Vegetable-based fat supplements, such as soybean oil, play an ever-increasing role in cattle nutrition.

Cattle feeders have known for years that fat is a great source of energy. Cow/calf producers are catching on to that lesson now, too.

Those ranchers are also learning that today's vegetable-based fat supplements offer some great potential benefits in cattle rations. These include:

  • Increased cold tolerance in the newborn calf,

  • Improved heifer development and pregnancy rates,

  • Improved rebreeding of calving females and

  • Increased weaning weights of first-calf heifers' calves.

Hugh Peltz, superintendent of operations for True Ranches, Wheatland, WY, has had enough experience feeding vegetable-derived fat to be impressed with what it's doing for the ranch.

Last winter, Peltz ran short of hay and made up a lot of the nutritional energy difference with the liquid fat supplement. He fed a vegetable fat supplement to nearly all of the ranch's “outside” cattle.

“We didn't have an easy winter last year. It's going to be interesting to see how these cows preg-check this fall — I don't think we'll be at all disappointed,” says Peltz.

“We've stopped feeding both our outside cattle and our feedyard cattle any kind of mammalian-derived feed,” he says.

It's important to note that the vegetable fats do provide the energy without the perceived problem of feeding animal fats. But the data are not in whether or not animal fats present a human health risk. Meat-and-bone meal — yes, but not animal fats.

Measuring Performance

Peltz says the vegetable fat products give him the energy advantages of fat in the diet without the bother and worry of trying to incorporate animal fat. Performance is what Peltz can measure, and from nearly every angle, he can point out the advantages of the vegetable fats.

“We didn't have as much trouble with the cold weather bothering our calves,” he says. “It was cold enough last spring to cause some problems with the calves — but we just didn't see as many freeze up as we have had in the past.”

In studies at the Fort Keogh Livestock and Range Research Lab, Miles City, MT, scientist Bob Bellows found that calves born from dams fed supplemental vegetable-based fat during late gestation responded better to cold exposure than calves from dams fed low-fat diets.

“Their temperature response to cold was greater, and they were able to maintain the increased temperature longer,” says Bellows. “These calves had more glucose available for metabolism and heat production, and probably more brown adipose tissue.”

The cows were fed supplemental fat during gestation, but the fat supplements were pulled nearly two months before the beginning of the breeding season. Even so, by feeding 10% supplemental fat before the breeding season, researchers have increased estrous activity — resulting in up to a 50% increase in pregnancy rate.

“This increase in pregnancy rate is especially interesting,” adds Bellows. “It suggests a carryover effect of supplemental fat fed during gestation on subsequent reproduction.”

Added Advantages

Vegetable-based fats may have advantages over other energy sources in some situations.

“With the specially processed vegetable fats there are no problems with rancidity as with animal fat,” says Pat Collins. He's a ruminant nutritionist with Agridyne LLC, Springfield, IL, which manufactures Mix 30 — a commercial liquid feed supplement with vegetable fat as the energy base.

“It's also been shown that vegetable fat is more digestible than animal fat and even assists in digesting other fats found in feeds,” adds Collins. “Some types of vegetable fats also exhibit bypass qualities that translate into improved feed efficiencies.”

The positive response to fat supplementation may be dependent on specific fatty acids in the fat. Polyunsaturated linoleic oil is found in body fat and helps regulate body temperature and metabolism.

Body fat containing more linoleic oil reduces the animal's stress of increased body warming, and this makes for healthier newborn calves, says Collins.

Linoleic acid is a major fuel in cells for heat production. It's stored in the brown adipose tissue, a fat tissue important to heat production in newborn calves.

Highly Digestible

Bellows' work with heifers at Miles City has included different vegetable seeds as fat sources. He has looked specifically at safflower, soybean and sunflower seed oils.

“There did not appear to be differences among the three fat sources,” explains Bellows.

While there was a slight increase in birth weight and calving difficulty, Bellows found significant increases in heifer pregnancy rates (13%) and the weaning weights of their calves (30 lbs.).

Peltz uses Mix 30 as his fat-based supplement of choice. “They're making a lot of claims about the linoleic fats in Mix 30,” he adds. “There might just be something to it that we haven't had before.”

In addition to providing supplemental energy, the vegetable fats are highly digestible.

“Fat supplementation does not decrease forage digestibility and can actually increase microbial efficiency and protein production,” says Collins.

“Fat has 2.25 times more energy than carbohydrate or sugar, resulting in additional improvements in feed efficiency,” he explains.

Broader Applications

A broader application for the fat-based supplements may be in drought situations.

Butch Whitman, Billings, MT, beef cattle nutritionist with MoorMan's, says their vegetable fat supplement is a popular substitute for forages during grass shortages.

“The fat-based supplements are very fiber-friendly and can really stretch what limited forages ranchers have during drought years,” says Whitman.

MoorMan's sells a solid soybean-based fat supplement that provides 18% crude protein and 16% crude fat. Called the “18/16 Hi Energy Tub,” the product is designed for self-fed systems in ranges and pastures.

Whitman says because the fats are more energy-dense than other energy sources, they can help cattle reach better body condition.

“In range programs we don't like to play catch-up,” says Whitman. “If you go into the winter with your cows in better body condition, it's a whole lot easier to keep them in good condition for calving and rebreeding.”

Most researchers and nutritionists don't completely understand the mechanisms of vegetable fats in cattle nutrition — especially in the area of energy transfer and metabolism. Bellows, who's now retired, wants to see more research into this potentially powerful and economical source of “renewable” energy for the beef cattle industry.

Meanwhile, cattlemen like Hugh Peltz have learned there is more to feeding fat than meets the eye.

“It's working for us,” he says. “And the more we learn about feeding fat, the more we are going to put it to work on our ranches.”