After talking to producers this spring, it seems there is an anomaly happening with difficult births. We all know that many things influence a calf’s birth weight, but even producers who pay close attention to the obvious factors like genetics or cow size might find themselves helping a cow that has never had any trouble. Much like unexplained high levels of twinning, could environmental factors impact dystocia?
What environmental factors could increase dystocia problems? Rainfall, temperatures, cool season forages, or maybe even the barometric pressure? As I write this article it is a beautiful 60-degree day in northeast Oklahoma, but this winter has not always been easy on our animals. I have written several articles on cold stress on cows and how when an animal is wet their lower critical temperature (LCT) is raised to somewhere around 59-degrees. For every degree drop in temperature below that LCT her energy requirement increases one percent. From Nov. 1, 2019, until March 1 the Mesonet weather station in Talala, OK has reported 38 days with measurable precipitation. That means that 31% of the time our cows were wet. It also reported that in the last 45 days there have been 135 hours where the Cattle Comfort Index was at a cold stress level. I say all this to say that although our winter might have mild, the combination of wind, temperature, and moisture is detrimental to a cow’s body.
This winter’s weather conditions have most likely led a cow to a negative nutrient balance. Meaning that she is burning more nutrients than she is consuming. Supplementation certainly helps negate this deficiency, but there are times when the cold stress is so severe that we could never feed enough supplement to counter act that stress. This negative balance could result in a weakened female at calving.
When the body is exposed to cold temperatures it begins to shiver and the blood supply is moved from the skin to the internal organs. This reallocation of the blood supply to the internal organs means that there is a higher level of blood supply to the fetus. The more blood supply to the fetus translates to a larger calf. Nebraska researchers observed six years’ worth of weather and production data and determined that the colder the winter the higher the calf birth weights. The study was summarized by saying that a one-degree drop in average winter temperatures resulted in a one-pound increase in calf weight, associated with a 2.6% greater calving difficulty. (Source: Deutscher, G.H. 1999. Climate Affects Calf Birth Weights and Calving Difficulty. Nebraska Beef Cattle Report)
So as farmers and ranchers we have to deal with the hand that was dealt to us and even though it may not be the winter that we wanted it is what we have. I encourage producers to pay close attention during calving season this year and help when it is time to help. It is suggested to give a cow thirty minutes and a heifer one hour before stepping in and helping. Be prepared by having animals close to your working facilities and if you see trouble, don’t wait. Have a conversation with your OSU Extension Educator and veterinarian about what you need to do to prepare for the worst.
Reducing the risk of a calf scours outbreak
The ongoing human health issue (COVID-19) serves as a reminder to cattle ranchers about the importance of sound, common sense biosecurity measures that can aid in reducing the risk of a disease outbreak in the new 2020 calf crop.
Neonatal calf diarrhea (commonly called “calf scours”) is one of the most costly disease entities in the beef cattle business. Fall-calving herds have the help of the hot, late summer/early fall sunshine to reduce the buildup and spread of the pathogens that cause calf diarrhea. However, in the spring, wetter, colder weather and muddier pastures often create environments that are favorable for calf diarrhea pathogens. Whether you have spring or fall-calving cows (or both) there are some key management procedures that will reduce the likelihood of a scours outbreak in your calves. These procedures are meant to decrease the pathogen exposure to the newborn calf.
1) Calve in clean and dry areas.
2) Calve heifers earlier than the cow herd.
3) Avoid congregating and creating muddy, pathogen infested areas in calving pastures.
a) If possible, avoid loose hay feeding in calving pastures.
b) If hay is fed, use bale rings or hay feeders and move feeders frequently.
c) Move pairs to larger pastures promptly. Larger herds may want to study and employ the Sandhills Calving System.
4) Use biosecurity and biocontainment measures for all herd additions:
a) Isolate, quarantine, and perform appropriate tests on all herd additions.
b) Introduce pregnant herd additions at least 30 days prior to the start of calving season. This will allow time for exposure to new pathogens, antibody development and secretion of antibodies into the colostrum.
c) Do not add calves to the herd until the youngest calf in the herd is over 30 days of age. Buying a calf at a livestock auction or from a dairy for a cow that has lost a calf can introduce diseases that your herd may not have immunity against.
5) Isolation and treatment:
a) Remove sick calves from the herd immediately. One sick calf can produce overwhelming pathogen exposure by shedding as many as 100 million bacteria or viruses per milliliter of feces (500 million bacteria and or viruses per teaspoon of feces).
b) Visit with your local large animal veterinarian to determine best treatment options for the pathogens affecting your calves.
c) Treating the sick calves should occur after handling the well calves. Clean and disinfect all equipment. Clothing, boots, gloves, etc. worn while treating sick calves should not be worn when handling well calves.
The concepts of quarantine of new arrivals, isolation and treatment of infected individuals, and cleanliness are important on the ranch as well as in human health.