Bacterial eggshell contamination in conventional cages, furnished cages and aviary housing systems for laying hens

The influence of housing system on the initial bacterial contamination of the eggshell was studied. Two long-term experiments were performed. Bacterial eggshell contamination, as expressed by total count of aerobic and Gram-negative bacteria, was periodically analysed for eggs from a conventional cage, a furnished cage with nest boxes containing artificial turf or grids as nest-floor material and an aviary housing system. Results were log-transformed prior to statistical analyses. For both experiments no systematic differences were found between the conventional cage and furnished cage. The type of nest-floor material in the nest boxes of the furnished cages also did not systematically influence the bacterial contamination. A possible seasonal influence on contamination with a decrease in the winter period (up to > 0.5 log cfu/eggshell) of total count of aerobic and Gram-negative bacteria was observed in the first experiment. The contamination with total aerobic flora was higher (more than 1.0 log) on eggs from the aviary housing system compared to the conventional and the furnished cage systems. For Gram-negative bacteria this was not the case. During the entire period of both experiments, independent of housing system, shell contamination was not influenced by age of hens or period since placing the birds in the houses. For the total count of aerobic bacteria a restricted positive correlation (r2 = 0.66) was found between the concentration of total bacteria in the air of the poultry houses and initial shell contamination.     

Selection for egg shell strength in laying hens using shell membrane characteristics

1. Divergent selection for attachment strength between the shell membrane and the calcium shell was performed in a White Leghorn strain. Multivariate analysis was used to estimate genetic parameters for shell membrane measurements and shell thickness. The aim was to investigate the possibility of improving shell strength in laying hens by selecting for increased attachment strength.

2. A significant direct selection response for attachment strength was achieved. There was a favourable correlated selection differential in the frequency of cracked eggs which resulted in a nonsignificant but favourable, correlated response. Selection for a strong attachment resulted in a thinner egg shell, and vice versa. Heritabilities were all relatively high (0.30 to 0.70). Most of the genetic correlations were in agreement with the achieved correlated responses.

3. Two factors that probably contributed to the responses in egg shell thickness were an unfavourable genetic correlation between attachment strength and shell thickness, and natural selection against changes in attachment strength, in the form of increased mortality during incubation and hatching. Problems connected with breeding for increased shell strength are discussed.     

Occurence of salmonellae in laying hens in different housing systems and inferences for control

As eggs represent now as ever the most important source for Salmonella infection in human beings and because of the currently occurring shift in housing conditions for laying hens from conventional cages to alternative systems it was studied whether the Salmonella prevalence in layers is influenced by the housing system. Following systems were considered: organic farming with free range management systems, floor management systems with free range, floor management systems without free range, conventional cages. 453 pooled faecal samples as single or double examination per herd from 329 flocks in different housing systems for table egg production from three Federal Lander were examined bacteriologically. The share of layer flocks which were Salmonella positive at least once independently of the housing system amounted to 32.2%. Analysis of the Salmonella findings in the single housing systems revealed that the share of Salmonella positive flocks was higher in conventional cage systems (46.3%) than in alternative housing systems (32.996% in organic farming with free range management systems, 21.9% in floor management systems with free range, 23.4% in floor management systems without free range).The results of the study clearly show that Salmonella Enteritidis (mostly phage type 4, other phage types rarely) presents with a share of 78% the dominant serovar in laying hens.The total number of all other serovars (apart from Salmonella Enteritidis and subspecies I rough) reached a share of ca. 14%, however, no other single serovar was dominant. As Salmonella Enteritidis is the predominant serovar in laying hens it is strongly recommended to use Salmonella Enteritidis vaccines for immunisation programmes of chickens during the rearing period. Because of the high prevalence of Salmonella organisms in the different housing systems, detailed information on the epidemiology of Salmonella in laying hens are needed to introduce effective control measures. Of particular interest is the question whether the Salmonella findings in laying flocks are the result of multiplication of already existing Salmonella organisms in the animals or whether the bacteria are introduced only during the laying period.     

Multi-factorial investigation of various housing systems for laying hens

1.?The advantages and disadvantages of various housing systems for laying hens were compared as a pilot study for work in commercial conditions.

2.?At 16 weeks of age, 284 hens were introduced into one of 6 housing systems: two types of conventional cages (small: SC; large: LC), furnished cages (small: SF; large: LF), and non-cage systems (single-tiered aviary: SA; free-range: FR).

3.?We evaluated the welfare, egg production, and immune response of the birds in these housing systems, built in the same location, for 18 months. For welfare evaluation, we examined their ethology, physiology, anatomy, production, and physical condition.

4.?The non-cage systems, especially FR, had a low score for freedom from pain, injury, and disease, together with other disadvantages, such as pale eggs and increased feed intake for production. However, the score for freedom to express normal behaviour was high and immune response was good in the non-cage systems.

5.?In the furnished cages, behaviour was more diverse in SF than in LF, and in SF immune response was comparable with the non-cage systems.

6.?For freedom from fear and distress, the non-cage systems had high scores for some indicators such as TI duration, H/L ratio and claw length, while aggressive pecking and feather pecking was worse in the housing systems with large group sizes.     

Limb bone strength and movement in laying hens from different housing systems

Walking and bouts of wing movement performed by 61-week-old ISA brown laying hens which had been taken from one batch of eggs and then kept in three different housing systems which allowed a gradation in spatial freedom, were recorded. After slaughter the breaking strengths of the humerus and tibia of birds from each system were measured. Birds from battery cages exhibited the fewest limb movements and had the weakest bones, their humeri having only 54 per cent of the strength of those of birds from a perchery. Birds from the Elson terrace system were heavier and had a stronger tibia than cage birds. Compared with perchery birds, terrace birds had weaker humeri and also performed fewer wing movements. The results indicate that the amount of movement possible for laying hens in battery cages was insufficient to avoid levels of osteopenia and consequent bone fragility much greater than in birds kept in the perchery and Elson terrace systems.     

Automatic weighing of individual laying hens in aviary housing systems

1. This study investigated when and where body weight and flock‐uniformity should be determined in an aviary system by using automatic weighing systems.

2. An Individual Poultry Weighing System (IPWS) was developed to record time, duration, location and body weight of visits of individual hens to 4 weighing scales.

3. The number of hens that visited the weighing scales per 3 h period varied from less than 10 during the dark‐period to more than 60 during the light‐period.

4. The average number of visits per individual hen was 1–4 and the average number of successful weighings per hen was 0–6 during the light‐period.

5. Body weight showed a diurnal rhythm: the difference between the maximum body weight at night and the minimum body weight in the morning was 63 g.

6. The location of the scales influenced number of visits, number of weighings, mean body weight, flock‐uniformity and duration of visits.

7. Body weight per 3 h period did not differ between hens which were individually recognised and those which were not.

8. Flock‐uniformity was 2–6% higher during the light‐period if it was based on weighings of identified hen visits.

9. The average duration of the visits to the scales in the middle of the feeding tier during the light‐period was 63 s.

10. Of all the hens that visited the scales during a 24 h period, 54% visited them only once.

11. Automatic weighing systems without individual hen recognition can deliver reliable management information on mean body weight and flock‐uniformity in aviary systems if the weighing scales are located on the feeding tier in the middle of the house and if they are used during the light‐period.     

Pathologic-anatomic investigations in laying hens in various housing systems]

Gross pathologic and histologic changes were investigated in a total of 1000 end-of-lay hens. Thirty animals were drawn from free range stocks, 270 from deep litter stocks, and 700 from caging systems. The following changes were evaluated with regards to housing systems: Pododermatitis, deformation of the keel bone and amputated beaks occurred primarily in free range hens. Deep litter hens also suffered from pododermatitis, keel bone deformation and amputated beaks in addition to pecking wounds. In caged hens severe fatty liver syndromes, injuries of the claws and inflammation of the feather follicles were mainly found. Furthermore, injuries and fractures due to handling and transport were almost exclusively found in caged hens. It has to be concluded that all of the investigated housing systems can predisposed hens to certain lesions. The documented changes--e.g. chronic inflammation, skelettal deformities and injuries--are painful and may lead to permanent alterations. Therefore, these changes should be condemned as conflicting with animal protection regulations.     

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。     

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。     

Nutritional and environmental factors involved in egg shell quality of laying hens.

1. Two experiments were conducted to assess the effects of lighting regime, dietary calcium source and sodium bicarbonate on production variables and egg shell quality of White Leghorn hens. In both experiments, hens were assigned to one of three lighting programmes that provided evening, morning or intermittent (midnight) lighting supplements in addition to natural daylight. Experimental diets used in the first study were formulated to contain (1) ground oyster shell flour, (2) limestone flour, or (3) and (4) the same +2/3 of the calcium source as hen-size oyster shell grit. The same 4 diets plus those containing hen-size limestone or hen-size limestone and oyster shells were used in experiment II. Additionally, diets in the first experiment contained either 0 or 10 g/kg sodium bicarbonate. 2. Hen-day egg production and food consumption were not affected by any of the experimental treatments. Hens fed on oyster shell diets or exposed to intermittent lighting regimes laid eggs of the highest specific gravity. Shell quality, as measured by specific gravity, was not affected by the addition of dietary sodium bicarbonate. 3. As expected, elevated temperatures (greater than 32 degrees C) significantly reduced egg shell quality. However, this effect was variable particularly in experiment II which used younger hens. 4. The shell quality of eggs from hens exposed to intermittent lighting in experiment II was significantly higher in each of the 4 sampling periods: morning (08.00-12.00), afternoon (12.00-16.00), evening (16.00-20.00) and night (20.00-08.00). 5. It is suggested that midnight lighting programmes provide a means of supporting egg shell quality of older laying hens during the summer months without a significant reduction in egg production.     

Phenotypic and molecular characterization of Brachyspira spp. isolated from laying hens in different housing systems

Several species of intestinal spirochaetes, Brachyspira (B.) alvinipulli, B. intermedia and B. pilosicoli, may cause reduced egg production and faecal staining of eggshells in chickens. The aim of this study was to characterize potentially pathogenic and presumably non-pathogenic Brachyspira spp. from commercial laying hens. Selective culture, phenotyping, PCR and 16S rRNA gene sequencing were used and clinical data were collected. Phenotypic profiles were obtained for 489 isolates and 351 isolates obtained after subculture, and 30 isolates were selected for molecular characterization. Seven isolates were positive by a B. intermedia-specific PCR based on the nox gene, and two were positive in a B. hyodysenteriae-specific 23S rRNA gene based PCR. By comparative phylogenetic analysis in combination with PCR and phenotyping, seven isolates were identified as B. intermedia, eight isolates as B. innocens, five as B. murdochii, and three isolates each as B. alvinipulli and "B. pulli". The remaining four isolates could not be assigned to any presently recognized species. Co-infection with several species or genetic variants of Brachyspira spp. were detected in some flocks and samples, suggesting a high level of diversity. Organic flocks with access to outdoor areas were at higher risk (RR=2.3; 95% CI 1.5-3.6) for being colonized than chickens in other housing systems. No significant differences between colonized and non-colonized flocks were found regarding clinical parameters, i.e. mortality, egg production, faecally contaminated eggshells, and wet litter. Our results show that a combination of traditional laboratory diagnostics, molecular tests and phylogeny is needed for identification of Brachyspira sp. from chickens.     

Heritabilities and correlations for egg shell crack frequency,body checking,egg number and egg weight in laying hens

1. Egg shell cracks and body checking were assessed on a total of 25 776 eggs collected from 744 hens of two selected White Leghorn strains between 65 and 72 weeks of age.

2. The sire‐component heritabilities in the two strains, respectively, were 0–59 ± 0.23 and 0.36 ± 0.20 for total cracks and 0.41 ± 0.20 and 0.49 ± 0.22 for body checking. The heritabilities for hole, star and hair cracks ranged from ‐0.03 ± 0.13 to 0.66 ± 0.24.

3. The frequency of total cracks did not bear any significant antagonistic relationship with body checking, egg number and egg weight. Body checking had variable relationship with egg number and egg weight. The correlations of shell cracks and body checking with each other and with egg number and egg weight appeared to vary between the strains.     

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     

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）。     

不同硒水平对蛋鸡产蛋性能及蛋品质的影响

硒作为一种动物机体必需的微量元素,在饲料配合中已被广泛应用,经过大量研究表明,微量元素在增强家禽的免疫机能,提高繁殖性能和维持正常的生长发育等方面有一定的作用。家禽饲粮中补加硒后,仔禽生长速度、饲料转化率、产蛋率和孵化率均得到提高。巩元芳等(1998)报道,在蛋鸡低硒(0.015mg/kg)饲粮中补加0.1mg/kg硒使产蛋率提高到75%以上;倪可德等(1994)研究表明,给含0.015～0.030mg/kg硒的母鸡饲料中添加0.1mg/kg硒,可提高产蛋率,改善孵化率和增加雏禽的生活力,并能预防渗出性素质症。Oishi(1987)报道,蛋鸡饲粮中硒浓度由0.06mg/kg增加到0.2…     

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)。     

The absorption and excretion of minerals by laying hens in relation to egg shell formation

The absorption and urinary and faecal excretion of calcium, phosphorus, magnesium, sodium, potassium and chloride were studied in four colostomised laying hens during 24 hr periods. The urinary excretion of ammonia was also determined. Data for 10 laying and 5 non‐laying days were obtained. On laying days (a) net absorption of all minerals, expressed either as actual weights or as a percentage of intake was greater, (b) urinary excretion of phosphorus, potassium and ammonia was greater and of calcium, magnesium and chloride less and (c) retention of all minerals was greater, than on non‐laying days.

The urinary findings can be largely explained in terms of the requirements of the shell gland for calcium and bicarbonate ions and the need to excrete the phosphate liberated from the skeleton during egg shell formation.     

不同饲养方式对蛋鸡生产性能、鸡蛋品质及经济效益的影响

文章旨在评估不同饲养方式对蛋鸡生产性能、蛋品质和血清生化指标的影响.试验选择产蛋性能接近的22周龄海兰褐壳蛋鸡540只,随机分为3组,每组5个重复,每个重复36只.笼养组蛋鸡采用三层阶梯饲养(0.6?m2/只),网上平养组蛋鸡在金属网丝上饲养(1.5?m2/只),垫料平养组在平铺20?cm稻壳的水泥地板上平养(1.8?...     

Control of landing flight by laying hens: implications for the design of extensive housing systems

(1) Ten domestic hens (Lohmann Brown) were video-recorded while moving between perches at a horizontal distance of 0.6, 0.8 or 1.15 m apart. The take-off perch was either 0.2 m above or below the landing perch. (2) Weight and wing area of the hens were measured at the end of the experiment. The same measures where taken from 10 jungle fowls. (3) Clumsy or missed landings were observed on some downward flights over 0.8 and 1.15 m. (4) Hens' trajectories on take-off were closely related to the position of the target perch, and variation in take-off trajectory decreased as the distance between perches increased. (5) The standard deviation of the horizontal distance between head and perch, at the point when the feet first contacted the perch, did not vary with flight distance, suggesting that timing of foot extension was equally accurate at all distances. (6) The standard deviation of the vertical distance between head and perch, at the point when the feet first contacted the perch, did increase with distance, suggesting increasing difficulty in controlling the height of the flight trajectory above the landing perch. (7) Wing loading of the hens (mean 213 N/m2) was approximately twice that of the jungle fowl (mean 111 N/m2). (8) Loss of accuracy in hens' landings at greater distances can be attributed specifically to the effects of high wing loading on the ability to generate and control lift.