Bunk management in the feedlot can have a huge impact on animal performance. But attempts to increase feed intake in feedlot cattle have been based on intuition and observations of groups. Little is known about the feeding patterns of individual animals in a pen and how specific factors may affect them.

Researchers have traditionally studied cattle feeding patterns and intake by observing feeding behavior and recording the amount of feed left over 24 hours after feeding. The information collected usually consisted of pen-averaged data obtained from a small number (10-20 head) of group-penned animals.

More accurate feeding behavior and intake information has been obtained using "Calan Gates." Here, animals fitted with magnets gain access to the bunks through electronically controlled gates so that individual feeding duration can be determined. This requires training the animals how to gain access to the feedbunk. The disadvantage is that some animals are slow learners or never learn how to use these gates at all.

A New System From Canada A Canadian company recently developed an electronic feed monitoring system that documents the feeding patterns of individuals within large groups of cattle in a commercial setting. The GrowSafe(tm) system (GrowSafe Systems Ltd., Airdrie, AB) uses radio frequency technology and consists of an antenna mat lining the front of the feedbunk, a reader panel and a computer.

Animals are eartagged with a passive transponder that, upon contact with the antenna, sends out a signal that identifies each individual animal (emits their ID code). The system can record and identify all animals at the bunk simultaneously.

Information from each transponder is collected every 6 seconds when the transponder (animal) is within 19.5 in. from the antenna. The system enables a producer or researcher to monitor how many times an animal goes to the feedbunk per day, the locations they choose to feed along the bunk and the length of time at the bunk.

Through cooperation with Roche Animal Nutri-tion and Health, work with the Grow-Safe system is being conducted in commercial and research feedlots in the U.S. and Canada. These include the Agriculture and Agri-Food Canada research feedlot in Lethbridge, Alberta, Can-ada; and commercial lots in Alberta (Highway 21 Feeders in Acme) and the U.S. (McElhaney Cattle Co., Yuma, AZ; and Cactus Feeders, Amarillo, TX).

Preliminary studies show the technology successfully detects differences in feeding behavior under a variety of circumstances. A study funded by Pfizer Animal Health conducted at the Lethbridge Research Centre found that:

* Cattle switched from twice- to once-a-day feed delivery during a period of limit feeding made fewer visits and spent less time at the feedbunk.

* More importantly, the study found that the time individual cattle spent feeding was consistent throughout a trial. It also found that time at the bunk may be a very good indicator of differences in intake between days for an animal.

Alberta Agriculture beef specialists, in cooperation with Montana State University, found that healthy (untreated) steers spent more time at the feedbunk than "sick" (treated) steers during the first four days on feed at the McElhaney feedlot. The "sick" animals in that study came to the bunk at the same time as the healthy animals but they left the bunk earlier. This has great implications for being able to detect sick animals early, possibly in advance of the pen checker.

A Valuable Tool It's clear the GrowSafe system will be a valuable tool for researchers to test and document effects of a number of management and environmental factors on the feeding patterns and performance of feedlot animals. These factors could include anything from feeding regimes and diets, bunk design, animal handling protocols and stocking densities to the effects of weather and climatic conditions.

The system could also be used to compare different types (age, sex, breed) of animals. This means we could potentially identify and select the type(s) of beef animals which perform best under specific management conditions and environments.

Another use could be to get a better idea of how social dominance at the bunk affects individual feeding behavior. Understanding this relationship has implications for improving management strategies with regards to sorting, mixing and combining animals in the lot.

Numerous Advantages Radio frequency technology has several advantages over traditional methods of quantifying feeding patterns. Most important is that individual feeding behavior can be identified which prevents any masking effect that may occur as a result of per-pen averaging.

It also has advantages over the use of Calan Gates since it can be used in large pens (over 200 head) and still identify all individuals within that pen. Animals don't have to be trained to use the system, nor do the animals have to feed at a particular location along the bunk. The strongest point, however, is that the data collected will more accurately reflect what happens in a commercial feedlot setting.

The system may have some potential for use by feedlot managers as well. It could be used to detect sick animals early in receiving pens or to monitor poor or roller coaster feeding patterns caused by acidosis.

Availability and cost, however, put the use of the GrowSafe system out of reach for feedlot managers for the near future. It's not scheduled to appear on the commercial market for four years, and the current price (for 120 ft. of bunk) is about $40,000 (CAN). Once in commercial production, unit cost would drop to about $20,000 (CAN). Commercial feedyards would likely use the system to monitor the feeding patterns of newly arrived cattle in receiving pens.

For now, GrowSafe's greatest contribution will be as a research tool allowing scientists to get accurate information on bunk behavior and its relationship to performance. The usefulness of the system will only be limited by the ability to design industry relevant research projects.

Research trials are currently under way at all of the research and commercial lots mentioned previously. In the next five years, the feedlot industry can expect to see some interesting results and get new insights into bunk management as a result of this technology.