Cut stillbirths!
By Bovine Veterinarian and Dairy Herd Management staff
| Wednesday, October 01, 2008
Stillborn calf is not just a calf born dead; it’s a calf that is either born dead or dies within the first 48 hours after birth. In the dairy industry, it’s estimated that 7 to 10 percent of calves are born dead or die within that time frame.
Most dairies realize the value of a live heifer calf and the cost of having to buy replacement heifers. “Some, however, seem to view stillbirths as a ‘given’ and don’t address a tremendous opportunity to improve,” says Sheila McGuirk, veterinary researcher at the
Every herd should strive to keep its stillbirth rate at 8 percent or less; in some herds, 6 percent or less is achievable.
Depending on where you are at, it may be possible to cut your stillbirth rate by as much as 30 to 40 percent. Here are some ways to do it.
1. Monitor risk factors.
“The greater the percentage of first-lactation cows in the herd, the higher the stillbirth rate,” McGuirk says. Be especially observant of first-calf heifers that calve at less than 22 months of age or those that calve at more than 26 months of age. Presumably, it is the small stature of the less-than-22-month heifers and over-conditioning of the older heifers that places them at risk.
Monitor heifer growth and health from an early age. “Remove the health issues, particularly pneumonia, that result in slow growth and poor reproductive performance in heifers,” McGuirk says. Small heifers can be picked out for a full examination or held back in a young group of calves to catch up. Over-conditioned heifers or pens of heifers can be identified early, when diet, exercise or a combination of factors can be adjusted.
A high body condition score can be a problem for both heifers and multiparous cows. “Our goal is to have fewer than 5 percent of calving cows greater than 3.5 body condition score (
And, stillbirth rates go up with short and long gestation rates. “Less than 275 and more than 289 days carrying a calf are a problem,” she adds.
2. Intervene only when necessary.
By identifying at-risk animals, you can be more observant at calving time and assist in delivery when needed. Yet, McGuirk says there is a “fine balance” between intervening when necessary and intervening too much. First-calf heifers need quiet, uninterrupted comfort to calve. “Turn off the lights and give first-calf heifers two hours and a comfortable place to deliver a calf,” McGuirk says.
“Few (people) realize how important the mechanics of delivery are to the survival of a calf,” she adds. “The feedback and stimulation from a strong delivery by the cow gives the calf stimulation to breathe, clear itself of bodily fluid and adjust to post-uterine life.”
“Don’t assist a cow that is progressing in labor just because she is taking too long,” she says.
3. Check for infectious causes.
Although difficult births and the percentage of first-calf heifers explain much of the stillbirth problem, some of it can be traced, as well, to infectious causes.
It’s important to rule out infectious causes of stillbirths, such as Neospora caninum, Salmonella spp, Listeria monocytogenes, Q Fever, Campylobacter fetus venerealis, Chlamydophilia and Brucella. Mycotoxins have also been incriminated.
If your herd experiences a sudden increase in stillbirths, McGuirk suggests sending tissue or blood samples from stillborn calves to a diagnostic lab. Samples from three to five stillborn calves may be needed in order to rule out any of the infectious agents. Work with your veterinarian on this.
4. Use genetics to your advantage.
A new genetic evaluation for stillbirths is part of the Lifetime Net Merit index, and is 3.6 percent of the index’s total emphasis, explains John Cole, research geneticist at the USDA’s Animal Improvement Programs Laboratory in Beltsville, Md.
The evaluation quantifies the likelihood of stillbirths for both the sire of the calves and the sire of the dam. How likely is it that the calves sired by this bull will be stillborn? And, do the daughters of the bull produce calves that are more likely to be stillborn?
If a bull’s
You might want to avoid a sire with an exceptionally high stillborn rate. But, as a general rule, don’t base your decision on stillbirths alone, Cole says. That’s why stillbirths are part of an index so they can be prioritized with other important economic traits.
The Holstein Association has added stillbirths to its new Type-Production Index or TPI formula.
McGuirk says some of the farms she works with have stillbirth rates below 6 percent on a whole-herd basis, including first-calf heifers and multiparous cows. She has seen other herds make significant progress, lowering their stillbirth rates from 12 percent to 8 percent. One herd that she works with in northeast
Yes, it’s possible to make significant progress by following the steps outlined above.
