Feeding a zoo: Wildlife nutritionist has to cook up a tasty menu for more than 10,000 animals

The primates now get a diet of “vegetables and beans and lovely healthy things”, he said.

“The orang utans hate me, because I took away the food that they love, but the keepers trust me,” he quipped.

Changing their diet, however, was no mean feat. Whereas it usually takes about two weeks to make such a change, it took four months to convince the primates about their new diet.

“They are very smart, so you have to go very, very slow, so the changes are imperceptible. Generally, the smarter the animal, the slower you have to go,” Cabana said.

The secret, he said, is not giving them a choice.  

"Even if you give a little bit of fruit, they are always going to eat the fruit, and then look at you very sadly, hoping that you will crumble and give them what they want. They are very smart," he said.

Cabana, who is from Canada, strategically chose to start with the diet of the orang utans when he joined Wildlife Reserves Singapore three years ago.

“I started with the orang utans, because it’s the iconic species of Singapore Zoo and because I was new to the animals, new to the zoo, new to the whole team, and the country, I kind of wanted to start off with a bang, so I started with the orang utans to gain everyone’s trust. It worked, yes,” he said, grinning.

WRS has two nutrition centres: One that services the Singapore Zoo, Night Safari and River Safari, and one at Jurong Bird Park. Cabana works with 14 full-time staff, five interns and four part-time staff to make sure all the animals are fed.

THE IMPORTANCE OF NUTRITION

Cabana, who has a doctorate in animal nutrition, started out working in a pet shop in Canada, before starting work as a zookeeper there.

“I was always trying to figure out how to take better care of my animals, how to make them happier, healthier, look better, act more natural. And I came to the conclusion that nutrition was the way to help the animals be more of all of that because nutrition is everything,” he said.

Bad nutrition shows up in the form of disease or other health issues, Cabana said, adding that different species tend to have different health problems.

However, the first problems that often emerge are related to dental issues, he said.

“They (animals) are just like humans. When we eat a lot of candy, we get cavities and bad teeth. (It's the) same thing for animals, except the animals can’t tell us, so we figure out when it’s very bad,” he said.

Other issues include abscesses, which are formed when pus collects. There are also weight challenges, with animals that are obese or too thin, diabetes and kidney issues, he said.

On the other hand, good nutrition can delay, prevent or improve an animal's condition, and even positively impact its behaviour.

Giving an example, Cabana said that glazing the fish that sea lions eat with concentrated carotenoids has shown to delay or prevent cataracts in mammals' eye. 

The way animals are fed can also have an impact on their behaviour in captivity.

Speaking about animals pacing from one end of an enclosure to the other, and standing and swaying from side to side, he said this behaviour has no apparent function. 

"The animals do this possibly out of frustration or because of a period of bad welfare in their lives. This is not necessarily because of the food we give them, but how we feed them,” he said.

REMEMBERING THE ANIMALS’ WILD TENDENCIES

To combat such issues, the team gets creative to mimic what happens in the wild.

“For large carnivores like lions or tigers you don't want to give them small pieces of meat, you want to give them large chunks and you want to hide them ... and you can hide all of this in a giant bag so they actually have to tear it up like they would shred up their prey,” he said.

The daily menu across all the parks is highly varied: There are red meats, like kangaroo, beef and mutton, insects, like locusts, cockroaches and grasshoppers, and many vegetables. For those species who might eat such things in the wild, there are mice and rats.

The animals also get fruit like apples and pears, with some, like elephants, chimpanzees and orang utans, treated to durians once a week.

While it is not possible to recreate the same diet as in the wild, recreating the nutrients in their meals can be done, Cabana said. It typically takes two weeks to create the perfect diet for a particular species.

FEEDING DIFFICULT ANIMALS

There is scientific literature and sharing by other zoos that help Cabana in picking the ingredients for the right diet for most animals. However, some problems emerge for which there is no immediately obvious cause or solution. 

Take the slow loris.

“They all had dental diseases, they had facial abscesses. You had rescue centres filled with slow lorises that only had half a jaw because they had the other half removed; they were all obese or wasting, so really, a terrible species to feed,” Cabana said.

That was the problem, and Cabana decided to find a solution. As part of his field work for his doctorate, he spent a year in an Indonesian jungle, becoming nocturnal like them as he observed them and what they ate in the wild from sunset to sunrise.

What they loved to consume was tree gum, bamboo leaves and insects, he found out. This was a far cry from what they were being fed in captivity.

He said: “In rescue centres and zoos, they used to feed a lot of fruits and meat. They would give chicks, baby mice, chicken and tons of fruit like bananas. The slow lorises would eat them but they would still get sick. In reality, what they needed was a high-fibre diet, and also medium protein.”

Cabana went into the kitchen to see if he could cook up a gourmet feast.  He mixed a bit of gum powder with water, added some vegetables, crickets and mealworms. Combined together, the perfect diet for the slow loris was created.

At Indonesian rescue centres where he tested the new meal, he found that there was less fighting among the animals. It also resolved the weight-related issues seen among some of the animals held in captivity.

“In an enclosure of four individuals, one was fat, and three were very thin. The moment we changed the diet, the fat one lost weight, and the thin ones gained weight, so it helped to kind of equalise,” he said.

At the Night Safari, where the slow lorises lick the concoction off a vine that hangs in their enclosure, the diet has gone down a storm.

“Since we changed the diet three years ago, our slow lorises have been making babies every year, which is definitely proof of how successful the diet is. They don’t have any obesity or thinness. Their body weight is constant, it doesn’t vary. They don’t have any more digestive issues or dental issues either,” he said.

TAKING CARE OF THE OLD

It is not just the mysterious or picky eaters that need special attention. The older animals do too.

“One thing that is unique to zoos is old animals. We take very good care of animals, they live a very long time. This generally doesn’t happen in the wild. And this also means that it’s not really known or not really well-studied how to take care of these old animals, specifically how to feed old animals,” he said.

Among the old animals at the Singapore Zoo are two Indian rhinos - Gomati, who is 40, and Mary aged 30. This species typically lives up to 50 years old in the wild.

They are given a special mix of supplements made up of probiotics, Vitamin B Complex, Vitamic C and calcium that is aimed at helping with their joints and skin quality, Cabana said.

“We have noticed a huge improvement in skin quality. It used to be bumpy and pale. But since then the skin has become thicker, it looks the same as a young little rhino. We’ve also seen huge success with their joint movement,” he said, adding that like humans, animals get arthritis as they grow old.

It is such success stories which give Cabana immense satisfaction.

“When I see animals actually thriving because of their new diets it makes me feel like my mission is somewhat accomplished. It’s a lot of work, but it’s really hopeful for me because it makes me feel like I am doing something (good).”