Finding the right milk formula for these orphaned elephants
SAN DIEGO: On a chilly, breezy morning at the San Diego Zoo Safari Park, an African elephant named Umngani was ready to nurse her hungry calf, Mkhaya.
But fi rst her keepers needed Umngani to cooperate in a research project meant to unlock the secrets of a lifegiving substance: mother’s milk. At stake was not just Mkhaya’s eager tummy but also the health and survival of orphan calves in elephant sanctuaries in Africa and zoos around the world.
Umngani’s trainers used hand signals, sweet words, and a bucket of sliced lettuce, cucumbers, carrots and yams to coax the 7,330-pound animal to the edge of a small holding area. Umngani, age 30, knew the drill.
“Lean in,” keeper Mistley Bennett told her softly. Umngani extended one giant front foot toward the iron bars that always separate keepers from the park’s 14 elephants.
Mindy Albright, the lead elephant keeper, reached through and gently began “expressing” one of Umngani’s nipples. Milk squirted into a small, sterile cup. A third keeper comforted sixmonthold Mkhaya, who waited nearby, impatient to nurse.
It’s well known that milk helps newborn mammals survive and prosper. But just why that is true remains a puzzle for scientists, even those who specialisze in milk, lactation and infant growth.
So when Umngani and her sister Ndulamitsi gave birth last year and began nursing their calves, the zoo decided it was time to launch a milk project.
The goal is to fi nd the right ingredients for an improved milk replacement for orphaned elephant calves - some of whose mothers are among the 20,000 or so African elephants killed by poachers each year - or calves whose mothers cannot or will not provide milk. Substitutes are already in use, but the researchers hope to help develop products that can be tailored to calves’ age, development and gender. Baby elephants drink milk for the fi rst three years of their lives.
A better understanding of milk’s nutritional composition “is integral to increasing survival of young calves in these ( perilous) situations,” said Katie Kerr, nutritionist for San Diego Zoo Global.
The milk will be analysed by zoo staff and milk researchers at the University of California at San Diego and the Smithsonian’s National Zoo milk repository. The project is being watched closely by staff at the Reteti Elephant Sanctuary in northern Kenya, where 15 calves are struggling to grow healthy enough to return to the wild.
Researchers do not expect their task to be quick or easy - some say it may take two years. Among other variables, a mother’s milk changes as her baby grows, and researchers need to understand that process.
“Not a lot is known about human milk and even less about other species’,” said Lars Bode, associate professor of paediatrics at UCSD and past president of the International Society for Research in Human Milk and Lactation. He said he became interested in Umngani and Ndulamitsi when he and his staff were on an outing to the Safari Park.
Two or three times a week, Albright expresses milk from the two mother elephants. The goal is to get five millilitres per week from each elephant, or just over a teaspoon.
The fi rst few drops of milk are watery and almost clear. Then the milk begins to have a higher fat content. The process is meant to be gentle but quick - a minute or two.
Albright pulled gently with gloved hands. “We’re still trying to perfect our technique, but each cow is different,” she said. “It’s really exciting stuff.”
Umngani is placid and takes to the procedure easily. Ndulamitsi is more tentative and is suspicious of anyone other than her keepers. The milking is done in an area off-limits to the public.
The samples are stored at subfreezing temperatures at the park laboratory. When the zoo has six months’ worth, researchers will begin examining it for proteins, fat, amino acids and other nutrients.
Michael Power, animal scientist at the Smithsonian repository, is enthusiastic about the project but also cautious about what it will yield.
“We’re getting an exploding amount of knowledge about the proteins, sugars, all the different things we now see in milk” of various species, he said. “But that is far outstripping our ability to understand their functions.” The repository - with 15,000 samples from more than 200 species - has studied elephant milk in the past. It has about 120 Asian elephant milk samples and 50 samples from African elephants. Most of the African samples were from cows whose calves were already a year old, making it difficult to determine whether younger calves might need a different formula.
But with new research techniques and the promise of multiple longitudinal samples from two cows, the San Diego project is bright with possibilities, Power said.
“This milk will be looked at completely,” Power said.
Power said he hopes to learn more about the nutrient composition of African elephant milk, how it changes over time and how milk differs among elephant cows.
When a zoo newborn cannot be nourished by its mother’s milk, keepers scramble to fi nd a substitute. This happened with the 2017 arrival of a premature baby hippo at the Cincinnati Zoo & amp; Botanical Garden, which then sent hippo milk to the National Zoo for analysis.
It’s well known that milk helps newborn mammals survive and prosper. But just why that is true remains a puzzle for scientists, even those who specialise in milk, lactation and infant growth.