Investigation of the nutritional and immune benefits of feeding a microbial protein product to laying hens

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As world populations continue to grow, the demand for resource efficient lean protein will continue to rise. As so, alternatives to traditional grains and oil seeds for poultry production need to continue to be developed and evaluated for use in animal production systems. The objective of this experiment was to determine the effects of feeding a microbial protein product (MPP) on performance and immune status of first cycle laying hens. In total, 144 Hy-line W36 laying hens (34 wk of age) were randomly assigned to 3 treatments with 12 replicates of 4 birds for each replicate. Hens were maintained two to a cage (120 sq in/bird) and two consecutive cages were considered an experimental group. Hens were on a 16:8 light and temperatures were maintained between 70 and 80 °F. The control fed birds consisted of a corn-soybean meal (SBM) diet, treatment fed birds consumed a corn-SBM diets with approximately 7.5% or 15% MPP formulated to replace mostly SBM and corn. The MPP was analyzed to contain 46.7% crude protein, 3240.5 kcal/kg gross energy, 5.6% crude fiber, 31.5% non fiber carbohydrate, 0.85% crude fat and 20.91% ash. To ensure hens did not over consume feed, feed intake was controlled to 95g/hen/d. Hen-housed egg production (HHEP) and mortality were monitored daily. Eggs were collected over four continuous days monthly for Feed Conversion Ratio calculations and egg quality analysis. At the end of 16 wk period, spleen samples were collected and weighed. All data were analyzed using ANOVA and means were separated either by repeated measures using a Turkey adjustment or using Fisher’s LSD test. In both cases, significance was accepted at P ≤ 0.05. Laying hens fed the control and 7.5% MPP resulted in significantly higher HDEP (86.7 and 88.7%, respectively) than the 15% MPP (83.5%). As expected, feed intake was similar due to controlled feeding and there were no mortality over the 16 weeks. There was no difference of relative spleen weights. Body weight loss was greater in the 15% MPP in comparison to both the control and 7.5% MPP fed birds. In summary, 7.5% of the MPP was able to at least maintain if not improve egg production in laying hens, but 15% MPP resulted in reduced performance, especially at the end of the 16 week experiment.