Lowlines star in grassfed beef studyWritten by Christy Hemken
“Lowline Angus are a smaller-framed animal with interest from producers for a variety of reasons,” says University of Wyoming Animal Science Professor Dan Rule, who leads the study.
He says Lowline cattle can get through a season and finish to whatever extent the producer desires in a shorter timeframe on the same feed capacity than current conventional cattle. “This project was an opportunity to get Lowline cattle and put them on irrigated pasture to accomplish those goals,” explains Rule.
The study is an opportunity to get the group of yearling cattle on pasture, then take a look at how meat composition might change during the growth season of the forage they’re consuming.
The second aspect of the study – Omega-3 fatty acids in grassfed beef – is one Rule says grassfed beef producers use to market their beef. “There is an advantage in the Omega-3 levels in the meat from these cattle, but it’s a slight increase compared to what is recommended that consumers take in.”
Rule says the reason he suggests the benefit is only small relates to how data is expressed. If you take the smaller amount of fat from lean beef and the larger amount of fat from conventional beef, the fat from the lean beef will be higher in Omega-3’s than the conventional, which has less Omega-3’s but more fat overall. When both are put back into the beef for consumption, levels come out about the same.
“We don’t usually eat fat-extracted meat. You just eat a piece of meat,” says Rule. “The Omega-3 concentration in grassfed beef is not as high as some suggest it is. That suggestion is based on the dairy industry, which looks at fat composition based on the fat they extract from milk. That’s the best way to do it for dairy, but I don’t think it’s appropriate for meat.”
The project will allow Rule and his team to look at when Omega-3’s might begin to increase in grass during the growing season. The study will be divided in thirds, with biopsies taken from the steers at one-third and two-thirds through the trial, with the final sample taken at marketing.
“One of the hypotheses of the project is that Omega-3 fatty acids will peak in the tissue relatively early,” says Rule. “The other hypothesis is if Omega-3’s can increase in animal tissue at a certain time during the forage growing season, then we want to address the potential for a supplement to increase it even more.”
Rule says he’s interested in time on pasture and how that influences fatty acid profiles. The group of steers will be divided into those receiving a control supplement, an Omega-3 supplement derived from fish oil – which has the greatest health benefit to consumers – and a third supplement containing a saturated fat.
“What we’re going to look at is when Omega-3’s begin to emerge in the tissue relative to the time the cattle start on grass,” says Rule. “We want to find out, in a short time on grass, what the Omega-3 levels look like. When we go beyond that by another eight weeks or so, do the Omega-3’s increase and do they increase even more in the cattle provided the Omega-3 supplement?”
According to Rule it’s possible the supplement may not provide the animal with more Omega-3 in the muscle tissue at all. “That has to do with the biochemistry in the muscle itself and there’s going to be a limit to how much Omega-3 can be taken up into the muscle,” he says.
“We want to determine when during the growth phase of the forage would Omega-3 fatty acids actually be higher,” explains Rule, saying the question is when is the best time to harvest those animals. “It may not be the best time relative to age, body weight and composition of the animal, but with respect to Omega-3’s that might be the best time to harvest them because that’s when the forage is optimal. It’s all based on hypothesis, and this is the initial test.”
At the study’s end there will be a taste panel evaluation because, Rule says, cattle fed on grass often have an off flavor if Omega-3’s are on the high side due to oxidation during the cooking process. “There might be a difference in flavor attributes compared to the cattle on Omega-3 supplements, and we need to find that out. It’s one thing to bump them up in Omega-3’s, but if you make your beef taste like salmon, that’s a problem.”
Rule says motivation for his study are statements from grassfed beef producers who say the nutritional value is all in the fat. “The biggest challenge is that if you make statements about the natural quality it needs to be backed up by research data, not by a producer or a company.”
“If the small benefit from the grassfed beef fat provides a tremendous amount of protection from high cholesterol, so be it, but if it doesn’t they’re going to have to quit saying all those things,” he continues. “This isn’t anti-grassfed-beef, it’s anti-over-consumption-of-animal-fat. We’ve had problems with that in the past.”
“In my opinion, the best thing about grassfed beef is it is typically going to be leaner,” says Rule. “We should be careful about how much animal fat we consume. Don’t make claims that haven’t been substantiated.”
He says in this study he and his team are trying to put some numbers behind the grassfed beef claims. “I want to try to find out for them the accuracy of that assertion.”
Rule says the trial is “timely and important” and he hopes to confirm or contradict the claims. “If it’s right I’m going to be really excited, and if it’s not they need to know,” he says.
The steers are planned for market in November or December, and results from the study are expected in early 2009.