Current Progressive Dairy digital edition

Living without NT in milk replacers

Tom Earleywine Published on 03 February 2010

In an effort to curb the usage of sub-therapeutic antibiotics, the FDA has ruled that milk replacers may no longer be manufactured with the combination drug of neomycin and oxytetracycline, better known as neo-terramycin or NT, in its common current 2-to-1 dosage.

This decision means producers who feed milk replacer products medicated with NT will need to make some changes.



Approximately 55 to 65 percent of all milk replacers sold in the U.S. are manufactured with NT. The FDA has allowed existing supplies of milk replacers manufactured with the 2-to-1 dosage of NT to be sold until fall 2010; however, most supplies are likely to be depleted before then.

Historically, neo-terramycin has been added to milk replacers for the treatment of scours, specifically scours caused by E. coli susceptible to oxytetracycline or neomycin. Acute E. coli primarily affects calves under five days of age. However, many other pathogens are known to routinely cause scours in pre-weaned calves, and NT offers little to no protection against these other disease agents.

Nutrition trumps medication
Producers considering their options for the replacement of NT in their milk replacer program will probably instinctively look for a replacement medication. While options do exist, it’s important to not only consider the decision on a “medication for medication” basis. We’ve heard on farms feeding a full potential plane of nutrition for years that they are able to “feed through” a disease challenge, as the extra nutrients they are providing their calves allow them to ward off disease and return to growth more quickly. Recent research confirms these farm-level observations.

Studies conducted by independent universities, as well as our company, have looked closely at the benefits of feeding calves a full potential plane of nutrition, consisting of a 28 percent protein, 20 percent fat milk replacer with soluble fiber technology, along with a highly palatable, high-protein calf starter. The benefits have included more efficient, lean structural growth, as well as an added ability to fight off disease.

In a study presented by the Cornell University College of Veterinary Medicine at the 2009 American Association of Bovine Practitioners meeting, calves were fed two levels of nutrition and challenged with Cryptosporidium parvum disease. The results showed that a full potential plane of nutrition reduced the effect of disease due to Cryptosporidium parvum in neonatal dairy calves. Calves fed the high plane of nutrition maintained hydration, had faster resolution of diarrhea, grew more and demonstrated greater feed efficiency than calves fed a conventional diet.


Additional research we conducted at our Answer Research Farm has compared NT-medicated milk replacers to different products and planes of nutrition. Over 200 calves have been involved in six trials that included calves fed a higher plane of nutrition. Only two groups from those six trials showed an improvement in gain from adding NT to milk replacer. There was no consistent improvement in scour scores in any trial, and in some cases, calves that were not fed NT displayed less scours.

The results of those and other studies did not consistently show a health benefit to adding NT to milk replacers when calves are fed a higher plane of nutrition. However, one consistent result has been that feeding calves to their full potential will allow them to better withstand disease and maintain growth.

Medication options available
In some cases, it may be important to look at medicated options either for aggressive disease treatment or for prevention against a past challenge. Producers who feed medicated milk replacers have several options to consider as they assess their calf nutrition program. Bovatec or Deccox are two medication options available for the control of coccidiosis. Bovatec is the more cost-effective of the two and is good insurance against these common pathogens. Neither offers any significant protection against pathogens susceptible to NT, such as E. coli, however.

Additionally, the FDA now allows the new 1-to-1 dosage NT to be fed in milk replacers for disease treatment at 10 milligrams per pound of bodyweight daily, but only for 7 to 14 days in calves up to 250 pounds. This is typically added as an add pack product mixed with milk replacer powder before water is added to the solution. This product fits on dairies challenged by E. coli scours and should only be used on an occasional basis, when other nutritional or medication options are eliminated.

A lower continuous feeding dose of 1-to-1 NT also was approved by the FDA. The total amount of the drug combination fed cannot exceed 0.05 to 0.1 milligrams per pound of bodyweight for an improvement in feed efficiency. At this low dosage, significant benefits are not likely.

The other medication options offer protection against specific pathogens. NT at times may contribute to an improvement in gain by reducing the numbers of bacteria in infected calves, allowing for a more efficient return to health. However, this is not a “cause and effect” relationship because of the many different calfhood disease agents that cause scours.


Other nutritional options
In addition to feeding calves a higher plane of nutrition, producers are encouraged to explore other nutritional additives and options. The most effective option is to feed a low dose of colostrum replacer for seven to 10 days early in life. Some producers in the Upper Midwest are successfully feeding a 1/10 dose of colostrum replacer starting at day 5. This recommendation is based on past work at the University of Wisconsin – Madison showing a benefit to feeding two to four ounces of maternal colostrum during the first two weeks of life. Though this will cost around $25 or $30 per calf, it is an effective way to provide valuable antibodies.

Several probiotics and nutritional supplements designed to provide an immune system boost in young calves are available in the marketplace. One example is Gammulin Functional Protein Supplement, which is a mixture of antibodies, growth factors, enzymes, peptides and albumen designed to maximize gut barrier function. These types of products are designed to be fed during the critical first 14 to 21 days of age.

Direct-fed microbials improve the health and efficiency of the gut and digestive system, providing more nutrients to ward off a disease challenge. It’s important for producers to carefully examine direct-fed microbials and select only products proven by independent research. Watch for those that produce harmful D-lactate. D-lactate production and accumulation in the blood causes calves to lose normal brain function and go off-feed.

Producers should work with their veterinarian, nutritionist or calf specialist to identify solutions to the challenges on their dairy. In many cases, medication may not be needed. Stepping calves up to a higher plane of nutrition can result in healthier calves and will improve the efficiency and future success of heifer-raising programs. PD

Tom Earleywine