From the hip A typical calf fresh weaned, sorted, trucked and stood overnight will lose 12 to 15 per cent of body weight, but that can be reduced by half or more
Shrinkage is a measure of stress in calves. The amount of weight an animal loses through fasting, standing, transportation and handling is a signal of how it is responding to change, a lack of food and water, and heat and cold, as well as its anxiety level.
There are two kinds of shrink. One is excretory weight, manure and urine, that is lost at the onset of any stress. This accounts for approximately three to four per cent of body weight, and cattle quickly recover from excretory shrink. The second is tissue shrinkage — the loss of body tissue or muscle fluid that occurs when the body must pull moisture from internal organs and muscle to maintain function. It takes a long time for an animal to recover from this type of shrinkage, and the condition can be life threatening.
Research into shrinkage and transportation is ongoing at the Lethbridge Research Centre, but we need to also be aware of all the other triggers to stress and shrinkage. Cattle are sensitive to light, movement and noise, and have a strong social structure that causes immediate stress when disturbed, even in a feedlot pen. Shrinkage will occur at any point of change in the environment and escalates when cattle are mixed.
Calves lose one-half of a per cent of their body weight for every 30 minutes they are being sorted and may lose another 3.3 per cent during the loading process. As they travel, they lose another 0.46 per cent for every 100 miles, with the majority of that loss in the first four hours. If calves are stood after arrival, such as in an auction market, the average weight lost on the stand is 5.9 per cent. It is interesting to note that even without stress, calves may lose up to two per cent of their body weight during the night.
Everything we do impacts the weight loss of a calf, yearling or fed animal. The younger the animal, the more severe the impact and the longer the recovery time. Research is clear that once you near nine per cent of body weight loss, the calf is in danger and the cattle feeder will have a problem on their hands, especially if the calf was commingled. Commingling during the marketing process spikes weight loss by double and is responsible for 75 per cent of BRD in calves. This sets them up for secondary infection which can be, and often is, fatal.
The typical calf — fresh weaned, sorted, trucked and stood overnight — will lose 12 to 15 per cent of body weight. At 15 per cent, the loss on a 600-pound calf is 90 pounds and at a $1.60/pound price, you are giving away $144 per head. Many calves exposed to a combination of stressors such as a sort, long haul, and standing without feed and water, will lose up to 20 per cent of body weight.
Ideally, you want to minimize weight loss during the marketing process to between four and six per cent. This assures a greater chance of a healthy calf on arrival and the buyer is not paying for gut fill (that is, excretory weight). When cattle are sold direct or in an electronic format and weighed on farm, the buyer will take a pencil shrink to compensate for the gut fill.
The recovery time on stressed calves is between 10 and 36 days depending on the degree of shrinkage. A trial in Alberta found sick calves gained 55.9 per cent less than their well pen mates. American studies have found that overall weight gain in sick calves will average 29 per cent below well calves in the same group. As stressed calves are more likely to become sick, it is important not to trigger disease through stress.
To avoid excessive shrinkage and improve your bottom line, work on reducing the stressors involved with the handling and marketing process. Sort your cattle at home using quiet, experienced help in appropriate facilities the cattle are familiar with. Buy or rent a farm scale or contact a neighbour with the nearest legal-for-tender scale and make arrangements to use it. Be quiet and patient when loading, and load when the truck is on a direct route to the final destination. Ensure cattle have feed and water through every marketing transaction. Starvation, dehydration and fear will cost you money and may cost the calf its life and our industry its reputation. Crowding deeply disrupts the social order of the animal and commingling with other groups is a sure way for buyer and seller to lose money. Watch the weather and avoid excessive cold or heat and always be present when your calf sells on the Internet, on the farm or at auction.