Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 6 Articles
Background: Infectious bronchitis virus (IBV) is one of the leading causes of mortality and morbidity in chickens.\nThere are numerous serotypes and variants, which do not confer cross protection resulting in failure of currently\nused IBV vaccines. Although variant IBV isolates with major genetic differences have been subjected to comparative\nstudies, it is unknown whether minor genetic differences in IBV variants within a serotype are different in terms of\npathogenesis and eliciting host responses. Two Massachusetts (Mass) variant IBV isolates recovered from commercial\nlayer flocks in the Western Canadian provinces of Alberta (AB) and Saskatchewan (SK) were compared genetically and\nevaluated for their pathogenicity, tissue distribution and ability to recruit and replicate in macrophages.\nResults: Although whole genome sequencing of these two Mass IBV isolates showed low similarity with the M41\nvaccinal strain, they had an identical nucleotide sequence at open reading frames (ORFs) 3a, 3b, envelop (E),\nmatrix (M), 5a and 5b. The rest of the ORFs of these 2 IBV isolates showed 99.9% nucleotide similarity. However,\nupon experimental infection, we found that the IBV isolate originating from AB was different to the one that originated\nin SK due to higher tracheal lesion scores and lower lung viral replication and lower genome loads in cecal tonsils.\nNevertheless, both IBV isolates elicited host responses characterized by significant macrophage recruitment to\nthe respiratory tract and there was evidence that both IBV isolates replicated within tracheal and lung macrophages.\nConclusions: Overall, this study shows that Mass variant IBV isolates, although possessing minor genetic variations, can\nlead to significant differences in pathogenicity in young chickens. Further studies are required to investigate the\npathogenicity of these two Mass variant IBV isolates in laying hens....
The incidence of Inactive ovaries of dairy cows in China is relatively high.\nThere is no complete early warning system for the occurrence of ovarian\nquiescence in clinical cows. This test provides early warning indicators for\nclinical prediction of ovary cessation in dairy cows. This experiment selected\nblood samples of dairy cows from 60 to 90 days postpartum in the inactive\novaries group and control group. Differential proteins were selected on the\nbasis of proteomics, three energy indexes: AST, Glu, NEFA. Four reproductive\nhormones: E2, P4, FSH, LH, and four differentially expressed proteins:\nIGFBP-2, AHSG, APO-A4, and RBP-4. Key enzyme activities: ALDOB,\nLDHB, ITIH3, GPX3, SPAM1, PKM2. The ELISA test kit was used to detect\nthe content and activity of the above markers in the test bovine serum.\nThrough correlation analysis, binary logistic regression modeling and ROC\nanalysis, a single indicator early warning technique for APOA4 and ITIH3\nwas established.................
Background: Food is an important environmental factor that affects animalsâ?? energy metabolism and food shortage\nhas significant effects on animalsâ?? behavior, physiology and biochemistry. However, to date few studies have focused\non the thermogenesis and its effects on the body condition of birds. In this study, we examined the effects of food\nrestriction on the body mass, basal metabolic rate (BMR) and body composition, and several physiological, biochemical\nand molecular markers potentially related to thermogenesis, in the Chinese Bulbul (Pycnonotus sinensis).\nMethods: Birds in the control group were provided with food ad libitum whereas those in the food restriction group\nwere provided with one-half of the usual quantity of food for 12 days. Oxygen consumption was measured using an\nopen-circuit respirometry system. Mitochondrial state 4 respiration and cytochrome c oxidase (COX) activity in the\nliver and pectoral muscle were measured with a Clark electrode. Avian uncoupling protein (avUCP) mRNA expression\nwas determined in pectorals muscle with quantitative Real-time PCR.\nResults: Chinese Bulbuls in food restriction group decreased in body mass, BMR and internal organ (heart, kidneys,\nsmall intestine and total digestive tract) mass compared with the control group over the 12-day period of food\nrestriction. Bulbuls in the food restriction group also had lower levels of state-4 respiration, COX activity in the liver\nand muscle, and mitochondrial avUCP gene expression in muscle compared to the control group. BMR was positively\ncorrelated with body mass, state 4 respiration in the liver and COX activity in the muscle.\nConclusions: Our data indicate that Chinese Bulbuls not only sustain food shortage through simple passive mechanisms,\nsuch as reducing body and organ mass and energy expenditure, but also by reducing energetic metabolism in\nthe liver and muscle....
Bovine viral diarrhea virus (BVDV) affects cows, pigs, sheep, goats, and other ruminants, as well as some wild animals. BVDV\ncauses considerable economic losses every year and many countries have developed programs aimed at the eradication of this\ndisease. The genetic diversity of BVDV in diseased goats has never been described in southwestern China.Thus, in this study, we\napplied antigen-capture ELISA and RT-PCR to survey the infection rate of BVDV in diseased goats in this region. Our results\ndemonstrated that the average BVDV infection rate in goats was 17.51%, with all positive samples indicating infection by BVDV-\n1 and not BVDV-2, BVDV-3, or Border disease virus......................
The failure of testicular descent (cryptorchidism) is known to cause abnormal\ntesticular development and function. Unilateral cryptorchidism is prevalent\nin West African Dwarf (WAD) goats particularly in some areas where affected\nbucks are presumed to have better libido and reproductive efficiency\nby farmers. Androgens produced by the testes can influence libido and other\nhormonal and metabolic processes in the body. The study investigated the influence\nof natural unilateral cryptorchidism on serum reproductive hormones,\ntotal protein, lipid profile, oxidative stress, and haematology and libido\nin WAD bucks. Ten WAD bucks (aged 12 - 14 months) comprising 5\nbucks with normal descended testes (N group) and 5 unilaterally-cryptorchid\nbucks (UC group) were studied. Blood and sera were collected and evaluated\nfor haematology, serum total proteins and lipids (cholesterol, triglycerides\nand lipoproteins) concentrations, serum oxidative stress (catalase and lipid\nperoxidation activity), and serum levels of reproductive hormones (testosterone,\nFSH and LH). Libido testing of bucks was also performed by randomly\nisolating and confining each individual male with a doe on standing heat and\nrecording the number of mountings made by the male within a period of 5\nminutes as the libido score. The evaluated haematological indices and serum\nlevels of proteins, lipids, oxidative stress indicators and reproductive hormones\nwere not significantly different between the N and UC groups (p >\n0.05). Although a higher mean libido score was recorded in N bucks compared\nto the UC group, this difference was not significant. Whereas no negative\neffects were observed in the evaluated physiologic indices in UC bucks,\nthese findings do not support the presumption by farmers that UC bucks \nhave better libido than bucks with fully descended testes. Therefore, these\nanimals should not be selected for breeding to avoid increasing the prevalence\nof unilateral cryptorchidism due to its genetic attribute....
Objective. To estimate current US herd-level and animal-level prevalence of bovine leukemia virus (BLV) in dairy cows and\ncharacterize epidemiologic features. Design. Cross-sectional observational study design and survey. Animals. 4120 dairy cows from\n103 commercial dairy herds in 11 states across the US. Procedures. Milk samples were collected from dairy cows through routine\ncommercial sampling and tested for anti-BLV antibodies by antibody capture ELISA. Based on the ELISA results of a sample of\nan average of 40 cows per herd, within-herd apparent prevalence (AP) was estimated by a directly standardized method and by\na lactation-weighted method for each herd. Within-herd AP estimates were summarized to give estimates of US herd-level and\nanimal-level AP.Differences in AP by lactation, region, state, breed, and herd sizewere examined to characterize basic epidemiologic\nfeatures of BLV infection. Results. 94.2% of herds had at least one BLV antibody positive cow detected.The average within-herd\nstandardized AP was 46.5%. Lactation-specific AP increased with increasing lactation number, from 29.7% in first lactation cows\nto 58.9% in 4th and greater lactation cows. Significant differences were not observed based on region, state, breed, or herd size.\nConclusions and Clinical Relevance.These results are consistent with a historical trend of increasing prevalence of BLV among US\ndairy cattle. Given the findings of other studies on the negative impacts of BLV infection on milk production and cow longevity,\nthese findings are clinically relevant for veterinarians counseling dairy clients on the risks of BLV to their herds....
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