Blood constituents of yeast fed chicks

Two experiments on broiler chicks raised to 4 weeks of age were carried out to study the effects of replacing soybean protein in a semisynthetic diet with yeast protein from molasses (CEPAH). Criteria measured were body weight, feed efficiency, plasma urea nitrogen, serum uric acid, serum total protein, albumin, globulin and albumin-globulin ratios. Analysis of the data showed that yeast protein produced from molasses depressed growth and feed efficiency at levels 10, 15, and 20% of the diet. The effects of yeast protein on blood nitrogenous constituents were variable and not significant, but in general, the inclusion of yeast protein caused an increase in serum albumin and a decrease in serum globulin resulting in a higher albumin-globulin ratio. The changes observed in blood nitrogenous constituents in this study do not explain all the detrimental effects of yeast protein on growth and feed efficiency of chicks receiving high levels of such protein.