Effect of dietary lipids on liver, serum and egg yolk cholesterol contents of laying hens

Supplementation of the basal ration of laying hens with 0.001, 0.005, and 0.01% neomycin sulphate did not produce any significant changes in the weight of the hens, their eggs, or egg yolks, nor did it alter egg production. Supplemental neomycin caused no significant changes in levels of plasma cholesterol. Plasma and yolk lipid levels varied considerably within as well as between groups of hens. Plasma squalene/plasma cholesterol and yolk squalene/yolk cholesterol ratios were approximately the same, indicating the presence of 250 times more cholesterol than squalene. Plasma squalene/yolk squalene and plasma cholesterol/yolk cholesterol ratios showed that both components were approximately 13 times more concentrated in the yolk than in the plasma. The variable plasma cholesterol levels for rats, rabbits, mice, human beings, as well as the laying hen, treated with neomycin, are suggestive of species differences in response.

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Egg Quality Parameters, Production Performance and Immunity of Laying Hens Supplemented with Plant Extracts

Animals ◽

10.3390/ani11040975 ◽

2021 ◽

Vol 11 (4) ◽

pp. 975

Author(s):

Muhammad Ammar Dilawar ◽

Hong Seok Mun ◽

Dhanushka Rathnayake ◽

Eun Ju Yang ◽

Ye Seul Seo ◽

...

Keyword(s):

Plant Extracts ◽

Proximate Composition ◽

Laying Hens ◽

Egg Quality ◽

Egg Yolk ◽

Cholesterol Content ◽

Production Performance ◽

Dependent Manner ◽

Yolk Cholesterol ◽

Dietary Treatments

This study examined the effects of Mentha arvensis (MA) and Geranium thunbergii (GT) extracts in drinking water on the production performance, egg quality, cholesterol content of egg yolk, proximate composition, and sensory qualities of egg and immunity parameters in laying hens. Ninety-six 28-week-old Hy-Line Brown layers were randomly divided into four dietary treatments for 16 weeks. The dietary treatments were (1) control, (2) T1 (0.01% 1 MA:1 GT), (3) T2 (0.05% 1 MA:1 GT), and (4) T3 (0.1% 1 MA:1 GT). Egg production increased significantly with increasing levels of MA and GT. The egg weight was increased in T2, and the feed intake was highest in T2 and T3 (p < 0.05). The Haugh unit and egg shape index were significantly better in T3 and the control than with other treatments (p < 0.05). The content of yolk cholesterol was significantly lower (p < 0.05) in T2 and T3. On the other hand, there were no significant differences in the egg proximate composition. A significant increase in the serum interleukin 6 (IL-6), tumor necrosis factor (TNFα) and immunoglobulins (IgG and IgA) concentration was observed in the birds fed plant extracts when compared to the control. On average, T2 and T3 showed significantly lower (p < 0.05) concentrations of NH3 gas from the feces as compared to the control. This study suggests that MA and GT supplementation could improve the laying performance, egg quality, and immunity, and decrease the egg yolk cholesterol content in a dose-dependent manner.

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