Keeping laying hens in furnished cages and an aviary housing system enhances their bone stability

1. Tibia and humerus breaking strength of Lohmann Silver hybrids kept in conventional cages, furnished cages and an aviary with outdoor run were examined in two production cycles. Each trial lasted a full laying period; feeding, management and healthcare were identical for all hens. In both trials bone strength was investigated at the end of laying months 6, 9 and 14. 2. The objective was to determine if bone strength increases when hens are kept in alternative housing systems, especially in furnished cages, and whether hen age affects bone stability. 3. The results indicated that housing system influenced bone breaking strength, which was consistently higher for hens in the aviary compared to hens in conventional and furnished cages. Furthermore, humerus breaking strength was higher for hens in furnished cages compared to conventional cages. No significant difference regarding tibia breaking strength was found between conventional and furnished cages. 4. Our results showed that lack of exercise contributed to the problem of weak bones more than did calcium depletion from eggshell formation. 5. Tibia breaking strength increased during the last third of the production cycle, whereas humerus breaking strength remained unaffected by hen age. 6. Genetic group affected only tibial bone breaking strength, which was lower overall in genetic group A than in group B, which in turn was lower than group C. 7. The increased bone strength in the aviary and in the furnished cages probably reduced the incidence of recently broken bones in these systems compared to the conventional cages. This increase in bone strength can be regarded as an improvement in welfare. Furnished cages, like the aviary system, might be considered an alternative housing system for laying hens, because both resulted in enhanced bone strength.     

Effects of dietary protein on egg production of laying hens housed in furnished or conventional cages

Abstract

In the present experiment the effects of dietary protein content on egg production of hens kept either in conventional cages (CCs) or furnished cages (FCs) were studied. A total of 1088 LSL (Lohmann LSL-Classic Layer) hens were housed in either FCs or CCs and offered high or low protein diets with a protein/energy ratio of 17 or 13, respectively, during three consecutive feeding phases of 20, 16 and 16 weeks, respectively. There was no interaction between the effects of cage design and of dietary treatment on laying performance. Hens kept in FCs consumed less feed than hens in CCs (p<0.05). After the first feeding phase, hens housed in FCs produced fewer eggs (p<0.01) than hens in CCs. No differences in the feed conversion ratio were found between the housing systems. Hens on the low protein diet laid smaller eggs than hens on the high protein diet (p<0.001). No effect of dietary protein on laying rate was found. It can be concluded that dietary protein affects egg production irrespective of the cage type.     

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.     

Development of furnished cages for laying hens

1. A 3-year trial was carried out of cages for laying hens, occupying a full laying house. The main cage designs used were 5000 cm2 in area, 50 cm high at the rear and furnished with nests and perches. F cages had a front rollaway nest at the side, lined with artificial turf. FD cages also had a dust bath containing sand over the nest. H cages had two nest hollows at the side, one in front of the other. They were compared with conventional cages 2500 cm2 in area and 38 cm high at the rear. 2. Cages were stocked with from 4 to 8 ISA Brown hens per cage, resulting in varied allowances of area, feeder and perch per bird. No birds were beak trimmed. In F and FD cages two further treatments were applied: nests and dust baths were sometimes fitted with gates to exclude birds from dust baths in the morning and from both at night; elevated food troughs, with a lip 33 cm above the cage floor, were compared with standard troughs. 3. Management of the house was generally highly successful, with temperature control achieved by ventilation. Egg production was above breeders' standards and not significantly affected by cage design. More eggs per bird were collected when there were fewer birds per cage but food consumption also then tended to be higher. 4. The number of downgraded eggs was variable, with some tendency for more in furnished cages. Eggs laid in dust baths were often downgraded. Those laid at the back of the cage were frequently dirty because of accumulation of droppings. H nests were unsuccessful, with less than 50% of eggs laid in the nest hollows. However, up to 93% of eggs were laid in front rollaways, and few of these were downgraded. 5. Feather and foot damage were generally less in furnished than in conventional cages, greater where there were more birds per cage. With an elevated food trough there was less feather damage but more overgrowth of claws. In year 2, mortality was greater in cages with more birds. 6. Pre-laying behaviour was mostly settled in front rollaway nests. Dust baths were used more for pecking and scratching than for dust bathing. Comfort behaviour was more frequent in furnished cages than conventional, although still not frequent. Locomotion was strongly affected by number of birds per cage or by space per bird, being reduced by crowding. Most birds perched at night except in one treatment providing only 10.7 cm perch per bird. 7. Behaviour was more unrestricted and varied, and physical condition was better, in furnished than in conventional cages. However, egg production will cost more in furnished cages, partly because more eggs are downgraded. Dust baths must be fitted with gates that the birds cannot open from outside, but gates for nest boxes were found unnecessary. If a low perch is fitted it must be far enough from the back of the cage for birds to walk there. 8. Where there was less space per bird (more birds per cage) than the requirements in the 1999 European Commission Directive on laying hens, there were: fewer eggs per hen, but still above the breeders' target; lower food consumption; more feather and foot damage, but less than in conventional cages; higher mortality in one trial out of three; less freedom of movement. However, the results were still very good even with 8 birds per cage, and support the principle that furnished cages provide an acceptable way of protecting the welfare of laying hens.     

Evaluation of foot pad health of laying hens in small group housing systems and furnished cages

Foot pad health was examined in a total of 648 Lohmann Selected Leghorn (LSL) in two trials and in 216 Lohmann Brown (LB) laying hens in one trial kept in small group housing systems and furnished cages. The effects of housing system, strain, month of laying period, rearing method, group size and body weight were tested for significance by using analysis of variance. The assessment of foot pads was performed each three months during the laying period. The alterations of foot pads were classified in severity on a scale from 1 (no hyperkeratosis, no epithelial lesions, no swelling of foot pads) to 5 (severe hyperkeratosis and/or deep and large epithelial lesions and/or moderate or high-grade swelling of foot pads). In addition to the macroscopic findings, foot pads were histologically examined. Pathological alterations of foot pads were found in 86.1% of the laying hens, whereas 57.4% of the examined animals showed mild hyperkeratosis (degree 2). Modest hyperkeratosis and/or superficial lesions of the epithelium (degree 3) were detected in 21.0% of the laying hens examined. Severe hyperkeratosis and/or deep epithelial lesions and/or mild swelling of the foot pads (degree 4) as well as very severe hyperkeratosis and/or deep and large epithelial lesions and/or moderate or high-grade swelling of foot pads (degree 5) occurred with frequencies of 5.9% and 1.9% respectively. LB laying hens' food pads were more frequently affected by hyperkeratosis, whereas epithelial lesions were more frequently found in LSL laying hens. The prevalence of pathological alterations in foot pads was significantly influenced by housing system and month of laying period. The results of this study showed that laying hens kept in small group housing systems and furnished cages develop proliferative hyperkeratosis in foot pads due to increased mechanical compression load, caused by the use of perches and staying on wire floor.     

Effect of production system and flock age on egg quality and total bacterial load in commercial laying hens

The shell of the egg is essential in providing shape to the egg and ensuring safe packaging of the internal contents; however, shell defects have been shown to increase the risk of microbial contamination of eggs. Eggs were collected from commercial cage and free-range flocks at the ages of 25, 35, 45, 55, 65, and 75 wk. From each collection per flock, 30 eggs were processed for the eggshell and egg internal quality determination, 30 eggs for cuticle estimation, 30 eggs for mammillary layer ultrastructural features scoring, and 60 eggs for egg microbial enumeration. Translucency score and shell reflectivity were significantly higher in free-range eggs and increased with flock age in both production systems. Egg weight, shell weight, percentage shell, shell thickness, albumen height, Haugh unit, and yolk color were higher for cage eggs. The amount of cuticle was higher in cage eggs and fluctuated with flock age in both production systems. For the mammillary layer ultrastructural variables, a significant effect of production system and flock age was observed for early fusion, Type A bodies, and Type B bodies, whereas aragonite, depression, erosion, and hole were rarely observed. Variability of mammillary cap size, the incidence of poor mammillary cap quality, incidence of late fusion, alignment, Type A bodies, Type B bodies, and cubic cone formation were greater in the free-range versus cage system and increased with flock age in both production systems. The incidence of confluence and early fusion were greater in cage eggs and decreased with age in both production systems. Significantly lower total microbial load was observed for cage compared with free-range eggs, but the overall bacterial load recorded in this study was low. It can be concluded that cage eggs were better in overall quality when directly compared with free-range eggs.     

耐镉乳酸菌对蛋鸡生产性能及蛋品质的影响

为研究日粮中分别或同时添加镉和具有耐镉特性的约氏乳酸杆菌对如草蛋鸡生产性能和蛋品质的影响,试验分为5组:对照组、镉组(Cd 5 mg/kg)、低剂量乳酸菌组(Lac 1×10¹⁰cfu/kg)、镉加低剂量乳酸菌组(Cd 5 mg/kg+Lac1×10¹⁰cfu/kg)、镉加高剂量乳酸菌组(Cd 5 mg/kg+Lac 1×10¹¹ cfu/kg)。试验期6周,全程统计分析蛋鸡日采食量、产蛋量、产蛋率和料蛋比。在试验的3周末和6周末各组连续收集三天的鸡蛋,测定蛋品质。结果显示:镉加低剂量乳酸菌组的产蛋量、产蛋率较对照组和镉组分别提高38%、16.22%和5.3%、2.44%,料蛋比降低1.09和0.17。6周时镉加低剂量乳酸菌组的蛋重为48.8 g,较低剂量乳酸菌组提高7.3%(P <0.05);而其蛋白高度较对照组和镉组分别提高24.4%和18.6%(P <0.05)。蛋黄色泽在3周时,各试验组比对照组低1～3级(P <0.01),而在6周时,各试验组比对照组高2～3级(P <0.01)。6周时镉组和镉加高剂量乳酸菌组的蛋黄质量均较低剂量乳酸菌组提高7.9%(P <0.05),而其蛋黄蛋白比均较对照组高12.3%(P <0.01),较低剂量乳酸菌组和镉加低剂量乳酸菌组提高8.5%和6.7%(P <0.05)。蛋壳厚度在3周时,试验组较对照组低0.01～0.02 mm(P <0.01)。蛋壳颜色L在3周和6周时,镉组较对照组值分别降低了4.9%和7.4%(P <0.05);蛋壳颜色a在3周和6周时,镉组较对照组分别提高63.3%和66.7%(P <0.01),在6周时镉组较低剂量乳酸菌组和镉加低剂量乳酸菌组分别提高26.8%和28.6%(P <0.05);蛋壳颜色b在3周时,试验组较对照组分别提高36.5%、25.3%、27.0%和26.4%(P <0.01),在6周时镉组较对照组提高15.4%(P <0.01)。综上,在蛋鸡低镉饲粮中添加1×10¹⁰cfu/kg的耐镉乳酸菌可提高蛋鸡的生产性能,且显著增加蛋白高度。     

Effects of age on the tryptophan requirement of laying hens

1. White Leghorn pullets which had been used for an assay of tryptophan requirement between 32 and 40 weeks of age were used for similar determinations between 63 and 73 and, after a moult, from 97 to 106 weeks of age.

2. A tryptophan‐limiting protein mixture was used and by dilution seven dietary protein contents were produced, supplying from 0.84 to 1–92 g tryptophan/kg diet. The diet of lowest protein content was also sup‐lemented with free tryptophan. These diets were fed in experiments using 24 groups of 72 pullets at 63 to 73 weeks and 45 groups of 21 hens at 97 to 106 weeks.

3. The relationship between egg output and tryptophan intake was the same in moulted hens as in young pullets, but pullets of 63 to 73 weeks of age yielded a different response curve; more tryptophan being needed for a given egg output.

4. It is concluded that tryptophan required, per day, does not decrease during the first laying year, despite a decrease in rate of egg output.     

Effects of dietary red yeast (Sporidiobolus pararoseus) on production performance and egg quality of laying hens

The purpose of this study was to evaluate the effect of dietary red yeast (Sporidiobolus pararoseus) on production performance and egg quality of laying hens. A total of 200 Esa Brown laying hens (23 weeks of age) were allocated equally to negative control group (no yeast supplement); positive control group (2 g/kg of Saccharomyces cerevisiae); 0.5, 1, 2 g/kg red yeast respectively. The experiment was lasted for 12 weeks. Feed intake, hen‐day egg production and egg weight were not different between control and supplemented groups. However, yeast‐supplemented groups were significantly improved feed efficiency (p < .05). Incremental levels of red yeast increased the colour score of egg yolk (p < .05). The cholesterol and triglyceride of serum and yolk were significantly (p < .05) lower in the laying hens fed dietary administration red yeast compared to the control diet; however, no significant (p > .05) differences among yeast‐supplemented groups were observed. The hepatic hydroxymethylglutaryl‐coenzymeA (HMG‐CoA) reductase activity was significantly lower (p < .05) in the 2 g/kg red yeast‐supplemented group compared to the control and other red yeast‐supplemented groups. Concentrations of caecal short‐chain fatty acids was increased (p < .05) in laying hens fed 1 and 2 g/kg red yeast as compared to the control group. Dietary administration of 2 g/kg red yeast (S. pararoceus) significantly improved egg yolk colour, decrease serum and egg yolk cholesterol levels.     

Observations on the laying behaviour of hens in battery cages

Observations were made on the laying behaviour of hens from each of two commercial strains kept in a Thornber battery cage system. Attention was paid to the following behavioural components of oviposition: the position of the hen in the cage; the stance of the hen; the height through which the egg fell; the orientation of the egg; the time taken to oviposit; the time taken for the egg to roll out of the cage and the incidence of pecking at the egg.

Less detailed observations were made on the pre‐laying behaviour of the hens.     

Endotoxin concentration in poultry houses for laying hens kept in cages or in alternative housing systems

1. Endotoxins as components of organic dust may have adverse effects on the respiratory health of workers in poultry buildings. The move towards more welfare-friendly housing systems for layers may increase worker exposure to air contaminants due to the use of litter.

2. The endotoxin concentrations in the inhalable fraction of airborne dust (below 100?µm) from cage and alternative system houses (on-floor, free range and aviaries) were compared under both experimental and commercial conditions.

3. The endotoxin concentration was higher in experimental aviaries (median: 565?EU/m³, range: 362-1491?EU/m³) than in cage housing (98?EU/m³ (51-470)).

4. In field conditions, the endotoxin concentration in the air of 13 alternative houses was higher (35 to 3156?EU/m³) than in cage system buildings (n?=?8, 78-576?EU/m³). It was correlated to the respirable dust concentration (fraction below 5?µm) and to the temperature inside the hen house but no seasonal variation was observed.

5. The present study emphasises that considerable worker exposure to endotoxins may occur in laying houses, especially in alternative systems.     

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.     

日粮添加黄芪多糖对蛋鸡机体抗氧化能力和鸡蛋品质的影响

选用540只27周龄海兰褐蛋鸡,随机分为4个处理,每个处理5个重复,每个重复27只鸡。采用单因素完全随机分组设计,对照组饲喂基础日粮,试验组饲喂在基础日粮中分别添加100、200、300mg／kg黄芪多糖的日粮,试验期为70d,探讨日粮中添加不同水平的黄芪多糖对蛋鸡机体抗氧化能力和鸡蛋品质的影响。结果显示：黄芪多糖能不同程度地提高（P〈0．05）血清和蛋黄SOD、血清GSH—Px和T-AOC活性,显著降低（P〈0．05）血清和蛋黄MDA含量、蛋黄胆固醇质量浓度。随着受试时间的延长,各组内血清sOD活性显著升高（P〈0．05）,血清MDA含量和T-AOC活性显著降低（P〈0．05）;对照组的蛋黄MDA含量显著升高（P〈0．05）,而血清GsH—Px活性显著降低（P〈0．05）。结果表明,黄芪多糖能改善蛋鸡机体及其产品抗氧化能力,对蛋黄胆固醇质量浓度有降低作用。     

日粮中添加女贞子粉对蛋鸡生产性能和蛋品质的影响

选择150只49周龄、平均体重(1.99±0.17)kg的健康海兰褐蛋鸡,采用单因素完全随机分组试验设计,随机分为对照组(基础日粮)、试验组Ⅰ(基础日粮+0.5%女贞子粉)、试验组Ⅱ(基础日粮+1%女贞子粉)。每组设5个重复,每个重复10只蛋鸡,试验期为8周,研究了女贞子粉对蛋鸡生产性能和蛋品质的影响。结果表明:与对照组相比,试验组Ⅰ、Ⅱ产蛋率分别提高了4.86%和11.75%(P0.05)。试验组Ⅰ蛋黄颜色显著高于对照组9.60%(P0.05)。日粮中添加女贞子粉可以提高蛋鸡产蛋率,改善蛋黄颜色,进而提高蛋鸡的生产性能和蛋品质。     

Effects of commercial enzyme preparations on egg and eggshell quality in laying hens

1. Four different commercial enzyme products were added to standard commercial layer diets, based on barley, wheat or triticale. 2. Diets were fed to 4 different strains of commercial laying hen: ISA Brown, Hy-Line CB, Tegel SB2 and Tegel HiSex. 3. Diets were given for 5 weeks prior to measurements of egg and eggshell quality. 4. The inclusion of commercial enzyme products in the diets had no effect on egg weight. 5. Positive effects of the enzymes were: improved eggshell breaking strength, shell weight, percentage shell and shell thickness for the barley-based diet and increased eggshell breaking strength for two of the enzymes with the wheat-based diets. 6. Negative effects of the enzyme products were slightly lighter coloured eggshells and reduced albumen quality for the barley-based diet and for two enzymes with the wheat-based diet. 7. The addition of commercial enzyme preparations had no main effect on egg and eggshell quality for the triticale-based diet, except for effects on yolk colour. 8. Yolk colour was lower than control for enzyme 3 in all diets and for enzyme 4 with the barley- and wheat-based diets. 9. Further investigation is required to elucidate the specific enzyme components that influence egg quality.     

酵母菌培养物对蛋鸡生产性能及蛋品质的影响

270只19周龄的ISABrow母鸡随机分3组处理,每个处理5个重复,研究酵母培养物对产蛋鸡产蛋性能和蛋品质的影响。试验为期16周。酵母培养物在试验中的添加水平分别为0%、0.1%、0.2%。试验中采用的玉米-豆粕型基础日粮中粗蛋白质为16.0%,能量为2800kcal/kg。试验结果表明,饲喂添加0.1%酵母培养物组产蛋鸡的生产性能和每日产蛋量显著提高(P<0.05);各处理组之间的蛋重、饲料摄入和饲料转化率无显著差别;试验组与对照组的蛋壳质量、哈氏单位、蛋黄颜色和蛋黄中脂肪酸含量也无显著差别。     

Bone strength of laying hens kept in an alternative system, compared with hens in cages and on deep-litter

1. Observations of vigorous wing movements and measurements of bone strength were compared in two experiments with birds in three different housing systems: a semi-intensive alternative system under development, a battery cage system and a deep-litter system. 2. A significant effect of housing system on the frequency of vigorous wing movements was found. The highest frequency was seen in the deep-litter system, about half this number in the alternative system, while in the battery cages they were never observed. 3. Corresponding to this a reduction in humerus strength of 9% was found in hens from the alternative system and of 45% in hens from cages, compared with deep-litter. A reduction in tibial breaking strength was also found in caged hens, when compared to deep-litter hens. 4. Keeping hens in cages thus restricts their movements, especially wing movements, to the degree that bone strength is greatly reduced. 5. This has welfare implications, for hens with low bone breaking strength risk a possibility of breakage, especially when handled and transported. When alternative systems are designed opportunities for movement in the three dimensions should be considered.     

优质蛋白玉米对产蛋鸡生产性能及鸡蛋品质的影响

国外培育的优质蛋白玉米通过大鼠（Mertz，1965；Sproule等，1988），猪（Knabe等，1992；Okai等，1994），肉鸡和蛋雏鸡（Liu等，1993；Osei等，1994）的试验已被证明营养价值优于普通玉米。而国内培育的优质蛋白玉米总能和代谢能与普通玉米相近；氨基酸组成发生了变化，尤其是赖氨酸、色氨酸等含量高于普通玉米所有氨基酸消化率不低于普通玉米。但是其在产蛋鸡上应用的研究还未见报道。为此，进行本次试验，研究优质蛋白玉米（中单9409）在产蛋鸡上应用的效果，为优质蛋白玉米的推广应用提供依据。     

Effects of dietary copper on production and egg cholesterol content in laying hens

1. This experiment was carried out to determine the effects of diets supplemented with different amounts of copper on egg production, food intake, food conversion ratio, egg weight, damaged egg ratio, specific gravity, mortality and cholesterol concentration in yolk. The experiment lasted 90 d and 400 Hisex-Brown hens, aged 27 weeks at the start of the study, were used. 2. There were no statistically significant effects of supplementary copper on egg production, food intake or food conversion efficiency. 3. There were no statistically significant differences between the groups in terms of damaged eggs, egg weight, specific gravity and live weight. 4. At the end of the experiment, the lowest yolk cholesterol concentrations were obtained in the 150 kg/kg copper group and the greatest concentrations were in the control group. 5. Consequently, the use of supplementary copper to provide 150 kg/kg in poultry diets was concluded to decrease yolk cholesterol concentrations without any effect on production performance.     

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...