with the less costly faba bean as a protein source, while maintaining growth performance, producers can reduce feed cost per unit of growth.

Digesting the results

Though researchers found that the antinutritional factors in faba beans may slightly reduce a pig’s ability to digest nutrients, this should not hamper growth if producers consider that fact when formulating diets. For feeding pigs, medium levels of tannins in faba bean are acceptable, provided that vicine and covicine levels are limited.

This study was led by Dr. Eduardo Beltranena, pork research scientist at the University of Alberta. In the barn and lab, graduate student Protus Nyende did the legwork, ensuring that all trials were completed accurately. The project was supported with funding from Swine Innovation Porc and Alberta Pork, which was provided to Dr. Ruurd Zijlstra.

As its next order of business, the team plans to delve deeper into characterizing faba bean cultivars and gaining a better picture of what is happening with this ingredient in western Canada. Wherever that may take them, they know their work to date should take a bite out of producer costs.

Now THAT’S food for thought.