Most beef cattle transition from one location to another during their life. I once followed a set of feeder cattle that left Pennsylvania, were unloaded in Oklahoma on wheat pasture, went to Colorado for finishing, and were harvested in Nebraska. This is not an unusual scenario. What effect does transportation have on cattle, since most of them will be subjected to a trip in a truck?
The reality is that transportation causes cattle to be stressed. Swanson and Morrow-Tesch (2001) have described several of the factors that are involved in transport stress:
- Pre-transport management
- New environments
- Temperature, humidity and exhaust gases
- Loading and unloading
- Time in transit
- Feed and water deprivation
Each of these factors will have a negative effect on cattle through weight loss, sickness and/or loss of pregnancy, and, secondly, each source of stress may be additive.
Shrink is usually defined as a weight loss associated with some stress. Transportation is a significant source of costly shrink. At a price of $1.50 per pound for a 600-pound feeder calf, each 1 percent of shrink costs $6 in reduced value of the calf. The major cause of shrink during transport is from feed and water deprivation. The loss of weight is not only from gut fill and fluids, but up to 60 percent of the weight lost is tissue loss (Coffey et al, 2001). Shrink loss in transport is significantly affected by ambient temperature. Results in Table 1 show that higher temperatures result in more shrink than lower temperatures, with most of the shrink from sources other than urine and fecal loss.
The rate of weight loss from shrink in transport is generally higher in the early part of feed and water deprivation. This loss generally ranges from .75 to 1.25 percent of body weight per hour (BW/hour) during the first three to four hours of transport, and decreases for more extended transportation time to .11 to .34 percent of BW/hour (Coffey et al, 2001). However, it must be considered that total weight loss is cumulative over the time of transit, regardless of the rate.
Handling procedures can result in variations in shrink during transport. Self and Gay (1972) reported that cattle shipped directly from the farm or ranch to a feedlot shrink 21 percent less than cattle going from the farm or ranch through an auction and then shipped to a feedlot. Grandin (1997) has shown that animal temperament will influence response to stress, and that handling procedures (calmness, less excitability, good stockmanship) prior to loading can reduce further stress from transport. The recovery time for shrink loss is a cost to the feedlot or backgrounder, since this is feed and time that simply regains the original value of the cattle after they are transported. Table 2 indicates the extent of recovery time in cattle.
Feed components (concentrates and/or minerals) and preconditioning (weaning, vaccination, feeding grain) prior to transport have not consistently resulted in less shrink after transport (Coffey et al, 2001). The one exception may be in feeding ionophores prior to shipment (Brazle, 1992; Coffey et al, 1997), where shrink was reported as 8.3 percent less in stocker cattle and 7.5 percent less in steers when fed lasalocid in a mineral mixture prior to shipment. Additionally, allowing cattle to graze pastures for three hours prior to shipment increased body weight and reduced the rate of shrink early in transit (Coffey et al, 1997).
Carcass traits and value in finished cattle can be affected by transportation. Carcass bruises are a major loss during shipment. Bruises are a people problem; they are caused by rough handling of cattle, poor handling facilities, overcrowding in trucks, and poor loading and unloading procedures. Table 3 shows recommended loading densities in the truck to prevent overcrowding.
Transport of pregnant cows can cause abortions. The time of transport after conception is the primary target for preventing losses. Cows are susceptible to problems during blastocyst formation, maternal recognition of pregnancy, and attachment to the uterus because of the hormone cascade that may result from the stress of transport. This is particularly true in days five to 42 after conception (Fields and Perry, 2007). Table 4 outlines some of the data available on pregnancy loss from transport.
Transportation is an inevitable part of the beef enterprise, but it is a significant source of economic and animal weight loss. Several factors influence these losses, and they should be reviewed and considered to remedy loss.
Dr. John Comerford is an associate professor of dairy and animal science at Pennsylvania State University.