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1.
The objective of this study was to evaluate the safety of a standardized Macleaya cordata Extract Product (MCEP) containing the quaternary benzophenanthridine alkaloids, sanguinarine and chelerythrine, when fed to dairy cows. Thirty‐six dairy cows were randomized into three groups with twelve cows/treatment in two replica pens for each treatment group: control (C) without MCEP added to feed, treatment 1 (SANG‐1000) with MCEP added to feed at 1,000 mg/animal/day (1.5 mg/kg bw/day) and treatment 2 (SANG‐10000) with MCEP added to feed at 10,000 mg/animal/day (15.5 mg MCEP/kg bw/day). After two weeks of acclimation, animals were observed for an 84‐day experimental period, with body weight, feed intake and milk production measured daily. Milk composition was analysed every two weeks. Haematological analyses were performed on Day 0 and Day 84, and clinical chemistry analyses were performed on Day 84 of the study. There was no statistically significant difference (p > .10) among the three groups on body condition score, milk production or milk composition over the study period. There were no significant differences in body weight gain or feed consumption among the three groups. Animals in the SANG‐10000 group had significantly higher mean corpuscular volume (MCV) than the C group (p < .1) and lower mean corpuscular haemoglobin concentration (MCHC) than the SANG‐1000 group (p < .1). Concentrations of sanguinarine and chelerythrine in milk samples collected on Day 84 were below the detection limit (LOD) as measured by high‐performance liquid chromatography‐mass spectrometry (HPLC‐MS/MS). In conclusion, this study presents compelling data supporting the hypothesis that the test product MCEP, when included in the TMR at up to 10,000 mg/animal/day (15.5 mg MCEP/kg bw/day), is well tolerated by dairy cows.  相似文献   
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Plasma concentrations of PAG‐1 are used for pregnancy diagnosis and as a marker of placental/foetal well‐being, while those of PAG‐2 may be an indicator of abortion risk in Neospora caninum‐infected cows. Studies have shown that N. caninum infection modifies PAG‐1 and PAG‐2 patterns in maternal blood plasma. However, no prior work has examined the effects of N. caninum infection on concentrations of PAGs in foetal fluids. In this study, PAG‐1, PAG‐2 and pH levels were determined in the amniotic and allantoic fluids of foetuses collected at 152 days of gestation from control uninfected dams and from dams experimentally infected with N. caninum on Day 110 of gestation. Foetal fluids from infected foetuses had significantly higher PAG‐2 concentrations (p = 0.026) and pH values (p = 0.02) than fluids from non‐infected foetuses. In infected foetuses, significantly higher concentrations of PAG‐1 (p < 0.001) and PAG‐2 (p < 0.001) were detected in fluid samples showing antibodies against N. caninum than those without antibodies. Moreover, pH values were significantly higher (p = 0.011) in foetal fluid samples with antibodies than in samples from non‐infected foetuses. In conclusion, this is the first report on the effect of N. caninum infection on PAG levels in foetal fluids. Our results indicate that following the experimental infection of dams with N. caninum on Day 110 of gestation, foetal fluids collected from the infected foetuses of these dams featured higher PAG‐1 and PAG‐2 levels and pH values than fluids from non‐infected controls, provided that the samples tested showed the presence of antibodies. The clinical implications of these findings are that following infection with N. caninum, most cows will experience some level of placental damage and that this injury correlates with foetal fluid PAG levels and pH.  相似文献   
4.
The reproductive performance of female Nile tilapia, Oreochromis niloticus L., reared in ponds under tropical conditions was studied. The experiments used stock matured to the age of 2–4 months and a size of 30–50 g. Oocyte development proved a better indicator for the determination of the size at first maturation than the development of the gonado-somatic index. The Nile tilapia became ‘stunted' in the sense that early breeding took place, but the somatic growth of the stock still continued. This result indicates that the earlier breeding of Nile tilapia is not a real bottleneck for the expansion of this production sector. No relationship was found between the condition factor and the size at first maturation or the relative fecundity. This led to the conclusion that aggravation of the living conditions is not a major cause of earlier breeding of pond-reared O. niloticus.  相似文献   
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The 'Muguga cocktail' which is composed of three Theileria parva stocks Muguga, Kiambu 5 and Serengeti-transformed has been used extensively for live vaccination against East Coast fever in cattle in eastern, central and southern Africa. Herein we describe the molecular characterisation of the T. parva vaccine stocks using three techniques, an indirect fluorescent antibody test with a panel of anti-schizont monoclonal antibodies (MAb), Southern blotting with four T. parva repetitive DNA probes and polymerase chain reaction (PCR)-based assays detecting polymorphism within four single copy loci encoding antigen genes. The Muguga and Serengeti-transformed stocks exhibited no obvious differences in their reactivity with the panel of MAbs, whereas Kiambu 5 differed with several MAbs. Kiambu 5 DNA was very distinct from the Muguga and Serengeti-transformed isolates in the hybridisation pattern with all four nucleic acid probes, whereas Muguga and Serengeti-transformed isolates exhibited minor differences and could not be discriminated with one of the probes. PCR amplification in combination with restriction fragment length polymorphism analysis indicated that Kiambu 5 was also markedly divergent from the Muguga and Serengeti-transformed stocks within two of the four antigen coding genes. The T. parva Serengeti-transformed stock did not contain a 130 base pair insert within the p67 sporozoite antigen gene, which has been observed previously in most T. parva parasites isolated from buffalo, and could not be discriminated from T. parva Muguga at any of the four single copy loci. Collectively the data indicate that two of the cocktail components T. parva Serengeti-transformed and Muguga are genetically closely related, while the third component Kiambu 5 is quite distinct. Based on the findings, there may be a need to include only one of the T. parva Muguga and Serengeti-transformed components in the immunising cocktail. The study demonstrates the value of molecular characterisation data for monitoring of live vaccines.  相似文献   
6.
Lactating dairy cows (n = 72) with a mature corpus luteum (CL) (diameter of > or = 17 mm) determined by ultrasonography and having a follicle with a diameter of > or = 10 mm were randomly assigned to four groups. Cows were treated with cloprostenol i.m. once or twice, or with dinoprost i.m. once or twice with an 8-h interval. The ovaries of each cow were scanned daily by transrectal ultrasonography to measure the changes in the areas of CL and the largest follicle and to determine the occurrence of ovulation. Oestrus was verified twice daily. In addition, blood sample was withdrawn from each cow daily for measuring progesterone (P4) concentrations. Significant decreases in the percentage changes relative to areas of CL and P4 concentrations or increases in the percentage changes in the area of the largest follicle on day 0 were detected in each group during the experiment. However, the type of the drug and the number of the treatments had no significant effect on those parameters. Cows ovulated with or without showing oestrus (group A) and cows exhibiting no oestrus and ovulation (group B) were also evaluated. In contrast to the mean area of the CL and the mean concentration of P4 on day 0, the mean area of the largest follicles between the two groups on day 0 differed significantly. Significant decreases in the percentage changes relative to the area of the CL and P4 concentration or increases in the percentage changes relative to the area of the largest follicle during the experiment were detected in both groups; however, there were no group differences. Treatment of dairy cows with two injections of prostaglandins (cloprostenol or dinoprost) at an 8-h interval resulted in more cows being observed in oestrus within 5 days after treatment and having significantly higher pregnancy rate than those treated with a single prostaglandin injection.  相似文献   
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The recent upgrade in IVP technology seen in cattle can be adapted to embryo production in small ruminants to overcome limitations exhibited by surgical procedures on preserving the reproductive potential of donors and the efficiency of embryo production. The aim of the present study was to assess the current procedures used in cattle for the production of IVP embryos in goats and sheep based on laparoscopic-aided ovum pick-up (LOPU) supplied oocytes. Sexually matured goat and sheep donors were treated during the breeding season with FSH and subjected to laparoscopic-guided follicular puncture under general anaesthesia. The collected cumulus-oocyte complexes were matured in medium 199 and fertilized by frozen-thawed spermatozoa using Talp medium supplemented with heparin and oestrus-sheep serum. Cleaved ova were either cultured in sheep in vitro fertilization medium plus amino acids or transferred to sheep oviducts. Blastocyst rate, hatching rate and development rate up to term were used as markers of embryo function. The results obtained for goat and sheep involving 30 and 35 donors respectively (10 and 9 LOPU sessions) were 81.2% and 85.2% of oocyte collection rate; 88.3% and 98.6% oocyte incubation rate; 85.6% and 76.0% fertilization rate; 82.4% and 93.4% of cleavage rate; 50.0% and 61.5% IVP blastocyst rate; 42.1% and 45.5% blastocyst rate in oviducts; 73.0% and 66.7% embryo survival up to term, respectively. The results are comparable to those obtained in small ruminants and in bovines suggesting that requirements for embryo production and development are similar.  相似文献   
9.
Three different histochemical methods for copper detection were compared. Atomic absorption analysis was used to substantiate the tissue stains. There was good correlation between rhodanine staining and rubeanic acid-stained tissue sections. The orcein reaction for copper-associated protein did not consistently correlate with the methods demonstrating copper. Prolonged staining (72 hours) with rubeanic acid more consistently and clearly detected increased copper in canine livers than did staining with rhodanine. Seventy-two hour staining with rubeanic acid is the method of choice for histochemical detection of copper in canine liver.  相似文献   
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