Effect of sequential implanting with zeranol on steer lifetime performance

Area of Science:

• Animal Science
• Beef Cattle Production
• Growth Promotion

Background:

• Optimizing feedlot performance and carcass characteristics is crucial in beef cattle production.
• The use of growth-promoting implants, such as zeranol, is a common practice to enhance efficiency.
• Understanding the impact of implanting at different production stages is essential for maximizing economic returns.

Purpose of the Study:

• To evaluate the effects of zeranol implants administered during the suckling and growing phases on subsequent feedlot performance.
• To assess the impact of early-stage zeranol implantation on final carcass characteristics.
• To determine if early implantation influences finishing phase performance and overall lifetime gain.

Main Methods:

• Conducted three trials with 513 exotic crossbred steers.
• Utilized six treatment groups involving various combinations of zeranol implants during suckling, growing, and finishing phases.
• Monitored preweaning gain, growing period gain, finishing performance, lifetime average daily gain (ADG), feed conversion, and carcass traits.

Main Results:

• Zeranol implantation in the growing period increased gains by 8.4% on average.
• All implant treatments significantly increased lifetime ADG compared to controls.
• Implanting twice in the finishing phase increased gain over unimplanted steers.
• All implant treatments increased hot carcass weight and reduced fat deposition.

Conclusions:

• Implanting exotic crossbred steers with zeranol during the suckling and/or growing phases does not compromise finishing performance.
• Early-stage zeranol implantation positively impacts lifetime ADG and carcass weight.
• Strategic implanting throughout the production cycle offers significant benefits for beef cattle producers.