Effects of melamine or urea-formaldehyde or their mixture on performance in laying hens

Abstract

Experiment was conducted to investigate the effects of melamine or urea-formaldehyde or their mixture on performance in laying hens (19-34 wk of age). Three hundred and twelve ISA Brown laying hens were allocated into thirteen dietary treatments, with four replications and with six hens each were fed with feeding trial for 112 d (4 x 28 d period). The diets were formulated to contain four graded levels (0.25, 0.50, 0.75 and 1.00%) of melamine or urea-formaldehyde (UF) or an equal mixture of both and also with no added for negative control. There were no significant effects on feed intake and survival rate (P>0.05) among each group. Egg production (EP), egg weight (EW), egg mass (EM) and number of egg were decreased (P<0.05), with the greatest decrease in hens fed 1.00% melamine. EP, EW, EM and number of egg decreased linearly (P<0.05) with increasing levels of dietary melamine or UF or their mixture. Hens that are fed on three products were less efficient (P<0.05) in feed conversion ratio compared with the controls. These results indicated that dietary melamine or UF or an equal mixture of both when fed at the level of > 0.75% depressed egg performance in laying hens.