Effects of dietary levels of sun-dried sheep manure on productive performance and egg quality parameters of Shika-brown layers

Résumé

An experiment was conducted to test the effect of dietary levels of sun-dried sheep manure (SSM) on egg quality parameters and productive performance of Shika-Brown layers. Six isonitrogenous and almost isocaloric diets were formulated to contain SSM at 0.0, 1.0, 2.0, 3.0, 4.0 and 5.0 % level of inclusion. Diet I, which had no sheep manure, served as the control. White maize was used for the formulation of the diets. Each of the six diets was replicated four times with five birds per replicate in a completely randomised design experiment. The birds were housed singly in cages. The laying hens were first maintained on the control diet which contained very little or no yolk pigmenting factor for a depigmentation period of twenty-one days. During this period, samples of eggs were broken out and yolk colour scores were determined using the Roche Yolk Colour Fan (RYCF). By the twenty-first day, the (RYCF) scores had dropped to the lowest value of one. The hens were then placed on the experimental diets for the study, which covered a period of twelve weeks. Parameters measured for the egg quality included egg yolk colour, Haugh unit value, yolk index and shell thickness. For the performance characteristics, parameters measured included percent hen day and hen housed egg production, percent peak egg production, feed intake, feed conversion efficiency (kg feed/12 eggs) and feed cost per /2 eggs produced. Results obtained indicate that dietary levels of SSM had a significant (P<0.05) effect on RYCF scores and feed intake but had no significant (P>0.05) effect on other parameters such as egg weight, Haugh unit, yolk index, shell thickness, shell weight, percent shell, feed conversion efficiency, feed cost (N/12 eggs), percent hen day, hen housed and peak egg production.