Ines Rodriguezis a large animal veterinarian at the University of Pennsylvania whose work focuses on swine and swine welfare. She’s a nursing mama to Amalia, 15 months, which gives her particular insight and fascination regarding her latest research project.
Ines has partnered with a swine ethologist (someone who studies animal behavior) to study pigs’ living environments and how they can make improvements in the farming world. They’re going to do a lifelong study of some different swine breeds to learn about their personalities, aggressive behavior, curiosity, etc. And lifelong studies begin, of course, at birth.
“We’re going to do pig cesareans!” Ines tells me, excited beyond belief.
She’s spent months playing an intricate game of pig chess to set up circumstances where a set of commercial American pigs (Yorkshire pigs) go into labor just as a set of heritage breed pigs (Large Black and Tamworth pigs) are ready to deliver. Ines plans to have the Yorkshire pigs nurse and raise the LB and Tamworth piglets to test whether genetics affect behavior.
She has a hunch that the heritage breeds are better adapted for alternative farming environments. “Yorkshire pigs have been bred for decades to live in gestation crates,” she says, “because they are aggressive and they fight. These crates prevent lots of negative animal behaviors.” However, consumers want pork from animals raised differently. “At Penn, we’ve been investigating alternatives for 10 years,” Ines says. “Retailers want gestation crate-free pork. Everyone from Wal-mart to McDonald’s and Burger King. We know it can work and we’ve already been part of removing 70,000 sows from gestation crates to live in a group setting.”
In preparation for the LB/Tamworth experiment, Ines has had to time a series of other pig deliveries and “bump wean” the piglets. “We’ve been weaning sets of piglets in one-week intervals, moving the piglets up to a new mother slightly further along so that the Yorkshire mother’s newborn piglets can move to a new nursing mother and the LB/Tamworth piglets latch right on to the Yorkshire mother.”
The method of delivery is important to the equation because pig lactation depends upon labor, not the release of the placenta as it does in humans–the pigs with cesareans might not even lactate. Ines says, “We need the Yorkshire pigs to go into labor on their own and we need the cesareans to be happening at the exact same time. This way, we can move the pigs to the Yorkshire mothers the moment they are born.”
Once all the bump-weaning was set up, she scheduled the cesareans for January 15 and induced the Yorkshire pigs over the weekend. Ines explains that in pigs, milk lets down 12 hours before birth, so they timed the cesareans to occur as soon as the Yorkshire pigs had let-down.
Ines says the sows most likely will not “miss” their babies after the cesareans.
“Most animals we study don’t have those human emotions,” she says.
“We have not seen mourning or sadness if piglets die or are weaned. I’ve seen sows lose entire litters and they do fine. Our donor sows (surrogates!) will recover and go off to live on a different farm.”
She’s been studying the experimental piglets since conception, noting their inter-uterine position and birth order, because this matters very much for pig lactation. Normally, when piglets are born, they get to pick a teat and that’s their teat forever. So the first piglet gets its choice of 16 teats. “That pig will walk around and latch on to a few, pick out the best teat,” says Ines. “With each piglet, there are fewer teats to choose from. Teat order, we think, has a lot to do with how pigs grow up and how dominant they become.”
The neonatal piglets born via cesarean will not really get a chance to choose a teat because the Yorkshire mothers will have some piglets latched on already, but Ines is still taking note of birth order and male/female ratios. She explains that generally, a pig who is born last is the smallest pig. The pig whose embryo implanted at the end of the uterus get the least blood supply and then is born last and gets the worst teat–a lifetime of being last in line to eat. “It’s a very Calvinistic view of the world, this idea that where your embryo implanted determines what you are and always, ever will be. And we’re going to study it in these new piglets!”
I know I’ll be looking forward to updates! I had no idea pig birth and lactation could be so interesting.