Nov. 18, 2019
Cattle industry focus on animal health begins at the ranch
By Derrell S. Peel, Oklahoma State University Extension livestock marketing specialist
The U.S. beef and cattle industry has increased production and productivity in many respects in the past several decades. Total beef production in 2020 is projected at a record 27.3 billion pounds. Cattle carcass weights have increased an average of 5 pounds per year for the past 25 years. Beef production per cow has increased more than 100 pounds per cow over the same period.
However, animal health is one area that has actually gotten worse in the past 25 years, with respiratory disease the biggest health problem in the beef industry. Bovine respiratory disease, or BRD, causes 70-80% of feedlot morbidity and 40-50% of feedlot mortality. Feedlot survey data from Kansas shows that average feedlot death loss has nearly doubled from 0.82% in 1995-1996 to 1.60% in the most recent 24 months. Respiratory disease is a significant source of animal morbidity and mortality at the stocker and cow-calf levels as well.
BRD causes the most economic losses at the stocker/backgrounding and feedlot levels but it is increasingly apparent that improvements in animal health must begin at the cow-calf level. There are several reasons for this. It is known that the incidence and virulence of BRD is increased by the stressors involved in cattle production especially weaning, commingling and shipping cattle. While shipping and commingling cattle are unavoidable, there are several things cow-calf producers can do to increase the odds that animals are healthy and stay healthy to perform well in later production stages.
Preconditioning programs add value to cattle and the value is consistently reflected in premiums for certified preconditioned calves in sold under programs such as the Oklahoma Quality beef Network. Weaning is arguably the most important component of preconditioning and preconditioning protocols routinely call for a minimum of 45 days of weaning prior to marketing calves. Anecdotal indications are that 45 days is becoming a bare minimum with 60 or more days of weaning preferred by buyers struggling with the continuing health challenges of cattle. Calves noted as unweaned are currently discounted four to more than five percent in Oklahoma auctions.
Complete vaccinations, including two rounds of respiratory vaccine, are important before cattle are marketed. Cattle arriving at stocker and feedlot operations are already subjected to pathogen exposure and the stress of commingling and shipping which compromise the ability of vaccines to support animal health at that point. Bovine viral diarrhea virus, also called BVDv, is one component of BRD and, though it occurs with low incidence in cow-calf operations, causes significant reproductive and pre-weaning losses when it occurs and is the source of persistently infected, or PI, feeder cattle that contribute to BRD impacts in stocker and feedlot operations.
Castration, dehorning and deworming are all important prior to marketing. Research shows that males marketed as bulls are three times more likely to get sick in stocker and feedlot operations and have reduced performance, due to both the stress of castration at heavier weights and also because lack of castration is likely an indicator of inadequate prior calf health management. For this reason, bull calves are currently discounted roughly seven percent at auction.
Lifetime animal health management is increasingly recognized as a significant challenge for the beef cattle industry with implications ranging from fetal programming that impacts lifetime health and productivity; to genetic identification of disease susceptibility; to improved economic incentives for better coordination of animal health management across multiple production sectors. Improved animal health management not only increases ranch returns but increases value to the entire industry.
Using wheat pasture as a winter supplement for cows
Dr. Glenn Selk, Oklahoma State University Emeritus Extension animal scientist
Limited grazing of wheat pasture has proven to be the best and also more efficient approach for utilizing this high-quality forage with mature beef cows. The protein requirements of a dry cow can be met by allowing her to graze on wheat pasture for one day and returning her to dry pasture grass and/or hay for 2 – 3 days. A pattern of one day on wheat and 1 day off, should meet the protein needs of the same cow after calving.
The day on wheat pasture should be defined as that amount of time required for the cow to graze her fill of wheat forage (3 – 5 hours) and not a full 24 hours. This short time on wheat allows the cow to gather adequate amounts of protein to carry her over the ensuing days on dry grass or hay. A 3 to 5 hour grazing limit helps to avoid the unnecessary loss of valuable forage due to trampling, bedding down and manure deposits. Depending on planting date, under normal weather conditions in the fall, enough wheat forage should be accumulated by late November or early December to supply the protein needs of about 1 to 1.5 cows per acre throughout the winter months when limit grazing is practiced.
Producers who decide to use continuous grazing of small-grain pastures, should watch out for the possibility of “grass tetany.” Grass tetany will normally strike when older cows are grazing small grain pastures in the early spring and the danger will tend to subside as hot weather arrives. A mineral deficient condition primarily due to calcium, and to a lesser degree to magnesium, is thought to be the major factor that triggers this disorder and normally affects older cows that are nursing calves under two to three months of age. Dry cows are seldom affected.
When conditions for occurrence of tetany are suspected, cows should be provided mineral mixes containing 12 to 15 percent magnesium and be consumed at 3 to 4 ounces per day. It is best for the supplements to be started a couple of months ahead of the period of tetany danger so that proper intake can be established. Because tetany can also occur when calcium is low, calcium supplementation should also be included. Symptoms of tetany from deficiencies of both minerals are indistinguishable without blood tests and the treatment consists of intravenous injections of calcium and magnesium gluconate, which supplies both minerals.
Cows grazing lush small grain pastures should be fed mineral mixes containing both calcium and magnesium.
Cow-Calf Corner is a weekly newsletter by the Oklahoma Cooperative Extension Agency.