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1.
蛋鸡养殖期间不同生长发育阶段的营养需求有所差异,为更好地满足不同阶段蛋鸡的生长需求,应对饲料配方做出动态化调整,加强营养调控技术的研究。通过对饲料配方进行科学调整,能保证营养供给更加充足,更加均衡满足蛋鸡生长需求,保证蛋鸡健康生长,减少饲料成本,提高饲料利用效率。该文主要论述蛋鸡在不同生长阶段的营养调控技术,并提出完善蛋鸡营养调控技术的措施。  相似文献   

2.
胆碱是蛋鸡所必需的营养物质,主要用来合成蛋黄的卵磷脂。蛋鸡能够大量合成胆碱,但在实际生产中蛋鸡能否合成足够的胆碱来满足其需要一直存在很大的争议。本文综述了饲料中胆碱的含量及其生物利用率的评价以及胆碱在蛋鸡养殖中的应用,为其相关研究及在生产中应用提供参考。  相似文献   

3.
1. The objective was to determine the relation between social rank and use of resources in a small furnished cage with sufficient resources per hen (SF) and a commercial large one with less adequate allowance of facilities per hen (LF). 2. Ninety-two cross layers were used. At the age of 16 weeks, the hens were divided at random into two groups. There were 4 furnished cages with 5 birds per cage and 4 large furnished cages with 18 birds per cage. The dominance hierarchy was determined, in which highest, medium and lowest ranking hens in each cage were identified. Behaviour, use of facilities and physical conditions of these hens were measured (one in each rank category in SF, two in each in LF). 3. Dustbathing and litter scratching were more frequent in the high ranking hens than the medium and low ranked hens in LF, while no significant difference was found between them in SF. 4. No significant difference between SF and LF was found in use of nest boxes. However, pre-laying sitting tended to be less frequent in low ranking than medium and high ranking hens in LF (Social order x Cage design). In the nest box most of time was spent in pre-laying sitting by SF hens, LF high and medium ranked hens (average 94.9%). However, LF low ranking hens spent their time escaping (33.1%), pre-laying sitting (27.7%) standing (25.7%) and moving (13.5%) in the nest. 5. In the large furnished cages with less facilities per hen, high ranking hens may be expected to have priority using the dust bath. In contrast, low ranking hens rarely performed nesting behaviour fully, and spend more time using the nest box as a refuge than for laying.  相似文献   

4.
Abstract

Two experiments were conducted to study the effects of different forage crops on productivity and some egg quality parameters of small flocks of organic laying hens fed whole wheat or concentrates. Each experiment was carried out in a split plot design with two different forage crops and two types of supplementary feed (typical concentrate for organic layers versus whole wheat) with three replications. In the first experiment the tested forage crops were of a well-established grass/clover and a mixture of forbs (Fagopyrum esculentum, Phacelia tanacetifolia and Linum usitatissimum). In the second experiment the tested forage crops were a well-established grass/clover and chicory (Cichorium intybus cv. Grassland Puna). The results on productivity and egg quality suggest that laying hens consume large amounts of foraging material when accessible. In nutrient restricted hens (wheat-fed) the forage may yield a substantial contribution to the requirements of amino acids and metabolizable energy although productivity parameters and measurements on dry matter in albumen showed that wheat-fed hens, on a short-term basis, were not able to fully compensate for the lack of protein and amino acids by increased foraging. Of the forage crops investigated especially chicory seems to contribute to the nutrition of the hens. Measurements on eggshell parameters showed that oyster shells together with foraging material were sufficient to meet the hens’ calcium requirements. Yolk colour clearly revealed that laying hens consume large quantities of green fodder irrespective of the type of supplementary feed. Yolk colour from hens with access to chicory tended to be darker, of a redder and less yellow hue compared with grass/clover fed hens, which is considered a positive quality.  相似文献   

5.
Rations in which all the protein was supplied by wheat and soybean meal or corn and soybean meal were fed to White Leghorn hens for 252 d. Rations based on wheat‐soybean meal which contained 14% protein supported a high and efficient rate of egg production when supplemented with sufficient lysine and methionine to ensure minimum intakes of 600 and 300 mg per hen‐day, respectively. Similarly, corn‐soybean meal rations which contained 12 to 14% protein and were properly supplemented with methionine and lysine supported satisfactory laying hen performance. Average egg size of hens fed on rations based on wheat was slightly smaller than that of hens fed on corn‐based rations. Lysine supplementation did not alleviate this.

The data re‐emphasise that protein concentration of laying hen rations can be reduced from the commonly used 15.5 and 16.5% levels to 14% without impairing productive performance, provided that rations based on wheat and soybean meal or corn and soybean meal are supplemented judiciously with lysine and/or methionine.  相似文献   


6.
1. The use of cross-wise perches by laying hens was investigated in 8 groups of 6 hens. During a period of 5 weeks each group was exposed to 4 different perch arrangements: a single straight perch of 60 cm (P60), a 30-cm perch crossing the middle of another 30-cm perch (P30 + 30), crossing a 45-cm (P45 + 30) or crossing a 60-cm perch (P60 + 30). 2. Perch arrangement influenced perch use. Perch occupancy (the mean number of hens using the perches) was lowest in the P30 + 30 treatment during daytime, evening and night. Perch occupancy was lower for P45 + 30 than for P60 + 30 during daytime and for P60 during evening and night. Perch occupancy did not differ between P60 and P60 + 30. 3. Perch utilisation (perch use per unit of total perch length provided) was lower for the three cross-wise perch arrangements than for P60, indicating that the area near the crossing was not used optimally. 4. There were indications that the process of taking roosting positions was more disturbed with cross-wise perches. 5. Legislation and guidelines about the minimal perch length per hen should be refined to take into account the arrangement of the perches. A perch of 30 cm cross-wise to another perch should not be included in the total amount of perch length provided to the hens. For longer cross-wise perches, the precise distance near the cross that should be excluded remains to be determined.  相似文献   

7.
The egg production industry is facing various problems that need to be solved. For amino acid nutrition to achieve scientific and economical feeding of laying hens, it is necessary to elucidate the content, digestibility, or availability of nutrients of feedstuffs and feeds and the requirement of amino acids for laying hens. In addition, improvement to quality of eggs and meat of spent hens, methods of management and development of new feedstuffs are essential. For sustainable animal production, decrease in excreta and animal welfare should be studied. The real‐time determination of content and digestibility of amino acids in feedstuffs are essential for formation of feeds. Recent advances in the near infrared reflectance analysis will be able to determine the content, digestibility and availability of nutrients in feedstuffs and feeds, if we have a supplemental amount of conventional analysis to define the calibration population. The amino acid requirements are affected by various factors. Therefore the method to quickly and exactly determine amino acid requirements in response to various factors is necessary. By using plasma free amino acid concentration as a criterion, it is possible to determine amino acid requirements in various conditions of laying hens within a short experimental period, repeatedly using the same animals. Because the amino acid requirements differ among individual animals, it should be expressed as grams per hen per day. Practically, it is impossible to formulate various feeds for individual hens. The various expressions have been developed and these expressions have advantages and disadvantages. The nitrogen excretion of laying hens is easily reduced by reducing dietary nitrogen levels and restricting the feed intake. The availability of amino acid may be improved by feeding management, and supplementing enzyme, but the quality of eggs and meat of spent hens and welfare of laying hens are not affected by amino acid nutrition.  相似文献   

8.
The third generation cephalosporin cefovecin has been shown to have an exceptionally long elimination half-life in dogs and cats, making it suitable for antibacterial treatment with a 14-day dosing interval in these species. Pharmacokinetic parameters for cefovecin were investigated in juvenile hens and green iguanas, following subcutaneous injections with 10 mg cefovecin/kg bodyweight. Preliminary studies in eight additional species of birds and reptiles were performed and results were compared with the parameters found in hens and green iguanas. The kinetics were characterized by rapid absorption with peak plasma concentration of 6 ± 2 μg/mL in hens and 35 ± 12 μg/mL in green iguanas. The mean plasma half-life for cefovecin was 0.9 ± 0.3 h for hens and 3.9 h in green iguanas. Volume of distribution was 1.6 ± 0.5 L/kg for hens and 0.3 L/kg for green iguanas and clearance was 1252 ± 185 mL·h/kg for hens and 53 mL·h/kg for green iguanas. Results from preliminary studies did not differ notably from those seen in hens and green iguanas. Cefovecin is not suitable for the treatment of bacterial infections with a 14-day dosing interval in hens or green iguanas and seems not to be in a number of other bird and retile species either.  相似文献   

9.
Calcium tetany is a poorly defined disease of broiler breeder hens that results from acute hypocalcemia. It is characterized by impaired mobility, increased mortality, and absence of gross lesions that would explain the impaired mobility. To evaluate if hens with impaired mobility had calcium tetany or other abnormalities, blood values from normal and affected hens were determined using the i-STAT handheld clinical analyzer. Three flocks were evaluated weekly prior to peak production (range 25-30 wk of age) comparing normal hens to hens with clinically apparent calcium tetany. Calcium tetany suspect (CaTS) hens from four additional flocks were also evaluated. Significant hypocalcemia (P < 0.001) was observed in CaTS hens (average = 1.14 mmol/L ionized calcium [iCa]) compared to normal hens (average = 1.53 mmol/L iCa) in only one of three flocks sampled weekly. Clinically affected hens from one of the other four flocks also had hypocalcemia. Blood value abnormalities in mobility-impaired hens without hypocalcemia included hypernatremia. Findings in this study indicate calcium tetany is one cause of impaired mobility in breeder hens, but mobility impairment without hypocalcemia can also occur. Calcium tetany should be confirmed by finding significantly decreased levels of iCa in the blood, as diagnosis based on clinical presentation and necropsy results can be inaccurate. The i-STAT handheld clinical analyzer is an efficient, relatively low-cost method to determine iCa and other blood chemistry values that may be associated with impaired mobility in broiler breeder hens.  相似文献   

10.
A corn-soybean meal diet was supplemented with 0, 1, or 2% Improved Milbond-TX (IMTX, a hydrated sodium calcium aluminosilicate) for Hy-Line W-36 laying hens selected for good or poor eggshell quality. Supplementing the diet with IMTX had no detrimental effects on egg weight, eggshell weight, albumen quality, feed consumption, or feed conversion during 5 consecutive 28-d periods. Increase in BW over the 5-mo experimental period was not influenced by the addition of IMTX. Results from this study show that an accidental oversupplementation of a laying hen diet with up to 8 times the recommended level of IMTX of the manufacturer, which may occur due to a feed mill mixing error, should not result in adverse performance of laying hens nor should it affect the concentration of moisture in the excreta.  相似文献   

11.
Groups of 20-week-old white (Lohmann LSL) and brown (Lohmann Brown) hens were reared under helminth-free conditions and both divided into two subgroups. One subgroup was artificially infected with 250 embryonated Ascaridia galli eggs, the other subgroup were kept as uninfected controls. During the following 12-month laying period individual faecal Ascaridia egg counts (FEC) were performed and bodyweight measured at monthly intervals. Laying performance and egg weights were determined daily. The mean FEC were significantly (P < 0.01) higher in infected white hens than in infected brown hens. The growth rate of the white hens was significantly (P < 0.05) higher in the control group, whereas in brown hens no significant group difference was observed. The laying performances and egg weights did not differ significantly (P > 0.05) between control and infected animals for either line. The estimated repeatabilities for mean log(10) FEC of different samples were reasonably high (0.16-0.54). Heritabilities for mean log(10) FEC were between 0.13 and 0.19 for white hens and between 0.0 and 0.10 for brown hens. Thus, it should be possible to select for A. galli resistance in chickens, which will be of importance for birds kept in alternative and organic farming systems.  相似文献   

12.
A model combining data from gas exchange measurements with nutrient balances, demonstrating energy transfer between the pools of protein, carbohydrate and fat and their partition in the body, is described. Data from energy metabolism experiments with growing pigs and laying hens is incorporated into the model in order to illustrate methods of calculations and interpretations of the model. The experiments with pigs were carried out with growing pigs (20–100 kg) measured alternately on high (ad libitum) and low (near maintenance) feed levels on diets with low or high fat concentration. When energy intake from digested carbohydrate covered the requirements for growth, heat from oxidation of carbohydrate contributed 85–90% to the total heat production, while there was no net oxidation of fat. When the intake of digested carbohydrate was not sufficient to cover requirements, fat was mobilized from the body and oxidized. Energy from oxidation of carbohydrate was in all measurements below the energy in the carbohydrate pool, indicating transfer of energy from carbohydrate to fat metabolism in the process of de novo lipogeneis. The experiments with hens were carried out with 62 hens during the laying period from 26 to 47 weeks of age. The hens originated from two strains (A and B); they were kept in battery cages either individually or 3 hens/cage and fed ad libitum with an identical commercial diet. The partition of the protein pool between oxidation and retention was not influenced by the housing system. However, the genetic origin of hens effected protein utilization with relatively lower oxidation and higher retention in Strain B. The main part of the carbohydrate pool was oxidized (45–60%), but the hens kept individually oxidized more carbohydrate than those kept 3 hens/cage. Further, there were significant differences between the strains. Generally, about half of the fat pool originated from de novo lipogenesis from carbohydrate, indicating the importance of this process for fat retention in eggs. Fat oxidation depended on the energy supply from carbohydrate, hence with higher use of carbohydrate for oxidation in Strain B less fat was oxidized and more was used for fat synthesis. The presented results indicate that by combining results from gas exchange measurements with nitrogen and energy balances it is possible to evaluate the contribution of nutrients to the oxidative processes and the energy transfer between substrate pools.  相似文献   

13.
A total of 72 White Leghorn grandparent hens was examined by ELISA for avian leukosis virus (ALV), ALV antigens and anti-ALV antibodies to identify and characterize the hens transmitting ALV to their embryos (transmitters) by using fertilized eggs. These hens were divided into 3 groups as no antibody and non-viremic (NANV) (49 hens), antibody-positive and non-viremic (APNV) (21 hens) and no antibody and viremic (NAV) (2 hens) by testing the sera for the presence of ALV and anti-ALV antibody. Egg albumen and embryos were tested for the presence of ALV and ALV antigens. As a result, no ALV was detected in both albumen and embryos in the NANV group. On the other hand, all albumen samples collected repeatedly from 3 hens of the APNV group and 2 hens of the NAV group contained infectious ALV, although the infectivity differed with the individual. Also, these 5 hens produced infected embryos at varying frequencies. However, on AP hen which shed neither ALV nor ALV antigens into the albumen produced an infected embryo at a lower rate. These results indicate that testing for infectious ALV in albumen from a newly laid egg per hen is effective to identify the transmitters to some extent. When virus titers in each of 8 tissue samples from the 6 transmitting hens were determined, the highest virus titers were found in washing from the ampulla of the oviducts in most of the shedders, suggesting that embryo infection is closely correlated with ALV produced at the oviduct, but not with ALV transferred from the other parts of the body.  相似文献   

14.
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   

15.
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.  相似文献   

16.
蛋鸡生长发育和生产过程受各种环境因子的影响,如温度、氨气、光照和二氧化碳等,其中温度和氨气是鸡舍冷热环境和空气质量环境控制中最为重要的两个方面,明确蛋鸡对重要环境因子的生理反应机制对鸡舍环境控制意义重大.文章综述了鸡舍内主要环境因子对蛋鸡影响机制的研究进展,尤其是温度和氨气对蛋鸡生产性能和生理影响的研究现状,总结了目前...  相似文献   

17.
Objective To determine the effects of the amount of beak removed and cauterisation time on neuroma formation in hens.
Design A pathology study with controls.
Animals Twenty domestic fowl were beak-trimmed. Three non-beak-trimmed domestic fowl were used as controls.
Procedure Beaks of two age groups with two levels of beak removal and either 2 s or 4 s cauterisation, were investigated macroscopically and microscopically for deformities.
Results Scattered trauma-associated neuromas were present in the beaks of pullets 10 weeks after moderate trimming at hatch. Neuromas were not present in beaks of adult hens that had been similarly trimmed. Sensory corpuscles were present 10 and 70 weeks after moderate trimming, though fewer in number than in intact control hens. In contrast, trauma-associated neuromas persisted in beaks of 70-week-old hens that had been severely trimmed at hatch. A range of deformities that were absent in moderately trimmed hens, were observed in hens with severely trimmed beaks. Receptors were not seen in severely trimmed beaks.
Conclusion Beak-trimming at hatch induces the formation of neuromas, regardless of the amount of tissue removed. There is a critical amount of beak tissue that can be removed, beyond which trauma-associated neuromas will not resolve, but will persist in mature hens.  相似文献   

18.
R K Gast  C W Beard 《Avian diseases》1990,34(2):438-446
Laying hens of three different ages were experimentally infected with a strain of Salmonella enteritidis by either oral inoculation or contact transmission. Total egg production was depressed in exposed hens of all three age groups. Persistent intestinal shedding was observed in a small number of hens. Eggs with contents contaminated by S. enteritidis were produced by exposed hens at a high frequency, but only during a fairly short period of time that extended through approximately 1 week postinoculation for older hens and through 2 weeks for younger hens. S. enteritidis was recovered from whole yolks and albumen of these eggs at similar frequencies, but not from the content of yolks. Eggs with contaminated shells were also produced, but at a lower frequency. Contaminated eggs were produced by orally inoculated and contact-exposed hens at similar frequencies. S. enteritidis was not isolated from the contents of eggs laid by hens infected with other S. enteritidis strains.  相似文献   

19.
There is a considerable lack of scientific evidence on the necessary feeder space with respect to the legal requirement that all hens of one battery cage must be able to feed simultaneously. Moreover it is likely that hens from different lines, differing in weight and width, have different space needs at the feeding trough. In order to ascertain the degree of simultaneous feeding in two types of laying hybrids with different weights, feeding activity was recorded in 29 cages, populated with four hens each with a feeder space of 12 cm per hen. Recordings took place over 6 days at seven feeding times under ad libitum feeding conditions. In all cages, the lighter and apparently slimmer LSL-hens (Lohmann Selected Leghorn, white) were able to feed simultaneously. However, for the somewhat heavier and apparently broader LT-hens (Lohmann Tradition, brown) this could not be observed in two of 16 cages. Nevertheless, was the average proportion of cages higher in LT-hens in which synchronous feeding of all hens could be noted at least once within each 30 minutes observation period. These were 35% of cages (LT) compared to 18% in LSL-hens (p < 0.001). Therefore, not only the physical space needs, but also possible differences in social and feeding behaviour may affect synchrony in different lines. In general, the proportion of observation time with simultaneous feeding was low (3.3% in LT, 1.7% in LSL, n.s.). As there are no comparable figures available for different feeder space allowances from the literature, an assessment of the presented data is not possible. Investigations on the synchrony of feeding behaviour in small groups of laying hens under varying environmental conditions and in different layer lines should be continued.  相似文献   

20.
The efficacy of the albumen test for infectious avian leukosis virus (ALV) was examined in detecting congenitally transmitting hens. Seventy-three White Leghorn non-viremic hens with antibody to ALV were used. Eleven of the hens shed infectious ALV into their egg albumen, whereas only 7 of the 11 ALV-positive hens shed ALV antigens. The egg albumen test for infectious ALV was shown to be more effective in detecting the congenitally transmitting hens than that for ALV antigens. Then, twenty of the 62 hens which shed no infectious ALV into the albumen were studied for transmission of ALV to their embryos and for discharging ALV into the oviduct and vagina. Six of the 50 embryos from 4 hens were found to be infected with ALV but all of the 227 embryos from remaining 16 hens were free from the infection. Discharge of the virus into the oviduct and vagina was found both in the 4 transmitting hens and in 6 of the 16 non-transmitting hens. These results suggest that the hens discharging ALV into the oviduct, even though they do not shed ALV into egg albumen, may transmit the virus sporadically to their embryos.  相似文献   

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