Implant technology has been used in beef production since the 1950s and includes natural and artificial compounds with anabolic properties, both of which are considered safe and effective for beef production according to the FDA.

Ralgro and Synovex C are the two options for nursing beef calves.

Ralgro contains zeranol, an estrogenc compound. It is approved for use in calves greater than 30 days of age. Ralgro is not to be used in bull calves and post-weaning heifers.

Synovex C contains progesterone and estradiol benzoate. Similarly, Synovex C should not be used in bull calves and the manufacturer recommends calves be at least 45 days of age.

As with any product, be sure to read the label before administration.



The effect of implants is variable and highly dependent on environmental factors and nutrition.

Implants are designed to increase average daily weight gain. Research data suggest you can expect a 10-30 pound increase in weaning weight in both steers and heifers when properly implanted.

Implants also increase the animal’s nutritional demands to support the added growth, so adequate pasture nutrition is required.

In steer calves, research shows implanting provided comparable weaning weight to bull calves left in-tact until weaning. Implanted steers experience significantly less weaning stress and improved post weaning gains compared to castration at weaning.

Replacement heifers can be implanted prior to weaning, but research suggests added weight gain is not generally advantageous and slight reduction in fertility can be observed. The general recommendation is to not implant replacement heifers.



Lets’ assume two people can gather and implant 30 calves per hour. Using an average 20 percent weaning advantage and a conservative calf value of $1.50 per pound, nets an additional $30 per calf (assuming no price slide).

In this case, implanting nets $870 in added gain value from 30 calves after the $1 per head implant cost. Divide that by two workers and you just made $435 each for your hour of working calves. That’s one job on the farm you should have on the top of your “to do” list!