August 13, 2018

By Amanda Bregenzer, Keeper, Animal Nutrition 

Here at the Saint Louis Zoo, you might be surprised to find out that we’re participating in our own version of the “farm-to-table” movement that is sweeping the nation. While our staff at the Orthwein Animal Nutrition Center work hard to make sure that all of the animals eat well, preparing nutritionally rich diets catered to each species, some of our animals have a special “home-grown” supplement to their diet:  trimmed tree limbs, otherwise known as browse.

These green boughs are an important addition to the diet of the Saint Louis Zoo’s herbivores and omnivores. Bark from the browse helps to keep an animal’s teeth clean (giraffes and gorillas in particular love eating bark) and the leaves contain fiber, vitamins, and other nutrients. Moreover, browse is great for our animals because it gives them a chance to eat foods they would encounter in the wild, a testament to the dedication of the Zoo’s animal care staff to providing world class care.

The Saint Louis Zoo began its browse program with Ameren Missouri, Saint Louis’ local energy company, in 2017 after Debra Schmidt, Ph.D., William R. Orthwein, Jr. Family Animal Nutritionist at the Zoo, learned of similar program at the Brookfield Zoo in Brookfield, IL in which the local electric company donated trimmed tree limbs for the animals. At the same time, zookeepers Becky Heisler and Nate Aalund were collecting fresh browse on their own accord for the antelope and elephants. A proposal was then made to Ameren Missouri to form a similar program with the Saint Louis Zoo, which Ameren Missouri accepted.

In maintaining its power lines around the Saint Louis area, Ameren Missouri trims tree limbs that could cause damage in a storm or bad wind.   Usually, the downed limbs are chopped and recycled as mulch.  Now, however, rather than go through the chipper, the browse is delivered directly to the Zoo. Five species of tree are used for browse: mulberry, hackberry, elm, ash and willow.  These trees are the most readily encountered species in the area that are safe and healthy for our animals.

Browse deliveries occur on Tuesday and Thursday mornings with an average of two to three loads of browse being delivered each day.  On Tuesdays, browse is sent straight to the animal areas to be fed out fresh.  On Thursdays, processing deliveries runs a bit different.  Browse committee members, animal keeper interns, and volunteers and staff from all areas of the Zoo gather together to pack the first load of browse into large totes that will be stored in the Orthwein Animal Nutrition Center freezer   This frozen browse is used during the fall and winter.  The leaves become slightly rubbery, but the animals still love the browse just the same.  The second load is delivered fresh to the animals, while the third load goes directly to the elephants as they consume much more browse than the other species. Using this format, the Zoo is able to provide fresh, healthy browse to many of our animals all year long.

The program, now in its second year, is a huge success. Last year, browse was delivered to the apes, primates, elephants, and antelopes. This year, it has grown to include the Zoo’s tortoises, bears, and various animals in the Children’s Zoo.  Not only is browse healthy and nutritious, the animals absolutely love it (especially when we get willow!), so with the help of our community and Zoo staff, we hope to keep the browse program “growing” in the future.

See our animals enjoying some browse  here.

Click on the photo below to see a larger image.