Implanting Stocker Cattle for Extra Gains on Grass

One technology that has not been adopted to its full potential is implantation. The unfortunate result of this low acceptance is that producers lose the opportunity for extra performance and profit. The primary concerns producers share that contribute to low acceptance can be addressed based on experience in research and the field.

Product Performance

Research indicates that there are a number of benefits, but the magnitude of the benefit is dependent on the product used. There are two major classes of drug used. The first have estrogenic activity (e.g. zeranol, estradiol), meaning they act as feminizing hormones. These products offset maintenance costs by increasing intake and thus growth. Androgenic compounds (trenbalone acetate-TBA, testosterone) are masculinizing hormones which improve muscle protein synthesis and retention rates. Thus, a given amount of intake is more efficiently used. Typically, these are higher potency products. Either type of product improves feed efficiency, and performance (growth), but not all products may be used across different stages of production. Some rules of thumb in terms of expectations:

• 5-20% improved performance (ADG)
• 5-10% improved feed efficiency
• 70-200 days activity
• cost ranges from $1 per low potency dose to $5 per high potency dose
• typically a 1 to 10 cost : benefit ratio

A conservative example: Assume the investment is $5 per animal for a 100 day period on a mid-potency product. If the live-weight gain increase on a 700 pound-starting-weight steer is a conservative 10%, it grows at 2.75 instead of 2.5 lb./d for 100 days. An additional 25 pounds of gain would be experienced over this period, and feed intake is similar. At $95 per cwt. this adds $23.75 to the value of the animal at $5 cost. In a strategic implanting strategy, actual performance will be far more striking! Local pharmaceutical and agri-business representatives can give pertinent advice on implanting strategies for grassed cattle, as well as other situations.

Labour (Handling)

If each implanted animal required an extra 3 min. (1/20^th of an hour) when routinely processing, the labour cost would be $1.25 per animal (1/20 x $25), assuming a labour cost of $25 per hour for handling (2 people at $12.50/hour each).

Ethical Concerns

Concerns exist despite the fact that these products are deemed safe and are registered for use by the Federal Government in various classes of livestock. There are markets for non-implanted beef, but they usually also have other considerations such as limits on total pharmaceutical use. To offset the unrealized benefits by not using implants, a premium must be paid for the lesser product volume, to stay competitive within the industry.

Nutritional Considerations - when using implants, nutrient densities need to be higher than in non-implanted cattle to support higher growth. As always, mineral should be made available. CP levels may need to be a full 2% higher for implanted (versus non-implanted) young cattle. On pasture, this means keeping CP above 16% which should be easy. More challenging is keeping feed value high by keeping forage youthful. Grasses should be grazed in or before the boot stage to provide the highest level of nutrition possible to realize the full potential of the product used.