The present study was carried out to determine the effect of feeding graded levels of toasted guar meal on energy and protein balances and availabilities of Ca, P and Mg in laying hens in replacement of preformed proteins.
Thirty six layers, 172 days-old were used In a 4x3x3 arrangement as groups A, B, C and D. To an experimental basal layer ration, isocaloric (2.82 Mcal/kg) and iso- nitrogenous (18.47%), 2.5, 5 and 7.5 % roasted guar meal was added respective to groups B, C and D. At the end of a feeding period of 8 weeks, balance trails were performed for nitrogen, energy, Ca, P and Mg during a collection period of 3 days. The feed intake was recorded, excreta were collected, air dried, weighed and chemically analyzed. Three eggs were randomly picked per treatment, weighed, boiled, shelled and composited before being subjected to proximate analysis.
The balances of these elements were satisfactorily positive, and increasing the level of toasted guar meal in the deit increased the apparent efficiency utilization of guar protein and energy for egg production. Phosphorous intake, retention, availability and Mg in the droppings increased with increasing level of guar meal while Ca intake, retention, availability and percentage values of P excreted in the droppings decreased. No adverse effects on the performance in general, or the balance of nutients were recorded at levels of guar meal as high as 7.5% in the feed formula. Preference for the level inclusion of guar meal in the layers rations practically showed that the low (2.5%) and the high(7.5%)were better than the 5% level.
Keywords : Guar meal Laying hens Energy balance Protein balance nineral availabilities