[Contribution to determining optimum size of granulated limestone particles as a source of calcium for layers [chickens]]
1984
Pejin, G.
The subject of investigation in this paper is the optimum size of granulated limestone particles used for feeding highly productive layers and its effects on the egg-shell quality. The experiment was made upon 75 layers of Shaver Starcross 288 breed, which were divided in 5 groups, 15 layers in each. The particles tested were sized: 2-4 mm (group 1), 4-6 mm (group 2), 2-6 mm (group 3), 5-8 mm (group 4), while the feed in the control group contained stock chalk. Following conclusions were drawn: -Particles of 2-4 mm of size have favourable effects on the egg-shell deformation. -In the first half of egg-laying period the hardness of the egg-shells is lower, disregarding the source of calcium in the feed. -In the second half the hardness does not decrease only when meals containing 2-4 mm limestone particles and 4-6 mm ones were given. -Granulated limestone in the meals brings about the increase of calcium content in the egg-shells in the laying period. The best effect is obtained when 2-4 mm particles are used. -Calcium content per 1 sq mm of egg-shells increases significantly when 2-6 mm particles are added. -Under extremely high temperature the calcium content varies the least if smaller particles are used.
显示更多 [+] 显示较少 [-]