Diets Formulation, mixing

Diets are isocaloric. The composition of the test and control (reference protein) diet (calculated on a dry weight basis) is 10% protein (1.6% nitrogen), 1 % AIN vitamin mix 76,3.5% AIN mineral mixture 76 (Nutritional Biochemicals), 0.2% choline bitartrate, 5% cellulose (only if test food is <5% total dietary fiber), corn oil to 10% total fat, and corn starch to total 100%. To account for differences in the protein content of the test diet, the level of corn starch can be adjusted (Joint FAO/WHO Expert Consultation, 1991). The chemical composition (proximate analysis) of the test protein must be measured before test diets are formulated. The proximate analysis of the test and control diets are to be measured after the diets are formulated, but before they are fed, to ensure that the protein content is the same for all diets, and that the diets are isocaloric. 

Purchase a supplement designed to be mixed with grain or grain and limestone (or oyster shell) to provide a complete laying hen diet. A supplement formulated in this way will contain 250- 400 g crude protein (CP) per kg protein. A grower supplement may be used prior to the start of egg production but a layer supplement should be used once the birds start to lay. 

Pectin appears to be better tolerated when it is included in the diet as a food source or completely hydrated in a food product (2) than when given as a powder mixed with water, juice or the subjects own food ( S). Subjects complained of the taste, gummy feel, and the stickiness in mouth and on teeth when powered pectin was given while food sources, even those formulated by the researchers, were well accepted. Some side affects noted by some subjects in human studies included rectal flatulence, flatulence, abdominal distention and abdominal cramps. 

Table III shows the composition of mineral mixes, NAS requirements, and extrapolated requirements. All groups except the Unilever group have used commercial mineral mix formulations. Agriculture Canada and Health and Welfare Canada changed the mineral mix for rats in 1974 in order to more closely approximate the copper, manganese, and zinc requirement specified by NAS. The level of supplementation of some of the minerals does not appear to conform to the 1972 NAS requirements. In the future, high fat diets should possibly contain the extrapolated NAS requirements.

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