Comparison of the effects of dietary supplementation of flavonoids on laying hen performance,egg quality and egg nutrient profile

1. The aim of this experiment was to compare the effects of dietary supplementation of hesperidin, naringin and quercetin on laying hen performance, egg quality and egg yolk lipid and protein profiles.

2. A total of 96 Lohmann White laying hens weighing an average of 1500 g at 28 weeks of age were randomly assigned to a basal diet and the basal diet supplemented (0.5 g/kg) with either hesperidin, naringin or quercetin. Each treatment was replicated in 6 cages in an 8-week experimental period. Data were analysed using one-way analysis of variance.

3. None of the dietary flavonoids affected laying performance and eggshell quality. Hesperidin and quercetin supplementations decreased albumen and yolk indexes.

4. As compared to the control group, egg yolk cholesterol content decreased and egg yolk protein content increased in response to dietary hesperidin and quercetin supplementation. The mean egg yolk cholesterol (mg/g) and protein (g/100 g) contents were 10.08/14.28, 16.12/14.08, 14.75/15.04 and 15.15/14.85 for the control group and groups supplemented with naringin, hesperidin and quercetin, respectively.

5. Egg yolk lipid and protein profiles were variable.

6. In conclusion, dietary supplementation of hesperidin or quercetin could be used in the diets during the early laying period to reduce egg yolk cholesterol and increase egg yolk protein, which may be attractive to consumers.     

Effect of age of the laying hen on the composition of the egg

1. All eggs laid by a group of 16 light‐body‐weight hens during the laying year were weighed and divided into yolk, albumen and shell and the wet and dry weights of the components determined.

2. After an initial period of about 2 months, the weights of egg, water, wet albumen, wet and dry yolk increased with age, whereas those of dry albumen and wet and dry shell remained constant. Dry shell per square centimetre surface area decreased with age but water per square centimetre surface area remained constant.     

蛋鸡产蛋性能和蛋壳品质耐受低水平磷的应用研究

本研究选择健康49周龄褐壳蛋鸡1296只,随机分为6组,每组2个重复,每个重复108只。A为对照组,含0.20%有效磷(AP)和0.9‰植酸酶;B、C、D、E、F组分别含AP0.16%、0.12%、0.20%、0.16%和0.12%,其中B、C组添加0.9‰植酸酶。试验期8周。结果显示,试验4、6、8周和试验全期,F组比对照组产蛋率分别降低6.67%、7.78%、7.87%和6.67%,差异均显著(P0.05);各组平均蛋重和采食量无显著差异;试验6、8周和试验全期,F组料蛋比较对照组分别高10.19%、11.30%和8.00%,差异均显著(P0.05)。8周试验全期,C、D、E、F组软破蛋率和各组斑蛋率均高于对照组(P0.05);F组出现9只瘫鸡,其他各组均没有出现。提示日粮AP降至0.12%时,对蛋鸡产蛋性能、蛋壳品质自第3～4周开始产生影响。     

The effects of dietary calcium iodate on productive performance,egg quality and iodine accumulation in eggs of laying hens

The aim of this study was to examine the effects of various levels of supplemental calcium iodate (CI) on productive performance, egg quality, blood indices and iodine (I) accumulation in the eggs in commercial laying hens. A total of 240 White Leghorn layers (Hy‐line W36) were divided through a completely randomized design into six treatments with five replicates and eight hens per each at 32 weeks of age. This experiment lasted for 12 weeks. Concentrations of I in the mash diets were 0.74, 3.13, 5.57, 8.11, 10.65 and 12.94 mg I/kg of feed in treatments 1–6 respectively. The added doses of CI were included 0.0 (control), 2.5, 5.0, 7.5, 10.0 and 12.5 mg/kg of diet for treatments 1–6 respectively. There were no significant differences in productive performance among the treatments. The highest eggshell strength was observed in group fed diet containing 3.13 mg I/kg (p = .014). The highest percentage of calcium and lowest percentage of phosphorus in eggshell were observed in group fed diet containing 12.94 mg I/kg (p = .0001). Feeding hens with diet containing 12.94 mg I/kg increased serum triiodothyronine‐to‐thyroxine ratio (p = .0001). Serum alanine aminotransferase activity in hens fed diet containing 12.94 mg I/kg was significantly more than control (p = .041). Blood Serum triglycerides in hens fed diet containing 8.11 mg I/kg were significantly higher than control (p = .0001). Edible fraction of the eggs of birds fed diet containing 12.94 mg I/kg was enriched by I almost 3 times more than those fed diet containing 0.74 mg I/kg. The results suggested that egg production, egg mass, feed intake and feed conversion ratio were not significantly affected by dietary I levels. Iodine accumulation in the eggs were increased by increasing dietary I levels and the level of 10 mg/kg CI could supply I enrichment of the eggs.     

Influence of dietary magnesium content on laying performance and egg shell magnesium content in the domestic hen

1. The effects of feeding diets containing various amounts of magnesium on laying performance in the domestic hen were investigated.

2. A reduction in egg number, egg mass, egg shell thickness and egg shell magnesium content occurred in birds receiving diets containing either 207 or 132 mg Mg²⁺/kg even though the duration of egg formation was unaffected.

3. The progressive increase in magnesium content normally observed towards the outer surface of the hen's egg shell was not present in birds receiving a diet containing 207 mg Mg²⁺/kg.     

Regulation of plasma oestrogen by dietary fats in the laying hen: Relationships with egg weight

1. Feeding a diet supplemented with maize oil was found to elevate plasma oestradiol concentration in laying hens.

2. In a larger‐scale experiment, isoenergetic and isonitrogenous diets containing 10, 20, 40 or 60 g/kg supplemental maize oil, tallow, coconut oil or fish oil were fed for 5 weeks.

3. Egg weights showed very different responses to the different fats. The responses could be described by quadratic functions that all gave optimum responses with supplemental dietary fat concentrations of about 40 g/kg. Egg weight increased the most with maize oil and was decreased with fish oil at the highest inclusion rate.

4. Measurements of egg components showed a relatively larger increase in albumen weights with maize oil than with other fats.

5. Across treatments, mean plasma oestradiol concentrations were very highly correlated (r = 0.96) with the changes in egg weights over the experimental period.

6. It is concluded that oestrogen is important in controlling egg weight and that the effect of dietary fats in influencing egg weight is mediated by an effect of the fats on oestrogen metabolism.     

饲料代谢能水平对农大3号小型蛋鸡生产性能的影响

180只140日龄的农大3号小型蛋鸡随机平均分为A、B、C、D、E五组,每组6个重复,每个重复6只鸡,体重大小基本一致,各组间生产性能差异不显著。分别饲喂代谢能水平11.5MJ/kg、11.3MJ/kg、11.1MJ/kg、10.9MJ/kg和10.7MJ/kg的饲料,其他营养成分含量设计上保持一致。通过30周的观察,发现在产蛋高峰前饲喂稍低能值的饲料(10.9MJ/kg)有利于采食量的增加和产蛋率的迅速上升。在一定饲料代谢能值范围内,饲料能值的高低对小型蛋鸡采食量影响不显著,所以从产蛋高峰期开始,必须使用代谢能水平较高的日粮,才能满足小型蛋鸡维持高产蛋率对能量的需求。综合来看,饲料代谢能为11.3MJ/kg时,小型蛋鸡有较高的产蛋量和饲料报酬。     

微生态制剂和异麦芽低聚糖对产蛋鸡产蛋性能和免疫力的影响

324只36周龄蛋鸡按3×3二因子完全随机设计分成9组,每组6个重复。微生态制剂添加水平为0%、1%和2%,异麦芽低聚糖的添加水平为0%、0.1%和0.2%。结果表明,添加1%或2%微生态制剂组蛋鸡平均日产蛋量均显著高于未添加组(P<0.10)。添加0.2%异麦芽低聚糖组蛋鸡日产蛋量显著高于未添加异麦芽低聚糖组和添加0.1%异麦芽低聚糖组(P<0.10)。添加0.1%或0.2%异麦芽低聚糖组料蛋比均低于未添加异麦芽低聚糖组(P<0.10)。添加2%微生态制剂组血清总SOD显著高于未添加微生态制剂组或添加1%微生态制剂组(P<0.10)。添加0.1%或0.2%异麦芽低聚糖组血清总SOD显著高于未添加组(P<0.10)。随微生态制剂和异麦芽低聚糖添加水平的提高,血清中IgA、IgM、IgG、C_3、C_4含量均有提高的趋势。     

Effect of magnesium deficiency in the hen on egg production and hatchability of eggs

The influence of the level of magnesium (Mg) in the ration on reproduction by the hen was studied in 2 experiments. In experiment 1, it was found that feeding a semi‐purified ration, containing 56 p.p.m. of Mg, resulted in decreased egg production and reduced serum Mg concentration within 10 to 14 days. Although fertility of eggs was not affected noticeably by Mg deficiency, hatchability of fertile eggs was decreased markedly. The influence of inadequate dietary Mg was partially alleviated by adding 250 p.p.m. Mg to the ration. In experiment 2, a decline in hatchability preceded decreases in egg production and food consumption. A decrease in Mg concentration in egg contents accompanied the decline in hatchability. Hens fed rations containing 50 or 150 p.p.m. added Mg produced eggs of relatively low hatchability by day 14 of the trial. Subsequent to being fed a ration containing 550 p.p.m. added Mg, these hens increased in rate of egg production while hatchability of fertile eggs also increased. The results indicate that the dietary Mg requirement of the laying hen, sufficient to maintain a high rate of production of eggs which hatch satisfactorily, is 400 or more p.p.m.     

当归补血散对高龄蛋鸡生产性能及蛋品质的影响

120只390日龄海兰褐蛋鸡,随机分为4组。以日粮中分别添加0.5%、1%、1.5%剂量的当归补血散饲喂Ⅰ、Ⅱ、Ⅲ组鸡群,Ⅳ组为对照组。连续给药15 d。分别观察各组每天的产蛋率、日产蛋量等生产性能指标;于第8、15、22、30天各组随机收集10枚蛋测蛋品质指标。结果:试验组Ⅱ、Ⅲ的产蛋率比对照组提高了8.80%(P<0.01)、4.99%(P<0.05);日产蛋量均与对照组差异极显著(P<0.01),分别提高了12.12%、6.82%;料蛋比与对照组相比降低了12.46%(P<0.01)、11.42%(P<0.05)。Ⅱ组的蛋形指数与对照组有显著提高(P<0.05);Ⅰ和Ⅱ组的蛋壳厚度与对照组有显著提高(P<0.05)。其余指标与对照组差异不大(P>0.05)。结论:1%剂量可以明显提高高龄蛋鸡的生产性能和蛋品质。     

Effects of beak trimming and cage design on laying hen performance and egg quality

1. Conventional cages are to be replaced by furnished cages or aviary systems to improve the welfare of hens. We compared the performance and egg quality of hens reared in two designs of furnished cages and of two standard cages. We also explored the consequences of the absence of beak trimming when using these designs. 2. Hens (2028) were housed from 18 to 70 weeks of age in 108 standard cages at 6 per cage (60 cmx63.5 cm), in 96 cages at 5 per cage (59.5 cmx55.5 cm) or in two designs of furnished cage at 15 per cage (24 F15M cages and 36 F15P cages made by two manufacturers) which contained equipment varying in size and location (nests, dust baths and perches). Half of the hens were beak-trimmed in each design. 3. Mortality was low in beak-trimmed hens (<5%) but was unacceptably high in non-beak-trimmed hens due to cannibalism (>40%, 516 hens). Mortality was worse in standard cages than in furnished cages. Consequently, hen-housed egg production was significantly lowered in non-beak-trimmed hens. 4. Egg laying in beak-trimmed hens reared in furnished cages occurred mainly in the nest (80 and 84.8% in F15M and F15P) but also in the dust bath (13.3 and 9.4% in F15M and F15P) and in other parts of the cage (6.7 and 5.8% in F15M and F15P). 5. The total percentage of broken (visual observation) and hair-cracked eggs (candling) was high in the furnished cage designs (15.4 and 19.6% in F15M and F15P, respectively) compared with standard cage designs (8.1 and 12.2% in S6 and S5). This was mainly due to hair-cracked eggs, the highest percentages occurring in the nests, especially in the design with a narrow nest and no egg saver (11.1% in F15M compared to 17.6% in F15P) as a consequence of egg accumulation in the cradle and relatively low frequency of manual egg collection. 6. Eggshell quality (index and breaking strength) was only slightly influenced by cage effects so differences in egg breakage were attributable to impacts related to cage design. 7. It is concluded that beak trimming remains the most effective way to prevent cannibalism, although furnished cages with a large group of hens slightly reduced the incidence, and that further development and optimisation of furnished cages is needed to reach egg quality similar to standard cages.     

蛋氨酸硒对产蛋鸡生产性能的影响及其在鸡蛋中沉积效率的研究

硒 (Ｓｅ)是人和动物一种必需微量元素 ,是谷胱甘肽过氧化物酶的组成成分 ,对于消除体内存在的自由基 ,保护细胞膜的正常功能。近年来研究表明 ,硒有抗癌、防癌、保护心脏、防治白内障、防治克山病和大骨节病、延缓衰老等功能。目前我国约有 1亿人的饮食中缺硒或低硒 ,通过富硒食品 (如富硒蛋 )来补充硒是比较安全有效的途径之一。富硒蛋的生产 ,以往多采用在饲料中添加高剂量的无机硒 ,本试验比较无机硒和有机硒对产蛋鸡生产性能的影响 ,以及对不同硒源在蛋中的沉积效率。1　材料与方法1 1　试验设计　采用单因子试验设计 ,设 3个处理 ,处…     

Effects of dietary supplementation with Gynura procumbens (Merr.) on egg yolk cholesterol,excreta microflora and laying hen performance

1. The present study investigated the effects of dietary supplementation with Gynura procumbens on egg yolk and serum cholesterol and triglycerides, excreta microflora, laying performance and egg quality.

2. A total of 160 Hy-Line Brown layers (45 weeks old) were randomly assigned into 4 treatments on the basis of laying performance. Each treatment had 4 replicates with 10 birds each.

3. Dietary treatments were basal diet supplemented with 0 (control), 2.5, 5.0 and 7.5 g/kg diet G. procumbens during 56-d feeding period.

4. Serum (d 21, 42 and 56) and egg yolk (d 28, 42 and 56) cholesterol and triglycerides concentrations were linearly reduced with increasing dietary concentrations of G. procumbens.

5. Increasing dietary concentrations of G. procumbens linearly reduced the excreta total anaerobic bacteria (d 28), Clostridium sp. and Escherichia coli (d 28 and 56) populations.

6. Overall egg production and egg mass were linearly increased, and overall feed efficiency was linearly improved with increase in dietary G. procumbens.

7. Dietary increasing concentrations of G. procumbens linearly improved egg yolk colour (d 28 and 56) and breaking strength of eggs (d 56).

8. The results obtained in the present experiment indicate that dietary supplementation with G. procumbens could reduce the egg yolk cholesterol, suppresses harmful excreta microflora and improves layers performance.     

An experimental study of the utilisation, by the laying hen, of dietary energy partially supplied as animal fat

Experiments were carried out at two centres in which laying hens were fed diets containing up to 28.25 per cent tallow and in which an attempt was made to maintain a fairly constant calorie : protein ratio. The most satisfactory production was obtained on a diet containing 3.5 per cent added fat in one experiment and 7.5 per cent added fat in the other experiment. Food conversion efficiency (kg food/kg eggs) increased with increasing dietary fat content.

The efficiency of ME utilisation (Mcal/kg egg) decreased with increasing dietary ME content. The data indicate that at the higher levels of fat addition the net utilisation of ME was decreased.

In both experiments mean egg weight was increased by the addition of tallow to the diet whilst at the highest level of addition there was a very high mortality.     

The effects of exogenous oestrogen and progesterone on laying and nesting behaviour in the hen.

1. It has been shown that if oestrogen and progesterone are given to ovariectomised hens nesting behaviour will occur. Thus if these hormones are given to normal hens the excessive pacing found in some hens before laying might be reduced. 2. Experiments showed that oestrogen produced no noticeable effects and progesterone caused a high incidence of delayed oviposition and abnormal behaviour.     

Effect of size and timing of photoperiod increase on age at first egg and subsequent performance of two breeds of laying hen

1. ISA Brown and Shaver 238 pullets were changed from 8 h to 8, 10, 13 or 16 h photoperiods at 42, 63, 84, 105, 126 or 142 d of age.

2. Age at first egg (AFE) was curvilinearly affected by the size and timing of the change in photoperiod. AFE was advanced most by a photoperiod change from 8 to 13 h made at 63 or 84 d. ISA birds were generally more responsive than Shaver to the photoperiod changes.

3. Longer photoperiods significandy increased survivors' egg production, but decreased liveability to 504 d, so that eggs per hen housed were unaffected. Retarding AFE by 10 d reduced survivors' egg numbers by 7.0, but increased mean egg weight by 1.26 g. Egg output by Shaver birds was unaffected by AFE, but that of ISA was curvilinearly affected, with an apogee at an AFE of 135 d. In both breeds, egg weight and egg output were greater following an early or late, rather than a mid‐term photostimulation.

4. Photoperiod significandy increased mean daily food intake during lay by 1.26 g/h. A 10 d retardation in AFE resulted in a reduction in food intake of 1 g/d. Efficiency of food conversion deteriorated according to the square of the photoperiod, and changed curvilinearly according to age at photostimulation. Food conversion efficiency improved by 0.05 g/g for each 10 d delay in AFE.

5. Shell quality was unaffected by AFE, but deteriorated with increasing photoperiod and was curvilinearly affected by age at photostimulation with the smallest shell weights associated with photostimulation at 63 d. The incidence of double‐yolked (DY) egg production increased with photoperiod and decreased with delayed photostimulation. There was an exponential regression of DY eggs on AFE.

6. Body weight at first egg increased by 75 g/d delay in AFE, but body weight at 504 d of age was unaffected by AFE, photoperiod or age at photostimulation. Body weight gain during lay increased by 15 g/h increase in photoperiod, decreased by 6 g per 10 d delay in photostimulation and by 40 g per 10 d delay in AFE. Fat content at 504 d increased by about 10 g/kg and by 23 g/bird for each 10 d delay in AFE.

7. Mortality in lay increased by 0.8%/h increase in photoperiod, but was unaffected by either age at photostimulation or AFE.