Time course of nutritional and functional property changes in egg yolk from laying hens fed docosahexaenoic acid-rich microalgae.

Marine microalgae (MA) has received wide attention as a promising source of omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) enrichment in animal products to improve the health status and wellbeing of the consumers. This study evaluated dynamic changes in n-3 LC-PUFA, color, and functional properties as well as atherogenic and thrombogenic health lipid indices of egg yolk from hens fed graded levels (0, 0.5, and 1.0%) of docosahexaenoic acid (DHA)-rich MA (Aurantiochytrium sp.) during a 56-D feeding period. Egg freshness parameters and yolk lipid oxidative stability were also measured after 0, 14, and 28 D of refrigerated storage. The hen performance and egg quality (except for yolk color) were not affected (P > 0.05) by MA supplementation. Docosahexaenoic acid contents in yolk from hens fed 1.0% MA increased quadratically with feeding time with a plateau at about 30 D (P < 0.05). Afterward, the DHA content leveled off to a constant value (946.3 mg/100 g yolk) with the n-6/n-3 ratio at 3.5: 1. Dietary inclusion of 1.0% of MA also significantly decreased the atherogenic and thrombogenic indices of yolk lipid (P < 0.05). Because the microalgal carotenoids incorporated into egg yolk, the L∗ value of yolk from hens fed MA decreased whereas a∗ value increased (P < 0.05), corresponding to yolk Roche color scores. As expected, there were no significant changes in yolk functional properties (e.g., viscosity and emulsifying activity) related to DHA enrichment (P > 0.05). Microalgal carotenoids enrichment also helped attenuate fatty acid oxidation of the DHA-enriched yolk and increase their lipid oxidative stability. In conclusion, dietary supplementation with up to 1.0% of MA significantly increased DHA contents with more health-promoting n-6/n-3 ratio and atherogenic and thrombogenic indices, as well as more intense yolk color within consumers' acceptability, and the feeding strategy had a minimal impact on yolk physical and functional properties or oxidative stability during subsequent refrigerated storage.

Comparison of Inorganic and Organically Bound Trace Minerals on Tissue Mineral Deposition and Fecal Excretion in Broiler Breeders.

This study investigated the effects of replacement of inorganic trace minerals (ITMs) by organic trace minerals (OTMs) on tissue mineral retention and fecal excretion in "Zhen Ning" yellow feather broiler breeders. Six hundred hens (initial BW: 1.70 ± 0.07 kg) aged 40 weeks were randomly divided into five treatments, with four replicates of 30 broiler breeders each. Experimental treatments were as follows: (1) ITM (Cu, Zn, Fe, Mn, Se providing commercially recommended concentrations), (2) L-ITM (50% of the ITM, except for Se), (3) VL-OTM (37.5% of the ITM, except for Se), (4) L-OTM (equivalent to L-ITM), and (5) OTM (62.5% of the ITM, except for Se). The duration of the study was 10 weeks including 2 weeks for adaptation. Compared with the L-ITM treatment, high-level supplementation of minerals in ITM and OTM increased the concentration of serum Mn and Se, pectoral Fe and pancreas Cu, and Fe (P < 0.05). Birds fed with OTM dietary exhibited comparable mineral retention in muscle compared with ITM. Differences were observed between L-ITM and L-OTM in serum Mn and Se, pectoral Fe, Zn, and Se, and heart Se with L-OTM retaining higher mineral concentrations than L-ITM (P < 0.05). L-OTM retained identical concentration with ITM treatment, except for the pancreatic Fe. All three organic diets reduced the Zn in excreta compared with the two inorganic diets (P < 0.05). This study indicates that replacement of dietary ITMs by OTMs improved mineral deposition in tissues and reduced fecal mineral excretion in broiler breeders under the conditions of this study.