Selim Shaimaa, Abdel-Megeid Nazema S, Alhotan Rashed A, Ebrahim Alia, Hussein Eman
Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Menoufia University, Shibin El-Kom 32514, Egypt.
Department of Cytology and Histology, Faculty of Veterinary Medicine, University of Sadat City, Sadat City 32897, Egypt.
Vet Sci. 2023 Jul 13;10(7):461. doi: 10.3390/vetsci10070461.
Grape pomace (GP) is an industrial by-product of grape juice making and is commonly discarded as a waste product, even with its large quantity of phytochemicals. Thus, the objectives of this trial were to examine the effects of graded dietary GP on laying rate, egg quality, yolk lipid profile, oxidative stability, shell quality and ultrastructure, and serum biochemistry. Two hundred 35-week-old laying hens were allocated to four dietary treatments with ten replicates each. Four diets were formulated by mixing a standard basal diet with GP at 0 g/kg (control), 30 g/kg (GP), 60 g/kg (GP), and 90 g/kg (GP). Egg production percent, egg weight, and egg mass were linearly improved ( < 0.01) due to adding GP to the diets of laying hens. Eggs obtained from laying hens fed with GP diets had ( < 0.01; linear, < 0.01) greater Haugh units, yolk color, albumen index, and yolk index than those of the control. The GP group had the greatest values ( < 0.05) for shell weight, thickness, and breaking strength. Electron microscopy scanning of eggshells indicated that the incremental dietary level of GP linearly augmented the thickness of the palisade layer but reduced both the mammillary layer and mammillary knob width ( < 0.01). Improved tibia-breaking strength and ash content were shown ( < 0.05) in the GP-fed laying hens. The dietary addition of GP by up to 90 g/kg linearly ( < 0.01) mitigated lipid oxidation and improved the antioxidant capacity in both the serum and stored eggs. A reduction in the percentages of saturated fatty acids was observed, while the contents of monounsaturated fatty acids, polyunsaturated fatty acids, and n-3 fatty acids were augmented because of increasing dietary GP levels ( < 0.001). Additionally, the eggs obtained from laying hens fed on the GP and GP had lower yolk cholesterol content ( < 0.001); this effect was confirmed by linear and quadratic responses ( < 0.001). Laying hens on GP diets had lower ( < 0.01) serum hepatic enzymes, cholesterol, triglycerides, and low-density lipoprotein but greater high-density lipoprotein compared to the control. To sum up, the addition of GP in the layers' diets by up to 90 g/kg increased laying performance, enriched the yolk with beneficial fatty acids, enhanced antioxidant potential in yolk lipids, and improved shell quality and ultrastructure.
葡萄皮渣（GP）是葡萄汁生产过程中的一种工业副产品，即便其含有大量植物化学物质，通常也会作为废品被丢弃。因此，本试验的目的是研究不同梯度日粮添加GP对蛋鸡产蛋率、蛋品质、蛋黄脂质谱、氧化稳定性、蛋壳品质及超微结构以及血清生化指标的影响。将200只35周龄的蛋鸡分为4个日粮处理组，每组10个重复。4种日粮通过将标准基础日粮与0 g/kg（对照组）、30 g/kg（GP组）、60 g/kg（GP组）和90 g/kg（GP组）的GP混合配制而成。由于在蛋鸡日粮中添加了GP，产蛋率、蛋重和产蛋量呈线性提高（P<0.01）。与对照组相比，采食含GP日粮的蛋鸡所产鸡蛋的哈氏单位、蛋黄颜色、蛋白指数和蛋黄指数更高（P<0.01；线性，P<0.01）。GP组的蛋壳重量、厚度和抗压强度最高（P<0.05）。蛋壳的电子显微镜扫描表明，日粮中GP水平的增加使栅栏层厚度呈线性增加，但使乳头层和乳头瘤宽度减小（P<0.01）。采食GP的蛋鸡胫骨抗压强度和灰分含量有所提高（P<0.05）。日粮中添加高达90 g/kg的GP可使血清和储存鸡蛋中的脂质氧化呈线性减轻（P<0.01），并提高抗氧化能力。随着日粮中GP水平的增加，饱和脂肪酸百分比降低，而单不饱和脂肪酸、多不饱和脂肪酸和n-3脂肪酸含量增加（P<0.001）。此外，采食GP组和GP组蛋鸡所产鸡蛋的蛋黄胆固醇含量较低（P<0.001）；线性和二次反应证实了这一效应（P<0.001）。与对照组相比，采食GP日粮的蛋鸡血清肝酶、胆固醇、甘油三酯和低密度脂蛋白含量较低（P<0.01），但高密度脂蛋白含量较高。综上所述，在蛋鸡日粮中添加高达90 g/kg的GP可提高产蛋性能，使蛋黄富含有益脂肪酸，增强蛋黄脂质的抗氧化潜力，并改善蛋壳品质和超微结构。
