细化搜索
结果 391-400 的 584
Small-scale poultry production in Bangladesh: challenges and impact of COVID-19 on sustainability 全文
2021
Masudur Rahman | Emdadul Chowdhury | Rokshana Parvin
Poultry meat is an important source of animal protein in Bangladesh. Small-scale poultry production plays a crucial role in the socio-economic development and nutritional requirements of rural and peri-urban households and provides an income source for resource-poor areas. Therefore, focusing on small-scale poultry production remains important. However, improper management, disease outbreak, market volatility and many other factors are typically responsible for the sustainability of this rising prospect of small-scale poultry production potential. The recent pandemic coronavirus disease of 2019 (COVID-19) tremendously influenced the sustainability of the small-scale poultry sector. This review addressed Bangladeshi small-scale poultry production and its market value, identified issues, and suggested potential guidelines to sustain the small-scale sector
显示更多 [+] 显示较少 [-]Genetic characterization of genotype VII.1.1 Newcastle Disease viruses from commercial and backyard broiler chickens in Egypt 全文
2021
Abdelmonem Dewidar | Azza El-Sawah | Salama Shany | Al-Hussien Dahshan | Ahmed Ali
The small-scale and backyard-raised poultry are extensively growing in Egypt. However, low biosecurity and/or vaccination practices are adopted. The current study was conducted to investigate and molecularly characterize Newcastle Disease (ND) strains circulating in small-scale and backyard poultry sectors in Giza governorate in Egypt from July 2018 to April 2020. Twelve broiler flocks (6 commercial and 6 backyard flocks) suffering from respiratory and/or nervous signs were included. Virus isolation and molecular characterization were conducted. In the present study, three NDV isolates were isolated from commercial (n=2) and backyards (n=1) flocks. The isolated viruses maintained the multi-basic motif112RRQKRF117 in the fusion protein cleavage site indicative of their virulent nature. Phylogenetically, the viruses are closely related to genotype VII.1.1. ND viruses are genetically different from NDV genotype II vaccine strains. Deduced amino acid sequences of the fusion (F) protein showed an amino acid change of S278P in the heptad repeat (HRb) in the two NDV isolates from commercial farms. Other amino acid substitutions were observed including the change at positions 442 (A/T) in the two commercial flocks isolates and position 317 (A/S) in the backyard ND isolate. Few silent nucleotide mutations were also observed in the F protein of the NDV isolate from the backyard flocks. In conclusion, the current study reports the genetic identification of virulent NDV viruses from commercial or backyard flocks related to genotype VII.1.1. ND circulating in Egypt. The amino acid substitutions and nucleotide changes warrant the need for continuous surveillance of NDV in these growing poultry sectors considering their importance as a spot for extensive NDV circulation and as the main source for live bird markets in Egypt.
显示更多 [+] 显示较少 [-]Experimental study of the efficacy of three inactivated H9N2 influenza vaccine on broiler flocks 全文
2021
Amal Essalah-Bennani | Yassmina Bidoudan | Asma Fagrach | Hanan Balil | El Abderrazak | Noursaid Tligui | Saâdia Nassik | Fassi Ouafaa
This study was carried out to evaluate the effect of different Low Pathogenic Avian Influenza (LPAI) H9N2 vaccines containing different virus strains (vaccine A, vaccine B, and vaccine C) on the productivity and immunity of 10 days-old broiler chickens. Two hundred day-old Cobb broiler chicks were divided into eight groups, 25 chicks in each group. Six groups were vaccinated with Vaccine A, Vaccine B, and Vaccine C (2 groups/each vaccine) at 10 day-old, respectively. Chickens of groups 7 and 8 were kept as control groups. One group from each vaccine was challenged at 28 days old with 106 EID50/0.2ml of A/chicken/Morocco/SF1/2016 (H9N2) virus via the oculonasal route. The remaining groups were kept unchallenged to evaluate the immune response. Chicks were sampled each week individually until 42 days old for zootechnical traits and serological evaluation. Two necropsies were done at 5 and 10 days post-challenge (DPC). Lungs and tracheas were collected for histopathology, and the virus shedding was monitored at 5, 7, 9, and 11 DPC by real-time RT-PCR. Results indicated that vaccine B provides significantly better growth performances (P < 0.05), final body weight gain (2689.6 g ± 73.2), and feed conversion ratio (2.10 ± 0.06) when compared to other vaccinated groups. During the challenge (28th -35th days), vaccine B showed a significant increase in antibody titer (26180 ± 1129.1) than other vaccines. In contrast, the vaccine C group had a similar immune response to that of the control group. Both vaccines A and B were able to stop virus shedding by 11 DPC with higher mean Cq values. However, the vaccine C group continued to shed the virus until 11 DPC. Pathological examination of challenged birds revealed lesions predominantly in the respiratory tract. At 5 DPC, fibrinous sinusitis, tracheitis with fibrin plug, pneumonia, and fibrinous airsacculitis were observed. By 10 DPC, the fibrinous inflammation inceased, and only congestion in the trachea, lungs, and sinuses with thickening of air sacs were observed. Histopathology revealed lymphoplasmacytic tracheitis and congestive pneumonia. Scoring of lesions generally revealed more severe lesions at 5 DPC. Statistical analysis of both macroscopic and microscopic scores showed no significant differences between groups in both necropsies. In conclusion, vaccine B has significantly better seroconversion, better growth performance parameters, and a relatively early stop of viral shedding compared to other vaccines.
显示更多 [+] 显示较少 [-]The role of diglyceride acyltransferase (DGAT) genes polymorphisms on milk production in dairy goats 全文
2021
Muhammad Safdar | Mehmet Ozaslan
Milk quantity, fat, and protein contents are important traits in dairy animals, particu-larly in dairy goats. However, little is known about the genetics and genomics in dairy goats that influence these traits. The diacylglycerol O-acyltransferase (DGAT) genes are considered the most important genes in dairy goats for milk quantity and fat con-tents. The DGAT genes have two isoforms as DGAT1 and DGAT2, that have similar re-actions but no sequence homology in-between. The DGAT1 gene in chromosome 14 is a functional and potential candidate gene for fat content in goats, while DGAT2 is associated with milk yield and fat percentage in goats. The phylogenetic analyses re-vealed similar topologies and evolutionary partitioning of DGAT family proteins into two major clades: DGAT1 and DGAT2. Moreover, DGAT1 proteins were found to play a significant role in the milk yield in dairy goats. In this review, the role of polymor-phisms in DGAT family genes on milk production in dairy goats is discussed
显示更多 [+] 显示较少 [-]Considerations in Selecting Turkey Bedding Materials 全文
2021
Jesse Grimes | Mahmoud Sharara | Praveen Kolar
Abstract The commercial turkey of today is a descendant of wild, then domesticated, turkeys from North America originating in regions of old Mexico. The modern commercial turkey enjoys a wide range of acceptance in many countries. Turkey production evolved rapidly from 1950 forward with many changes in production and management. Turkey production changed from range rearing to mostly total confinement. Rearing birds under increased density in confinement facilities has created both opportunities and challenges. Once confined, organic materials have been used as bedding (also referred to as litter). There have been many materials evaluated and used for bedding. Availability, cost, and bird performance were early key considerations. More recently, bird health and welfare are now important considerations as well. Optimal management programs of the modern turkey reared in confinement can be elusive and difficult to define. However, controlling litter moisture which aids in reducing ammonia and footpad dermatitis should be a key management component of confinement rearing. Therefore, bedding choice and litter management in turkey production require thoughtful consideration and active management.
显示更多 [+] 显示较少 [-]Brucellosis in Iranian buffalo: Prevalence and diagnostic methods 全文
2021
Maryam Dadar | Gamal Wareth | Heinrich Neubauer
The water buffalo (Bubalus bubalis) in Iran represent an important source of meat and milk products with high biological value. Given the importance of water buffalo in Iran and the prevalence of brucellosis as one of the most important zoonotic diseases in this ruminant species, this study summarized available data on history, epidemiology, diagnosis, and control of brucellosis in water buffalo from previous studies that have been carried out in Iran. According to the documented data, there are three main groups of Iranian buffalo, including the Khuzestan ecotype (Khuzestan province); the Azary ecotype (Western/ Eastern Azarbaijan and Ardabil provinces); and the North ecotype (Gylan and Mazandaran provinces). Preliminary studies conducted on Iranian buffaloes either by serological or molecular tools reported that buffaloes\' infection occurred due to natural exposure to a wild strain of Brucella abortus and Brucella melitensis. Previous studies dealing with brucellosis in Iranian buffalo are next to none. This review notifies the importance of reliable and detailed epidemiological investigations of Iranian buffaloes through continuous monitoring systems of the health status of buffalo populations. Continuous test and slaughter strategy, vaccination, and re-planning of veterinary activities are required to mitigate buffalo\'s role in disseminating and maintaining brucellosis in Iran
显示更多 [+] 显示较少 [-]A genome-wide analysis of cardiac lesions of pigs that die during transport: Is heart failure of in-transit-loss pigs associated with a heritable cardiomyopathy? 全文
2021
Zurbrigg, Katherine | Bertolini, Francesca | Walugembe, Muhammed | Van Dreumel, Toni | Alves, David | Friendship, Robert | O'Sullivan, Terry L. | Rothschild, Max F.
While heart failure is a primary cause of death for many in-transit-loss (ITL) pigs, the underlying cause of these deaths is not known. Cardiomyopathies are considered a common cause of heart failure in humans and often have a genetic component. The objective of this study was to determine if genes associated with cardiomyopathies could be identified in ITL pigs. Samples from the hearts of pigs that died during transport to an abattoir in Ontario, Canada were collected and genotyped along with samples from pigs that did not die during transport (ILT hearts: n = 149; non-ITL/control hearts: n = 387). Genome-wide analyses were carried out on each of the determined phenotypes (gross cardiac lesions) using a medium density single nucleotide polymorphism (SNP) chip and 500 kb windows/regions for analysis, with 250 kb regions of overlap. The distribution derived by a multidimensional scaling (MDS) analysis of all phenotypes demonstrated a lack of complete separation between phenotypes of affected and unaffected animals, which made diagnosis difficult. Although genetic differences were small, a few genes associated with dilated cardiomyopathy (DCM) and arrhythmogenic right ventricular cardiomyopathy (ARVM) were identified. In addition, multiple genes associated with cardiac arrhythmias and ventricular hypertrophy were identified that can possibly result in heart failure. The results of this preliminary study did not provide convincing evidence that a single, heritable cardiomyopathy is the cause of heart failure in ITL pigs.
显示更多 [+] 显示较少 [-]Repeatability and accuracy of fingertip pulse oximeters for measurement of hemoglobin oxygen saturation in arterial blood and pulse rate in anesthetized dogs breathing 100% oxygen 全文
2021
Ambrisko, Tamas D. | Dantino, Stephanie C. | Keating, Stephanie C. J. | Strahl-Heldreth, Danielle E. | Sage, Adrianna M. | Da Costa Martins, Felipe | Harper, Tisha A. M. | Wilkins, Pamela A.
OBJECTIVE To evaluate the repeatability and accuracy of fingertip pulse oximeters (FPO) for measurement of hemoglobin oxygen saturation in arterial blood and pulse rate (PR) in anesthetized dogs breathing 100% O2. ANIMALS 29 healthy client-owned anesthetized dogs undergoing various surgical procedures. PROCEDURES In randomized order, each of 7 FPOs or a reference pulse oximeter (PO) was applied to the tongue of each intubated anesthetized dog breathing 100% O2. Duplicate measurements of oxygen saturation (Spo2) and PR were obtained within 60 seconds of applying an FPO or PO. A nonparametric version of Bland-Altman analysis was used. Coefficient of repeatability was the interval between the 5th and 95th percentiles of the differences between duplicate measurements. Bias was the median difference, and the limits of agreement were the 5th and 95th percentiles of the differences between each FPO and the PO. Acceptable values for the coefficient of repeatability of Spo2 were ≤ 6%. Agreements were accepted if the limits of agreement had an absolute difference of ≤ ± 3% in Spo2 and relative difference of ≤ ± 10% in PR. RESULTS Coefficient of repeatability for Spo2 was acceptable for 5 FPOs, but the limits of agreement for Spo2 were unacceptable for all FPOs. The limits of agreement for PR were acceptable for 2 FPOs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that some FPOs may be suitable for accurately monitoring PRs of healthy anesthetized dogs breathing 100% O2, but mild underestimation of Spo2 was common.
显示更多 [+] 显示较少 [-]Assessment of the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway 全文
2021
Wang, Pengju | Takawira, Catherine | Taguchi, Takashi | Niu, Xiao | Nazzal, Munir D. | Lopez, Mandi J.
OBJECTIVE To assess the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway. ANIMALS 5 nonlame adult light-breed horses. PROCEDURES Kinetic data were obtained for each horse when it was trotted across a force platform within a concrete runway unshod (control) and shod with standard horseshoes; standard horseshoes with high profile–low surface area calks, with low profile–high surface area calks, and coated with a thin layer of tungsten carbide (TLTC); and plastic-steel composite (PSC) horseshoes. Kinetic data were obtained for the control treatment first, then for each of the 5 shoe types, which were applied to each horse in a random order. Kinetic variables were compared among the 6 treatments. RESULTS Body weight distribution did not differ among the 6 treatments. Compared with the control, the greatest increase in forelimb peak vertical force was observed when horses were shod with PSC shoes. In the hind limbs, the greatest increase in peak braking force was observed when horses were shod with PSC shoes, followed by the TLTC and low profile–high surface area calked shoes. The PSC shoes yielded the greatest coefficient of friction in both the forelimbs and hind limbs. Stance time was longest when horses were shod with standard shoes. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that PSC and TLTC shoes provided the best hoof protection and traction and might be good options for horses that spend a large amount of time traversing paved surfaces.
显示更多 [+] 显示较少 [-]Comparison of Anaplasma and Ehrlichia species–specific peptide ELISAs with whole organism–based immunofluorescent assays for serologic diagnosis of anaplasmosis and ehrlichiosis in dogs 全文
2021
Qurollo, Barbara A. | Stillman, Brett A. | Beall, Melissa J. | Foster, Paulette | Hegarty, Barbara C. | Breitschwerdt, Edward B. | Chandrashekar, Ramaswamy
OBJECTIVE To compare the performance of 5 synthetic peptide–based ELISAs with that of 3 commercially available immunofluorescent assays (IFAs) for serologic diagnosis of anaplasmosis and ehrlichiosis in dogs. SAMPLE A convenience set of 109 serum samples obtained before and at various times after inoculation for 23 dogs that were experimentally infected with Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, Ehrlichia chaffeensis, or Ehrlichia ewingii and 1 uninfected control dog in previous studies. PROCEDURES All serum samples were assessed with 5 synthetic peptide–based ELISAs designed to detect antibodies against A phagocytophilum, A platys, E canis, E chaffeensis, and E ewingii and 3 whole organism–based IFAs designed to detect antibodies against A phagocytophilum, E canis, and E chaffeensis. The species-specific seroreactivity, cross-reactivity with the other tick-borne pathogens (TBPs), and diagnostic sensitivity and specificity were calculated for each assay and compared among assays. RESULTS All serum samples obtained from dogs experimentally infected with a TBP yielded positive results on a serologic assay specific for that pathogen. In general, sensitivity was comparable between ELISAs and IFAs and tended to increase with duration after inoculation. Compared with the IFAs, the corresponding ELISAs were highly specific and rarely cross-reacted with antibodies against other TBPs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that peptide-based ELISAs had enhanced specificity relative to whole organism–based IFAs for detection of antibodies against Anaplasma and Ehrlichia spp, which should facilitate accurate diagnosis and may help detect dogs coinfected with multiple TBPs.
显示更多 [+] 显示较少 [-]