The influence of handling on egg production,egg shell quality and avoidance behaviour of hens

1. Egg production was similar in non‐handled and in regularly handled hens, but was reduced by handling hens unaccustomed to the procedure.

2. Handling reduced avoidance behaviour (”flightiness“) in growers and pullets but its effect declined with age and it had no influence in these hens when mature.

3. Handling affected egg shell quality; it resulted in an increased incidence of cracks and of equatorial bulges. Previous work has suggested that this defect is an indication of stressors applied at a critical period during egg formation. Therefore, handling may be a stressor.     

Interrelationships between shell quality and egg production and egg and shell weights in white leghorn and white rock hens

Interrelationships between shell quality, production rate, egg and shell weights in relation to seasonal changes were compared in White Leghorn (WL) and White Rock (WR) hens. An increase in the average egg weight was observed in both breeds during the hot summer months. The weight and quality of the shell decreased gradually in eggs laid by WL hens, but increased in those from WR during the summer.

Significant negative correlation coefficients were found between shell quality and egg weight in only the WL, when analysed on the basis of individual averages for the entire experimental period and on weekly averages for the breed. No significant correlation was found between shell quality and production rate in WL hens. Great variabilities were obtained between individual birds regarding the correlations between shell quality and egg weight and between shell quality and production rate, when calculated on the basis of seasonal changes in both breeds.

Multivariate analysis, in which shell quality was correlated with the other variables in all combinations possible, supplied a wider explanation than the simple correlations calculated.

The differences between the two breeds are discussed.     

Effects of 1 alpha,25-dihydroxycholecalciferol on disuse osteoporosis in the dog: a histomorphometric study.

Disuse osteoporosis was produced in dogs by immobilization of the left rear limb in a plaster cast. The trabecular bone volume of the calcaneus was then determined following treatment with 1 alpha,25-dihydroxycholecalciferol for 4 weeks with oral dosages of 60 to 240 ng/kg of body weight. The trabecular bone volume percentage of the immobilized calcaneus was in direct relation to the dosage of 1 alpha,25-dihydroxycholecalciferol.     

乳酸锌对蛋鸡生产性能及蛋壳质量的影响

为研究乳酸锌对蛋鸡生产性能及蛋壳质量的影响,试验采用单因子随机分组试验设计,选取1600只360日龄的罗曼粉壳蛋鸡,随机分为4个处理组,每个处理组8个重复,每个重复50只鸡。础饲日粮为玉米-豆粕型粉状饲粮,处理1组饲喂基础饲粮+60 mg/kg一水硫酸锌(以锌计),处理2组饲喂基础饲粮+60 mg/kg乳酸锌(以锌计),处理3组饲喂基础饲粮+40 mg/kg乳酸锌(以锌计),处理4组饲喂基础饲粮+60 mg/kg锌(一水硫酸锌和乳酸锌提供的锌各一半)。结果表明,蛋鸡日粮中添加60 mg/kg乳酸锌(以锌计)能显著降低平均破蛋率、提高平均蛋壳强度(P<0.05)和明显提高平均蛋壳厚度,并且平均死亡率最低,但对蛋鸡的平均产蛋率、平均蛋重、平均日采食量和平均料蛋比无显著影响(P>0.05)。     

鲎素抗菌肽对蛋鸡产蛋后期蛋品质及蛋壳超微结构的影响

旨在探索鲎素抗菌肽对海兰褐蛋鸡产蛋后期蛋品质及子宫CaBP-D28k mRNA表达量的影响及其机理探讨。随机选取600只385日龄海兰褐蛋鸡,分为对照组、试验组,每组各3个重复,每个重复100只鸡。对照组饲喂基础日粮,试验组在基础日粮中添加鲎素抗菌肽,鲎素抗菌肽发酵液最适添加剂量为0.01 L/kg,按饲料所需量配比添加,预饲期7 d,试验期35 d。结果显示,与对照组相比,试验组产蛋率提高8.86%(P0.05),料蛋比、破蛋率分别降低2.68%和12.76%(P0.05);试验组蛋壳强度比对照组提高了18.97%(P0.05),哈氏单位、蛋壳相对质量和蛋壳厚度均有上升的趋势;试验组蛋壳表面皴裂纹数较少,裂隙变小,纵切面结构中垂直晶体层完整,栅栏层结构整齐,上下层面平滑,栅栏层气孔数量少,乳头层乳头数目少且宽;试验组蛋鸡子宫内CaBP-D28k mRNA表达水平显著提升(P0.01)。可见,鲎素抗菌肽可提高CaBP-D28k参与产蛋过程中钙的代谢过程,调控蛋鸡体内钙代谢发挥功能作用。     

Studies on egg shell strength,shell stiffness,shell quantity,egg size and shape

Physical properties which included shell stiffness, egg weight, width and length, shell weight and thickness, percentage shell, shell weight per unit area, shape index and roundness were studied in relation to maximum force and energy absorbed at failure in 2733 eggs produced by sixty SCWL pullets. Pooled‐egg, bird‐average and individual‐bird bases were used for correlation and regression analyses.

All physical properties in combination accounted for 61.9 and 88.2 per cent of the variation in force and 19.6 and 59.5 per cent of energy absorbed at failure in pooled‐egg and bird‐average analyses respectively. The non‐destructive measurements of shell stiffness, egg size and shape gave R ² values of 60.5 and 86.9 per cent with force and 16.2 and 55.0 per cent with energy in corresponding analyses.

Shell stiffness proved to be the most important predictor of force at failure. Analyses in which variation of shell stiffness was explained by other physical properties supported the conclusion based on theories of elasticity applied to shell structures that shell stiffness was largely an indirect measurement of egg shell quantity together with lesser effects of egg size and shape.

Bird‐to‐bird variation in relations between physical properties and shell strength was evident from individual bird analyses. Coefficients of determination from force at failure regressed on shell stiffness had a mean value of 0.455 with a standard deviation of 0.178 (n = 60).     

乳酸锌对蛋鸡生产性能及蛋壳质量的影响

本试验旨在研究乳酸锌对蛋鸡生产性能及蛋壳质量的影响。试验采用单因子随机分组试验设计,选取1600只360日龄的罗曼粉壳蛋鸡,随机分到4个处理组,各处理组8个重复,每个重复50只鸡。基础饲粮采用为玉米－豆粕型粉状饲粮,处理1饲喂基础饲粮＋60mg／kg－水硫酸锌（以锌计）,处理2饲喂基础饲粮＋60mg／kg乳酸锌（以锌计）,处理3饲喂基础饲粮＋40mg／kg乳酸锌（以锌计）,处理4饲喂基础饲粮＋60mg／kg锌（－水硫酸锌和乳酸锌提供的锌各一半）。试验结果表明,在产蛋鸡饲粮中100％以乳酸锌替代硫酸锌（提供的锌含量为60mg／kg）,能显著降低平均破蛋率,提高平均蛋壳强度和平均蛋壳厚度（P〈0．05）,死亡率最低,对蛋鸡的平均产蛋率、平均蛋重、平均日采食量和平均料蛋比无显著影响（P〉0．05）。     

Effects of an induced pause in egg production and supplementation of the diet with iron on egg shell colour,quality and performance of brown egg layers

1. A pause in egg production was induced in brown‐egg laying hens, aged 68 weeks, by feeding them whole oats for 7 d. Subsequently, these hens, together with control groups, were given laying diets with either 400 or 600 mg/kg iron. The 200 mg/kg of supplemental iron was added in the form of either ferrous sulphate or iron proteinate (chelated iron).

2. The feeding of whole oats halted egg production in 5.7 ±0.22 d and the duration of the pause was 8.3 ±0.78 d.

3. The induction of a pause improved the subsequent rate of egg production, egg output, efficiency of food utilisation, albumen quality, egg specific gravity and shell colour. It also increased food intake and body weight gain but neither egg weight nor the rate of mortality were affected.

4. Neither supplementation of the diet with iron nor its source had any significant effect on laying performance, egg quality or shell colour.     

合生素对蛋鸡生产性能及蛋品质的影响

在我国传统养殖生产中,抗生素一直被用作饲料添加剂来控制畜禽疾病和提高生产性能。但随着抗生素的大量使用,其带来的负面影响日趋严重。药物残留和耐药菌株的产生及畜禽产品质量的下降,已对畜牧业可持续发展和人类健康带来严重的影响。研制开发无公害和无残留的饲料添加剂替代     

牛磺酸对产蛋后期母鸡生产性能的影响

试验采用 14 4只 5 6周龄海兰褐蛋鸡 ,研究添加不同水平的牛磺酸对产蛋后期母鸡生产性能和蛋壳品质的影响。试验结果表明 :添加 0 .0 5 %的牛磺酸能够提高蛋鸡的产蛋率、平均蛋重 ,并且可以降低蛋鸡的日采食量和料蛋比 ,对蛋壳品质也有一定的影响。     

大豆黄酮对产蛋鸡蛋壳品质和骨骼代谢的影响

大豆黄酮(Daidzein)属于异黄酮类植物雌激素(Isoflavonic phytoestrogen)，主要存在于豆科的蝶形花亚科植物中。20世纪90年代以来，国外流行病因学研究证明，膳食中的异黄酮具有防癌和抗癌的作用，使人类乳腺癌、结肠癌发病率降低，近年来动物营养研究表明大豆黄酮具有促进动物生长，增加产     

Effect of yeast cell wall supplementation in laying hen feed on economic viability,egg production,and egg quality

Yeast cell walls can strengthen the immune system and promote agglutination of gastrointestinal tract pathogens, thereby improving animal health and productivity. This study evaluated the effect of supplementing the diet of commercial laying hens with 0, 225, 450, or 900 ppm of yeast cell wall supplement on hen productive performance, egg quality, and economic viability. Yeast cell wall supplementation increased the feed intake, egg production, egg mass, albumen height, and Haugh unit score. Shell thickness and yolk color also were affected by the treatments. The economic viability analysis demonstrated that although feeding costs more with supplementation, the production of more eggs is possible, resulting in a greater than proportional increase in the gross margin. Thus, yeast cell wall supplementation had beneficial effects on the productive performance of laying hens, improved the internal and external egg quality, and contributed to greater profitability.     

使用氯霉素对种鸡产蛋性能及种蛋质量的影响

在种鸡饲养管理过程中,特别是在种蛋使用阶段,由于人工授精,很容易造成肠道疾病的发生与传播.因此需定期投药加以预防.由于氯霉素对沙门氏菌、大肠杆菌等细菌敏感性较高,故氯霉素常作为种鸡常用药物之一.但是关于氯霉素对种鸡受精率的不利影响时有报道,众说不一,影响了该药在种鸡生产中的正常使用.为此,我们对使用氯霉素对种鸡产蛋性能及种蛋质量的影响进行了试验研究,现将试验情况报告如下.     

Parental diet effects on egg component weights and shell quality

An experiment was conducted to investigate the effects of feeding laying hens a low protein and energy diet (LPE), a high protein and energy diet (HPE), and a commercial protein and energy diet (control) on whole egg components, egg weight, and shell quality. The hens were fed their respective diets from 15 to 30 wk of age. At 30 wk of age, egg component weight and percentages were measured along with eggshell quality. The results demonstrated that birds fed the LPE diet had significantly lower albumen, yolk, and total egg weights that the control and HPE groups. The LPE group had significantly lower levels of total albumen protein than the control group. The HPE hens had significantly lower shell thickness and pore concentration than the LPE group, demonstrating that dietary levels of CP and ME can alter not only shell quality component but also albumen protein levels.     

The application of shell strength measurements in egg shell quality determination

Comparisons of shell thickness, specific gravity and shell strength (breaking strength and shell deformation under load) for individual loads have been made and correlation coefficients determined. The relationship between egg size, shell strength and shell deformation have been investigated.

Shell strength has been correlated with shell thickness and specific gravity, but due to the complex nature of shell strength, it has been concluded that for routine work the measurement of shell thickness either indirectly or by specific gravity or by direct shell thickness measurement gives the most practical indication of shell quality.     

茶皂素对蛋鸡生产性能、蛋品质和养分利用率的影响

试验旨在研究饲粮中添加不同水平茶皂素对蛋鸡生产性能、蛋品质和养分利用率的影响.选取600只40周龄健康的海兰褐商品蛋鸡,随机分为4组,每组6个重复,每个重复25只鸡.对照组饲喂基础饲粮,试验组在基础饲粮中分别添加100、200、300 mg/kg的茶皂素.预试期7d,正式试验期56 d.结果表明:与对照组相比,100、...     

饲粮添加生姜粉对蛋鸡生产性能和蛋品质的影响

试验旨在探讨饲粮添加不同水平的生姜粉对蛋鸡生产性能和蛋品质的影响。选取27周龄罗曼褐壳蛋鸡120只,随机分为4组,每组设3个重复,每个重复10只。对照组饲喂基础饲粮,试验组分别添加0.5%、1.0%、1.5%的生姜粉。预饲期7 d,试验期4周。结果表明:饲粮中添加适量的生姜粉可以提高蛋鸡的平均日产蛋量和试验3~4周的产蛋率以及试验1~2周的平均蛋重(P<0.05)。饲粮中添加适量生姜粉能够提高鸡蛋的哈夫单位和蛋比重(P<0.05)。结果提示,饲粮中添加生姜粉可提高罗曼褐壳蛋鸡的生产性能和蛋品质,以1.0%生姜粉为最适添加量。     

矿物质和维生素与蛋壳品质的关系

蛋壳平均含有机物质 4％、碳酸钙 93％、碳酸镁 1％、磷酸钙和磷酸镁 2.8％。蛋壳质量指标包括蛋比重、壳重、蛋壳变形值、蛋壳厚度、蛋壳抗裂强度及单位表面积的壳重等。无论种蛋还是商品蛋，每年因蛋壳质量而引起的损失相当大。营养是影响蛋壳品质的重要因素，本文将着重阐述营养因素中矿物质和维生素与蛋壳品质的关系。 1矿物质 1.1钙 　　日粮钙的供应水平是影响蛋壳质量的决定因素，它决定蛋壳的脆性。成年母鸡每日维持需摄入钙 0.17g，产一枚蛋需钙 2.0g～ 2.2g，而产蛋前半期钙的吸收率为 55％～ 60％，产蛋后期减至 40％，故每产一…