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1.
Stress and feather pecking in laying hens in relation to housing conditions   总被引:4,自引:0,他引:4  
1. Possible association between high rates of feather pecking and increased stress were investigated in laying hens. 2. From week 19 to week 30 after hatching, 16 groups of 11 hens (white Lohman Selected Leghorn hybrids) were kept in pens with or without long-cut straw as foraging material and provided with food in the form of pellets or mash. 3. Stress was assessed by egg production, weight gain, tonic immobility (TI), heterophil/lymphocyte (H/L) ratio and antibody titres to sheep red blood cells (SRBC), tetanus toxoid (TT) and human serum albumin (HSA). 4. Provision of foraging material and food form influenced feather pecking. Rates of feather pecking were highest in groups housed without straw and fed on pellets. 5. Egg production was reduced in pens without straw but not affected by food form. Both the duration of TI and H/L ratios were influenced by provision of foraging material and food form. TI was longer and H/L ratios were increased in hens housed without straw and in those fed on pellets. Antibody titers to SRBC and TT were lower in pens without straw than with straw but not influenced by food form. 6. In conclusion, foraging material and food form affected both feather pecking and indicators of stress, suggesting that feather pecking in laying hens is associated with stress.  相似文献   

2.
1. Bunches of white string (polypropylene twine) are particularly attractive pecking stimuli for both chicks and adult laying hens. Furthermore, these devices can retain the birds' interest over lengthy periods. It has also been demonstrated that birds with trimmed feathers elicit feather pecking. The present study was designed to determine whether string devices would retain their attractiveness in the presence of a competing stimulus: a trimmed hen. 2. Lohmann Brown hens were reared in 20 groups of 5 in floor pens with perches from 17 weeks of age. They were exposed to one of two treatments when they were 23 weeks old. One hen was removed from every pen and the feathers on her rump were trimmed. Immediately before her return two string devices were suspended from a perch in treatment 1 whereas no devices were included in treatment 2. Pecking behaviours were immediately observed for 30 min; this procedure was repeated later that day. The devices remained in the pens used in treatment 1 and these birds were observed again for 15 min after 14 d. 3. The string devices were pecked earlier and more than either the trimmed or untrimmed hens. Furthermore, the devices were still being pecked 2 weeks after their introduction. 4. The virtual absence of severe feather pecking and of aggressive head pecks precluded test of our hypothesis that the devices would divert potentially injurious pecking away from other birds. However, the fact that the birds showed sustained interest in the devices, even in the presence of a competing stimulus, supports our proposal that string may represent a practicable and effective form of environmental enrichment.  相似文献   

3.
1. In order to reduce injurious pecking, the influence of environmental enrichment on pecking and perching behaviour was studied in young male and female turkeys. 2. Two different types of enrichment and a control treatment (TO) were tested: T1, metal objects and straw; T2, similar to T1 + wood perches. Birds were housed in 36 m2 pens at a light intensity of 5 lux with 4 replicates per treatment in a 2x3 factorial design. 3. Pecking at objects and perching behaviour were observed weekly. Behaviour was video recorded at weeks 5 and 10. Birds were examined daily for the occurrence of injuries. At the end of the rearing period, an ACTH challenge was performed and H/L ratio was measured. 4. Objects were regularly pecked at. Perching was more common in females, peaked at week 5 (10% to 13% of birds perched) and declined to 0% by week 10. Aggressive pecking was more frequently observed in males in T0 than in T1 or T2 at week 10. Wing (in males and females), tail and head (in males) injuries were more common in T0 than in T1 or T2. T1 and T2 were similar Response to ACTH challenge and H/L ratio were not consistently influenced by treatments. 5. It is concluded that metal objects and straw reduced injurious pecking in young female and male turkeys by redirecting, pecking activity.  相似文献   

4.
1. The objective of the present study was to examine the behaviour of laying hens in single-tiered aviaries with and without outdoor areas with particular reference to the proportion of each behaviour and the ways it changed. 2. In all, 144 interbred cross layers (WL/RIR cross-breed) were used. At the age of 16 weeks, the hens were divided at random into two groups and moved to single-tiered aviary (SA) and free-range systems (FR, SA with in addition an outdoor range area covered with clover) with 18 hens per pen. Behavioural observations were conducted before, during and after access to the range. 3. All behaviours using the beak (eating, grazing, drinking, preening, aggressive pecking, feather pecking, litter pecking, object pecking and mate pecking) were recorded as pecking behaviour. 4. While most of the FR hens spent their time outside foraging, the proportion of hens eating, preening, litter pecking, object pecking, aggressive pecking and feather pecking was higher in SA than in FR hens. 5. The proportion of hens performing pecking behaviour of all types was very similar in SA (61.7 +/- 2.0%) and in FR (64.0 +/- 0.8%). The proportion of hens performing overall pecking behaviour increased as pre-laying sitting decreased. 6. The proportion of hens feather pecking decreased in FR during access to range and a similar tendency was found for aggressive pecking. 7. In conclusion, the total proportion of hens pecking was almost the same regardless of whether an outdoor area was provided or not, but the incidence of different types of pecking behaviour differed between SA and FR. The risk of feather pecking in FR may be lower when an outdoor grazing area is provided, although further testing on a larger scale would be essential.  相似文献   

5.
1. The effect of the presence of loose feathers (on the floor) on the behaviour and plumage condition of laying hens (Lohmann Silver, LS) was studied during the rearing and laying periods. 2. From one day old, 60 birds in each of 4 straw-bedded pens (n = 240 in total) with 6.5 birds/m(2) were either kept under conventional rearing and management conditions (CT: control group with feathers on the floor; n = 120) or in pens from which the feathers were collected from the floor 4 times/week (FR: feathers removed; n = 120). Fifty birds from each of these 4 groups (n = 200 in total) were randomly selected at the age of 16 weeks and allocated to 4 identical pens in a poultry layer house (PH; with perches and 1/3 slatted floor) with access to an outside area (winter garden, WG) at a stocking density of 6 birds/m(2) in both PH and WG. 3. Observations on feather pecking and other behaviours (feeding, drinking, preening, standing, sitting, foraging, moving and dust bathing) were carried out at 8 ages: 6, 10, 15 (rearing period), 20, 25, 30, 35 and 40 weeks (laying period). Feather scoring was carried out at 15, 32 and 39 weeks of age. 4. There were no differences in feather pecking rates, forms (gentle, severe and aggressive pecks) as well as in the plumage condition between groups at the end of the rearing period. 5. Birds in the FR group exhibited lower rates and less severe feather pecking during the laying period. Accordingly, birds in the control group had worse feather condition at 32 and 39 weeks of age. Feather pecking rates within groups were, in general, greater in the afternoon compared to the morning periods. Birds in the control group were more active in walking. 6. Wings, rump, tail and back were the main targets for feather pecking. The majority of feather pecking occurred on the floor (66%) followed by feeding area (26%), perches (4%) and slats (4%). 7. Our results suggest that loose feathers on the floor may play an important role in the development and severity of feather pecking behaviour in laying hens and support the hypothesis (McKeegan and Savory, 1999) that feather pecking can be viewed as redirected foraging behaviour.  相似文献   

6.
1. The study investigated the effects of providing sight barriers in breeding pens on pheasant mortality, feather damage and behaviour. 2. Data were collected from 11 conventional pens (control) and 11 pens with additional sight barriers (barrier) over the course of a ten week breeding season. Each pen contained 8 males and 56 females at the beginning of the season. 3. There was a higher rate of mortality in males (6 x 25%) than females (2 x 11%) that was unaffected by treatment. 4. Feather damage increased over the breeding season and both male and female pheasants showed better feather condition in the pens with barriers at the end of the season. 5. The pheasants spent most of their time walking or standing. Providing barriers increased perching, but reduced preening. 6. The provision of sight barriers had no effect on the incidence of courtship and mating, but did reduce aggressive interactions such as pecking and chasing. 7. The study provides baseline data on the behaviour of breeding pheasants under these husbandry conditions, and suggests that barriers may improve pheasant welfare by reducing potentially harmful aggressive interactions, without affecting activity patterns or reproductive behaviour.  相似文献   

7.
Effect of foraging material and food form on feather pecking in laying hens   总被引:2,自引:0,他引:2  
1. The aim was to test whether provision of foraging material and food form influence feather pecking and feather damage in laying hens. 2. From week 19 of age, 16 groups of 11 hens (white Lohman Selected Leghorn hybrids) were kept in pens with or without access to long-cut straw as foraging material and fed on either mash or pellets. 3. Foraging behaviour was increased in hens with access to straw and time spent feeding was increased in hens fed on mash. In addition, hens fed on mash had longer feeding bouts and higher rates of pecking at the food during feeding than hens fed on pellets. 4. There were interaction effects of foraging material and food form on both feather pecking and feather damage. High rates of feather pecking and pronounced feather damage were only found in hens housed without access to straw and fed on pellets. In groups characterised by high rates of feather pecking the hens also showed more severe forms of this behaviour. 5. Differences in the time budgets of hens kept in different housing conditions suggested that birds fed on mash used the food not only for feeding but also as a substrate for foraging behaviour. 6. In order to avoid problems with feather pecking it is recommended that laying hens are provided with foraging material and fed on mash.  相似文献   

8.
1. Behavioural patterns of 4 slow-growing local breeds of chickens in Taiwan and China, Taiwan Country chickens, Beijing Fatty chickens, pure Silkies, and upgraded commercial Silkies, were studied from 5 to 16 weeks of age as a reference of management for commercial production. 2. Fifteen males and 15 females of the same breed were housed in a pen. Every breed had 6 pens and 24 pens were studied. 3. Taiwan Country chickens displayed more aggressive, sexual and feather pecking behaviours, had less resting time, the fastest feeding rate and used perches more often. The fast-growing and heavy commercial Silkies had more feeding activity and less preening activity. They were also similar to the crested and docile Beijing Fatty chickens and had less stand/walking and more resting time. The pure Silky bantams showed much more foraging activity than the other breeds. 4. When males started to display more aggression and sexual behaviour, after 8-12 weeks of age, resting time for all birds started to decline and stand/walking increased. 5. These results could imply that different local breeds need different housing systems for the bird's welfare.  相似文献   

9.
We reported previously that behavioral development of chicks was promoted remarkably by the presence of a broody hen. Here we report that these effects at an early age persist after maturity. A total of 60 female chicks were randomly assigned to one of two treatment groups: six pens with five chicks (brooded group) each were reared by a broody hen and six pens with five chicks (non‐brooded group) each were provided with an infrared heating lamp. We evaluated the persistent effects of broody hens by measures of behavior, physical condition and production at 9, 16, 35 and 55 weeks of age. The numbers of threatening, aggressive pecking, fighting and severe feather pecking behaviors were higher in non‐brooded than in brooded chickens (all P < 0.05). Egg production was lower in brooded than in non‐brooded chickens (P < 0.05), while the number of brooding chickens was higher in the brooded than in the non‐brooded group (P < 0.05). In conclusion, the presence of broody hens at an early stage of chicks' lives has a persistent effect on behavior. Although brooded chickens showed more brooding and lower egg production than non‐brooded chickens, feather pecking and aggressive interaction were decreased in brooded hens.  相似文献   

10.
1. Behaviours associated with a high or low tendency to feather peck could be used as predictors of feather pecking behaviour in selective breeding programmes. This study investigated how strain and age at testing influenced responses in behavioural tests. 2. Four layer-type strains (ISA Brown, Columbian Blacktail, Ixworth and a high feather pecking (HP) and a low feather pecking (LP) line of White Leghorn) were reared in 6 same-strain/line pens of 8 birds from one day old. Birds in half the pens were given an open field test, a novel object test and a test with loose feather bundles between 4 and 12 weeks of age and a tonic immobility (TI) test at 13 weeks of age. All pens were tested with fixed feather bundles at 26 weeks, and undisturbed behaviour in the home pens was videoed at 1 and 27 weeks of age. Daily records of plumage damage were used as an indicator of feather pecking activity in the home pens. 3. Strain did not influence novel object test, open field test or loose feather test behaviour, although age effects in all three tests indicated a reduction in fearfulness and/or an increase in exploratory behaviour with increasing age. 4. White Leghorns showed longer TI durations than the other strains but less pecking at fixed feather bundles than ISA Browns and Columbian Blacktails. 5. There were few associations between behaviour in the 5 different tests, indicating that birds did not have overall behavioural traits that were consistent across different contexts. This suggests hens cannot easily be categorised into different behavioural 'types', based on their test responses and casts doubt on the usefulness of tests as predictors of feather pecking.  相似文献   

11.
1. Additional straw or grain was supplied to hens during rearing in floor pens with litter floors. During lay, hens were housed in pens with partly-littered partly-slatted floors. The effects on foraging behaviour and feather pecking were studied and feather damage was scored at 17, 30 and 42 weeks of age. 2. Supply of grain in the litter during rearing caused an increase in ground scratching. Ground pecking also tended to increase. Supply of straw had no significant effect on the observed behaviours. 3. Feather damage in the laying period was significantly reduced by providing grain during rearing. A similar tendency was found for groups that received straw during rearing. On the basis of the behavioural observations it was concluded that this better plumage cover was caused by less feather pecking. 4. The frequency of pecking at food was decreased during rearing by the supply of grain. This could not be explained solely on the basis of a lower food intake. Apparently the efficiency of pecking at food had changed as well. Behavioural data from the laying period suggest that this change was of a more permanent character. 5. The incentive value of the ground and the substrate covering it might be increased by the supply of grain during the rearing period. This causes foraging-related behaviours like scratching and pecking to be directed to the ground. The hens' perception of incentive stimuli for pecking is apparently influenced by experience during rearing. 6. To prevent birds redirecting their ground pecks to the feathers of other birds, not only the peckability/scratchability of the ground seems to be important but also other aspects like nutritive value or taste.  相似文献   

12.
To improve the welfare of caged laying hens, a pecking device made of stones was introduced on the cage floor. Twenty‐four White Leghorn hens aged 15 months were divided into four groups: single‐housed hens with device, single‐housed control hens, pair‐housed hens with device and pair‐housed control hens. Hens housed with the device pecked at various pecking objects less often than control hens. Agonistic behavior was also lower in hens with the device than in hens without the device, implied a possibility of improvement in quality of pecking stimuli with the device. Not only time spent pecking, but also quality of pecking might be important to fill their need for stimulation. Both single‐ and pair‐housed hens more often pecked at the device in the evening. Response to various pecking objects also showed that pecking behaviors were most frequently expressed in the evening. Increased foraging at dusk is a well‐known habit; therefore, the increase in pecking behavior in the evening might reflect the hens' general circadian rhythm. These results indicate that the device made of stones could promote some instinctive behavior. Enhancement of behavioral repertories and reduced agonistic behavior with the pecking device might improve the welfare of caged laying hens.  相似文献   

13.
1. We examined the effect of density (5, 7, 9 and 11 birds/m2) and season (summerand winter; different hens each season) on stress and behaviour in two flocks of 64 broiler breeder females divided among 8 pens. 2. The hens, approximately the same age and body mass in each season, were maintained on hard-packed ground, without litter, in an open-sided chicken house and were offered the same amount of food each season. 3. Mean house max/min temperatures varied between 18 and 33 degrees C in summer and 7 and 17 degrees C in winter. Mean relative humidity in summer varied between 68% at 08:00 h and 42% at 14:00 h and in winter was 64% at 08:00 h and 47% at 14:00 h. 4. No difference was found in heterophil:lymphocyte ratios among densities and between seasons; however, basophil numbers were higher in winter than in summer indicating prolonged stress in winter. 5. Stereotyped pecking increased with an increase in density and was higher in winter than in summer. Pecking on the ground was higher in winter, but was not affected by density. 6. In summer the hens spent more time lying and eating than in winter, whereas in winter the hens spent more time walking, preening and drinking than in summer. They spent the same amount of time standing in both seasons. None of these behaviours was density dependent. 7. We conclude that season had more of an effect than density on stress and behaviour in broiler breeder hens under the conditions of our study.  相似文献   

14.
活性干酵母对肉鹑生长性能及内脏器官的影响   总被引:1,自引:0,他引:1  
为研究活性干酵母对肉用鹌鹑生长性能和内脏器官的影响,探讨日粮中添加活性干酵母在鹌鹑生产中的效果,选用1日龄鹌鹑180羽,随机分成4组,每组设3个重复,每个重复15羽鹌鹑。对照组饲喂基础日粮,试验组在基础日粮中分别添加0.06%、0.1%、0.2%的活性干酵母。结果表明:日粮添加活性干酵母均可降低14日龄鹌鹑料重比(P<0.05);0.06%活性干酵母可降低25日龄鹌鹑采食量(P<0.05),0.06%和0.2%活性干酵母可降低25日龄鹌鹑料重比(P<0.05),0.2%活性干酵母可增加25日龄鹌鹑体增重(P<0.05);0.06%活性干酵母可增加35日龄鹌鹑体增重(P<0.05),降低35日龄鹌鹑料重比(P<0.05)。活性干酵母各添加组与对照组相比肝脏、脾脏、法氏囊指数差异不显著(P>0.05),0.2%活性干酵母可提高鹌鹑心脏指数(P<0.05);0.1%活性干酵母可提高鹌鹑胰腺指数(P<0.05)。说明饲喂0.06%活性干酵母提高肉鹑生长性能效果最佳,提高活性干酵母浓度后,鹌鹑生长性能影响没有明显变化,但可改善内脏器官指数。  相似文献   

15.
1. Two experiments were conducted to examine the effect of feeding higher supplemental vitamin E (VE) concentrations on male reproductive variables, fertility and hatchability of quails. 2. In experiment 1, sixty 5-week-old male quails, reared in individual cages, were fed male breeder diets supplemented with 0, 75, 150, 225 or 300 IU alpha-tocopherol acetate/kg. At 10 weeks, observations on cloacal gland size, foam production, testes weight and blood samples for testosterone estimation were taken. 3. In experiment 2, 50 male and 50 female cage-reared quails (5 weeks old) were fed male breeder and layer rations, respectively, supplemented with 0, 75, 150, 225 or 300 IU/kg. At 13 weeks, 9 different mating pairs (5 pairs/group) were formed. Group 1 contained one control male and one control female in each of 5 pens. In groups 2 to 5, control males were paired with females on supplements of 75, 150, 225 or 300 IU/kg. In groups 6 to 9, control females were paired with males on supplements of 75, 150, 225 and 300 IU/kg. During subsequent adaptation and egg collection periods, each of 10 d, control layer ration was fed to all groups. All the eggs laid during the 10-d egg collection period were incubated artificially to estimate fertility and hatchability. The trial was repeated at 15 weeks. 4. Adult male quails receiving moderate supplemental VE (75 and 150 IU/kg) had a higher cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone than quails fed on either VE-deficient or more highly supplemented diets (225 and 300 IU alpha-tocopherol acetate/kg). 5. It was concluded that a supplement of 75 IU VE/kg in maize/soybean diet could provide the best reproductive performance of male breeder quails. Cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone can serve as indirect indicators of testicular activity and fertilising ability in quails. Supplemental VE did not affect the fertility and hatchability of male and female Japanese quails.  相似文献   

16.
不同水平枯草芽孢杆菌对鹌鹑内脏器官及小肠发育的影响   总被引:1,自引:0,他引:1  
选用健康1日龄黄羽雏鹑80只,随机分成4组,每组设2个重复,每个重复10只。1组为对照组,饲喂基础日粮,2、3、4组为试验组,在基础日粮中分别添加0.05%、0.1%、0.2%的枯草芽孢杆菌制剂。结果表明:各处理组与对照组相比胰腺鲜重都有减小趋势,且0.1%组胰腺鲜重与对照组的相比差异显著(P<0.05);0.05%组脾脏干重与对照组的相比差异显著(P<0.05);0.1%组和0.2%组胰腺干重与对照组的相比显著降低(P<0.05);芽胞杆菌对空肠,回肠以及十二指肠未见明显影响(P>0.05)。  相似文献   

17.
The present study investigated the effects of pecking stones on feeding behaviour of hens from 16 to 46 weeks of age. Eighteen flocks of Hy-Line Brown hens were housed in 2 commercial free-range housing systems. Farm A housed 10 flocks of beak trimmed (infrared beak treatment) hens in fixed sheds. Farm B housed 8 flocks of hens with intact beaks in mobile sheds. On each farm, flocks were equally assigned to control groups (no access to pecking stones) and treatment groups (access to pecking stones). Data were evaluated every 10 weeks. At each time point, 10 hens per flock were housed in individual pens, and each hen was provided with 250 g of mash diet and ad libitum water for 24 h. After 24 h, feed samples were collected and used to determine 24-h feed intake. Nutrient and particle selection was measured by subtracting nutrients and particles present in the leftover feed from the vaules obtained in the offered feed and expressed the change (Δ). In addition, pecking stone consumption was recorded for each flock. Data were analysed separately for each farm using fixed effects of pecking stone availability and hen age. Spearman's rho correlation coefficients and linear regression models were constructed to evaluate the relationship of beak length and pecking stone usage, discrete mean particle size (dMEAN) consumption (Δ dMEAN), and Δ nutrient intake. Hens with access to pecking stones consumed significantly lower quantities of large feed particles (>2.8 mm) on farm A (P = 0.029) and selected significantly more fine particles, on farm B (P = 0.013). Overall, positive relationships (P = 0.001) between beak length and pecking stone consumption, Δ dMEAN, and Δ phosphorus consumption were observed. In conclusion, pecking stone consumption resulted in reduced selection and consumption of feed particles in hens housed on both farms. Further research is warranted to investigate the effect of pecking stones on sensory innervation of the beak.  相似文献   

18.
1. The aim of the present study was to investigate whether individual birds specialise in feather pecking. Growers were individually marked and reared in groups of 30 or 31 in pens with a slatted floor. At an age of 4 to 6 weeks feather pecking was frequent in all pens. 2. On average 83% of all group members (10 groups, experiment 1) were recorded at least once as initiator of a feather pecking interaction. In each group 2 to 6 individuals feather pecked more than twice as often as the average for the group, and were defined as 'high rate peckers'. They initiated 39% of all recorded feather pecking interactions. 3. Every interaction was classified (with increasing intensity) as pecking, pinching, pulling or plucking. Compared to the others, 'high rate peckers' had more of their feather pecking classified as plucking and less classified as pecking. 4. There was no evidence that particular individuals specialised in pecking at other specific birds, at specific areas of the body or at birds engaged in specific activities. 5. Growers (3 groups, experiment 2) that had just feather pecked engaged in more feather pecking during a subsequent 2-min focal observation than control birds that had not pecked before the start of the observation. 6. It was concluded that feather pecking interactions are clustered in time and that the behaviour is not performed by just a few members of a group. However, some individuals are characterised by relatively high rates and more severe forms of feather pecking.  相似文献   

19.
The aims of this study were twofold: to develop and test an animal-based protocol for the assessment of the physical and emotional elements of the welfare of laying hens on free-range units and to investigate the effects of different approaches to housing and management on the welfare of the birds. The protocol was tested on 25 free-range units for laying hens, each of which was visited on four occasions by one of five trained observers; further information about husbandry, health and productivity was gathered from interviews with the farmers. Measures of the birds' attitude included arousal, noise, flight distance and response to a novel object, measures of their activity included feather pecking, aggression and use of range, and measures of their physical welfare included mortality, body condition and egg quality. Increased arousal was associated with increased flight distance, greater reluctance to approach a novel object and higher levels of feather pecking and feather loss, but the correlation between pecking and feather loss was low. The birds maintained body condition throughout the period of lay. Neither body condition, feather pecking nor feather loss was affected by the extent of beak trimming. Estimated losses (deaths and culls) ranged from 1.8 to 21.4 per cent (median 6.95 per cent). Few birds showed signs of ill health, limb lesions or red mite infestation. No feature of building design had a significant effect on mortality, but there were consistent differences in the birds' attitude, behaviour and performance attributable to the type of floor and the presence or absence of perches, which suggested that the welfare of the hens was inferior when they were housed on plastic floors with no perches.  相似文献   

20.
1. An experiment was carried out to examine the suitability of using maize silage, barley-pea silage and carrots as foraging materials for egg-laying hens. Production performance, nutrient digestibility, gastrointestinal characteristics, including the composition of the intestinal microflora as well as feather pecking behaviour were the outcome variables. 2. The protein content of the foraging material (g/kg DM) was on average 69 g in carrots, 94 g in maize silage and 125 g in barley-pea silage. The starch content was highest in the maize silage (312 g/kg DM), and the content of non-starch polysaccharides (NSP) varied from 196 to 390 g/kg, being lowest in carrots. Sugars were just traceable in the silages, whereas carrots contained on average 496 g/kg DM. 3. Egg production was highest in hens fed either carrots or maize silage, whereas hens fed barley-pea silage produced less (219 vs. 208). Although the consumption of foraging material was high (33, 35 and 48% of the total feed intake on 'as fed' basis for maize silage, barley-pea silage and carrots, respectively) only a minor effect on nitrogen corrected apparent metabolisable energy (AME(n)) and apparent digestibility was seen. At 53 weeks of age, hens fed maize silage had AME(n) and apparent digestibility values close to the control group (12.61 and 12.82, respectively), whereas access to barley-pea silage and carrots resulted in slightly lower values (12.36 and 12.42, respectively). Mortality was reduced dramatically in the three groups given supplements (0.5 to 2.5%) compared to the control group (15.2%). 4. Hens receiving silage had greater relative gizzard weights than the control or carrot-fed groups. At 53 weeks of age, the gizzard-content pH of hens receiving silage was about 0.7 to 0.9 units lower than that of the control or carrot-fed hens. Hens fed both types of silage had higher concentrations of lactic acid (15.6 vs. 3.2 micromoles/g) and acetic acid (3.6 vs. 6.1 micromoles/g) in the gizzard contents than the other two groups. The dietary supplements had a minor effect on the composition of the intestinal microflora of the hens. 5. Access to all three types of supplements decreased damaging pecking in general (to feathers as well as skin/cloaca), reduced severe feather pecking behaviour and improved the quality of the plumage at 54 weeks of age. 6. In conclusion, access to different types of foraging material such as silages and carrots improved animal welfare.  相似文献   

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