How Are You Feeding: Feed Weighing Accuracy

by Daniel Linden, MS and David E. Anderson, DVM, MS, Dip ACVS
The Ohio State University
College of Veterinary Medicine
www.icinfo.org

Reprinted from the Newsletter of the Willamette Valley Llama Association The Llama Lletter Vol. 20, No. 5 September/October 2005

Measuring feed for llama and alpaca consumption is not as easy as it sounds. At a recent conference, we asked 48 people to place 1.0 pound of commercial camelid pellets into a feed bowl. The bowl was then weighed on a portion scale to determine the amount of feed that was actually present. Four groups of people were represented in this trial: 9 veterinarians, 7 veterinary students, 12 veterinary technicians, and 20 owners and breeders participated. The participants were classified as successful if they were able to measure the feed within 0.25 pound (+/- 0.25 pounds) of the 1.0 pound goal. One pound of feed was used as the target amount because the commercial pellet that was used was designed to be fed at 1.0 pound of feed per 175 pounds live body weight.

How accurate were the different groups? Of the 48 people that tried, fewer than 1 out of 3 was accurate. Veterinarians were the most accurate with 44% of them able to estimate to within 0.25 pounds, which was our mark of success. They were followed by the owners and breeders of which 35% were able to come within 0.25 pound. The veterinary technicians followed in third place with 33% of them within 0.25 pound. Veterinary students were in last place with only 14% within the 0.25 pound allowance.

However, it is not as simple as all this. The veterinary students had the lowest percentage of people within 0.25 pound, but were the only group to not feed in excess of one pound. The owner and breeder category had an average weight of 0.71 pound, which was the closest to 1.0 pound of any of the groups, but also had the highest standard deviation of the four groups. This means that the range of answers was larger than any of the other groups, from 1/8 pound to nearly 2 pounds.

What does it all mean? Simply ut, most of us, over 2/3 of us, were unable to accurately weigh the proper amount of feed for our animals without a scale. Many owners say, “Well, I feed by cups,” which is fine as long as one knows the number of cups, cans, scoops, or whatever to accurately feed the recommended amount of feed for your animals. Until this amount is known, scales are recommended. Appropriate portion scales can be bought at most restaurant supply stores and many grocery stores for a reasonable price.

Another thing to consider is feed type. Every feed is different. Pellets weigh differently by volume depending on the manufacturer. A feed with molasses will likely weigh more by volume than a composite feed. If you change from one feed to another, another weight should be obtained and your scoop marked to know how much of the new feed to use.

Group Mean Stand. Dev. Range
Vets 0.67 0.34 0.25-1.25 lbs.
Vet Students 0.43 0.29 0.13-1.00 lbs.
Vet Techs 0.64 0.38 0.25-1.50 lbs.
Owner / Breeders 0.71 0.40 0.13-1.75 lbs.