Drought strategies: Early-weaning considerations for calves
August 20, 2012
As pasture conditions continue to deteriorate, producers are considering early weaning their calves to reduce cows' grazing pressure. Dr. Richard Randle, University of Nebraska extension veterinarian, cautions producers to plan ahead for early weaning.
"There are many things to consider," Randle explained during a recent University of Nebraska beef webinar. Topics include vaccinations, parasite control, castration and dehorning, facilities, feeding, and heat stress.
With the record heat, Randle said producers need to take every precaution they can to minimize stress to get calves off to a really good start. This includes tight facilities to hold young calves and a well-mixed, high-quality, palatable ration with the correct balance of vitamins and minerals. Most importantly, once the calves are weaned, their health needs constant monitoring.
VACCINATIONS ARE A MUST
"The vaccinations we give early-weaned calves are not different than what we normally try to protect against," Randle said. Producers should consider: Clostridials (7-way); Virals (IBR, BVD, BRSV, PI3); Mannheimia/Pasteurella; and Histophilus/Hemophilus.
"It is important to consult with a veterinarian to get a plan in place in regards to what vaccines to use, and to determine the appropriate timing to give them," Randle explained. "It would also benefit the calves if there is enough time to get two doses into those animals, if it is necessary."
Ideally, stockmen would administer vaccinations at least 2-4 weeks before to weaning. "It gives the calf some time to build up immunity before it goes through weaning. Being younger, the calf's immune system may not be as mature, so it may not respond as well to some of these vaccines," he cautioned.
In very young calves, some maternal antibodies may still influence calves, and their response to the vaccine. "That is why it is critically important to follow the label directions and give booster vaccinations, if necessary," Randle said.
In addition, if calves are vaccinated prior to weaning and put back with their mothers during breeding, producers need to be sure the vaccine has a label that allows them to give that vaccine, he explained. "It can be particularly important with viral vaccines if you have modified-live or killed vaccines. Following the label directions is critically important," he said.
"Young animals less than one year of age are the most susceptible to internal and external parasites," Randle said. "Young, growing calves can benefit more from worming than any other class of calves out there." During drought, pasture contamination will be lower than normal, but research shows that deworming calves gives them one to three tenths of a pound advantage in average daily gain, he said.
Fly control is also a necessity. "Face flies are the major vectors for the transmission of pinkeye," Randle said. Weaning, extreme heat, dust and stress combine to make conditions even more favorable for pinkeye.
Randle also encouraged producers to castrate or dehorn calves using bloodless methods like banding or electric dehorning. "I would encourage producers to get castrating and dehorning finished before weaning to spread the stress out," he said. If they can't, producers should wait at least 30 days after weaning.
Producers may also want to consider growth implants to improve weight gain and feed efficiency. However, calves that may be kept as replacements shouldn't be implanted, Randle said.
WATCH FOR SICK CALVES
Stockmen should be particularly vigilant about watching fresh-weaned calves for signs of Bovine Respiratory Disease (BVD), and should consult with a veterinarian prior to weaning to establish a treatment program.
The combination of drought and heat can put a lot of stress on freshly-weaned calves, Randle said. "If calves break with respiratory disease, it can cause significant lung damage in a matter of hours," he said. "It is critical to find these calves and treat them early. When they are freshly weaned, they should be checked at least two to three times a day for the first couple weeks," he suggested.
Early diagnosis is important. The calves should be monitored to make sure they all move to the bunk when they are fed. Producers should also plan to spend time outside the pen listening and observing calves for coughing, wheezing and abnormal breathing that can signal calves in distress.
"I would also encourage producers to move the cattle around the pen very slowly without riling them up," he explained. Watch for animals that look sick with things like lack of rumen fill indicating they are not coming to the bunk to eat, ones with obvious nasal discharge, or a dry nose that is dirty indicating they don't feel well enough to keep their nose clean.
Rapid breathing can also signal illness. Calves will have more rapid respiratory rates when the temperature and humidity increase, but rapid breathing beyond 80 breaths per minute can signal distress.
Other signs to look for include calves that are disinterested in their surroundings, slow and reluctant to move, and a lowered head. "Any of these signs can indicate the calf is in some stage of expressing problems and needs treatment," Randle said. "With BRD, erring on the early side is better than waiting… Move the calf into a treatment area, and follow through with the treatment protocol."
Randle said dust can irritate airways making way for pathogens like BVD to infect the calf. If dust is a particular problem, producers may want to use sprinklers, water down pens or even wet the calves, which may be necessary to cool them down. He encouraged stockmen to consider working calves in the early morning and be finished before the heat of the day to help calves combat heat stress, and provide shade.