1) Diet formulation: to formulate a diet, please enter the animal data and select the feeds you want to use within the database. (Figure 1)
2) Performance Prediction: In this option, the user can check the production potential of a diet. The user should enter the animal body weight and the quantities (in natural matter or dry matter basis) of the feeds that are supplied to provide the expected gain. (Figure 2)
3) Summary Table: the user can check the composition of the feeds that are available for the diet formulation or performance evaluation. (Figure 3)
4) Send Feeds: In this section the user can add their feed with the respective composition. The information on the feed composition must be proved by a document issued by the laboratory of data source.
5) To calculate the nutritional requirements: The user can calculate the nutritional requirements of different categories of animals (calves, growing and finishing beef cattle, lactating beef cows), from their body weight, average daily gain or milk production. (Figure 5)
6) On the top bar, the user can open the pdf files of all chapters available of Tables of Nutritional Requirements of Zebu Beef Cattle (BR-CORTE) in Portuguese and English . If the user needs to purchase the printed tables, he can use the link that takes him to the book publisher’s page. The user can also access the instructions, how to collaborate, the authors and how to cite (Figures 6 and 7)
The user must click on "Diet Formulating" on the top bar (Figure 1). A bar below the top bar indicates which of the steps of formulating the user is at. The inputting of the animal data corresponds to step 1. In this screen should be added the initial body weight (IBW), final body weight (FBW). The program will automatically calculate and display the average body weight in the screen average body weight (ABW), being a diet formulated for this body weight. The user should put the average daily gain (ADG) and choose a category (growing and finishing, cow or calf), by clicking on one of these. If the user clicks on growing and finishing, other tabs will open for choice of breed (Nellore or crossed), rearing system (feedlot or pasture) and sexual condition of the animal (bulls, steers or heifers). If you choose cow you need to enter the physiological state (lactating or dry) and if you choose calf you should enter the milk yield of the cow, since the milk will come as a dietary ingredient and will be deducted from the requirements before the inclusion of other ingredients. If the milk yield of the cow is unknown, the program will estimate the average value of the race.
As an example we present below:
After completing all fields, click next. (Figure 8)
The next screen will show step 2 where all requirements will be presented. On this screen the user will have access to his entered data (animal data). Much information on this screen concerns nutritional requirements that are not directly necessary for diet formulation. Any information that you are unable to select refer to the intermediate calculations to arrive at the values of TDN requirements, rumen degradable protein (RDP), rumen undegradable protein (RUP), crude protein (CP) and macro and microminerals. The requirements that allow it to be selected are those that can be met by the dietary ingredients. The values of ether extract (EE), non-fiber carbohydrates ( NFC), and neutral detergent fiber (NDF) are not requirements in themselves but have restrictions on intake and minimum and maximum limits that should be observed.
The requirements supplied by the diet are:
The user can choose all requirements available for selection by clicking on select all or manually selecting the nutrients of his choice (Figure 9).
The user can also change the value of the requirements by clicking on change the requirements (Figure 10). The changes made will be valid only for the calculation that the user is running at that moment. If the user exits the program or generates a new ration, the requirements calculated are those obtained with the original program data. Only some values of requirements can be selected to change. The user takes responsibility for changes to the diet formulation requirements. These new data of requirements will be described in the final report of the diet (diet with data requirements changed by the user).
Once selected, changed or not changed the requirements, click the next button if you want to continue the formulation (Figure 9). You can go back if you want to change any of the animal data, such as weight gain (ADG), IBW or FBW. If you click "get a new ration" the program will return to step 1 with all fields blank. After advancing onscreen requirements, the user has access to step 3. On this screen he can choose feeds within the titles (Figure 11).
If the user chooses select the "feed type", he can choose between dry or green forages, silages, energetic or protein concentrated feeds, additives and others feeds, by-products and mineral sources.
The feeds available are obtained from the feed composition table (CQBAL 3.0):www.ufv.br /cqbal, and only feeds that have composition data to get the requirements are imported to this database summarized. The feed must have data of DM,OM or ash, CP, EE, NFC or nutrients to calculate it, NDF, Lignin, acid detergent insoluble nitrogen (ADIN), fractions A and B of CP and degradation rate of B fraction (kd), or RDP and RUP, the data needed to calculate the TDN using the equations of Detmann et al. (2010) or TDN content. The user can send their feed to register if it is not summarized in the database, since the conditions described in "Send Your Feed" on the home screen of the program are supplied.
Continuing the example, let's assume that the user wants to get a diet using corn silage. The user should click "silage" and mark corn silage; to choose the other ingredients, the user must re-click on the titles field and choose an energetic concentrate – click "energetic concentrate" and choose your preference. In this example we select citrus pulp, rice bran and grounded corn (Figure 12). For protein concentrates, we will select 38% cottonseed meal, soybean meal and urea. For sources of minerals, the user chooses the most used sources or uses some mineral core of their choice; in this example we will select the most common sources by clicking "select more common" and then "next".
Clicking on advance, the program opens the window of step 4. On this screen the user will have the option to change the ratio F:C, change the composition of all feeds selected, add costs and choose the minimum or maximum quantities to be used in the diet.
To change the feed composition, click the name of the feed on the left side of the screen (Figures 13 and 14).The screen that opens will permit you to put a new value for the composition. The user should observe the unit in which is the nutrient is expressed. After making the change you must click to change. An important observation must be made, so as to change requirements; the program's authors are not responsible for diets generated using feed composition values changed by the user and a warning will come in the final report stating the change in the feed composition.
The user can choose to generate a diet without cost and without restrictions of minimum and maximum for the feed. If you do not add costs, the program will consider R $ 1.00 per kg of each ingredient in natural basis. (The costs per kg must be entered in natural basis). The program will generate a diet that meets the nutritional requirements at the lowest cost (Figure 15).
The requirements imposed by the mathematical program do not always generate a diet feasible for a practical condition, therefore the nutrition knowledge of the user is of fundamental importance. The user should return to onscreen restrictions clicking "change" restriction, change the minimum and maximum quantities of the ingredients till your diet meets the requirements, a reasonable price and feasible from a practical standpoint (Figure 16). The program will always generate the first operation with the minimum cost, but the minimum cost will not always provide optimal from the applicable standpoint.
If the user clicks "generate report" a file that can be saved or printed will open.
For performance prediction provided by a certain diet, the user should click the "Performance Prediction" (Figure 2) and enter the body weight and the average daily gain wished to be achieved with the diet. Next, the user should choose the animal category, breed, feeding system and sex. Considering a crossbred steer, growing and finishing in feedlot with a body weight of 400 kg and expecting a daily gain of 1 kg with the diet, the user should report these data in step 1 and click next (Figure 17).
The screen that then opens, corresponds to the second step and presents animal data and the option of selecting the ingredients of the diet; this step is exactly the same as described for diet formulation (Figure 12). Choose silage as forage, grounded corn grain and grounded sorghum grain as energetic concentrate, 38% cottonseed meal and urea as protein concentrates, and mineral mixture as a source of minerals, then click to advance.
The screen of step 3 should be reported based on the quantities of natural matter (NM) or dry matter (DM). In this example we use DM, remembering that it is vital to set the unit (kg, g or mg) so that each ingredient is entered to obtain the results. Then click to calculate (Figure 18).
The screen of step 4 presents the animal data, a table with the amounts of ingredients, one with the amounts of nutrients provided by the diet and in the bottom of screen 3 are smaller tables related to the prediction of performance (Figure 19).
Analyzing the three smaller tables, one shows the expected average daily gain (ADG) and the possible ADG calculated by the program considering the metabolizable energy and protein supplied by the diet. The two other tables refer to dry matter intake estimated by the BR-CORTE provided by the diet evaluated, and the other shows the possible gains considering the amounts of major minerals in the diet supplied (Figure 20).
If the user wishes he can click "Generate Report" and a file of two pages will be opened; this file can be saved or printed.
In this example the diet will provide a gain greater than expected since it will be limited by the metabolizable energy intake; in other words, the predicted gain will be 1.06 kg. In this case we do not consider minerals.