Saturday, December 1, 2001

Preshipment Programs for Beef Cattle

Preshipment Programs for Beef Cattle
Tradition and economics form the basis for current methods of marketing beef cattle. The present marketing system has somewhat divided the industry, resulting in limited communication between the calf-producing segment and the feedyards. However, several attempts have been made to change the system with various alliance programs.
The system of marketing cattle impacts the veterinarian’s work, because of increased diseases that occur when cattle are congregated, stressed and transported to feedyards.
The greatest health problem—bovine respiratory disease complex—is estimated to cost the beef industry $250 million to $750 million annually. Cow-calf producers, order buyers, salebarn owners, back-grounders and feedyard operators strive to maximize production and minimize expenses and disease loss. Now they are giving a renewed attention to the maximization of animal health through procedures performed before the animal reaches the feedyard.
Various programs have been used for several years that are specifically intended to prepare an animal for shipment. Some are designed for a particular feedyard or grazing operation. Programs also have been formulated that allow cattle to progress through the marketing system with a minimum of health-related disorders at the gathering point before shipment to the feedyard. Collectively, these programs are referred to as preshipment programs.
Preshipment preparation is thus defined as those procedures performed before or during shipment that better prepare the animal for subsequent grazing or feeding at a particular operation.
Preshipment programs are similar to preconditioning programs in that both are designed to increase cost-effectiveness during the first few weeks at the final destination.
Preconditioning programs (before a calf leaves its original home) have been slow in coming, because ranchers feel they don’t get paid for the additional trouble and cost. The costs of preconditioning involve labor, feed health products and veterinary services.
Preshipment programs use only procedures that give direct cost benefits to the buyer. Eliminated are the questionably cost effective procedures of extended feeding, parasite control, giving commercial implants and surgery. The cost of these programs is fully borne by the buyer of the cattle.
The goal of preshipment programs is not to fully process cattle at the point of origin but rather to meet immediate medical, immunologic and nutritional needs in order to (1) better enable these animals to face the stresses of transport and commingling, and (2) minimize the physiologic disruption that occurs at this time.
Programs are divided into (a) those for use at the ranch (before exposure to respiratory pathogens) and (b) those for use at the order buyer’s facility or salebarn.
The programs outlined here are intended to be examples. As with other animal health programs, input and guidance from the veterinarian is essential in forming a program that meets the needs of the cattle involved.

Ranch Program
In Texas Panhandle feedyards, numerous calves are received from large ranches; especially some located in New Mexico and Arizona. Most of the cattle are received during the fall, are freshly weaned and are native-type British or British crossbreeds.
These calves come from isolated environments with little or no exposure to the common respiratory pathogens they will face in the feedyard. Rarely do they have previous vaccination and they appear to be immunologically naive on arrival at the feedyard.
Initially, these calves experience acceptable health and performance (less than 0.5% mortality) until approximately days 21 to 28 on feed. At this time, a sharp decrease in feed consumption is observed, followed by a dramatic increase in cattle requiring treatment for respiratory disease. In five to seven days, morbidity peaks (25 to 35 days on feed) at approximately 25%; while overall morbidity for the feeding period can approach 50%. Mortality rates for cattle involved in the outbreak average 2% to 4%.
Diagnostic information gained from these out-breaks and from subsequent study of the herd environment demonstrated that calves become sick and die because of mixed viral and bacterial bronchopneumonia. Bovine viral diarrhea (BVD), Pasteurella haemolytica (Mannheimia) and Hemophilus somnus often are cultured in the laboratory.
Increased susceptibility apparently stems from the lack of exposure at the ranch and the immunologic naive of calves on arrival at the salebarn or the feedyard. Feedlot practitioners have found that low level of selenium or copper increase health problems. However, there is no data to support these claims. The problem present in these calves also occurs in other calves that originate in the western United States and in Florida. Preshipment programs involving calf vaccination have helped.
The calves are inoculated at least 21 days before shipment to the feedyard. Studies show that calves vaccinated then do have an adequate period in which to develop primary immunity by the time they are shipped to the feedyard. Weight loss incurred in handling the cattle at this time normally is not a problem for the seller. Inoculation is aimed at controlling viral and bacterial agents known to be associated with bovine respiratory disease complex.
If the calves are still nursing at this time and there is concern about the use of a modified live virus and shedding by pregnant cows, alternatives are a temperature-sensitive intranasal IBR-PI3 or a killed virus product.
The nutritional status of calves should be addressed if history shows that it is difficult to start them on feed. Creep feeding can be implemented approximately 21 days before shipment. Thus, the calves become accustomed to a concentrate ration and to eating from a bunk.
Studies have demonstrated that limited creep feeding is cost-effective at the ranch, improves later feedlot performance, and provides health advantages. But, weaning before shipment has had variable effects on weight gain at the ranch. Therefore, preweaning is not specifically recommended in this program.
Order Buyer Program
Historically, the order buyer has functioned as the intermediary between the cattle seller and the feedyard or stocker operator. Order buyers draw from large geographic areas in order to supply a buyer with a specified type of cattle, a process that can takes normally five to seven days; however, it may take as long as two or three weeks. During this time, health problems can be encountered that are not fully realized until receipt at the buyer’s locale.
Inadequate nutrition and management can predispose to respiratory and digestive disorders. Cattle purchased from salebarns can have pre-existing health problems and serve as sources of infection for other susceptible animals.
Cattle held or sorted at the order buyer’s facility can become sick as they are subjected to the stresses of commingling, crowding and a contaminated environment. Most order buyers do their best to supply healthy, high-quality cattle, but they are faced with a difficult task because of the volume of cattle they handle and the cost of preventive and therapeutic procedures.
Many order buyers are willing to cooperate on a preshipment program prescribed by the feedyard veterinarian. Identifying problems seen on and shortly after arrival at the feedyard is the key to program design. The preshipment program at the level of the order buyer should focus on (a) proper nutrition, (b) correcting bacterial infectious processes, and (c) stimulating effective active immunity for respiratory pathogens.
On arrival or when gathered at the order buyer’s facility, the cattle are vaccinated with an intranasal modified live IBR-PI3. This establishes a relatively rapid onset of upper-airway secretory immunoglobulin A immunity and stimulates the release of interferon. Interferon provides some cross-protection against other viruses, such as adenovirus and rhinovirus. Respiratory and digestive diseases can be combated by giving antibiotic therapy just before shipment.
The question often arises: Should antibiotics be included in the feed to deal with disease problems? Because feed consumption is highly variable among individual animals, especially those that are sick, injectable antibiotics would be more therapeutic and cost-effective.
Although attention to nutrition at the order buyer’s facility may be inconvenient, it is cost-effective and benefits health and performance. A 55% concentrate diet, plus free-choice native grass hay is the optimum preshipment diet for stressed cattle. However, when grain exceeds 55% of the total ration, there is an increase in morbidity.
Cattle fed this type of preshipment diet have health and performance advantages that extend to the first few weeks at the feedyard.
Salebarn Program
Many stocker cattle and feeder cattle are bought at auction markets. The risk of infection from exposure to pathogenic organisms is limited if cattle spend minimal time in the market environment.
If the cattle are traded by a middleman or hauled from sale to sale with the idea of making a modest immediate profit, health problems will be intensified. Disease—primarily respiratory and digestive disease—will occur as a result of poor nutrition, repeated stresses of transport, water and food deprivation, and commingling.
Because cattle normally are not kept at salebarns for extended periods, a one-time preshipment program focusing on treatment of existing disease and establishment of quick upper-airway immunity has been beneficial.
Market veterinarians are knowledgeable about the antibiotic sensitivity pattern of a particular salebarn and can be helpful in implementing a program.
Nutritional support can be difficult at salebarns, because of the high turnover rate of cattle as well as the lack of direct cattle ownership by the salebarn operator. At least, cattle should have fresh, clean water and hay available in the holding pens. Ideally, a 55% concentrate ration also would be available, but labor and expense usually make this cost-prohibitive.
Failure to provide adequate nutritional support can cause die off of normal ruminal microflora and can result in decreased fermentative and digestive capacity of the rumen. Probiotics have become popular in treating ruminal malfunction; they are quick and easy to give.
The easier and more economical that preshipment procedures are to perform, the more likely you will get cooperation in carrying out these procedures at the point of origin. Ongoing communication with the people who execute the program is necessary to ensure results.
Generally, the impetus for initiating a preshipment program starts with the buyer. The veterinarian involved in the salebarn or with the order buyer also can initiate cost-effective programs that will benefit the client and the health of the cattle care.