Liver Biopsies Can Reveal Nutrition-Health Links
Dairy nutrition and health is an interdependent relationship. Achieving the correct balance between the two requires a team approach among dairy managers and their nutrition and veterinary counselors. One blaming the other is counterproductive, but a team working together can drive progress and forward performance.
There’s a simple, on-farm procedure that stands at the fulcrum of this relationship: the liver biopsy. Taken periodically on specific groups of animals, liver biopsies can identify nutritional imbalances that can lead to health and performance problems.
Brooke Loeffler with Utah-based livestock mineral supplier Redmond said the liver is a living storage compartment that can reveal a lot about an animal’s history and current nutrition status. The liver is also the most regenerative organ in the body, so removing a tiny sample causes absolutely no disruption in its function.
Bovine livers are also quite large. Sampling is fairly easy for trained veterinary practitioners, and new extraction equipment makes the procedure far less invasive than it used to be.
Liver biopsies are becoming routinely employed on dairies as both a surveillance and diagnostic tool. Many dairies are using liver biopsies routinely on sets of cows at dry-off, for example. Screening calves also can help steer early life nutrition programs. Liver biopsy results are applied in three main strategies:
- As a micromineral assessment tool – Liver samples can assess levels of cobalt, copper manganese, selenium, and zinc. Both too much, or too little, of any of these minerals can cause health and performance issues. Ronald Tessman, DVM, PHD, DACVIM, DACVPM, with Elanco Animal Health, noted that selenium deficiency, for example, is associated with decreased reproductive performance, higher incidence of retained fetal membranes, and increased disease susceptibility. He also said too much copper – defined as copper toxicity – can lead to depression, anorexia, and decreased milk production in cattle. Additionally, many trace minerals have antagonistic effects on one another, meaning an excess level of one can interfere with the functions of another. Plus, micro-ingredients can be expensive; liver biopsy results can indicate where quantities can be dialed back.
- To check for fatty livers – Loeffler explained that healthy livers only store small amounts of fat, which is distributed by lipoproteins throughout the body. But negative energy balance can lead to higher stores of fat in the liver, causing subsequent metabolic disease problems. Thus, periodically screening recently fresh cows can be another helpful application of liver biopsies.
- As part of a diagnostic work-up – If a herd is struggling with a specific health or performance problem, checking the livers of the animals in question may provide a window revealing the answer. Lagging growth performance, fertility, milk production, or fresh-cow health all could have roots in micromineral imbalances.
This video from the Kansas State Veterinary Diagnostic Laboratory demonstrates how liver biopsies are performed.
For efficient and low-stress biopsy sampling, Tessman advised that adult cows be restrained in a squeeze chute. Calves may require sedation instead. The required incision is so small that no antibiotic therapy is recommended unless an unusual situation of contamination or injury occurs during the procedure. Afterward, out of an abundance of caution, he suggested isolating and observing sampled animals for 2 hours to detect any adverse effects.
For more on nutrition, read:
- How a Spreadsheet Can Help Simplify Calf TPI Tracking
- Two Reasons Why Feeding Hay Could Help Alleviate Cross-Sucking
- The Sweet Spot for Oral Calcium Supplementation
- Can We Improve Colostrum Through Dam Nutrition?
