肉种鸡养殖管理技术要点

相较于其他家禽养殖,肉种鸡养殖有着更严格的技术要求,要求养殖系统性、精细化。部分养殖户在发展肉种鸡养殖过程中不注重做好养殖管理工作,普遍存在技术空缺,很容易造成各种传染性疾病发生,影响肉种鸡正常生长,最终影响养殖户经济效益。该文在总结以往养殖经验的基础上,探讨肉种鸡饲养管理技术要点。     

Effect of Organically Complexed Copper,Iron, Manganese,and Zinc on Broiler Performance,Mineral Excretion,and Accumulation in Tissues

Supplementation of trace minerals with a large safety margin in broiler chickens has resulted in a high level of mineral excretion that ends up in the environment. Organically complexed trace minerals (organic minerals) may be able to replace the inorganic trace minerals, because the former appear to have a greater bioavailability. Therefore, a 29-d cage study that included diets with supplemental trace minerals from organic and inorganic sources based on a trace mineral deficient control diet was conducted to examine the possible response of broiler chickens to organic mineral supplements. The results showed that supplementation with 4 mg of Cu and 40 mg each of Fe, Mn, and Zn from organic sources may be sufficient for normal broiler growth to 29 d of age. It is possible to use these lower levels of organic trace minerals in broiler diets to avoid high levels of trace mineral excretion.     

Immunization of broiler breeder chickens against Newcastle disease with an oil-emulsion vaccine

Antibody response was rapid and high in broiler breeder chickens receiving 1 or 2 vaccinations with oil-emulsion vaccine against Newcastle disease at 23 or at 23 and 26 weeks old. The antibody titers remained high during the 41-week experimental period. At 64 weeks old, about 41 weeks after vaccination, the geometric mean hemagglutination-inhibition antibody titer was 67 from the single vaccination, and 103 from the double vaccination. The immune response to live-virus vaccine given at 2, 9, 20, 30, 42, or 54 weeks of age via the drinking water was high, but uniformity was lacking in the antibody response in the breeders and maternal antibody response in the progeny. Maternal antibody levels in one-day-old chicks were related to the titers of antibody in the dams. Maternal antibody titers of chicks originated from breeder flocks that were vaccinated with the oil-emulsion vaccine remained high for all hatches.     

Effects of ad libitum feeding on performance of different strains of broiler breeders

(1) Tolerance to ad libitum feeding was compared in three genotypes of broiler breeder hens: a standard broiler breeder fed ad libitum (SA) or restricted (SR), a slow growing 'label' broiler breeder (L) and an experimental dwarf heavy broiler breeder (E). Two similar experiments were conducted in two distinct research centres. (2) Feed intake and body weight were measured every 3 weeks from hatch to 40 to 49 weeks of age. Egg production and egg abnormalities were recorded. The number of yellow follicles in ovaries was counted at the age of 32 weeks. (3) Body weight was stabilised at 2.2, 3.7 and 5.4 kg after 24 weeks of age in L, E and SA hens, respectively. Growth of the SR hens was similar to that of L up to 20 weeks and stabilised at a similar level to that of E hens after 30 weeks of age. (4) Sexual maturity was delayed by 6 weeks in restricted breeders compared to ad libitum fed hens that started to lay at 20 weeks. SA hens had low egg production and a high proportion of defective eggs, which was largely compensated for by feed restriction. However, productivity of SR hens remained lower than that of L breeders. (5) Compared to the low viability and reproductive fitness observed with SA hens, the E dwarf broiler breeder tolerated ad libitum feeding and had better egg production, fewer egg abnormalities and yellow follicles per ovary and a higher egg production. However, laying rate was still lower than that of the SR and L groups. Energy conversion (kJ/g egg) from 32 to 40 weeks of age was much higher in the SA group than in the other three groups. 6. The feasibility of feeding a dwarf broiler breeder ad libitum calls for further research on implications of specific IGF and GH-receptor expression at the level of the ovary in dw chickens.     

Application of the Sperm Mobility Assay to Primary Broiler Breeder Stock

A new quantitative trait affecting male fertility was discovered in the 1990s. The term sperm mobility denotes the net movement of a sperm cell population against resistance at body temperature. Even though sperm cells are self-propelled DNA delivery vehicles, their self-propulsive nature is neither uniform among sperm within an ejaculate nor among males within flocks. Such variation is evident when semen quality is evaluated by sperm penetration of an Accudenz solution, hence the term sperm mobility assay. It is noteworthy that populations showing modest variation with respect to semen volume or sperm concentration often show considerable variation with respect to sperm mobility. Likewise, it is noteworthy that broiler breeder fertility is a function of sperm mobility phenotype when hens are inseminated artificially. This article outlines the following: 1) a series of experiments in which the sensitivity of the commercial sperm mobility assay was improved using semen donors from lines of chickens selected for either low or high sperm mobility and 2) the application of the improved technique to pedigree broiler breeders. Male fertility is subject to genetic selection when sperm mobility is the selection criterion. Therefore, sperm mobility may be a useful trait for improving broiler breeder reproductive efficiency.     

Seroprevalence of Ornithobacterium rhinotracheale infection in broiler and broiler breeder chickens in West Azerbaijan Province, Iran

Ornithobacterium rhinotracheale is a pleomorphic Gram-negative rod shaped bacterium of the rRNA superfamily V that is associated with respiratory disease in poultry. This study was conducted to determine the seroprevalence of O. rhinotracheale infection in broiler and broiler breeder chickens in West Azerbaijan (Urmia lake region) by using a commercial enzyme-linked immunosorbent assay. In this study, 463 serum samples were obtained from 50 broiler flocks and 472 blood sera from 42 broiler breeder flocks. Results showed that 41 broiler flocks (82%) and 39 broiler breeder flocks (92.8%) were positive. Ornithobacterium rhinotracheale antibodies were detected in 205 (44.2%) of the 463 broiler serum samples. Of the 472 blood sera examined from broiler breeder, 340 (72%) were positive. The results of this study indicated that the prevalence of O. rhinotracheale antibodies is high in the broiler and broiler breeder flocks in West Azerbaijan.     

The broiler breeder paradox: ethical, genetic and physiological perspectives, and suggestions for solutions

1. Due to intensive selection, broiler chickens became the most efficient meat-producing animals because of their fast growth, supported by a virtually unlimited voluntary feed intake. These characteristics cause many problems in the management of broiler breeder hens because of the negative correlation between muscle growth and reproduction effectiveness. 2. This problem, namely the fast muscle growth versus reproduction health paradox, induces a second paradox, acceptable reproduction and health versus hunger stress and impaired welfare, because broiler breeder hens require dedicated programmes of feed restriction (1) to maximise egg and chick production and (2) to avoid metabolic disorders and mortality in broiler breeders. 3. Given that poultry selection is a global large-scale business and chickens are a prolific species, improvement in profit can only be obtained by selecting on feed conversion and/or for higher breast meat percentage, which will intensify the broiler-breeder paradox. 4. New feeding strategies are being studied, but it is questionable if the paradox can be solved by management tools alone. Because breeding and selection are long-term processes, involving animals, farmers, consumers, industry, environment etc., a more sustainable breeding goal needs to be determined by a multidisciplinary approach and an open debate between several actors in the discussion. 5. Using dwarf broiler breeder hens could be one alternative, because dwarf hens combine relatively good reproductive fitness with ad libitum feeding. Another possibility is to accept lower broiler productivity by assigning economic values to welfare and including integrity traits in an extended breeding goal.     

Subclinical infectious bursal disease in an integrated broiler production operation.

A field study was designed to determine the prevalence of subclinical infectious bursal disease (IBD) in broiler chickens from a commercial poultry company. Bursae of Fabricius (BF) from two vaccinated and three nonvaccinated broiler flocks were evaluated histologically, and antibody profiles of these broiler and matched parent breeder flocks were established. Lesions of IBD, including lymphoid necrosis, stromal edema, and infiltrates of heterophils and macrophages, were first detected in BF at 24 days of age in both vaccinated and nonvaccinated chickens. At 41 days, all BF had lesions characteristic of IBD, including severe lymphoid depletion, proliferation of epithelial cells, and mild fibroplasia. Although mean maternal antibody levels (measured by enzyme-linked immunosorbent assay) in broilers were apparently protective through day 12, IBD antibodies decreased to nonprotective levels (below 1,000) by day 16 or 20. Titers began to increase by day 28 or 32 because of field exposure. Sentinel birds, placed with broiler flocks, also developed IBD antibody titers. Broiler breeders had low and nonuniform antibody titers. Prevalence of field IBD exposure was high, and existing vaccination programs were not effective.     

霉变饲料中添加复方霉菌毒素吸附剂对肉鸡人工感染发生的影响

本试验旨在研究霉变饲料和／或添加复方霉菌毒素吸附剂对肉鸡人工感染发生的影响。选取140羽1日龄健康的AA肉鸡随机分成7个组．每组4个重复。第1组为空白对照组,饲喂基础日粮;第2组饲喂霉变饲料;第3～7组以混合感染病鸡病变组织匀浆饮水制作人工感染疾病模型;第3～7组分别饲喂基础日粮、霉变饲料、霉变饲料＋复方霉菌毒素吸附剂、霉变饲料＋复方霉菌毒素吸附剂＋抗氧化剂、霉变饲料＋复方霉菌毒素吸附剂＋抗氧化剂＋中药增免剂。试验期35d。结果发现,肉鸡摄入霉变饲料与摄入正常饲料相比,提高肉鸡料重比和死淘率,显著降低肉鸡增重、胸腺指数、法氏囊指数,显著降低血清IBDV、H9N1v和NDV抗体水平（P〈0．05）。给人工感染肉鸡饲喂霉变饲料与饲喂正常饲料相比．显著提高料重比和死淘率,显著降低肉鸡增重、胸腺指数和脾脏指数,显著降低血清IFN-1、IL-2、IL-4和IL-12含量以及LTR,显著降低血清IBDV、H9N1V和NDV抗体水平（P〈0．05）。霉变饲料中添加复方霉菌毒素吸附剂能显著提高混合感染肉鸡增重,并降低料重比和死淘率（P〈0．05）,显著提高胸腺指数、法氏囊指数（P〈0．05）,显著提高血清IBDV、H9N1V和NDV抗体水平（P〈0．05）。可见,霉变饲料可导致肉鸡免疫功能抑制,加重肉鸡混合感染病情;复方霉菌毒素吸附剂能有效缓解霉变饲料对人工感染肉鸡生产性能、免疫功能和病情的不利影响,抗氧化剂和免疫功能增强剂可减轻霉变饲料的毒性作用。     

A highly fatal vascular disease of broiler breeder chickens

A broiler breeder operation experienced a sudden outbreak of high mortality in nine different houses of breeders at eight different locations. In the first house to be affected, the losses were mainly in the females, but later flocks had losses up to 6.4%, mainly in the males. Affected chickens ranged in age from 7 to 22.5 weeks. Multifocal areas of necrosis and vasculitis were found in skin, muscle, and internal organs. No involvement of the brain was identified, but many of the birds had uveitis. The outbreak lasted 3 weeks and ended without treatment. Neither infectious agents nor mycotoxins were identified.     

Improved broiler performance associated with Ornithobacterium rhinotracheale vaccination in breeders

During a field study in 2010 the daily growth, feed conversion, first-week mortality, broiler loss due to mortality and slaughterhouse condemnation, and production index were monitored in 100 broiler flocks derived from four breeder farms vaccinated with Nobilis OR inac and four Ornithobacterium rhinotracheale-unvaccinated breeder farms of the same organization in Belgium. Other parameters related to the broiler flocks, such as flock size, season, age of the breeders, and corresponding breeder farms, were also noted. All gathered data were examined with ANOVA, linear correlation, and linear regression analyses. Results demonstrated a significant 22.3% lower broiler loss and a significant 3.9% higher production index in the broiler flocks derived from breeders vaccinated with Nobilis OR inac. These results confirm field observations obtained in 1999, thereby providing further evidence for an effect of O. rhinotracheale vaccination in breeders with regard to the improved performance of broilers.     

Detection of chicken anemia virus in the gonads and in the progeny of broiler breeder hens with high neutralizing antibody titers

Previous evidence for the presence of chicken anemia virus (CAV) in the gonads of immune specific-pathogen-free chickens raised the question whether this occurs also in commercial breeders. The presence of CAV was investigated by nested PCR in the gonads and spleens of hens from two 55- and 59-week-old, CAV-vaccinated (flocks 2 and 3), and two 48- and 31-week-old non-vaccinated broiler breeder flocks (flocks 1 and 4). In addition, lymphoid tissues of 20-day-old embryos from these hens were also investigated for the presence of CAV. CAV was detected in the gonads and of 5/6 and 11/22 of the vaccinated hens and in some hens also in the spleen alone. Embryos from 7/8 and 5/18 of these hens were positive. In the non-vaccinated flocks, CAV was detected in the gonads of 11/34 and 10/10 hens in flocks 1 and 4, respectively. In addition, 11 birds in flock 1 had positive spleens. CAV DNA was detected in 3/11 and 2/10 of their embryos. CAV-positive gonads and embryos were detected in samples from hens with moderate as well as high VN antibody titers. Vaccinated chickens positive for CAV in the gonads and in their embryos had VN titers ranging from >1:512 to <1:2048. In non-vaccinated chickens, the VN titers of CAV positive chickens ranged from 1:128 to 1:4096. These results demonstrate that CAV genome can remain present in the gonads of hens in commercial broiler breeder flocks even in the presence of high neutralizing antibody titers that have been associated with protection against CAV vertical transmission. It also suggests that transmission to the progeny may occur irrespectively of the level of the humoral immune response in the hens.     

Seroprevalence and identification of Ornithobacterium rhinotracheale from broiler and broiler breeder flocks in Thailand

Ornithobacteriosis is an infectious disease of avian species that has been reported in almost all countries around the world, except Thailand. The objectives of this study were to determine the seroprevalence of Ornithobacterium rhinotracheale (ORT) and to isolate and identify ORT in broilers and broiler breeders in Thailand. Chicken antibodies had been randomly checked from 17 farms (19 flocks) of broilers and 23 farms (28 flocks) of broiler breeders. The seropositive flocks were 63% and 100% in broilers and broiler breeders, respectively. The sera analysis showed that the individual 280 broiler sera antibody responses were 67.5% negative, 12.9% suspect, and 19.6% positive. The individual antibody responses of 510 broiler breeder sera revealed 12.2% negative, 38.0% suspect, and 49.8% positive samples. The bacteria were isolated and identified by polymerase chain reaction (PCR). Bacterial isolation and identification revealed that nine isolates of the 12 PCR analysis samples showed positive results to PCR analysis. All the positive PCR samples were collected from the broiler breeder farms.     

The avian major histocompatibility complex influences bacterial skeletal disease in broiler breeder chickens

This study evaluated bacterial skeletal disease in conjunction with the major histocompatibility complex (MHC) in a genetically pure line of broiler breeder chickens. Chickens from six broiler breeder flocks were examined for skeletal lesions, bacterial pathogens, and MHC genotype. During a 10-week period, eighty-eight, 9- to 21-week-old lame chickens and 34 normal, age-matched controls were selected. Tenosynovitis, arthritis, and femoral or tibiotarsal (or both) osteomyelitis occurred in 86 of 88 (97.7%) lame chickens. Ninety-five bacterial isolates were obtained from 83 of 88 (94.3%) lame birds and 4 of 34 (11.8%) controls. Staphylococcus spp. was isolated from 72.6% of the skeletal lesions, predominantly Staphylococcus aureus (38.9%). MHC B complex genotypes were determined by hemagglutination for 88 lame birds, 34 controls, and 200 randomly selected birds from each of the six flocks (1,200 total). Combined chi-square analysis revealed that the homozygous MHC genotypes B(A4/A4) (chi(2) = 14.54, P = 0.0063) and B(A12/A12) (chi(2) = 42.77, P = 0.0001) were overrepresented in the sample of symptomatic birds compared with random samples from the same flocks. The homozygous A4 and A12 MHC genotypes influenced flock chi-square values more than the corresponding heterozygotes. An MHC B complex influence on bacterial skeletal disease was apparent in this line of broiler breeders.     

Ovarian follicular structure of White Leghorns fed ad libitum and dwarf and normal broiler breeders fed ad libitum or restricted until point of lay

1. Yellow follicle numbers when the first egg was laid were 6.3, 9.0 and 12.4 for ad libitum reared Leghorns, sex-linked Dwarf (AL Dwarf) and Normal broiler breeders respectively. Multiple ovulation resulted in low egg production and a high proportion of defective egg shells in AL Dwarf and Normal broiler breeders during early lay. 2. Restricting the growth of broiler breeders during rearing by restricting food intake (R Dwarfs) reduced the number of yellow follicles to 6.8 and increased the rate of lay. 3. Atretic yellow follicles were common among broiler breeders but not in Leghorns or R Dwarfs when the first egg was laid. 4. Poor egg production in older broiler breeders was caused by birds with few or no developing yellow follicles, atresia in yellow follicles and the continued occurrence of multiple ovulations. 5. There was no relationship between the number of yellow follicles and the number of white follicles less than 5 mm diameter but atresia in white follicles 2 to less than 5 mm was negatively related to the number of yellow follicles. 7. No relationship was observed between abdominal fat weight and yellow follicle number, though birds which ate more had more yellow follicles. 8.The sex-linked dwarfing gene dw was associated with increased atresia among the white follicles and low numbers of yellow follicles compared with the Normal DW broiler breeder genotype.     

A survey for parvovirus-like virus (so-called chick anemia agent) antibodies in broiler breeders

A prospective study to survey for the presence of parvovirus-like virus (PVLV; so-called chick anemia agent) antibody in broiler breeder pullets in Georgia, North Carolina, and Florida was conducted by collecting serum samples from 52 breeder flocks that ranged in age from 1 day to 55 weeks old. Results indicated that PVLV infection was widespread. Ninety-eight percent (51/52) of chicken flocks and 62% (530/861) of chickens had PVLV antibody. Rates of antibody-positive chickens among flocks ranged from 0% to 100% and averaged 76%. Upon initial examination, the percentages of chickens positive for PVLV appeared evenly distributed with respect to several convenient age groups and geographic locations. However, compared with young chickens (less than or equal to 19 weeks old), markedly significantly lower proportions of positives were present among chickens more than 19 weeks old (P = 0.00001) or chickens 30 weeks old or more (P = 0.000004). Also, there were significant (F = 7.7, df = 3/827, P less than 0.001) differences among the rates of PVLV antibody in chickens among various companies. The relatively high rate of PVLV antibody among broiler breeder chickens helps explain the low incidence of clinical disease among their offspring.     

Swollen head syndrome: clinical observations and serological examinations in West Germany

Swollen Head Syndrome (SHS) affects both broiler and broiler breeders and has become a problem in many countries. Clinical signs similar to those described in SHS conditions have been observed in northern Germany with the disease observed mostly in chicken broilers between 4 and 5 weeks of age and in broiler breeders between 24 and 36 weeks of age. The mortality rate in broilers has been variable from negligible to 5%. In broiler breeders, the symptoms were accompanied with a drop in egg production reaching 2-3% after 1 to 2 weeks. 422 Serum samples from 21 broiler flocks were examined for the presence of antibodies to TRT-virus using indirect ELISA tests. Antibodies were detected in 2 flocks which suffered from SHS, but not in 2 flocks showing respiratory manifestations nor in 17 apparently healthy flocks. The results obtained from testing 178 serum samples from 10 breeder flocks revealed that antibodies to TRT-virus were present in one flock with SHS signs as well as in 6 apparently healthy flocks. In addition, no antibodies were found in sera collected from 3 flocks--one with SHS and respiratory disease history; one recovered from respiratory infection and one without disease history. Examination of paired serum samples from 3 breeder flocks that suffered from typical SHS-signs collected at the onset of the disease and during the convalescent stage, as well as sera from one broiler and one breeder flocks that showed respiratory manifestations, showed that there are significant increases in the number of positive sera in the flocks with SHS symptoms. The other flocks remained free from TRT antibodies.     

Clinical encephalitis following avian encephalomyelitis vaccination in broiler breeder pullets

Twelve-to-fourteen-week-old broiler breeder pullets and cockerels from two different companies were found to have encephalitis 2 weeks after vaccination with avian encephalomyelitis (AE) vaccine. Histologic examination and virus isolation indicated that affected chickens had AE. All chickens had been vaccinated with either one of two serials of AE vaccine approximately 2 weeks before the onset of clinical signs.