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Don’t feed manure to calves – it kills them

Alfonso Lago Published on 18 January 2013

New data confirms that contaminated colostrum impairs calves. How can you get a cleaner colostrum? Calves from different dairies, even after they’ve been transferred to a custom raising facility, often have different destinies.

Having consulted with large calf ranches in the West and Midwest, I found that operations with low mortalities overall still have a calf mortality range of 1 to 20 percent, depending on the dairies they get calves from.

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These calves share facilities and receive the same level of care at the calf ranch no matter where they came from. This raises the question: How much do the few hours calves spend at home dairies impact their future health?

In order to address this question, we have to understand what affects calf health. At the risk of oversimplifying, calf health is a function of reduced exposure to pathogens and preparation to fight diseases. The antibodies absorbed from colostrum, known as passive transfer of immunity, play a very important role in defending the animal from disease.

About 50 percent of the differences in calf mortality among dairies shipping calves to the same calf ranch are due to differing proportions of calves with passive transfer of immunity failure (total serum proteins less than or equal to 5.2 g per dl).

OK, but what about the other 50 percent? The level of exposure to pathogens at the home dairies explains a good portion of it. There are many opportunities for oral contamination on the first day of life.

Newborn calves ingest manure when they are face-first in contaminated bedding (at the calving pen or in calf holding areas), when they lick the dam or other cows’ legs, flanks or udders (if not removed soon enough from the maternity area), when they lick other calves’ coats (when held in communal areas), when they are fed contaminated colostrum or other liquid feed and when they are not handled in properly cleaned, disinfected and well-bedded calf transportation vehicles (i.e. carts, trailers, etc.), calf hutches or pens.

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In a recent study, we collected colostrum from 67 herds in 12 states and found that 43 percent of the samples were contaminated with total bacteria counts over 100,000 cfu per ml – and 17 percent exceeded one million. In a consequent study, we were able to quantify the association between contaminated colostrum and calf health.

Calves receiving colostrum with coliform counts over 10,000 cfu per ml had a four times higher mortality risk pre-weaning than calves receiving clean colostrum. In addition to the direct effect on mortality, high coliform counts in colostrum decreased the absorption of the colostrum immunoglobulins (antibodies) by 25 percent.

Coliform counts are an indicator of fecal contamination in colostrum. We also studied whether other bacteria had an effect on calf health, and we found that most of the negative effect was through coliforms.

There are three major sources of microbial contamination of colostrum: an infected mammary gland or fecal contamination during harvest; contaminated collection, storage or feeding equipment; and bacterial proliferation prior to storage, during storage or before feeding.

In order to avoid calves suckling from infected glands, or from manure-contaminated udders, calves should be removed from the calving area within one hour of calving (30 minutes is preferable).

When harvesting colostrum, special attention should be given to the udder preparation routine in order to milk clean, dry teats. Milk from cows with mastitis or Johne’s disease should be discarded, and colostrum should not be pooled if it is not all pasteurized.

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Previous research has shown that most bacterial contamination of colostrum occurs during the process of milking the colostrum into buckets. Milking machine maintenance (bucket units are in need of attention) and cleanliness is important.

Milk buckets, storage containers, bottles, nipples, esophageal feeders and any other feeding equipment should be rinsed with lukewarm water (not hot) to remove as much milk residue as possible, then scrubbed with a brush and hot water (120 to 140 degrees F) containing a chlorinated detergent solution, rinsed with warm water containing acid and allowed to dry with the containers facing upside-down but not touching the floor.

Each time we transfer colostrum to a new container, we are increasing the chances of contamination. In one of the previously mentioned nationwide studies, colostrum was transferred to different containers an average of 2.5 times, with some colostrum transferred four or more times before feeding.

The number of coliforms in warm colostrum doubles every 20 minutes. If colostrum is being fed fresh, it should be fed less than one hour after collection.

If colostrum is being stored first, it should be chilled to less than 60 degrees in less than 30 minutes (i.e., place bottles or bags in a container full of ice) and refrigerated or frozen within 60 minutes after collection. The average time from colostrum collection to feeding or storage was greater than 60 minutes in more than half of the aforementioned 67 herds.

Colostrum should not be stored in buckets or open containers. Stored bottles or bags should be labeled with the collection date, cow ID and quality (Brix refractometer or colostrometer reading) and should be fed in order of refrigeration or freezing date.

Refrigerators should be at about 38 degrees F and freezers should be at -5 degrees F. We recommend placing a thermometer in the refrigerator or freezer to monitor temperatures.

Frost could delay the time it takes for colostrum to refrigerate or freeze, as well as resulting in temperature oscillations. Colostrum can be refrigerated and stored for up to two days or frozen for months.

The shelf life of refrigerated colostrum can be extended up to four days if a preservative, such as potassium sorbate, is used – or up to eight days if the colostrum is previously pasteurized.

Often the process of warming or thawing colostrum before feeding is an opportunity for bacteria proliferation. Bottles or bags should be placed into pails filled with 120 to 130 degrees F water (use a thermometer to verify temperature).

In order to achieve fast and complete warming to temperatures of 100 to 105 degrees F, it is preferable to use large volumes of water for adequate heat transfer instead of extremely hot water (The water must never be over 140 degrees F or it will destroy immunoglobulins).

When troubleshooting calf health problems on referred dairies and on dairies where I provide scheduled calf management monitoring programs, we will culture colostrum from the bottle, nipple or feeder tube. If coliform counts exceed 10,000 cfu per ml, we work our way back to the cow, culturing colostrum at different steps of the process.

Additional options designed to reduce or eliminate pathogen exposure from colostrum include pasteurizing colostrum and feeding commercial colostrum replacers. PD

Dr. Lago holds a veterinary degree from Spain, a Dairy Production Medicine Residency from the University of Wisconsin and a Ph.D. from the University of Minnesota . He works at DairyExperts, a consulting, management and research firm.

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Alfonso Lago
Herd Health and Production Consultant
DairyExperts

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