The impact of phytoestrogen source supplementation on reproductive performance,plasma profile,yolk fatty acids and antioxidative status in aged laying hens

The objectives of this study were to investigate the effects of flaxseeds and/or fenugreek seeds as a source of phytoestrogens in laying feed on productive performance, egg quality, yolk fatty acids, plasma profile and antioxidative status in aged laying hens. A total of 120 Bovans Brown hens at 65 weeks of age were housed individually in laying cages in an open‐sided building under a 16‐hr light: 8‐hr dark lighting schedule. Hens were randomly divided into four experimental treatments (n = 30 each): (a) control (basal diet without any supplementation); (b) 1 g/kg of flaxseeds; (c) 1 g/kg of fenugreek seeds; and (d) combination of 1 g/kg flaxseeds and 1 g/kg fenugreek seeds from 65 to 71 weeks of age. Hen‐day egg production and egg mass were significantly increased by dietary supplementation of flaxseeds and/or fenugreek seeds, while feed intake was not affected; thus, feed conversion ratio was improved (p < 0.05). Weights of egg, albumen, yolk and shell were increased by the dietary treatments. Shell thickness and yolk colour were improved by supplementation of flaxseeds and/or fenugreek seeds. Yolk crude protein was not significantly affected by treatments; however, crude fat and calcium contents in yolk were increased and egg yolk cholesterol content was decreased. Interestingly, dietary supplementation of flaxseeds, fenugreek seeds and their combination had a significant positive effect on plasma luteinizing hormone, follicle‐stimulating hormone, oestradiol‐17β and triglycerides. Inclusion of flaxseeds and/or fenugreek seeds in the diets enhanced the serum glutathione peroxidase and superoxide dismutase activities and reduced the malondialdehyde and total cholesterol concentrations in plasma. Dietary supplementation of flaxseeds and/or fenugreek seeds increased α‐linolenic and linoleic acids in egg yolk. It could be concluded that inclusion of mixed sources of phytoestrogens in diets improved laying performance, egg quality, the antioxidative status, hormonal profile and steroidogenesis in aged laying hens.     

菊苣提取物对蛋鸡鸡蛋胆固醇、肠道菌群和生产性能的影响

本文旨在研究菊苣提取物对蛋鸡生产性能、鸡蛋品质、肠道菌群、血清胆同醇和卵黄胆同醇的影响.300只尼克红蛋鸡随机分为5组,每组6个重复,每个重复10只,各组日粮中分别添加0、0.5%、1.0%、1.5%的菊苣提取物和1.0%的菊粉,试验进行4周.结果表明:与对照相比,不同水平的菊苣提取物或菊粉对蛋鸡产蛋率、蛋重、采食量、料蛋比、破蛋率、蛋黄重、蛋壳厚度和哈氏单位没有显著影响(P>0.05),但能显著降低鸡蛋胆固醇浓度(mg/g蛋黄)和含量(mg/蛋黄)(P<0.05),1.5%菊苣提取物添加组的动脉粥样硬化指数显著降低(P<0.05);日粮添加菊苣提取物或菊粉显著降低蛋鸡盲肠大肠杆菌数量和pH(P<0.05),1.5%菊苣提取物添加组和菊粉添加组显著增加盲肠双歧杆菌数量(P<0.05);鸡蛋胆固醇含量和盲肠大肠杆菌数量随菊苣提取物添加水平的增加线性降低(r=-0.957和r=-0.977)(P<0.05).结论:本试验在蛋鸡日粮中添加菊苣提取物或菊粉能显著降低鸡蛋胆固醇和盲肠有害菌(大肠杆菌)的数量,且不影响蛋鸡生产性能和鸡蛋品质.故在蛋鸡日粮中添加菊苣提取物或菊粉可为生产低胆同醇鸡蛋提供一条途径.     

Effect of different levels of black cumin (Nigella sativa L.) on performance,intestinal Escherichia coli colonization and jejunal morphology in laying hens

This study was conducted to investigate the effects of different levels of black cumin seeds (Nigella sativa L.) on performance, intestinal Escherichia coli count and morphology of jejunal epithelial cells in laying hens. A total of 100 Leghorn laying hens (Hy‐Line W‐36) of 49 weeks old were randomly distributed among five cage replicates of five birds each. Experimental diets consisted of different levels (0%, 1%, 2% and 3% of diet) of dietary black cumin inclusion. The experimental period lasted for a total of 10 weeks, and egg quality indexes and laying hens' performance were measured as two 35‐day trial periods. At the final day, two hens per replicate were slaughtered to investigate the influence of dietary treatments on intestinal E. coli colonization and morphology of jejunal cells. Although dietary black cumin in all supplementation levels decreased (p < 0.05) the enumeration of ileal E. coli, the morphological and histological alterations in small intestine such as enhancement of villus height to crypt depth ratio, increased goblet cell numbers and proliferation of lamina propria lymphatic follicles were observed after dietary supplementation with at least 2% black cumin. Dietary treatments decreased (p < 0.05) the concentration of serum cholesterol and triglycerides and increased (p < 0.05) serum HDL concentration and relative weight of pancreas; however, the egg yolk cholesterol was not influenced by dietary treatments. In addition, dietary supplementation with black cumin improved (p < 0.05) eggshell quality and Haugh unit. The best feed conversion ratio was obtained when diets were supplemented with 2% black cumin. This improvement was due to the increase (p < 0.05) in egg mass and contemporaneous decrease (p < 0.01) in feed consumption. The present results indicated that regardless of supplementation level, dietary inclusion of black cumin decreased E. coli enumeration in ileal digesta and improved serum lipid profile and eggshell quality, whereas the best intestinal health indices and haying hens' performance were obtained by at least 2% black cumin seeds.     

Tea polyphenols increase the antioxidant status of laying hens fed diets with different levels of ageing corn

This study was conducted to evaluate the effects of ageing corn levels (stored for 4 years) with or without the supplementation of tea polyphenols (TPP) on the performance, egg quality and antioxidant status of laying hens. A total of 288 Lohmann commercial laying hens (63-week-old) were used under a 2 × 4 factorial arrangement with 4 levels of dietary ageing corn (0%, 25%, 50%, or 100%) and 2 levels of TPP (0 and 600 mg/kg) for 8 wk. Dietary ageing corn linearly decreased (P < 0.05) the egg production, serum total antioxidant capacity (T-AOC), liver glutathione peroxidase (GSH-Px) of laying hens, yolk index, yolk colour, 1,1-diphenyl-2-picrylhydrazyl (DPPH) value and the reducing power value of egg yolk, but it linearly increased (P < 0.05) the feed conversion rate, ovary malondialdehyde (MDA) content of laying hens, and the protein carbonyl content of egg yolk. Tea polyphenol supplementation increased (P < 0.05) the serum T-AOC, serum superoxide dismutase (SOD), liver SOD, liver GSH-Px, ovary SOD, GSH-Px, the expression of antioxidant-related genes of laying hens, albumen height, Haugh unit, DPPH value and the majority free amino acids of egg yolk, but it decreased (P < 0.05) the serum MDA content of laying hens, MDA and protein carbonyl of egg yolk. In conclusion, the ageing corn significantly reduced the performance, egg quality, antioxidant status and egg antioxidant capacity of laying hens, while TPP supplementation partially counteracted the adverse effects, especially antioxidant status and egg antioxidant capacity of laying hens.     

饲粮缬氨酸水平对蛋鸡生产性能、蛋品质及血清生化指标的影响

本文旨在研究饲粮不同缬氨酸水平对蛋鸡生产性能、蛋品质及血清生化指标的影响,并探讨蛋鸡饲粮中缬氨酸的最适添加量.试验选用720只体重相近的40周龄的海兰褐壳蛋鸡,随机分成5组,每组4个重复,每个重复36只鸡,分别饲喂缬氨酸水平为0.6％、0.7％、0.8％、0.9％、1.0％的饲粮,试验期为56 d.结果表明:1)0.8％水平组料蛋比和1.0％水平组平均日采食量分别最低,与其他各组均差异显著(P＜0.05);各组产蛋率、平均蛋重和日产蛋均重均无显著差异(P＞0.05).2)0.8％水平组蛋壳强度最大,1.0％水平组蛋清蛋白质含量最低,与其他各组均差异显著(P＜0.05)或有显著的趋势(P＜0.10);各组蛋壳厚度、哈夫单位、蛋黄颜色、蛋白高度、蛋黄和蛋清相对重均无显著差异(P＞0.05).3)0.8％水平组血清葡萄糖含量最高,显著高于其他各组(P＜0.05);0.8％水平组血清尿素氮和尿酸含量最低,总氨基酸含量最高,与其他各组均有差异显著的趋势(P＜0.10).4)二次曲线分析表明:当饲粮代谢能为11.31 MJ/kg、粗蛋白质水平为15.81％、赖氨酸水平为0.77％时,以料蛋比为评价指标,产蛋高峰期蛋鸡缬氨酸需要量为0.78％,以蛋壳强度和血清白蛋白含量为评价指标,缬氨酸需要量分别为0.81％和0.75％.由此可知,基础饲粮中添加一定量的缬氨酸可降低产蛋高峰期蛋鸡料蛋比,增强蛋壳强度和提高血清葡萄糖含量.     

Effect of dietary supplementation of organic zinc on laying performance,egg quality and some biochemical parameters of laying hens

This study was conducted to evaluate the effects of zinc methionine (Zn‐Met) supplementation on the performance, egg quality, antioxidant status and some biochemical parameters of blood serum in laying hens from 22 to 34 weeks of age. A total of 120 Hisex Brown laying hens of 22‐week‐old were randomly allocated into five treatments with six cage replicates for each (four hens/replicate). Dietary treatments consisted of the basal diet with no Zn‐Met supplementation (control group) and basal diet supplemented with 25, 50, 75 or 100 mg Zn‐Met/kg diet. No significant differences were observed on body weight, body weight gain or feed conversion ratio due to dietary Zn‐Met supplementation. However, highly significant impact was observed on daily feed intake. Egg number, egg weight and egg mass were increased in the group fed diet supplemented with the highest level of Zn‐Met (100 mg/kg of diet) as compared to other groups. All egg quality traits were statistically (p > .05 or .01) affected as a response to dietary Zn‐Met supplementation except egg shape index, shell percentage and yolk index. In comparison with the control group, dietary supplementation of 25, 50, 75 or 100 mg Zn‐Met/kg decreased serum triglyceride and LDL‐cholesterol levels. Serum cholesterol level was increased with all dietary levels of Zn‐Met in comparison with the control group. Dietary Zn‐Met supplementation increased the serum content of zinc, where the highest values were recorded with 50 and 100 mg Zn‐Met/kg diet. Dietary Zn‐Met levels did not affect the antioxidant indices in blood serum except for the activity of copper–zinc superoxide dismutase (Cu‐Zn‐SOD). The activity of Cu‐Zn‐SOD was increased with Zn‐Met supplementations with no differences among supplemental zinc levels. It is concluded that dietary Zn‐Met supplementation reduced serum triglyceride, LDL‐cholesterol and increased Zn status and resulted in promoting antioxidant ability of laying hens, and the addition of 100 mg Zn‐Met/kg to layer diet was appropriate for improving the above parameters in addition to egg production indices and Haugh unit score.     

日粮添加甜菜碱对夏季高温蛋鸡生产性能、蛋品质及血液理化特征的影响

本研究旨在评估夏季高温时日粮添加甜菜碱对蛋鸡生产性能、蛋品质及骨骼和血液理化特性的影响.试验将480只产蛋性能一致的罗曼粉壳蛋鸡随机分为2组,每组240只,每组10个重复(24只/重复).对照组饲喂基础试验日粮,处理组蛋鸡饲喂基础试验日粮+150?mg/kg甜菜碱,试验为期8周.结果:日粮添加150?mg/kg甜菜碱对...     

Effects of Microbial Phytase Supplementation on Egg Production and Egg Quality in Hy-line Brown Hens During the Late Laying Period

The objective of this study was to evaluate the effects of microbial phytase on egg production and egg quality in older hens. A total of 216, 63-week-old Hy-line brown laying hens were distributed in a randomized complete design 10-week feeding trial of 3 dietary treatments with 12 replications per treatment and 6 hens per replication. The 3 dietary treatments were corn-soybean meal-based diets supplemented with 0% (CON), 0.06% (TRT1), and 0.12% (TRT2) microbial phytase. Significantly higher hen-day egg production was observed in the TRT1 treatment compared to CON (P<0.05), except during the first two weeks of the experiment. During weeks 3, 4, and 9, TRT2 had a greater hen-day egg production percentage than CON (P<0.05). The damaged egg ratio was not affected. The egg quality parameters (e.g., eggshell color, eggshell strength, albumen height, egg weight, and the Haugh unit) were affected by microbial phytase supplementation (P<0.05). However, there were no significant effects on the eggshell thickness and yolk color. In conclusion, microbial phytase supplementation to the diets of older hens could improve production performance, extend the peak laying period, and alter the egg quality parameters.     

Effects of supplementary iodine on the performance and egg traits of laying hens

1. This experiment was carried out to determine the effects of dietary iodine supplementation on the performance and egg traits of laying hens. A total of 600 SHSY type brown layers aged 21 weeks of age were chosen at random from a large flock. They were randomly distributed into 30 pens at 20 hens per pen. Each treatment comprised 6 replicates of 20 layers in groups of 5 birds. The diets were supplemented with 0, 3, 6, 12 and 24 mg/kg iodine as calcium iodate. The experimental period lasted 30 weeks. 2. There were no significant differences among the groups in body weight, food consumption, egg production, food consumption per kg eggs, eggshell index, eggshell breaking strength, shell thickness or egg yolk index. 3. Supplementation of the diet with 12 mg/kg iodine increased food consumption per dozen eggs compared to the groups fed on diets supplemented with 0 and 6 mg/kg iodine. 4. Egg weight was less in groups fed on diets supplemented with 12 and 24 mg/kg iodine than in the group receiving no iodine supplementation. 5. Iodine supplementation to provide 12 and 24 mg/kg reduced egg albumen index and egg Haugh units. 6. There were no significant differences among the groups in egg cholesterol and egg yolk cholesterol contents. 7. The iodine concentrations in egg yolk, egg albumen and whole egg increased with increased iodine supplementation. 8. As a result, the 3 and 6 mg/kg iodine supplementation of diet could be used to enrich the eggs with iodine without any adverse effect on performance and egg traits.     

Effect of dietary Rhodobacter capsulatus on lipid fractions and egg-yolk fatty acid composition in laying hens

The present study was conducted to investigate the effect of dietary Rhodobacter capsulatus on lipid fractions and egg‐yolk fatty acid composition in laying hens. Thirty‐six laying hens (30 weeks old) were randomly assigned into two dietary groups fed diets with (0.04%) or without (control) R. capsulatus for a 60‐day feeding trial. Dietary R. capsulatus decreased (p < 0.05) serum and hepatic cholesterol and increased (p < 0.05) the excreta cholesterol, and resultant lower (p < 0.05) cholesterol contents in egg yolk. The concentration of polyunsaturated fatty acids (PUFA) and ratio to saturated fatty acids in egg yolk was improved (p < 0.05) by dietary R. capsulatus. The concentration of hepatic bile acid was increased (p < 0.05) and excreta bile acid was decreased (p < 0.01) in the laying hens fed R. capsulatus diet. The incorporation of 1‐¹⁴C‐palmitic acid into hepatic lipids and lipid fractions was increased (p < 0.05) in laying hens fed R. capsulatus diet. Moreover, dietary R. capsulatus did not appear to cause any adverse effects on laying hen performances. Therefore, dietary supplementation of R. capsulatus in layer diets may be a feasible means of producing eggs with lower cholesterol and higher PUFA contents for health conscious consumers.     

Evaluating the nutritional value of date pits and demonstrating their application in laying hen diets

This experiment was carried out to study the feeding value of ground date pits (DP) (Phoenix dactylifera L.) with and without enzyme supplementation on laying hens’ performance. Apparent metabolizable energy value of DP was determined by the total collection method using 10 adult Leghorn cockerels. After that, a total number of 144 Lohmann 50‐week‐old LSL‐Lite hens were randomly allocated into six groups consisting of four replicates of six birds, based on a 3 × 2 factorial arrangement of the treatments. Six iso‐caloric and iso‐nitrogenous experimental diets including I‐corn–soya bean meal‐based control, II‐corn–soya bean meal oil‐based control and III‐ corn–soya bean meal‐based diet (180 g/kg DP) were formulated. Each of the diets was supplemented with two levels of an enzyme (0.0 and 0.07 g/kg Natozim Plus). The experiment lasted 10 weeks after 7 days of adaptation. The results revealed that there was no significant difference in feed intake, feed conversion ratio, egg production, egg mass, eggshell weight, eggshell thickness and Haugh unit among the treatments. Dietary inclusion of DP significantly decreased body weight gain (BWG), egg weight and yolk colour score. On the other hand, corn–soya bean meal‐based control diet with vegetable oil significantly increased egg weight and BWG of birds in comparison with other treatments. The serum biochemical metabolites were not affected by DP and enzyme supplementation. Thus, DP can be used as alternative feedstuff in laying hen diets, up to 18% of the diet with little effect on the performance of hens, including egg weight, and also, it had an adverse effect on yolk colour. Eventually, in terms of performance, the results failed to demonstrate any positive effect of Natozim Plus on either the controls or 18% DP diets.     

黑水虻幼虫粉对蛋鸡产蛋后期生产性能、蛋品质及血液生理生化指标的影响

本试验旨在研究饲粮中添加黑水虻幼虫粉对蛋鸡产蛋后期生产性能、蛋品质及血液生理生化指标的影响。选取60周龄、健康、产蛋率接近的海兰褐蛋鸡1080只,随机分为4组,每组6个重复,每个重复45只鸡,对照组饲喂基础饲粮,试验Ⅰ、Ⅱ、Ⅲ组在基础饲粮中分别添加1%、2%、3%的黑水虻幼虫粉。预试期7 d,正试期60 d。结果表明:1)与对照组相比,试验Ⅱ、Ⅲ组蛋鸡产蛋后期的产蛋率显著提高(P<0.05),料蛋比显著降低(P<0.05),试验Ⅲ组的破软蛋率显著降低(P<0.05)。2)饲粮中添加黑水虻幼虫粉对蛋鸡产蛋后期的蛋壳颜色、蛋形指数、蛋白高度、哈氏单位、蛋壳厚度、蛋壳强度、蛋黄相对重、蛋壳相对重及蛋黄胆固醇含量均无显著影响(P>0.05)。3)与对照组相比,试验Ⅱ、Ⅲ组蛋鸡产蛋后期血清中天冬氨酸氨基转移酶活性和葡萄糖含量显著提高(P<0.05),试验Ⅲ组血清高密度脂蛋白胆固醇含量显著提高(P<0.05),但饲粮中添加黑水虻幼虫粉对蛋鸡的血液生理指标和其他血清生化指标均没有显著影响(P>0.05)。由此可见,饲粮中添加黑水虻幼虫粉可提高蛋鸡产蛋后期的生产性能,改善血清生化指标,且不会对蛋鸡机体内环境稳态产生不良影响。     

Effect of dietary threonine on laying performance and intestinal immunity of laying hens fed low‐crude‐protein diets during the peak production period

Threonine (Thr) may be a limiting amino acid for laying hens fed diets with lowered protein level. An experiment was conducted to examine laying performance, and the intestinal immune function of laying hens provided diets varying in digestible Thr levels. Lohmann Brown laying hens (n = 480), 28 weeks of age, were allocated to six dietary treatments, each of which included five replicates of 16 hens. Dietary crude protein (CP) 16.18% diet was offered as the positive control diet. L‐Thr was added to the negative diet (14.16% CP) by 0, 1.0, 2.0, 3.0 and 4.0 g/kg, corresponding 0.44%, 0.43%, 0.49%, 0.57%, 0.66% and 0.74% digestible Thr. At 40 weeks, a reduction in CP level decreased laying performance (p < 0.05). In the low CP, increasing dietary Thr increased (p < 0.05) egg production and egg mass and rose to a plateau between 0.57% and 0.66%. The hens fed 0.66% Thr showed the lowest value (p < 0.05) of feed conversion ratio (FCR). Serum level of uric acid showed the lowest values (p < 0.05) at 0.57–0.66%. In addition, serum‐free Thr maximized (p < 0.05) between 0.66% and 0.74%. Digestive trypsin activity decreased (p < 0.05) when hens fed the low‐CP diet compared with hens fed CP (16.18%) and hens fed 0.57–0.66%. Expressions of ileal MUC2 mRNA maximized (p < 0.05) at 0.66% Thr. Occludin mRNA increased with increasing Thr level (p < 0.05). sIgA mRNA reached to the maximum level (p < 0.05) at 0.66% and 0.74% Thr. INF‐γ mRNA reached to the lowest level (p < 0.05) at 0.65%. Expressions of ileal IL‐2, IL‐6, IL‐1β mRNA decreased with increasing Thr level (p < 0.05). In conclusion, Thr supplementation resulting in optimal laying performance and stimulated the mucosal immune system, suggesting that it is a limiting amino acid in the low‐crude‐protein diet of laying hens during the peak production period.     

Effects of cerium oxide supplementation to laying hen diets on performance,egg quality,some antioxidant enzymes in serum and lipid oxidation in egg yolk

This study was conducted to determine the effects of dietary cerium oxide levels (0, 100, 200, 300 or 400 mg/kg) on the laying performance, egg quality, some blood serum parameters and egg lipid peroxidation of laying hen. In total, one hundred and twenty 22‐week‐old brown Lohman LSL laying hens were randomly assigned to five groups equally (n = 24). Each treatment was replicated six times. Dietary supplementation of cerium oxide had no significant effect on feed intake and egg weight. The addition of cerium oxide to the laying hens' feed improved feed conversion ratio and increased (p < 0.05) egg production. Quality criteria of egg for except shell breaking strength were not affected by supplementing cerium oxide. In particular, supplementation of 200 and 300 mg/kg cerium oxide to the laying hens feed led to a significant (p < 0. 01) increase in egg shell breaking strength. Calcium and phosphorus concentration of serum increased significantly (p < 0.05) with supplementation of 100 mg/kg cerium oxide to laying hen diets. It was also observed that serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentration decreased significantly with supplementation of cerium oxide in diets. Inclusion of cerium oxide resulted in a significant reduction in thiobarbituric acid reactive substance (TBARS) values in egg yolk in this study. It can be concluded that the addition of cerium oxide had positive effects on egg production, feed conversion ratio and egg shelf life. Based on the results of this study, it could be advised to supplement laying hens feed with cerium oxide as feed additives.     

维生素E对蛋鸡产蛋后期产蛋性能和蛋品质的影响

文章旨在研究日粮中不同梯度维生素E添加水平对蛋鸡产蛋后期产蛋性能和蛋品质的影响。试验选择60周龄罗曼白壳商品蛋鸡300羽,试验随机分为5组,添加水平分别为0(对照组),30、60、120、240 mg/kg,每组6个重复,每个重复10羽鸡,预试期1周,正试期8周。结果表明:与对照组相比,蛋鸡产蛋后期日粮中添加120 mg/kg的维生素E可显著提高蛋鸡产蛋后期产蛋性能(P<0.05);与对照组相比,蛋鸡产蛋后期日粮中添加120 mg/kg的维生素E可显著提高蛋壳硬度、蛋壳相对重、蛋黄相对重以及蛋黄颜色(P<0.05),蛋黄总胆固醇含量极显著降低(P<0.01)。综上所述,在蛋鸡产蛋后期日粮中添加120 mg/kg的维生素E可显著改善其产蛋性能和蛋品质。     

黄粉虫、小麦胚芽对初产蛋鸡生产性能、蛋品质和抗氧化机能的影响

试验旨在研究饲粮中添加黄粉虫、小麦胚芽对初产蛋鸡生产性能、蛋品质、蛋黄和血清抗氧化指标的影响。选用20周龄产蛋率基本一致且健康的京红蛋鸡560只,随机分为7组,每组4个重复,每个重复20只鸡;采用双因子试验设计,3个黄粉虫水平(0.5%、1.0%、2.0%)×2个小麦胚芽水平(1%、2%)。试验期为8周,其中预试期1周,正试期7周。结果显示:①黄粉虫和小麦胚芽对初产蛋鸡的蛋壳厚度、蛋黄颜色以及血清和蛋黄总抗氧化能力(T-AOC)活力、丙二醛(MDA)含量存在显著交互作用(P<0.05)。②在饲粮中添加黄粉虫对产蛋率、日采食量和料蛋比没有产生影响(P>0.05);对蛋重、蛋黄重、蛋壳厚度、哈氏单位和蛋黄颜色无影响(P>0.05),但能显著提高蛋壳强度(P<0.05);显著提高血清超氧化物歧化酶(SOD)活力、降低血清和蛋黄MDA含量(P<0.05),对蛋黄和血清的谷胱甘肽过氧物酶(GSH-Px)活力、T-AOC活力无显著影响(P>0.05)。③在饲粮中添加小麦胚芽对生产性能、蛋品质以及血清和蛋黄的抗氧化指标均无影响(P>0.05)。综合分析,黄粉虫和小麦胚芽协同提高初产蛋鸡的蛋品质和抗氧化能力,其中以同时添加2.0%黄粉虫和1.0%小麦胚芽的效果较好。     

Impact of supplementing diets with propolis on productive performance,egg quality traits and some haematological variables of laying hens

One hundred and twenty eight, 28‐weeks‐old Lohmann LSL hybrid layers were used in this experiment, which lasted 12 weeks to investigate the effect of propolis supplementation on the productive performance, egg quality traits and haematological variables of laying hens. All hens were randomly classified into four equal experimental groups, eight replicates (4 birds/each). Hens in group 1 were fed on a commercial diet and considered as control group, while those in groups 2, 3 and 4 were fed on the same commercial diet and supplemented with 250, 500 and 1000 mg propolis/kg diet. The obtained results revealed that daily feed consumption/hen increased insignificantly with increasing propolis level than that of the control group. Regarding the means of egg mass and egg production rate, it was observed that the laying hens fed diets containing 250 and 1000 mg propolis/kg significantly (p < 0.05) produced more and heaver egg in comparison with control group. External egg quality traits have not affected with increasing the level of propolis, while eggshell weight was significantly (p < 0.05) increased. The internal egg quality traits except albumen and yolk percentages increased significantly (p < 0.05) with increasing propolis level for treated hens as compared to those in the control. Concerning the haematological parameters, the results showed that the levels of total protein and globulin increased significantly with increasing propolis level, while cholesterol and liver enzymes were significantly decreased (p < 0.05). Heterophils count of hens in the treated groups significantly decreased, whereas the lymphocyte count significantly increased, resulting in a decreased H/L ratio than that of the control group. Thus, it could be concluded that the supplementation of 250 mg propolis/kg diet is highly recommended to improving egg production, blood constituent and haematological parameters of the commercial laying hens.     

Effect of dosage and application mode of l‐carnitine on plasma lipid and egg‐yolk cholesterol of turkeys,hatchability of eggs and post‐hatch growth of their offsprings

The effect of dosage and application mode of l ‐carnitine on plasma lipid and egg‐yolk cholesterol of breeder turkeys, hatchability of eggs and post‐hatch growth response was investigated using 180 breeder hens. The hens were assigned to six dietary treatments in a 2 × 3 factorial arrangements of two application modes of l ‐carnitine (diet and drinking water) supplemented at 0, 50 and 100 ppm (mg/kg or mg/l) levels, respectively. Each treatment was replicated five times with six hens per replicate. Dietary inclusion of 50 ppm l ‐carnitine showed the lowest (p < 0.01) plasma total cholesterol (TC) and low‐density lipoprotein concentration (LDL). Breeder hens offered 50 ppm l ‐carnitine with no regard to application mode recorded the highest (p < 0.01) plasma high‐density lipoprotein (HDL). Hens offered 50 and 100 ppm l ‐carnitine irrespective of application mode also showed reduced (p < 0.01) egg‐yolk TC concentration at 32 weeks of age. Dietary supplementation of 50 ppm l ‐carnitine for breeder turkeys recorded the lowest (p < 0.01) egg‐yolk triglyceride (TG) at 40 weeks of age. Hens offered 50 ppm l ‐carnitine irrespective of application mode recorded the highest (p < 0.05) hen‐day egg production. Incidence of dead‐in‐shell also reduced (p < 0.05) with increasing dosage of l ‐carnitine. Dietary supplementation of 50 ppm and oral application in drinking water of 100 ppm l ‐carnitine for breeder turkeys resulted in highest (p < 0.05) egg fertility. Offsprings from breeder hens fed diets supplemented with l ‐carnitine recorded no post‐hatch mortality. Highest (p < 0.05) post‐hatch final live weight and weight gain was obtained with poults obtained from hens fed diet supplemented with 50 ppm l ‐carnitine. In conclusion, dietary supplementation of 50 ppm l ‐carnitine for turkey hens showed improved serum lipid profile, egg fertility, reduced dead‐in‐shell, egg‐yolk cholesterol and resulted in improved post‐hatch growth performance.     

Effect of dietary karaya saponin on serum and egg yolk cholesterol in laying hens

1. The objective of the study was to investigate the effect of dietary karaya saponin on cholesterol deposition in laying hens. 2. A total of 40 Boris Brown hens were randomly assigned at 20 weeks of age to 4 treatment groups and fed on diets supplemented with 0 (control), 25, 50 or 75 mg/kg karaya saponin for an 8-week experimental period. 3. After 8 weeks of dietary supplementation, karaya-saponin-treated groups had significantly lower serum cholesterol (23·0%) and triglycerides but increased high density lipoproteins cholesterol concentration than controls, irrespective of karaya saponin content in the diet. Egg yolk cholesterol and triglycerides were also significantly reduced by dietary karaya saponin. Hepatic cholesterol and triglycerides were significantly reduced by karaya saponin but bile acids concentration in the faeces and liver were significantly increased by karaya saponin. The concentrations of oleic, linoleic and linolenic acids in the yolk were greater in hens receiving karaya saponin than in controls. Karaya saponin significantly increased egg production, feed efficiency and yolk colour compared with controls. Karaya saponin tended to increase egg weight, feed consumption, Haugh units, albumen weight and yolk index. 4. In conclusion, karaya saponin is a potential agent for reducing yolk cholesterol concentration together with an overall increase of production performance and improvement in egg quality.     

Effects of inulin on performance, egg quality, gut microflora and serum and yolk cholesterol in laying hens

1. The present study was conducted to investigate the effects of inulin on laying hens. A total of 360 Brown Nick laying hens were divided randomly into 6 groups of 60 with 6 replicates of 10 hens and fed on diets containing 0 (control), 0·1, 0·5, 1·0, 1·5 or 2·0% inulin during the 4-week trial. 2. Dietary supplementation of inulin reduced cholesterol concentration (mg/g yolk) and content (mg/egg) in eggs. Cholesterol content in eggs decreased linearly with increasing levels of dietary inulin level. 3. Supplementation of inulin in diets decreased coliform bacteria counts and pH in the caecum. The lowest coliform bacteria counts (6·30 ± 0·03 log10 cfu/g) and pH (6·47 ± 0·01) were obtained in the 2·0% inulin group, the two indices decreasing by 21·6% and 3·0% respectively, compared with the control group. Coliform bacteria count and pH were changed linearly in accordance with increasing levels of dietary inulin level. Caecal Bifidobacteria counts were increased in the 2·0%-inulin group. 4. Inulin supplementation of layer diets did not appear to have any adverse effects on laying rate, egg weight, feed intake, feed conversion efficiency, cracked-egg rate, eggshell thickness or Haugh unit compared with the control laying hens. 5. Therefore, dietary supplementation with inulin may lead to the development of low-cholesterol chicken eggs as demanded by health-conscious consumers.