Soybean meal enriched with microelements by biosorption--a new biological feed supplement for laying hens. Part I. Performance and egg traits.

The aim of the study was to evaluate the effect of soybean meal enriched with Cu(II), Zn(II), Fe(II) and Cr(III) by biosorption on egg traits (egg weight, eggshell strength, eggshell thickness, yolk colour, albumen height) and performance of laying hens. Also, the effect of increased microelement doses in biological form on egg quality parameters and hens performance was investigated. A consumer questionnaire was undertaken to evaluate the organoleptic parameters of the eggs. Generally, our study showed that in the groups fed with the new biological supplement, egg quality parameters improved, including eggshell strength, eggshell thickness, albumen height and yolk colour. The biological form of microelements also improved the feed conversion rate, especially in the group fed with a biological form of Cr(III). Moreover, the new supplement improved organoleptic parameters of the eggs, in comparison to the inorganic form of microelements as well as to chelate. Enriched soybean meal could constitute an alternative for currently used feed additives with microelements.

Effect of iodine-enriched yeast supplementation of diet on performance of laying hens, egg traits, and egg iodine content.

The aim of the study was to evaluate the effect of iodine yeast (I-yeast) supplementation on the performance, egg traits, and iodine content of eggs of laying hens. The experiment was conducted as a completely randomized design. A total of 60 laying hens (Hy-Line Brown), 25 wk of age, was divided into 3 groups (4 replicates), and a feeding experiment was conducted for 12 wk. The concentrations and forms of iodine added to the basal diet were as follows: control group, 1 mg of iodine/kg of feed, Ca(IO(3))(2)•H(2)O; experimental groups E1 and E2, 1 and 2 mg of iodine per kilogram of feed, I-yeast, respectively. The iodine yeast did not significantly affect BW gain. Lower level of hen day egg production for groups E1 and E2 was not confirmed statistically; however, it was probably the consequence of low replication. Feed intake was the lowest in the E1 group and feed conversion rate was the highest in the E2 group. Furthermore, the egg and albumen weight was the highest in the group supplemented with 2 mg/kg of iodine from I-yeast (P < 0.05). The concentration of iodine in the egg yolk from groups E1 and E2 was respectively about 80 and 90% higher, compared with the control group. Eggshells from the group fed with 2 mg/kg of I-yeast contained almost 3 times more iodine than eggshells from the control group. The results suggest that iodine yeast supplementation in the diet of laying hens is an effective method for increasing iodine concentration in eggs and thus could contribute to elimination of iodine deficiency disorders in humans consuming iodine-enriched eggs.

Effect of macroalgae enriched with microelements on egg quality parameters and mineral content of eggs, eggshell, blood, feathers and droppings.

This study presents results obtained from feeding experiment on laying hens, which were fed with the diet supplemented with two marine macroalgae: Enteromorpha prolifera and Cladophora sp., enriched with microelements [Cu(II), Zn(II), Co(II), Mn(II), Cr(III)]. The applicability of the preparation was tested on five experimental groups of laying hens and one control group. In the control group, microelements were supplemented in the inorganic form, whereas in experimental groups, Cu, Zn, Co, Mn and Cr were replaced by macroalgae enriched with a given microelement ion. During feeding experiment, weight of laying hens, weight of eggs, eggshell thickness and mineral content of blood, feathers, droppings, eggs content (separately yolk and egg white) and eggshell were measured. Also egg number was counted and microclimate (temperature and relative humidity) was monitored. Supplementing bio-metallic feed additives to the diet of laying hens resulted in higher microelement transfer to eggs and enhanced the colour of yolk. It was also found that the presence of Enteromorpha prolifera and Cladophora sp. in laying hens diet influenced advantageously eggs weight, eggshell thickness as well as body weight of hens. On the basis of these results, it could be concluded that Enteromorpha prolifera and Cladophora sp. enriched with microelement ions could be potentially used as mineral feed additives in laying hens feeding.