THE FLORIDA CATTLEMAN AND LIVESTOCK JOURNAL
THE FLORIDA CATTLEMAN AND LIVESTOCK JOURNAL
For questions or comments regarding this publication contact: Dr. Raoul Boughton, University of Florida, IFAS
There are two major periods of reproductive concern in cow-calf operations that are responsible for the largest loss in return for producers. The first being inability of a cow to become pregnant and/or early embryonic death, and the second, calf loss that occurs from confirmed pregnancy to weaning. Calf loss from pregnancy diagnosis to weaning can range from a 3-4% up to 24% across Florida herds, with an average of 8%. In most cases losses are unexplained and unquantified. The causes possibly include mineral deficiencies, reduced immunocompetence, diseases, genetic disorders, poor maternal behaviors, and predation, to name a few. But what are the really important calf loss causes? The fact is we don’t know! You ask why not? Because it is really hard on the ranch with large herds using large areas of land to efficiently and effectively monitor all calving, and most calf loss occurs within hours or days of birth. Quantifying causes of calf loss is essential for Florida cattlemen to make improvements and position the industry to make highly informed production decisions and implement measures to improve overall production and economic return.
A survey of calf loss conducted in 2006 with 44 ranchers across Florida showed that calf loss was often higher than expected (up to 24%), as compared to University of Florida research herds (6%).Calf loss was greatest in the southern part of the state where many large ranches operate. The average reported loss of 8% to the Florida industry equates to 64,000 calves a year (based on 800,000 calves) and the number could be much higher some years. At current calf prices ($500/calf) this in turn is an unexplained loss of $32 million. By identifying the major causes of calf loss we can promote efficient management strategies and identify where effort should be spent to prevent the largest portions of calf loss. A reduction in even just 1% on average is a $3.2 million recovery to the industry. Calf loss is a serious and reoccurring economic loss to beef cattle production in Florida, and severely understudied.
What we do know is that, early studies from the 1950’s and 1960’s from around the world have reported incidences of still or dystocia births from 2% to up to 11% and that they accounted for up to 56.4% of calf loss from birth to weaning (1-7). More recently calf loss has been reported in northern states of America to be 6-9% (8), with most loss 85% occurring within the first 40 days and 60% within the first 3 days. Surprisingly there are relative few calf loss studies since this time and even less that document causation. A number of specific studies have been undertaken to understand loss to predators and control of predators (9-11). Loss of calves due to predation can be substantial, and may be so in Florida. An excellent bench mark to follow is the 20 year summary from UF beef research herds that show an average calf loss in UF herds to be 6%, considerably lower than many ranchers report, but that should be expected due to the high level of management and small herd size. Importantly, the summary shows that cow age is highly significant with 2 and 3 year old cows having substantially higher than the average calf loss, 12%. Like other studies the cause of calf loss was either unknown or inconclusive, as many calves are found days after death.
In 2007-2008 the University of Florida and MacArthur Agroecology and Research Center initiated the first “on the ranch” neonatal and postpartum calf loss study (unpublished) and conducted a survey of 44 ranchers on calf loss. From the study it became apparent that early calf loss (1-7days) was most common and often missed (even in the study). Nearly, all ranchers felt that the majority of calf loss occurred between 0-10 days, matching reported studies. A further 49% of ranchers felt predators were a problem, and of ranchers that performed mineral testing 64% reported deficiencies especially in selenium. The survey results suggest that both mineral deficiencies and predators may be major causes of high calf loss in Florida.
Excitingly, we now have the technology to remotely signal when parturition is occurring, easily find the calf, and increase our understanding of the greatest period of early calf loss, which has previously been almost impossible to study in a ranch setting. This technology allowing the detection of birth, is known as a birthing transmitter and is inserted into the birthing canal in front of the cervix sometime (days to months) before parturition (Figure 1). The sensor sends signals to a base station that can monitor several hundred acres of ranch for expulsion events immediately prior to birth. The sensor continually records temperature profiles and uses a decreasing temperature profile as a trigger a signal that the sensor has been pushed out of the birthing canal. The base station is connected to the internet and informs the user via a website and text messages that an event has occurred. In this way researchers can be onsite within hours of a calving event, check on the calf, tag calf with mortality tracking devices, and overtime, document all causes of calf loss from late gestation all the way through to weaning.
Figure 1: Vel’Phone ® birthing transmitter provided by JMB North America.
The Rangeland Wildlife and Ecosystem Program and collaborative partners are committed to identifying and quantifying the causes that most affect calf loss in Florida. This information will focus our future resources and research to provide the greatest economic return to producers through increasing calf survival. Without new technology to help gather important information we would be unable to conduct this type of work. Stay tuned for future updates.
You are invited to join us by webinar on December 15, at noon, when Raoul will present the information covered in this Ona Report and he will be available for questions. To participate this webinar you simply need to register online here: https://attendee.gotowebinar.com/register/1842161742125026564. If you are nearby, you are also welcome to attend the presentation in person. Join us at the Center in the Grazinglands Education Building.