PUFAs

As a child of the 90’s, I truly did believe that the tub of Country Crock that sat on the table was butter. I was so confused when I would go to my grandmother’s house, because her butter was in a stick, and harder to spread. However, it tasted even better, so I spread it liberally on the morning sourdough toast she would make me (only for my mom to come behind me and take some off).

Well, times have changed. Butter is back, and while there is still a sizable market for what are now called “plant-based butters,” there is a move towards using fats such as whole animal fats, olive oil, avocado oil, and coconut oil in the kitchen. Recently, however, this trend has escaped the kitchen and entered the chicken coop. Customers and mills are calling in asking for “PUFA-Free or Low-PUFA” feed recipes for their livestock. (PUFA= Polyunsaturated Fatty Acids) They are attempting to avoid adding fats and meals from seeds and legumes, such as sunflower, safflower, soy, peanut, and corn. But why?

The composition of the fat in the diet of livestock effects the composition of the fat in the livestock’s products (meat, fat, milk, eggs). This effect is more pronounced in mono-gastric (poultry, swine) than ruminants (cattle, goats, sheep). This is because the microbes in the rumen change from unsaturated fats to saturated fats. Without the effect of the rumen microbes, fats are absorbed in a similar form to how they are eaten, which leads to the animal’s tissues more closely reflecting the composition of the diet. For example, if a laying hen has a high consumption of one form of fat in her diet, her eggs will be higher in this form of fat as well. This is why you sometimes hear of hogs that are on a diet heavy in soybeans or acorns having “loose” fat, because these ingredients are high in unsaturated fats.

In the past several years, there have been claims made about the negative health implications of consuming a diet high in polyunsaturated fatty acids. Largely, the concern of these claims is linoleic acid, also known as omega-6 fatty acids (n-6). Whether these claims hold water is a hot topic in the world of human nutrition, especially online and on social media. I’m not a researcher, doctor, human nutritionist, or anyone involved in this field, so I don’t feel qualified to weigh in. But what I can do is comment on the way we would make a ration that is lower in PUFAs, if that is what you are interested in doing.

First priority would be exchanging the major fat source in your ration. If you are feeding whole soybeans, those would have to be removed. If you are adding any oil or fat, this would need to be low in omega-6 fatty acids (n-6). Of the plant oils, these would include coconut oil (2% n-6), olive oil (10% n-6), palm oil (10% n-6), and flax oil (14% n-6). Animal-based fats are typically lower in omega- 6 fatty acids: tallow is 0-3% n-6 and lard is ~10% n-6 . The fatty acid composition of these will vary, depending on the diet of the animal. The issue with many of these options is expense and mixing. In cold weather, the highly saturated options (coconut oil, tallow, palm) will have to be liquified before mixing.

Another option for a lower omega-6 oil is canola. I am mentioning it separately, because it seems to be a divisive ingredient (which is its own article). But when you look at its fat profile, it is relatively low in omega-6. On average, it is about 60% omega-9 fatty acids, and 20% omega-6 fatty acids. This is much lower in omega-6 than oils like safflower, corn, soy, peanut and sunflower, which range from 30-75% omega-6.

After looking at the source of fat, you will need to look at your protein sources and grains.

Typically, a major source of protein in rations is an oilseed meal. Of all the typical options, flaxmeal and canola meal are the lowest in omega-6. Aside from this, the only protein options are peas, fishmeal, and meat/meatmeals.

The limits on the protein options are the main reason why these “Low-PUFA” rations are so difficult. Meatmeal is not a widely used ingredient in the natural/organic world, and fresh meat can only practically be added at the farm or homestead. Peas are not a great source of protein and are low in certain amino acids. Fishmeal can only be added in low amounts. For this reason, a commercial ration that aims to be low PUFA will have to include an oilseed meal, in order to make it close to a balanced ration.

When looking at grains, the highest omega-6 options are corn (2.14% n-6) and oats (2.3% n-6). Wheat is the lowest option (0.72% n-6), followed by milo (0.76% n-6) and barley (0.78% n-6). To build out a quality ration, I would suggest prioritizing milo, as it is highest in starch and most digestible, compared to the other options. (White rice is very very low in n-6, but it is not a common feed ingredient).

I hope I have spelled out that making a balanced, low-PUFA rations is difficult, especially at scale. But if a low-PUFA ration is your goal, it is possible.

If you are interested in trying to build out a ration like this, feel free to reach out to us. We would be happy to help.