Hydroxychloride trace minerals sources

Hydroxychloride trace minerals (HTM) have covalent bonds and thus are less reactive both in the feed and in the digestive tract compared to inorganic trace minerals, which contain ionic bonds (ITM) such as sulphate forms. Therefore, HTM may have higher bioavailability than ITM.

This study aimed to evaluate the effects of replacing sulphate forms of zinc (ZnSO₄), manganese (MnSO4) and copper (CuSO₄) (ITM) with HTM sources on tibia bone traits and mineral content in eggs of layers during post-peak production. Hy-line Brown hens at 45 wk old (n = 600) were randomly distributed into 300 cages, with 10 cages (20 birds) per replicate and 15 replicates per treatment. There were two treatments (ITM or HTM) with Zn, Mn, and Cu supplemented at 80 mg/kg, 80 mg/kg, and 15 mg/kg, respectively, for 12 weeks. At the end of week 2, 6, and 12 of the study, two eggs per replicate were collected to determine mineral content in the eggshell and yolk. At the end of the study, tibia bones were excised from two representative birds per replicate after euthanasia to measure breaking strength and mineral content. The tibias were subjected to breaking strength by an Instron instrument. The content of Ca, Zn, Cu, and Mn in the eggs and tibias was measured using inductively coupled plasma optical emission spectroscopy. Tibia data were analysed via a one-way ANOVA and mineral deposition in the eggs was analyzed via two-way ANOVA including 2 diets and 3 ages. Means with significant differences were separated by Tukey’s HSD test at P < 0.05.

The tibia samples from birds fed HTM contained more Cu (1.36 µg/g vs. 1.16 µg/g, P < 0.05) and tended (P = 0.075) to have higher breaking strength than those fed ITM. No significant interaction between diet and age for mineral deposition in the eggshell and yolk was observed (P > 0.05). Birds fed the HTM diet had increased Cu concentration in the eggshell compared to those fed ITM (1.084 µg/g vs. 0.936 µg/g, P < 0.01). As the birds aged, the Ca and Cu content of the shell increased (P < 0.01). The HTM group had higher Zn content in the yolk than the ITM group (84.4 µg/g vs 82.6 µg/g, P < 0.05), but other minerals were not affected by mineral source. The yolk Mn content was lower at week 2 than at week 6 (3.24 µg/g vs. 3.53 µg/g, P < 0.05).

The results indicate that replacing sulphate sources of Zn, Mn, and Cu with hydroxychloride sources resulted in a tendency for increased tibia breaking strength in birds and increased mineral accumulation in eggs.

ACKNOWLEDGEMENTS: This study was funded by Trouw Nutrition, a Nutreco company.