By Colton Massey
Cedar Vale senior
Growth promoting hormones used in beef production, also known as implants, are an area of growing concern amongst consumers. Implants are small pellets placed in the ear of the animal that contain natural or synthetic estrogenic and androgenic hormones. The hormones are released slowly over the course of several months to improve feed efficiency and the rate of muscle growth.
Estrogenic and androgenic hormones are naturally occurring in cattle and in humans. Estrogen is a hormone found in males and females that regulates and stimulates female characteristics, androgen is a hormone found in both male and females that stimulates male characteristics. Implants influence an increase in circulating somatotropin and insulin-like growth-factor 1, causing an increase in muscle growth. Many studies have been conducted to determine the effect implants have on the hormone levels in beef, as well as compare those levels to other foods. Studies referenced by Dan Loy, Iowa State University, and R.L. Preston, Texas Tech University, have shown that 100 grams (about 4 ounces) of peanuts contains 20,000 nanograms of estrogen compared to 10 nanograms in 454 grams (16 ounces) of beef from implanted cattle. That is over 2,000 times more estrogen in a handful peanuts than in a 16-ounce steak.
Before hormone products are available to cattle producers, they are approved for use by the U.S. Food and Drug Administration. Approval is only obtained after numerous studies have proven that the treated animals do not contain harmful levels, and no harm is done to the animal or the environment by the product. Table 1 compares the estrogenic activity between beef from implanted cattle, beef from non-implanted cattle, and other common foods. The numbers in the table are given in nanograms of estrogen per 500 grams (1.1 pounds) of the food.
Keep in mind one gram contains one billion nanograms.
| Table 1. Estrogenic activity of several common foods. | |
| Food | Estrogenic Activity |
| Soybean oil | 1,000,000 |
| Cabbage | 12,000 |
| Wheat germ | 2,000 |
| Peas | 2,000 |
| Eggs | 17,500 |
| Ice cream | 3,000 |
| Milk | 65 |
| Beef from pregnant cow | 700 |
| Beef from implanted cattle | 11 |
| Beef from nonimplanted cattle | 8 |
| Nanograms of estrogen per 500 grams of food. | |
| Source: Preston, R.L. |
The next table shows how the amount of estrogen from 500 grams of beef compares to what is produced in the human body on a daily basis.
| Table 2. Estrogen Production in humans, and potential estrogen intake from beef from implanted cattle | |
| Item | Estrogen amount |
| Estrogen production in humans: | |
| Pregnant woman | 90,000,000 ng/d |
| Non-pregnant woman | 5,000,000 ng/d |
| Adult man | 100,000 ng/d |
| Pre-puberal children | 40,000 ng/d |
| 500 g beef from implanted cattle | 11 ng |
Adapted from: Preston, R.L.
The potential increase in daily estrogen amounts by consuming beef taken from implanted or non-implanted cattle is incredibly small. The difference between them, three nanograms, is inconsequential when comparing to the levels naturally in the body or in other foods.
Producers should consider implanting from an economic standpoint and how it could impact their bottom line. Implants are available for each stage of production – nursing calves, stockers, and feeders – the difference being the amount and combination of daily hormone absorption the animal receives from the implant. Studies conducted on the effectiveness of implanting have shown that implanting a nursing calf under the weight of 400 lbs. can increase weaning weights by 15 to 30 lbs.
In stocker animals, average daily gain (ADG) realized as much as a 20-percent increase when an implant was used. In feedlot animals, steers show a greater response to implants than heifers, and ADG was increased as much as 0.35 lbs. and 0.25 lbs. respectively.
Before using implants, a strategy should be created based upon when and how the cattle will be marketed, and what type of replacement heifer program is in place. Implants can increase ribeye size and overall yield, but may reduce marbling. Producers maintaining ownership through feed-out and selling beef on the rail should estimate the monetary value of the increased weight gain and feed efficiency, while considering the possible negative affects to the marbling score caused by implants.
If the cattle do not receive an implant in order to obtain a premium for no added hormones, the producer should consider whether the premium pays more than the extra weight gain would pay if the animal was implanted. A publication from the Oklahoma Cooperative Extension Service, called “Implants and Their Use in Beef Cattle Production,” says, “Research has shown heifer calves intended for use as breeding animals can be implanted one time between 45 days of age and weaning with no significant effect on subsequent conception rates or calving difficulty. Heifers implanted immediately at birth, following weaning or multiple times prior to weaning had significantly lower conception rates compared to heifers receiving a single implant prior to weaning.”
The agriculture industry will need to continue producing more product with less resources in order to feed the growing population. Implants improve rate of gain and feed efficiency which reduces the amount of resources needed to grow a pound of beef, reducing our environmental impact.
Jude L. Capper, PhD., a livestock sustainability consultant, writes, “Through improvements in genetics, nutrition and management between 1977 and 2007, the U.S. beef cattle industry increased average slaughter weight (1,338 lb in 2007 vs. 1,032 lb in 1977) and overall growth rate (2.60 lb/d in 2007 vs. 1.59 lb/d in 1977) which resulted in the total average days from birth to slaughter being reduced from 609 d (1977) to 485 d (2007). In combination, these productivity improvements resulted in considerable reductions in feed (19%), land (33%), water (12%) and greenhouse gas emissions (16%) per lb of beef over the thirty-year time period.”
Productivity enhancing technology such as implants have contributed to these reductions in environmental impact and also reduced production costs. Capper also said, “growth enhancing technologies (i.e. growth hormones) reduce the environmental impact of beef by 10.7%! More specifically, 4.2 metric tons of feed, 1 acre of land, and 22,722 gallons of water per 800 pound carcass are reduced if growth enhancement technologies are used.”
Consumers have become increasingly inquisitive about how their food is produced. This is a great opportunity for beef producers to address the concerns of consumers and improve their vital relationship. Together we can continue improving the efficiency and sustainability of beef production.
Colton Massey, a 2015 Cedar Vale High School graduate, graduated this spring with a degree in agriculture (animal science) from Fort Hays State University. He is the son of Todd and Peggy Massey, Cedar Vale.
This essay on a topic in agriculture was researched and written by a student as part of a project in a senior animal science class at Fort Hays State University. The project director is Dr. Brittany Howell, associate professor of agriculture, bjhowell@fhsu.edu, 785-628-4015.