Denise Schwab, interim IBC director column
October 2024
I love the fall and harvest time with its warm days and cool nights, combine time and meals in the field with my family. It can be a hectic time, but seeing the excitement on the grandkids faces when riding with Dad and Papa is unforgettable! October also brings weaning and calf shipping, so I thought I’d share a little of the research data from our ISU staff and students.
Transportation can be one of the most stressful times in a calf’s life, especially if coupled with weaning. Preconditioned calves will typically experience 2% to 8% bodyweight shrink during transport, while unweaned calves see 10% to 15% shrink. Much of this is due to gut fill and being off feed and water which can be recovered fairly quickly, but tissue shrink also happens after about 12 hours on a truck and this loss is much more difficult to recover. So, ISU staff and students have been studying the impact of antioxidant vitamin and mineral nutrition prior to and immediately after transportation.
Since Vitamin C is an antioxidant, one study looked at injecting Vitamin C prior to shipment. The initial test resulted in a 15-pound increase in body weight during the first 60 days on feed, however that was not repeated in the second year of the study, so more research is needed on the effectiveness of vitamin C. Another study looked at zinc supplementation above normal requirements prior to and after shipping. The zinc-supplemented calves out-performed the unsupplemented calves during the preconditioning period by an additional 13-pounds of body weight. They also demonstrated better dry matter intake recovery after transport. All calves received additional zinc supplementation following transport, and the previously unsupplemented calves caught up to the supplemented calves in intake and body weight by the end of the 56-day trial. This research is being continued to try to find nutritional answers to reducing transport stress.
There are several management practices producers can do to reduce transport stress on feeder calves. First is setting the calves up to be healthy by weaning and preconditioning calves for 30-45 days prior to shipment. This includes administering vaccinations prior to weaning, low-stress weaning like 2-phase or fenceline weaning, and starting calves on feed. Numerous studies over several states have shown that a preconditioning program like Iowa’s Green Tag and Gold Tag programs adds value to sale prices. If possible, sort calves based on how they will be marketed (by sex or weight) at least a couple days prior to sale or shipping. This allows calves to establish a new group/pecking order and recuperate from that stress prior to shipping. Time of day also has an impact on shrink. Cattle eat their biggest meal first thing in the morning, so gathering, sorting, or shipping after that big meal helps reduce shrink.
Low-stress cattle handling helps to reduce the stress of shipping, including how the cow-calf pair is handled, sorted and brought to the loadout area. Appropriate load size for the trailer/truck is also important. BQA standards suggest a 600-pound calf needs about 8.5 square feet per head during transport, so a 7’X32’ trailer should haul no more than 26 calves. Acclimating calves on arrival by asking them to move to every corner of the yard at a walk, and allowing them to find the water tank and feed bunk also aids in recovery after transport.
October and November are slow for Extension programs but we hit the meeting season hard in late November. Watch for additional BQA programs. Registration for the December 16 & 17 Genetics Symposium will open soon. And watch the calendar in our IBC Growing Beef newsletter for upcoming events. If you aren’t already receiving Growing Beef, sign up at https://go.iastate.edu/UIQJTM or by clicking this QR code.
The IBC at Iowa State University serves as the university’s extension program to cattle producers. Our center comprises a team of faculty and staff from the College of Agriculture and Life Sciences, the College of Veterinary Medicine and Iowa State University Extension and Outreach. We work together to develop and deliver the latest in research-based information to improve the profitability and vitality of Iowa’s beef industry. If you’d like to be notified of updates on progress of research projects or programs that might be coming to your area, please subscribe to our “Growing Beef” newsletter by following the link on our website, www.iowabeefcenter.org. If you have a question, use our “Ask our Experts” link. Also, feel free to call us at 515-294-BEEF or email us at beefcenter@iastate.edu. You can follow @iowabeefcenter on Facebook, Twitter, YouTube and Instagram.
