This tab is used to specify additional ingredient constraints. In WinFeed, constraints may be placed on groups of ingredients. Thus, the total inclusion of animal ingredients or oilseed meals may be constrained or controlled. There is no limit to the number of ingredient constraints that may be defined for a given feed. However, a feasible solution becomes progressively less likely as the number of ingredient constraints is increased.Examples of the type of nutritional information that may be specified with these additional ingredient constraints are:
The sum of certain ingredients might need to be within certain bounds, e.g. the sum of bran, pollard and hominy chop may not exceed 30% of the feed.An ingredient might need to be incorporated into the feed at a certain ratio of another ingredient e.g. equal amounts of soya and sunflower must be used.To add a constraint, click on the New constraint button. A new column will be added. If the bounds are to be expressed as percentages, click the –is percent constraint row. Type in the upper and lower bounds. Specify the coefficients of the ingredients used in the constraint by typing them in the relevant ingredient’s row.Example 1If you wish to specify that the sum of sunflower 37 and soybean 46 must be between 9 and 14 percent of the feed, you would tick the ‘– is percent constraint’ row, put in 9 and 14 as the lower and upper bounds and put in coefficients of 1 for sunflower 37 and for soybean 46.Example 2Suppose you want fine bran to be twice the amount of middlings. Let x1 and x2 be the amount of fine bran and middlings respectively:i.e. you want: 1. x1 = 2. x2  <=>1. x1 – 2. x2 = 0 <=>0 <= 1. x1 – 2. x2 <= 0Therefore to get the desired ratio you would make the upper and lower bounds both 0, and put in coefficients of 1 and -2 for fine bran and middlings respectively.To remove a constraint, select the constraint to delete by clicking anywhere in its column, and click on the Delete constraint button.Instead of formulating a single feed, it is also possible to select a folder and formulate all feeds in that folder. A message will display how many of the feeds in that folder formulated successfully.