Sue Lani Madsen: Stress and common sense

Springtime on the ranch, and we’re just kidding. It’s not an April Fool’s Day celebration. We have 62 baby goats prancing in the barnyard – all born since St. Patrick’s Day – with a few more does left to kid.

By the end of April, we’ll have a herd of about 280.

And if we treated our domestic livestock the way public wildlife managers treat “their” herds of bighorn sheep, we’d have animal welfare activists pounding on the barn doors.

Even though our animals are used to us, best practice is to keep intervention during pregnancy and kidding to a minimum to avoid stress to either the mothers or the kids. The weather has been perfect, although it’s still getting down to freezing overnight. The touchiest time is immediately after a doe gives birth. The mother has to clean the newborns quickly to prevent kids suffering hypothermia.

One reason we still subscribe to the print versus digital edition of the newspaper is kidding season. If we intervene, it’s with a handful of crumpled newspaper to give bloody, wet newborns a quick rubdown and speed along the drying process in a chilly barn. We avoid actions that may interfere with good bonding. It’s critical for the kids to nurse well in the first 24 hours on colostrum, the early milk that carries antibodies to fight disease. A kid that doesn’t get enough colostrum is pretty much doomed – maybe not immediately but in the first few months.

Fifteen years of hands-on practical experience in animal husbandry teaches common sense about birthing healthy babies. That’s why I was shocked at the methodology in a scientific paper studying health problems in bighorn sheep that may be linked to domestic animals. It’s not my first choice for lighthearted spring reading, it’s preparation for interviewing scientists on the technical background of USDA Forest Service NEPA analysis.

The paper, published in the online scientific journal PLOS ONE (www.plosone.org), describes a study of bighorn sheep in South Dakota’s Black Hills. In order to study newborn lambs, pregnant ewes were captured in winter by a drop net from a helicopter or by using a dart rifle. Pregnancy was confirmed by ultrasound and the ewes were collared. Some of the ewes also had a transmitter shoved into the womb so the scientists would know when the ewe gave birth. Other ewes were followed on a daily basis and watched for signs of birthing.

The paper describes how scientists tracked ewes who had just given birth, waited until they bedded down, then “we rapidly approached the animals’ location causing the ewe to flee, and the (newborn) lamb would hide or attempt to flee at which time we attempted to capture the lamb.”

That’s stressful and it’s important. The study was seeking to identify whether lamb deaths in the first year could be linked to a particular common bacterium. But lambs whose mothers had been artificially stressed during pregnancy and chased off during critical bonding, and who may not have had adequate colostrum to receive immunity from the mother are not normal. The intervention itself may be a factor in triggering illness, yet this possibility isn’t acknowledged.

Many of us have experienced the onset of a roaring head cold under stress, but the link between stress and illness isn’t just anecdotal. Scientific studies of humans have identified a clear link between objective physical stress on a mother during pregnancy and the long-term negative impact on her children.

It isn’t studied by chasing pregnant women down with helicopters and tossing a net over them. Natural disasters provide the opportunity for study. A 2014 paper also published at PLOS ONE found the “number of days an expectant mother was deprived of electricity during Quebec’s Ice Storm in 1998 predicts the epigenetic profile of her child.” Epigenetic means the changes are permanently in the children’s DNA, and early results show the stressed human kids are more susceptible to immune system-related illness.

The South Dakota bighorn sheep study concluded, “Nearly all lambs in the herds we studied died in their first year.” If we treated our herd the way that flock was treated, our herd’s mortality rate might be similar.