NovaVive Inc., an animal health immunobiology company, today announced that an article has been published in the Journal of Animal Science ( The article summarizes a research study evaluating the effect of peripartal (around the time of calving) administration of mycobacterium cell wall fraction (MCWF) (Amplimune®) on the incidence of disease during early lactation and the subsequent fertility of dairy cows. The study was conducted by researchers at Colorado State University (CSU) on a USDA organic-certified diary operation.

In this study, cows were randomly assigned to either a treatment group (n=65) or control group (n=71). The treatment group received 5 mL of Amplimune by subcutaneous (SC) injection 7 days before expected calving, with a second dose within 24 hours after calving. The control group received a placebo (saline) at the same time points. Outcome variables that were analyzed included incidence risk of peripartal and early lactation health disorders, and pregnancy at first artificial insemination (AI), 100 days in milk (DIM) and 150 days in milk.

The CSU researchers found that the incidence rates of both clinical mastitis (bacterial infection of the udder) and metritis (uterine infection) before 28 DIM was lower in the Amplimune-treated group than in the control animals (clinical mastitis: 6.3% vs. 19.7%, respectively [a 68.6% reduction]; metritis: 36.9% vs. 50.7%, respectively [a 27.2% reduction]). Pregnancy was analyzed at three time points: first AI, 100 DIM and 150 DIM. In multiparous cows (animals having more than one pregnancy), the Amplimune-treated cows outperformed the control animals at all time points (35.6% pregnancy vs. 19.2% pregnancy at first AI; 51.1% vs. 25.0% at 100 DIM; and 64.4% vs. 40.4% at 150 DIM). Overall, median intervals from calving to pregnancy were 90 days in the Amplimune-treated group vs. 121 days in the control group.

These findings echo those of a Canada-based embryo transfer (ET) research group. Their study involved synchronized Holstein heifers receiving a single 5 mL dose of Amplimune by intramuscular (IM) injection on the day of heat, approximately one week prior to ET (control animals received no Amplimune). Pregnancy per synchronized recipient at day 60 was greatly improved in the Amplimune group, with 131 of 292 heifers pregnant (45%) as compared to the control group, in which only 83 of 296 heifers were pregnant (28%). These data were presented at the 2021 International Embryo Technology Society (IETS) Virtual Conference (January 2021) and published in the journal, Reproduction, Fertility and Development (

The CSU research group noted that the incidence of respiratory disease in cows less than 28 DIM was greater in the Amplimune-treated group than in the control animals (0% vs. 7.7%). A number of these cases occurred in animals that were previously diagnosed with other diseases (puerperal metritis, clinical ketosis, acidosis, abomasal displacement) and the researchers speculated that these co-morbidities may have made the cows more susceptible to developing respiratory symptoms. NovaVive’s President, Graeme McRae, stated that this respiratory finding was unexpected, considering that MCWF products, including Amplimune, have been used for many years to treat and prevent respiratory diseases in domestic animals.

About Amplimune

Amplimune is approved by regulators in the USA, Canada, New Zealand and the United Arab Emirates to reduce the clinical signs and mortality associated with E. coli K99 diarrhea in neonatal calves. The product is an emulsion of mycobacterium cell wall fractions (MCWF) that enhances innate immunity to fight bacterial infections without the use of antibiotics. When injected into the animal, Amplimune enhances both innate and adaptive immune responses to fight bacterial infections. Amplimune is OMRI listed in the USA and Canada for use in organic production.