The diet that you devise for the ewe is determined by the availability of the
feedstuffs, feed processing and handling equipment, costs of the feedstuff, and the
productive phase that they are in at the time.
The first step in developing a diet is to know the nutrient requirements that the ewe needs during each phase of her production. The best way of doing this is to look in a table that the National Research Council (NRC). The NRC recommendations are the most commonly used guides for nutrient requirements in the farm/companion animals. The recommendations are subject to continuing modification as new information is acquired.
Your next step is to list all the available feedstuffs that are to be considered for the diet and their composition. The best way to get the composition of the feedstuff is through a laboratory or you can check the NRC tables for the average composition data. You should also check the maximum percentage allowances for a particular feedstuff before it can be considered in a diet formulation.
You must also consider whether the feedstuff should be processed. If its to be processed you must find out what way its to be processed and the cost of the processing.
Most small farm flock breeders will rely on their feed store to recommend the diet formation that fits their needs. Make sure that you know what you are getting and that the diet meets all the ewe's nutrient needs.
Generally diets are first formulated for on nutrient and then it is checked to see if it meets the requirements. Then if other nutrients are needed they are then added into the diet. One method is to first balance for protein and then checked for energy levels to see if they meet the requirements. Then the ration can be checked for other nutrients such as Ca and P.
There are two methods that are used to balance a diet. The algebraic and Pearson's square are widely used but with the use of computers has led to innovative approaches to balancing rations. Most nutrition consultants and feed stores are now using computer programs to balance their diets.
The only time range ewe's need to be fed is if they are either experiencing inclement
weather or if they are confined for shed lambing. In these instances you can feed them the
same way that you would if they were farm flock ewe's.
Range ewe's may be supplemented during breeding, late gestation, early lactation, and/or during severe drought periods when forage is not available or of poor quality. Gestation occurs during the winter when forage nutrient contents are lowest. During this time alfalfa hay is usually supplemented of choice.
Energy, protein, phosphorus, and vitamin A are the nutrients that are limiting for range ewes. Energy is usually the most limiting in winter because of limited forage available. Usually during this time grain is used as a supplement to the ewes diet.
Body condition scores are the best indicator of the nutritional status of range ewes and are an initial indicator of nutritional adequacy of available range forage.