published in


December 2017

Florida Calf Loss Research Update
by Raoul Boughton

Ona Report - Dr. Raoul Boughton

For questions or comments regarding this publication contact: Dr. Raoul Boughton, University of Florida, IFAS

Shelby Albritton and Dr. Boughton prepare and place sensors in cowsAfter many months of preparation, the calf loss team has started collecting data on two ranches (Diamond K Cattle Company and Longino Ranch) with a third to be implemented by the end of year (Buck-Island Ranch). The goal of the study is to quantify causes of calf loss, an essential piece of data for Florida cattlemen to make highly informed production decisions and implement measures to improve overall production and economic return. 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 on some ranches some years. A reduction in calf loss of just 1% on average is millions of dollars recovery to the industry. 

Our approach starts with being alerted to when a cow is about to calf, and this is achieved using birthing sensors that are monitored by a central base station. During pregnancy checks, conducted by collaborating veterinarians, each cow in the study receives a sensor placed against their cervix which remains until pushed out by parturition (Figure 1). Rapid changes in temperature, as sensor is expelled, switch sensor into beacon mode which is picked up by central base station (Figure 2). The base station then pushes that information to responder’s cell phones focusing the team onto the calving event. In the field, ranchers and researchers alike investigate each birth event (Figure 3 & 4), if all is well calves are match tagged with their mother and given a second trackable Very High Frequency (VHF) ear tag (Figure 5). This VHF tag produces a continuous pulse transmission at a specific frequency for each ear tag, but when a calf becomes completely stationary for more than 2hrs that pulse is doubled in rate and the team can check on the calf (Figure 6). Also, if a frequency disappears as can occur in some predation events the team can search further afield for the ear tag. The base station has a second function in that it also continuously monitors all VHF ear tags and a daily report can be checked to ascertain if any calves have gone astray. The VHF technology was developed originally for wildlife monitoring studies and the team has brought both the birthing sensors and VHF tags together on a remote solar powered base station tower to monitor calves from birth to weaning across 600 acre areas. 

The “fancy” monitoring only gets the team so far in that it signals critical events. The tracking of calves, field observations, and rapid response to events is critical to success of the study. Once a calf loss event is observed all attempts are made to identify what caused death. This is most difficult on deaths that occur during difficult births (dystocia) or shortly after, as the calf could be still born, premature, weak, or deformed and when these events happen vultures and other predators can be attracted and make determination of scavenged carcass difficult. If our signals, monitoring, and responses are rapid enough we can collect the carcasses of dead calves and have them necropsied shortly (<24hrs) after post mortem by the FDACS Bronson Animal Disease and Diagnostic Laboratory (BADDL). Rapid responses reduce degradation of animal tissues and make determination of causes possible. Further determination is possible through direct consultation with collaborating veterinarians, Dr. Liz Steele and Dr. John Yelvington, on any symptoms shown in the field. Older calves thought to have been healthy found with evidence suggesting a predator was involved in death will be investigated in collaboration with Florida Wildlife Conservation (FWC) Commission and US Fish and Wildlife Service (USFWS) biologist to determine predator species, and follow up necropsy by BADDL. 
Dr. Boughton puts the final touches the calving tower at Longino Ranch

The study is only in early stages and calving has just begun. Already, the team has captured two dystocia causes of death, a still born death followed by vulture scavenging, a stillborn twin, an unhealthy weak calf with nasal mucus discharge and breathing difficulties, and a premature calf born blind that was unable to nurse. The calf loss team is made up of a dedicated group of UF/IFAS researchers and extension agents, ranchers, private veterinarians, FDACS BADDL diagnosticians, and FWC and USFWS biologists. Please visit the Range Cattle Research and Education Center, Wildlife and Rangeland Ecosystem program at www.rangelandwildlife.com to meet all who are involved and learn more about the study.

Mary-Jene Koenes and Heath Crum respond to calving alerts and search pastures for calves.

Dr. Boughton works with JMB North America to improve functionality of sensors

Newborn calf is given ID tag 90 and a small VHF tag to record any mortality events.Heath Crum checks for mortality signals on the VHF tagged calves