Field trials for another beef cattle growth dose

Press, 2 November 1984, Page 24

Field trials for another beef cattle growth dose

Two field trials in Canterbury are part of a series which Elanco Products (N.Z.) hopes will lead to the full registration of another cattle growth promotant, Compudose.

Steers have been implanted with Compudose on the properties of Mr John Jones, Coopers Creek, and Mr Malcolm Monteath, of Ashburton.

• Elanco, a division ,of the United States group Eli Lilly, wants to introduce Compudose into New Zealand and provide competition for Ralgro, the only growth promotant at present licenced for use in cattle in this country.

Compudose has an active ingredient called bse.tridial 17-beta, a natural osetrogen or hormone, whereas Ralgro contains zeranol, a synthetic hormone. Compudose is already approved in 13 coun-

tries, including the United States, United Kingdom, Canada, and Australia. .

Elanco claims that Compudose will lift daily growth rates in young steers on good feed by 20 to 30 per cent.

For the expected retail cost of $5 per implant, Compudose is claimed to give an extra $3O per steer, on average, upon slaughter. It comes impregnated around the outside of a small silicone rubber implant which is placed under the skin and above the ear cartilage of cattle. The oestridial 17-beta diffuses into the bloodstream at a constant rate throughout 200day or 400-day periods, depending on the implant used. . ■■

The silicone rubber implant is not destroyed and can be seen or felt under the skin of the ear. Occa-

sionally it can be lost from the ear.

For the purposes of the latest trials, the cattle will be killed for the domestic market and the implants will be recovered. Elanco is confident that Compudose will be registered for export use in New Zealand and when that occurs the company expects that a withholding period will not be imposed. This may give the product an edge over Ralgro, which has a withholding period after dosing before the stock can be slaughtered. In its promotion for Compudose, Elanco has stressed the “naturally-occurring” oestridial 17-beta versus the synthetic zeranol. ' A trial at Lincoln College in 1981 returned a 26 per cent growth- improvement with Compudose compared with a control mob, another trial in the Waikato demonstrated a 30 per cent lift, and a third trial in the Waikato earlier this year also demonstrated a 27 per cent improvement. It is also being trialled at Ruakura in bulls to determine any growth promotant and behaviour modification effects. L At, Mr Jones’ Coopers property Compudose has been implanted into 21 Friesian steers which are one year old while another

line of steers with the same average weight will be run alongside as a control. The steers all range from 175 to 250 kg in liveweight. The trial will run for 200 days and the results will be available from Elanco at the end. However, the company hopes to have full registration for Compudose shortly.