The long-term effects of using a higher amount of iodine supplement on the efficiency of laying hens

Abstract

1. Two different levels of dietary iodine supplement (K + 0, 3·57 mg/kg; K + I, 6·07 mg/kg) were used in a 52-week experiment using 32 ISA Brown laying hens.

2. The greater iodine content in the diet impaired the egg production (K + 0, 319·9 ± 1·31 eggs/hen; K + I, 312·4 ± 4·19 eggs/hen), the egg weight (K + 0, 64·4 + 0·66 g; K + I, 63·1 ± 0·61 g) and the food to egg mass ratio (K + 0, 2·13 ± 0·023 kg/kg; K + I, 2·22 ± 0·030 kg/kg).

3. The greater dietary iodine content had significant (P<0·05) negative effects on Haugh units, yolk index and eggshell weight.

Acknowledgements

The authors thank Mrs Judy McPherson for language correction. The results were obtained as part of Research Project of Mendel University of Agriculture and Forestry in Brno MSM 432100001.

Notes

¹The premix supplemented to 1 kg of the diets with the following amount of nutrients: Cu 4·94 mg, Fe 142·8 mg, Zn 60·4 mg, Mn 59·9 mg, Co 0·24 mg, I 3·57 mg, Se 0·44 mg, retinol 3·3 mg, cholecalciferol 0·05 mg, alpha-tocopherol 25·2 mg, menadione 2·2 mg, thiamin 2·24 mg, riboflavin 7·85 mg, pyridoxine 3·27 mg, cyanocobalamin 0·018 mg, biotin 0·11 mg, niacin 25·1 mg, folic acid 1·05 mg, calcium pantothenate 9·8 mg, choline 508·8 mg, L-lysine 44 mg, DL-methionine 773·6 mg, L-threonine 39·6 mg.

^a,bMeans of the same order designated by different letters are significantly different (P < 0·05).

^A,BMeans of the same order designated by different letters are significantly different (P < 0·001).