Historically, criminals who have been sentenced to death have been granted a sumptuous last meal before their execution. Reportedly, this final repast consists of whatever the doomed inmate desires. One imagines that the convict’s appetite is poor and their attention is distracted due to their imminent demise. Nonetheless, the “last meal” has had enduring significance in our culture as the last food those on death row consume.
A sad and unintentional parallel is found in maternity pens when a calf’s first meal — that of life supporting colostrum — unintentionally also becomes its effective “last meal.” How does this unfortunate event happen? It happens when colostrum, rather than being a source of antibodies and numerous beneficial compounds such as growth factors, probiotics, minerals, and energy sources, becomes a lethal cocktail of pathogenic bacteria and toxins.
A race to the gut
The newborn calf is never more vulnerable to attack than at or soon after birth when its intestinal tract is permeable and porous in anticipation of absorbing antibodies. It is well known that the administration of colostrum is most effective within the first few hours of birth, with absorption declining rapidly as the gut becomes increasingly less permeable or “leaky.”
It is a race among harmful bugs, toxins, and beneficial compounds (and likely beneficial microbes, as we learn more about the microbiome). Sadly, in many poorly managed maternity pens, the calf receives the former — adulterated colostrum that is laden with pathogens.
The negative effects are both immediate and long term. “Bad actors” can proliferate in the gut, competing with the establishment of a healthful microbiome. They produce toxins locally and invade the bloodstream, seeking distant organs (the eye, brain/meninges, kidneys, and liver) and joints, in addition to creating critical interference with the absorption of antibodies.
Sources of risk
What risk factors favor bacterial contamination and growth in colostrum, thus thwarting our efforts to get a calf off to a healthy start? Unfortunately, there are many.
Mastitis, acquired during or persisting through the dry period. This has multifold negative consequences. Should the bacteria not be eliminated by host defenses or antibiotic therapy, depending on the species, the calf will consume a dose of lethal coliforms, toxin-producing Staph or even salmonella. Inflammation of the mammary gland will result in lower antibody levels in colostrum and an altered nutritional profile, including lower protein, fat, minerals, and growth factors. And the amount of colostrum produced by the mammary gland will likely be reduced.
We can avoid this calf “coup de grace” (French for “death blow”) through adopting several best practices. These include excellent teat prep and technique when using intramammary teat sealants and antibiotics; applying external teat sealants when needed; excellent environmental management by maintaining clean and dry bedding; and encouraging excellent teat health before dry-off by using high emollient dips, ensuring proper milking machine vacuum levels, and conducting regular teat scoring.
When adopting selective dry-off routines, carefully consider which algorithm to adopt to best work in your system. Determine if you should use somatic cell score, culture results, or both. Monitor somatic cell count (SCC) at dry-off and first milking, and then intervene if necessary.
Poor teat cleanliness at time of colostrum collection. This is an obvious and common reason for contamination of collected colostrum. Maternity employees who have delivered calves — becoming soiled in the process — often also conduct the first milking. Legendary Green Bay Packers coach Vince Lombardi famously said, “Fatigue makes cowards of us all.” Fatigue also tempts us to take shortcuts. Ideally, workers should change into clean gloves and coveralls before collecting colostrum and change gloves between other tasks such as prepping and milking; milking and colostrum storage; collection and feeding; and attending to calves. Teach employees the “why” of the “what” they are being asked to do.
As for quality control steps, do routine ATP testing of barrels of prepared teats and/or use white towel or cotton ball evaluations of teat end cleanliness. Remember that teats may be swollen in fresh cows and need special-sized inflations to be milked best, encouraging maximal harvest of colostrum volume. Be sure teat-end vacuum levels of milking units are optimal as well.
Dirty equipment. Unsanitary equipment used in collection and delivery of colostrum is a major risk factor in contamination of first milk. I often incriminate inadequate cleaning and inappropriate storage of equipment in cases of contamination. Make sure the clean-in-place (CIP) process of the milking unit is of the same effectiveness as parlor units. Other equipment to assess routinely for cleanliness are colostrum storage bottles, buckets, and bags. Also, check feeding equipment, including nipples, bottles, and esophageal feeders.
Delayed cooling and freezing of colostrum. Much variation and drift from protocols happens here; thus, prompt colostrum cooling should be rigorously audited and enforced. Excessively slow thawing, long post-thaw intervals, and prolonged time to oral delivery all create conditions of the classic — and lethal — quartet of conditions for bacterial incubation: food source, heat, moisture, and time. Again, explain the “why,” because bacteria reproduce exponentially, to your staff.
Contaminated water sources. Farms that store spring water in a tank (rather than pump it from a drilled well) are too common. Some farms may use standing water from ponds or reservoirs for nonpotable needs such as stock water. Such origins can be forgotten during ownership and management changes, resulting in the use of unsanitary water for tasks requiring potable water, such as equipment cleaning.
Contamination of original sources and holding tanks with pseudomonas and coliforms is common, so don’t neglect routine culturing of water sources. Be sure to include more “micros” than just coliforms in your request.
A dirty calving environment. This raises the risk that the calf will ingest bacteria-laden manure, bedding, or fluids.
Off to a good start
Additional quality control steps to monitor if clean colostrum is being collected and delivered can and should include Brix testing of colostrum; ATP testing of teats after premilking preparation; and ATP testing of collection buckets, bottles, and administration gear such as feeders and nipples. Culture colostrum just before feeding, milk right before dry-off and after calving, and water sources, both hot and cold.
Total protein or Brix testing of calf serum will establish those with failure of passive transfer. Necropsy of calves should include organ culture. Evidence of meningitis, nephritis, omphalitis, cholangitis, hepatitis, and uveitis are a big red flag pointing to unsanitary colostrum practices.
Raising healthy calves can be one of the most gratifying and important accomplishments on the dairy. Get them off to a good start by taking these steps to prevent their first meal from becoming effectively their last.
