Aviary Systems and Conventional Cages for Laying Hens: Effects on Production,Egg Quality,Health and Bird Location in Three Hybrids

Abstract

In two experiments, a total of 4346 laying hens housed in battery cages, with three hens per cage (C), and in two aviary systems, both with tiered wire floors and litter (Lövsta with two tiers (L) and Marielund with three tiers (M)), were used for studies on production, egg quality, health, plumage and foot condition, bone strength and bird location. Three hybrids were used: Lohmann Selected Leghorn (LSL) were kept in all three systems, Dekalb XL (DK) were kept in both aviaries and Lohmann Brown (LB) in M only. Production and feed conversion in M were inferior but not significantly different from C but significantly better than in L. Proportions of dirty eggs were significantly higher in the avaries. No significant differences were found in interior egg quality traits between keeping systems. LSL showed higher production and better feed conversion than the other hybrids and a tendency for a lower proportion of mislaid eggs. Mortality varied considerably between the aviary pens, reaching 35% in LB mainly owing to cannibalism and salpingitis. Keel bone lesions and bumble foot appeared in the aviaries, while toe pad hyperkeratosis was observed in C. Hens in aviaries had significantly stronger bones (tibia and humerus) and showed more wounds from pecks, inferior plumage condition and dirtier feet than in C. LSL had more bumble foot injuries than LB but better plumage condition than DK. The birds used the different parts in the aviaries well, especially the perches on the resting top tier during the night.     

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.     

Effects of group size on performance,health and birds’ use of facilities in furnished cages for laying hens

A total of 1584 Lohmann Selected Leghorn hens were kept in 144 modified cages furnished with—perch, nest and sandbath for 5, 6, 7 or 8 hens per cage or in 162 conventional cages for 4 hens. Cage floor area was 600 cm² per hen excluding nest and sandbath. Doors to nests and sandbaths were time monitored. Production, mortality, exterior egg quality, health, integument and the birds use of facilities were registered from 20 until 80 weeks. No effects of group size or keeping system on production or mortality were detected, but the furnished cage gave more cracked and less dirty eggs than the conventional cage. Hens in the furnished cage had better plumage condition, less toe pad hyperkeratosis, shorter claws, less rear body wounds and stronger humerus, but dirtier feet than hens in the conventional cage. Hens in the larger group sizes had the dirtiest feet. In the furnished cage, on average, 86% of all eggs were laid in the nests and 0.6% in the sandbaths. The rolling out efficiency from nests was best in the larger group sizes. During night less than 0.5% of the hens stayed in the sandbath and less than 2% stayed in the nest. Average use of perches was 28% during the day and 91% at night. Hens in the small group sizes used the sandbath most. Dust‐bathing behaviour also occurred on the wire floor.     

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.     

不同笼位对鹌鹑生产性能及羽毛评分的影响

试验旨在研究不同笼位对鹌鹑生产性能及羽毛评分的影响,以期为鹌鹑的饲养管理提供参考。鹌鹑48周龄时,在鹌鹑舍的中间区域随机取一排作为研究对象,共60笼,分为6层10列。其中,从上至下分别为第1~6层,从南到北将前3列设为A组,中间4列设为B组,其余3列设为C组。每笼饲养鹌鹑50只,每天统计产蛋数和蛋重。连续统计7 d。于统计期的第1天及第7天,每笼随机取10只鹌鹑进行称重及羽毛评分。结果显示:不同层次鹌鹑的产蛋率和蛋重无显著差异(P>0.05);不同列次鹌鹑的产蛋率和蛋重差异显著(P<0.05),其中蛋重的差异极显著(P<0.01);不同的笼位鹌鹑的羽毛评分差异显著(P<0.05)。研究表明,高度为0.8~1.2 m的中间列为最适宜饲养鹌鹑的笼位,其他笼位的鹌鹑更需加强饲养管理。     

Bitter vetch as a single dietary ingredient for molt induction in laying hens

Molting is used to increase productivity in the second laying cycle of commercial laying flocks. We report here the applicability of whole grain of bitter vetch as an alternative method for molt induction in laying hens. A total of 120 laying hens were molted by feed withdrawal (FW), a high-Zn diet (HZn), a moderate-Zn and Ca-P-deficient diet (MZn-CaP), or whole grain of bitter vetch (BV). Egg production ceased first in FW-treated hens and last in MZn-CaP-treated hens (P < 0.05). The rest period was longer (P < 0.05) in hens exposed to the BV diet, which proved to be comparable with the FW treatment for postmolt egg production. Egg mass for 4 to 16 wk after the molting was greater (P < 0.05) for hens molted by BV than hens molted by the MZn-CaP diet. Egg weight and yolk color were not (P > 0.05) significantly different among various molting induction methods. Albumen height and Haugh unit of eggs from hens molted by BV, for the most part of the experimental period, were significantly (P < 0.05) greater than for birds on the MZn-CaP diet and unmolted hens. In conclusion, use of BV grain as a single dietary ingredient proved to be effective in molt induction and improving postmolt egg production and internal egg quality when compared with unmolted hens.     

Performance of Four Hybrids of Laying Hens in Modified and Conventional Cages

Abstract

In two trials, production, feed consumption, mortality, egg quality and birds' live weight of a total of 2877 caged laying hens of four hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in Trial 1 and ISA Brown and LSL in Trial 2, were studied during full production cycles. The cage designs were Get-away cages (GA) with 15 hens per cage, a special version of the “Edinburgh modified cage” called “Modified and enriched cage” (ME) with 4 ISA or 5 Leghorn hens per cage, conventional cages of metal (CO) with 4 hens per cage and conventional cages of plastic (PL) with 3 hens per cage. GA and ME included nests, perches and sandbaths. LSL produced significantly better than the other hybrids. Shaver had a significantly lower live weight than Dekalb and LSL, while ISA was significantly heavier than LSL. Production in ME was similar to that in conventional cages and, in Trial 2, birds in ME, CO and PL produced significantly better than those in GA. The highest mortality was registered in GA, where in Trial 2 it was significantly higher than in ME. GA gave a significantly higher and CO a lower proportion of cracked eggs than ME and PL. In both trials ME gave significantly lower proportions of dirty eggs than GA and in Trial 2, the lowest. Few differences between the systems were registered regarding interior egg quality. It was concluded that ME is better for production, mortality and management than GA but similar to conventional cages.     

Stress parameters and immune response of layers under different cage floor and density conditions

The aim of the experiment was to investigate the effects of cage floor and cage density on stress parameters of laying hens. A total of 162 brown laying hens (Hyline Brown), aged 34 weeks, were used in the experiment. Compact-type battery cages, with three floors, were used. Hens were allocated as one, three or five hens in each of 18 cages to obtain three different cage density groups of 1968, 656 and 393.8 cm² floor area per hen, respectively. The same number of cages with different cage density were allocated to three different battery floors (first floor=top, second=middle, third=bottom) systematically. Values for body weight, mortality rate, egg weight, egg production, egg quality characteristics, egg yolk cholesterol content, the levels of blood plasma corticosterone, serum glucose, total cholesterol and triglycerides, the ratio of heterophils to lymphocytes (H-L ratio), antibody titers, claw length score, foot health score, plumage score and throat skin injuries were taken as indicators of stress. The values for egg weight (P<0.01) at the first floor were greater than the other floor levels. The group with five hens per cage had significantly lower mean estimates (P<0.01) than other groups with respects to body weight (P<0.001), egg production (P<0.001), egg weight (P<0.001) and plumage score (P<0.01), while significantly higher mean estimates for egg albumen index (P<0.01), Haugh unit (P<0.01), serum glucose (P<0.001), and H-L ratio (P<0.001). Serum cholesterol was higher in cages with one hen than that with five hens, whereas plasma corticosterone was lower. Antibody titers in cages with one hen was similar to that with three or five hens; however, those with three hens had higher titers than those with five hens. Values for egg breaking strength, yolk index, egg cholesterol content, and foot health score were not affected by cage density or floor. The results suggest that the allocation of three hens per cage had no measurable effect on health and welfare.     

Effects of Eimeria mitis on egg production of single-comb White Leghorn hens.

Single-comb white leghorn hens infected with either B4 or C2 strain of Eimeria mitis produced watery droppings as early as day 5 PI. E. mitis infection did not affect egg weight. However, specific gravities of the eggs produced by the hens infected with E. mitis were lower than those produced by the controls. Egg production was significantly reduced temporarily, but most birds returned to production within 14 days. Many of the birds that ceased to lay went through a complete-body molt (56% of the C2-infected hens and 20% of the B4-infected hens). Hens that ceased to lay regained considerable amounts of pigment in their skin, beaks, and shanks.     

Evaluation of feeding spray-dried bovine plasma protein on production performance of laying hens exposed to high ambient temperatures

The purpose of this study was to evaluate feeding 2 levels of spray-dried bovine plasma protein (SDP) on production performance of laying hens subjected to high ambient temperatures. Two groups of 96 Hy-Line W-98 hens (38 wk of age) were housed in each of 2 environmentally controlled chambers. At 40 wk of age, all hens were fed 3 diet treatments consisting of (1) a control diet (0% SDP); (2) the control diet supplemented with 0.75% SDP; and (3) the control diet supplemented with 1.50% SDP. Hens in each chamber (8 cages of 4 hens per cage) were ad libitum fed 1 of each diet for 5 wk. The heat stress (HS) chamber was maintained at 21°C (wk 1), 29°C (wk 2), and 35°C (wk 3 to 5). The thermoneutral chamber was maintained at 21°C during wk 1 to 5. A significant main effect of week was observed for hens maintained in the HS chamber for egg production, egg weight, egg mass, and feed consumption, which resulted in acute heat stress causing a reduction in these parameters. Hens fed the 1.50% SDP diet in the HS chamber produced greater (P < 0.05) egg mass on average than hens fed the control or 0.75% SDP diet (wk 1 to 5). During the second week of acute HS (wk 4), hens fed the control and 1.50% SDP diets had greater (P < 0.05) egg production than those fed the 0.75% SDP diet. During wk 5, hens in the HS chamber that were fed the 1.50% SDP diet produced more (P < 0.05) eggs than those fed the control diet. Therefore, based on the results of this study, acute HS negatively affected short-term production performance. In addition, feeding hens an SDP-supplemented diet may have a slight positive effect on production performance when maintained in acute HS conditions.     

Effects of Alternative Molting Programs and Population on Layer Performance: Results of the Thirty-Fifth North Carolina Layer Performance and Management Test

A study involving 7 white-egg and 3 brown-egg commercial layer strains was conducted at the North Carolina Piedmont Research Station to assess the effects cage population 3-bird vs. 4-bird cages and alternative molt programs on performance through 113 wk of age (791 d). The flock was divided into 3 groups; not molted (NM), maintained in continuous production; molted using feed restriction (FR), an industry-type 14-d feed withdrawal molting program initiated at 463 d of age; and molted using a nonfasted/anorexic program (NF), in which an ad libitum supply of a low protein, low energy molt feed was provided. Productivity, egg size, and egg quality were monitored at 28-d periods throughout the test providing the performance data for the white-egg and brown-egg strains with regard to these management factors. Detailed results by strain are available on the following Web site: http://www.ces.ncsu.edu/depts/poulsci/tech_info.html#layer. The performance for the 3-bird or 4-bird cage groups for either type of layer was similar, except that birds in 4-bird cages had higher feed consumption in the first production phase than did the birds in 3-bird cages. In the same time period the white-egg birds in the 3-bird cages had a greater percentage of cracked eggs and a smaller percentage of Grade A large eggs than those in 4-bird cages. No differences were observed in egg income for the 2 population sizes for either type of layer. However, due to their higher feed consumption, the white egg birds in the 4-bird cages had higher feed cost per hen for the first cycle, which was offset by the egg income component due to their increased production rate. The molted layers outperformed the nonmolted layers for both types of layers in terms of overall income over feed costs. The FR molted hens, under a program that has traditionally been used by commercial producers, outperformed NF-molted hens, indicating that further refinements are needed to make the NF program economically competitive with the FR molting program.     

Evaluation of the effects of cage height and stocking density on the behaviour of laying hens in furnished cages

1. Limited information is available on how changes in horizontal and vertical space within enriched or furnished layer cages (as defined by Directive 1999/74/EC) influence hen behaviour. This study evaluated the effects of varying minimum cage heights and space allowances on the behaviour of laying hens housed in furnished cages. It was conducted on two flocks of medium brown hybrid hens housed in furnished cages with access to perches and nest boxes on a semi-commercial scale at ADAS Gleadthorpe. 2. Flock 1 consisted of two layer strains (ISA Brown and Babcock 380), housed at two minimum cage heights (38 and 45 cm) and 5 stocking densities between 609 and 870 cm2/bird, with 12 replicates of each of the 20 strain/cage height/stocking density treatment combinations. Stocking density was varied by varying the number of birds per cage from 10 to 7 in standard full-width cages or housing 7 hens in a narrower cage. As a consequence stocking density, group size and trough width per bird co-varied for 4 out of 5 stocking density treatments. 3. Behaviour of flock 1 was sampled at 33 to 36, 46 and 68 weeks of age. At each age one top-tier, one middle-tier and one bottom-tier cage was sampled for each treatment. 4. Few behavioural differences due to cage treatments were detected. Hens at 870 cm2 had shorter feeding bouts than hens at 609 and 762 cm2. Yawning was more common in the cages with greater cage height. 5. Video recordings of flock 1 examined cage height effects on hens' use of vertical space and provided additional data on stretching and self-maintenance activities. No differences in behaviour between 38 and 45 cm cages were found except that scratching head was more common in cages with greater cage height. 6. Flock 2 consisted of two layer strains (Shaver Brown and Hy-Line Brown), housed at 38 and 45 cm and 609, 762 and 1016 cm2/bird, with 18 replicates of each of the 12 strain/cage height/stocking density treatment combinations. Stocking density was varied by housing 10, 8 or 6 hens in standard full-width cages. Behaviour of flock 2 was sampled at 30, 48, 60 and 67 weeks from video recordings. Three cages per treatment from middle-tiers only were sampled at each age. 7. Hens housed at 609 cm2/hen had the longest mean feeding bout, greater than for hens at 762 cm2/hen but not hens at 1016 cm2/hen. More unsuccessful attempts to reach the feeder and sideways and backwards displacements from the feeder occurred at 762 and 609 cm2/hen than at 1016 cm2/hen. A maximum of 8 hens were observed feeding synchronously. 8. These results suggest that changes in horizontal and vertical space over the ranges we studied had little effect on behaviour other than feeding behaviour. Specifying a minimum useable trough space per hen, rather than calculating feeder space from total length of feeder per cage, irrespective of accessibility, might help avoid crowding at the feeder and associated disturbance of feeding bouts.     

Behavior, physiology, performance and physical condition of layers in conventional and large furnished cages in a hot environment

The aim of the present study was to compare old layers' level of welfare and performance between conventional and large furnished cages under hot environmental conditions. At the age of 80 weeks, 104 Boris Brown layers were divided into two groups: 12 conventional cages (two hens/cage) and four large furnished cages (20 hens/cage, 240 cm wide × 62 cm deep). The room temperature was set to fluctuate between 25 and 33°C in a day. The hens' behavior, immune response, performance and physical condition were measured. Aggression and moving were more frequent in furnished than in conventional cages (P < 0.05 for both items). Egg production (P < 0.05), egg mass (P < 0.05) and feed conversion ratio (P < 0.01) were better in conventional cages than in furnished cages. No significant differences were found in the birds' immune responses or physical condition between the cage designs. In conclusion, under a hot environment, the performance of old layers in large furnished cages was lower compared with that in small conventional cages, which might be due to their greater aggressive interactions. However, it was not evident that welfare level was lower in large furnished cages compared with conventional cages. Hereafter, additional studies about large furnished cages using young layers over a long term should be performed.     

The effect of visual pattern complexity of feeders on food consumption of laying hens

One hundred and twenty‐eight commercial laying hens were used to investigate the effects of pattern complexity on quantitative food intake. Independent variables were represented by eight pattern displays placed in trough feeders in the front of birds and exposed for 1 week intervals to groups of four hens in individual cages. As independent variables were also declared the location factors associated with the usual commercial type of hen house (tier levels, sides of the room and distance from working area). Dependent variables were weekly food consumption, egg production, egg weight, egg mass and food utilisation. Prior to the experiment the birds were adapted to the cages for one month. Birds were 24 weeks old at the commencement of the experiment which lasted for 26 weeks.

Food consumption was positively effected by chromatic pattern complexity and by colour preference. Effects of complexity of achromatic displays, as used in this study, indicated a similar trend, but were not of such a magnitude as to reject the null hypothesis. Location of cages contributed to the variability of some dependent variables. Some psychophysical factors associated with usual cage arrangement in pens are considered to explain such effects.     

Effect of Perches at Different Positions in Conventional Cages for Laying Hens of Two Different Strains

Production, health and behaviour were studied in 648 White Leghorn hens of two strains, LSL and Shaver 288, housed in three-tier battery cages (four hens per cage, 600 cm2 per hen) with three treatments; two with a perch fitted across the cage, 17 (PB) or 24 cm (PC) from the back of the cage, respectively, and control cages without perch (NP). Introducing a perch did not significantly affect production, but PC gave more dirty eggs, and both PC and PB tended to give more cracked eggs. The perch caused inferior keel bone condition and hygiene of the cage floor and a stronger tibia. LSL hens showed higher production, better feed conversion ratio, fewer cracked eggs, better keel bone health and shorter claws than Shavers. Use of the perch averaged 25 and 90% during day and night, respectively. The perch did not significantly affect other behaviours. There were significant interactions between strain and cage design regarding laying percentage, egg weight, cracked eggs, live weight, foot- and perch hygiene, keel bone condition and toe pad hyperkeratosis.     

Behavior, performance and physical condition of laying hens in conventional and small furnished cages

The aim of the present study was to compare the welfare level and performance of laying hens between conventional and small furnished cages. At the age of 54 weeks, 120 White Leghorn layers were divided into four groups: four (C4) or six hens/cage in conventional cages and four or six (F6) hens/cage in furnished cages. Their behavior, number of steps taken, performance and physical condition were measured. Sham dust‐bathing was greater in conventional cages than in furnished cages (P = 0.05) and dust‐bathing, litter scratching and litter pecking were also observed in furnished cages. Other comfort behavior, moving and number of steps taken were more frequent in the four‐hen cages than in the six‐hen cages (P < 0.01, P < 0.001, P < 0.001, respectively). Though egg production and egg mass in C4 and F6 were lower than in the other groups, no significant differences were found in the other production measurements. Bodyweight gain was larger in the four‐hen cages than the six‐hen cages (P < 0.01). In conclusion, behavior was not restricted in the furnished cages, but activity and bodyweight gain were affected by group size (density) rather than cage design. Hereafter, the studies on suitable density in each cage design, using young layers, are required.     

Effects of Chinese herbal mixture on performance,egg quality and blood biochemical parameters of laying hens

The aim of the study was to evaluate the effect of Chinese herbal mixture (CHM) in laying hen diets on performance, egg quality and egg nutrition components, as well as selected blood biochemical parameters. A total of 270 Lohmann Brown laying hens, 24 week of age, were randomly distributed into three dietary treatments and fed for 6 week. The CHM was used at the levels of 0%, 0.5% and 1.0% in the diets of the control and two treatment groups respectively. Each dietary treatment was divided into five replicates, comprising of 18 hens each. Hens were housed in a 3‐tier battery system. Feed and water were provided ad libitum. Blood samples and eggs were collected at the end of the experiment. The results showed that dietary treatments did not affect egg weight, mortality, eggshell thickness, albumen height, Haugh units, eggshell‐breaking strength and egg‐shape index. Dietary supplementation of CHM significantly improved (p < 0.05) laying rate and the lowest feed conversion ratio were observed with 1.0% CHM supplementation diets. CHM supplementation decreased (p < 0.05) cracked‐egg rate, egg yolk cholesterol, blood serum levels of cholesterol, triglyceride, low‐density lipoprotein cholesterol (LDL‐C) and alanine aminotransferase (ALT) and increased blood serum levels of high‐density lipoprotein cholesterol (HDL‐C). No differences in serum total protein, serum albumen, serum glucose and aspartate amino transferase (AST) were observed in hens fed CHM. In conclusion, dietary supplementation with CHM improved egg production and egg quality and reduced serum cholesterol concentrations in laying hens. Dietary supplementation of 1.0% CHM in layer diets may be a feasible means of producing eggs with lower cholesterol and higher egg yolk phospholipid contents for health conscious consumers.     

Perch Arrangements in Small-Group Furnished Cages for Laying Hens

In 2 trials, including 2,768 birds in total, 3 different perch arrangements were evaluated in furnished 8-hen cages for laying hens. The hybrids used were Lohmann Selected Leghorn and Lohmann Brown in trial 1 and Hy-Line White and Hy-Line Brown in trial 2. The furnished cages were identical in all other respects than the arrangement of perches. A perch was either fitted across the cage, providing 12 cm of perch per hen, or 2 perches were installed in a cross, implying 15 cm per hen. Although the perches arranged in a cross provided more perch per hen than the single perch fitted across the cage, perch use at night by the birds was similar or lower as compared with the single perch. Hence, the way perches are arranged in the cage may be as important as perch length itself to achieve a high use at night. Perch arrangement did not affect production, mortality, or egg quality. Compared with a conventional battery cage, also included in the trials, hygiene was inferior in the furnished cages, but there was no difference in proportions of dirty eggs. Differences in proportions of cracked eggs were found between furnished and conventional cages in 1 of the trials. However, on the whole, production, mortality, and egg quality were at similar levels in all cage models. Genotype differences were found in production traits, egg quality, hygiene, and in the use of perches and nests.     

Evaluation of pearl millet and flaxseed effects on egg production and n-3 fatty acid content

1. A 6-week trial was conducted to evaluate the effects of pearl millet (PM) as a replacement for maize, in combination with flaxseed (FS), on productivity, egg trait parameters and egg n-3 fatty acid (FA) content in White Leghorn hens. 2. Six diet treatments were used: a control (CTL, maize-soybean meal based) diet, and diets containing 0, 2, 4, 8 or 12% FS, in which all maize was replaced by PM (PM-0, PM-2, PM-4, PM-8 and PM-12, respectively). All diets were isocaloric and isonitrogenous and met NRC (1994) requirements. Eight cage replicates per treatment were used (three hens per cage). At the end of each week, three eggs were randomly collected from each cage to measure egg trait parameters and yolks were separated, pooled and lyophilised for FA determination. Body weights and feed consumption were recorded weekly. Egg production (number of eggs and egg mass produced) was recorded daily. At the end of the experiment, all hens were killed to determine liver haemorrhage score. 3. Egg traits and flock performance parameters were not different among treatments except at week 4, when birds on the PM-12 diet produced smaller eggs than hens on the PM-0 and PM-2 diets. Yolk pigmentation scores were lower for the PM-0 and PM-2 diets (1.60 +/- 0.24 and 1.80 +/- 0.20, respectively), increased with higher inclusions of FS (2.75 +/- 0.47 for PM-12 diet) but did not reach control levels (6.00 +/- 0.01). Liver haemorrhage scores were not affected by dietary treatment. Hens given the PM-8 and PM-12 diets produced eggs with n-3 FA content higher than required to be considered as n-3 FA enriched eggs, and had a lower n-6/n-3 FA acid ratio than eggs of hens consuming CTL or the PM based diets with lower FS supplementation. 4. These results suggest that PM can be used to substitute for maize in the diets of layers and may reduce the amount of FS needed to obtain n-3 FA enriched eggs.     

评价一种新型肉用种鸡双层饲养笼

1 524只艾维茵肉用种鸡被随机安置在一种新型自然交配笼中或以常规方式(1/3竹床,2/3垫料)饲养了一个产蛋周期.笼养种鸡繁殖、生产性能优于常规组:成活率提高15.5%;产蛋数增加20.9枚;大群用药减少75%.肉用种鸡双层饲养笼的优点还包括无垫料购置和贮藏费用、改良种鸡生产环境、减轻工人劳动强度和降低生产成本等.