Meat packers and their customers are demanding the production and delivery of market animals with weights that must meet progressively tighter windows for acceptable weights. Marketing animals, whose weights fall outside the specified weight ranges, usually results in significant deductions from market prices for such underweight or overweight animals.

Simultaneously, producers are increasingly conscious that underfeeding or overfeeding not only hurts their bottom line profitability, but feeding a feed that is not optimum each phase of the growth cycle unnecessarily burdens them with waste nutrient disposal costs and regulatory review.

Historically pig producers selected animals for market by simple visual inspection, relying on pig judging skills to identify market animals. Such methods are neither sufficiently accurate nor reliably consistent for modern markets. The use of single-animal farm scales, such as the Osborne Accu-ARM scale, is sufficiently accurate to select animals for market. Using such scales has been shown to amply reward the user with a profitable payback at market for both the cost of equipment and labor for weighing.

To manage feed, phase feeding is increasingly employed, changing feed composition to match growth utility at multiply intervals during the growth cycle. These changes are best accomplished with an accurate understanding of the daily weight distribution and its rate of change for the animals. Although visual inspection or fixed calendar-based growth curves have usually been the methods used to make phase feed changes, visual inspection is approximate at best and growth curves do not take into account the effects of environmental temperatures or pen stocking densities which both effect actual rate of gain.

Although using scales to weigh market animals or measure weight distributions is clearly desirable, weighing one animal at a time requires substantial labor and time, two commodities that are often unavailable in modern finishing operations. Furthermore, weighing animals that fail to meet the marketing range always causes a temporary, but costly interruption to their normal growth. For phase feed changes, weighing of small samples of the pen is the only practical method, but is not really much more accurate than visual estimating. If large numbers of animals must be inspected, the use of single-animal scales is simply too slow to be practical.

Recognizing the limitations of single-animal scales, Osborne began studying methods to automatically weight pigs without direct intervention of the herdsman in 1997. A wide array of possible systems were reviewed, developed, and tested on the Osborne Demonstration Farm. Many methods were eliminated and discarded. But in 2001, the Weight Watcher system was invented and preliminary tests of the concept were successfully completed.

The first step in automated weighing must be to spread the cost and equipment maintenance over a large number of animals. This consideration leads naturally to the conclusion that managing finishing pigs in large pens is highly desirable. Our first step was to carefully measure the performance of finishing pigs in large pens versus those managed under identical conditions in small pens of 30 animals/pen. As we tested groupings of 60, 90, 120 and 240 animals per pen, no significant penalty was encountered in ADG, F/G, or weight distribution compared to the same type of animals kept in the small pens.

Our tests also found that no significant difference in performance is found when the pigs in a large pen must pass over a modified Accu-ARM scale, called a Survey Scale, to travel between a water pen and a feed pen. The idea of separating water and feed to use a mechanical scale to select market hogs in a large finish group is not new, having been used about 25 years ago for outdoor feedlots of large groups of finish pigs. But we tested the idea during the heat of the Kansas summer on market-weight hogs and found no effect. We were careful to provide cooling in the feed pen by a combination of water drippers and Super Jet air circulation with some evaporative cooling using the Super Jet Mist Kit. Otherwise, pigs might have monopolized the waterers as a way to cool off during hot days.

The key to the Weight Watcher system is the Accu-ARM Survey Scale. The Survey Scale measures the weight of pigs each time that they pass through the scale. The survey scale is equipped with a microprocessor-based controller, which very rapidly detects and stores the weight of each pig as it moves from water to feed pens. A single load cell, using the proven Accu-ARM weigh system, makes the measurement. The load cell is located at the top of the scale so it stays clean and away from manure and debris.

The weight is so quickly acquired that stopping of the movement of the pigs through the scale is not needed so the survey scale does not require entrance and exit gates for the Weight Watcher system. To the pigs, the survey scale appears to be a clear, unobstructed passageway between the water and feed pens. Occasionally more than one pig enters the survey scale simultaneously. Our Survey Scale weighing program immediately recognizes the additional pig and rejects that weight measurement. Such weighing failures, however, are infrequent and, in any case, do not detract from the ultimate success of the Weight Watcher system as will be understood in a moment.

The Survey Scale is equipped with both sort gates and spray markers. Although not needed for the Weight Watcher system, entrance and exit gates can also be provided as accessories, if desired. Each Survey Scale is equipped with a small screen on its integrated controller so that it can display weight information. Using this screen and a touch button, sorting decisions can be entered in the barn.

A system of Survey Scales can be economically linked together to a remote PC. If the PC is equipped with a choice of weight management software from Osborne, it can graphically monitor weight distributions and pen median weights, and multiple parameters can be set at the PC to execute management decisions, using sort gates or spray markers at the scale.

Although the Survey Scale can be equipped with entry, exit, and sort gates, like other automated market scales, the Weight Watcher system is much more than sorting of market pigs. The Weight Watcher system automatically divides pigs into two to four feeding groups as they grow, based on their rank in the weight distribution for the pen. This rank and weight distribution changes daily for each pig and for the pen group, respectively. The Weight Watcher tracks these changes and ensures that each animal is always fed for its proper weight and rank in the group distribution. With controlled feeding throughout the finishing cycle, the opportunity exists to limit the spreading of the weight distribution that causes sort losses at market and makes market sorting necessary.

The Weight Watcher system uses the movement of pigs from water to feed to automatically divide the pigs as they move across the Survey Scale with a sorting gate at the median or middle weight for the group. The median weight is determined from all the weights recorded each day by the Survey Scale controller. This median weight is adjusted daily as the pigs grow. The actual measured growth for the group determines the median, not an arbitrary or static growth curve. The heavy half of the pigs are automatically directed to a heavyweight-feeding pen and the light half of the pigs, to the lightweight-feeding pen.

The Weight Watcher system helps the manager feed the pen to reach market quicker at the exact weight that the packer demands. The weight distribution of the pen is known each day so that phase-feed changes are efficient, easy, and accurate. Lightweights can receive a high performance feed to accelerate gain and finish fast. Heavyweights can receive a feed that maximizes return on gain. Both feeds can be automatically phased to match growth and minimize wasted nutrients.

Penning is arranged to partition a room into a watering pen (15-20% of the room) and a feeding pen (80-85% of the room). This penning contains at least two one-way gates opening into the watering pen on either side of the Survey Scale. The Survey Scale is equipped with a sort accessory to direct pigs into either side of the feeding pen. The penning also is equipped with large gates that can be opened to make access to the watering pen from the feeding pen very easy for the first few weeks after the room is stocked with a new group of pigs.

Penning also divides the feeding pen into two equal areas. Dry ad libitum feeders are arranged for maximum access in each of these areas. Gates between two feeding areas are arranged to open both sides of the feeding area initially. At least two bulk bins supply the feeders in each side of the two feeding areas so that each side can receive a separate feed. Provision must also be made to wet and cool the pigs in the feeding area if summertime heat is expected to slow growth rate. This can be done with water drippers and power circulation fans like the Agri-Aide Super Jet fans equipped with Mist Kits to create directed evaporative cooling.

When the room is stocked, the pigs are moved into the watering pen first so that they quickly learn where the water is located. The one-way gates are fixed open and all partition gates are also open so pigs can move freely about the entire pen.

After a few weeks, but before the average weight of the pigs is about 70 lbs, the partition gates are closed. This limits movement to through one-way gates and the Survey Scale, which both remain inactive for a few additional days until the pigs learn to move through them. Then the one-way gates and the Survey Scale are activated. The Survey Scale begins to sort pigs into the heavyweight and lightweight sides of the pen.

As soon as the starter or transition feed is exhausted, then split-weight feeding can begin. The nutritional supplier can suggest an optimum feeding program for each weight range. Until a better strategy is devised, a starting point might be the use of a split-sex feeding strategy, because most of the lightweight pigs are likely to be gilts with a few lightweight barrows and most of the heavyweight pigs are likely to be barrows with a few heavyweight gilts. Alternatively, one could begin feeding a six phase feeding program by feeding Phase 1 to the lightweight pen and Phase 2 to the heavyweight pen.

The Weight Watcher automatically provides the median weight for the entire room and the median, or middle, weights for the heavyweight and lightweight pens, also called the quartile weights. Using these values, very accurate timing of phase feed changes can be made, eliminating wasted nutrients. The feeding program for the heavyweight pigs can be optimized for best return on gain. The feeding program for the lightweight pigs can be optimized for rate of gain to cut time to market and improve facilities utilization. Strategies such as adding products like Paylean from Elanco Animal Health to boost growth for the lightweight pigs may help eliminate multiple sorts for market. And, well before market day, one can determine time-to-market for the entire group or the need for a pre-market sort, if any.

The Weight Watcher system, therefore, is not just a market-day automated sorter. It is a way to totally manage the feeding and production of market hogs. Notice that each day all pigs return to a common watering pen to drink. Each day they are resorted based on the median. If a heavy pig falls behind because of illness, environment, or genetics, it is automatically promoted to the lightweight side and a recovery feed. If the growth of a lightweight pig excels, it is automatically promoted to the heavyweight side and a more economical feed. No social problems arise, because all pigs remain part of the larger group through earlier socialization and continued contact in the watering pen.

The "food court" system essentially groups all of the feeders into a relatively small area of the finishing room. The remainder of the finishing room is reserved as a loafing area without feeders. Both the food court and the loafing areas are provided with water.

Several weeks prior to marketing, the sorting scale is moved into position and pigs must enter the food court through a sorting scale in order to be fed and return to the loafing area via one-way gates. At some point, a sort weight or weight range is assigned to the sort scale and the food court is divided into a market animal pen and a reject pen for pigs outside the sort range. The reject pigs can return to the loafing area via a one-way gate, but the market animals are prohibited from remixing in the loafing area by locking the one-way exit gates. After about 24-hours, the market animals are loaded out and the pen is returned to normal operation. The sort off of market animals is repeated until all animals have been selected for specific markets or fed out to meet the target ranges set earlier.

Although the Survey Scale can be used in this way, this food court method has several distinct disadvantages:

The Survey Scale and Weight Watcher system are prepared for the future now. Both are ready for RFID eartag technology. In fact, RFID eartags were used in all of our system testing to give us complete and continuous understanding of the animal behavior with the system. The animals with superb or delayed growth can be quickly identified. "Poor doers" can be quickly culled, saving feed and space. Accuracy of animal weights is improved. A computer tracks individual growth curves of each animal and signals when an animal is falling behind or failing to eat or drink. Total traceability from "Farm-to-Fork" is a by-product of pin-point management knowledge. Step up to RFID when you are ready.

Daily Weigh™ Software – Your Information Manager. With our software options, growth curves for groups or non-standard pigs can be checked, average daily gains for the group and for exceptional pigs can be inspected, and pen or entire barns averages can be followed by location or by manager. Predict and anticipate group and animal weights and know how many days to target weight.

MarketWeigh™ Software – Your Market Manager. With this software option, the production information from the Daily Weigh program can be matched to marketing opportunities through buying grids and marketing options can be explored, using current feed costs, current real daily gain rates, and market inventory availability. This program takes the guesswork out of market day and even estimates the loss if marketing is earlier or later than the optimum market day.

For more information on the Osborne Weight Watcher™ System and the range of options available for the Osborne Accu-ARM Survey Scale, please call us at BOSMAN Agri Inc. at 519-848-2500.

BOSMAN Agri Inc., R.R. # 1, 8182 Concession 16, Moorefield, Ontario, N0G 2K0

Telephone: 1-519-848-2500; Fax: 1-519-848-5202; Email: sales@bosmanagri.com

Web: http://www.bosmanagri.com