Merial today announced the planned release of “Longrange,” (eprinomectin) the first extended-release parasite control product for cattle. A single injection will provide 100 to 150 days of protection, helping break the parasite lifecycle, according to Merial veterinarian Joe Dedrickson.

Veterinary parasitologist James Hawkins notes that internal parasites can go unnoticed in beef cattle as most of their effects are sub-clinical. They can however damage immunity and reduce feed intake, feed efficiency, weaning weights in calves, conception rates in cows and milk production. Research has shown that effective parasite control can provide returns up to $200 per head in beef herds.

Hawkins says current parasite-control products do a good job of killing worms, but their duration of activity is relatively short, and within days or a few weeks after treatment, cattle can become re-infected with worms as they consume the larvae on pastures. Strategic parasite-control programs can help break the cycle of re-infection but require multiple treatments.

With Longrange, Dedrickson says, a single dose in the spring can protect cows through the entire grazing season while also preventing pasture contamination, resulting in less exposure for calves.

Hawkins says the product, which must be prescribed by a veterinarian, works in two stages. Immediately after the injection, the blood concentration peaks, then gradually declines over 70 days. At about 70 days, the product releases a second dose, causing another peak in blood levels, resulting in protection for up to 150 days.

Prescribed dosage for the product is 1 ml per 110 pounds of animal weight, so a 50 ml bottle will treat 10 550-pound cattle. The product will be available in 50 ml, 250 ml and 500 ml containers. The product is not approved for dairy cows older than 20 months or for use in veal calves. In beef cows, it can be used at any stage in the reproductive cycle.

It also is not approved for use in feedyard cattle or in intensive rotational-grazing programs in which cattle are rotated at least once every four days and stocked at a rate of 50,000 pounds per acre. It carries a withdrawal period of 45 days prior to slaughter.

Dedrickson says the product will cost about one penny per pound of animal treated, so treating a 1,200-pound cow would cost about $12.

For more information, visit Merial’s Longrange website.