Garry: Simple nursing technique decreases losses in compromised calves
Every calf that is lost in a herd is a loss of 550 pounds of sellable weight, which cuts into profits, says veterinarian Frank Garry, who works in the Integrated Livestock Management Program at Colorado State University.
“We have already put input costs into that calf, so the only way to make it up is to increase the weight of the next 11 calves by 50 pounds,” he says. “That increase needs to be more if we are weaning calves at 600 pounds or more.”
He also notes that the majority of death loss for animals pre-weaning occurs when they are first born.
“This is not shocking or surprising, and it’s true for all mammals,” Garry explains. “The consistent trend is that about 50 percent of calf deaths occur in the first 24 hours and about 70 percent occur in the first three days. Almost all of those are attributable to physiological problems.”
Transition of birth
One of the reasons that death loss is so high after birth, according to Garry, is that birth is the single-most major transition that an animal will ever make.
“The transition from living inside the uterus to living outside the uterus is the single most major transition of physiologic function the animal will make until it dies,” he says. “It doesn’t always work well, and it isn’t always successful because a lot of complicated things are happening.”
Each system within the animal’s body must adapt within the first one to two minutes, he adds.
Garry looks at changes in the respiratory, cardiovascular and muscular systems changes that the animal must undergo at birth.
“The calf has never breathed in its whole life,” he says, adding that the heart and blood vessels have never worked in concert with the lungs to oxygenate the blood. “The calf has, for its entire existence, been taking energy from its mom. Within a few minutes, it has to start putting energy out. That is a radical transition for most animals.”
Thermoregulation is also an issue for newborn calves. Prior to birth, calves have never been responsible for maintaining their own body temperature.
“We also have to look at the muscular skeleton,” he says. “Calves move when they grow, but it isn’t the same as lifting a 70-pound body off the ground and moving around.”
“All of these things have to change, and they have to change right now,” Garry adds. “If they don’t, the calf dies.”
When calves breathe for the first time, Garry explains that they have to begin by expanding the lungs.
“The blood goes from the right side of the heart, through the pulmonary artery and into the lungs,” he says. “Then it goes from the pulmonary vein to the left side of the heart where it goes to the tissues to the rest of your body.”
As the blood returns from the right side of the heart to the left side, the calf must take several big breaths to expand the lungs and allow the blood to flow properly.
“Physical and muscular activity is critical,” Garry continues. “As the calf moves, it expands its lungs.”
This creates a vicious cycle, he adds, explaining that if the calf doesn’t have oxygen, it doesn’t have the strength to move, but if it doesn’t have the strength to move, it has trouble expanding its lungs fully.
“The calf has to be strong, active, vibrant and start moving, or it is in trouble,” he says.
Fluid and heat
The second consideration is fluids in the calf.
“Calves are always born with less whole blood volume than they really need to maintain good blood pressure,” Garry says. “When calves come out, they need to be dried off, and they need fluid immediately.”
Heat is the third component that is essential.
“The third item is to be able to generate body heat,” he explains. “There are three ways that can be done – non-shivering thermogenesis, shivering thermogenesis and physical activity.”
Non-shivering thermogenesis is metabolic activity, Garry notes. Brown fat, which makes up two percent of the body weight, is used to create energy and convert that energy to heat.
Shivering thermogenesis is heat generation through shivering, and he says, “We shiver to generate body heat.”
“The third mechanism is physical activity. That is the most profound way of generating heat,” Garry says. “Calves that are quiet and lie down don’t generate body heat, so they get cold faster.”
Each of the major components for calf survival are interconnected, Garry adds.
“If we have decreased activity and lethargy from a weak or compromised calf, the calf will have low blood oxygen, which makes the calf weak or further depressed,” he says. “The calf will also probably experience heat loss and have low body temperature.”
Calves with lower body temperature will struggle to oxygenate blood, further exacerbating calf health problems.
“Calves need warmth, and they need fluid,” Garry explains. “We need to maintain the physiologic integrity for the calf to stay alive.”
Garry spoke during the 2015 Range Beef Cow Symposium, held in mid-November 2015.
Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at email@example.com.