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51.
52.
The objective of this study was to estimate parameters required for genetic evaluation of Simmental carcass merit using carcass and live animal data. Carcass weight, fat thickness, longissimus muscle area, and marbling score were available from 5,750 steers and 1,504 heifers sired by Simmental bulls. Additionally, yearling ultrasound measurements of fat thickness, longissimus muscle area, and estimated percentage of intramuscular fat were available on Simmental bulls (n = 3,409) and heifers (n = 1,503). An extended pedigree was used to construct the relationship matrix (n = 23,968) linking bulls and heifers with ultrasound data to steers and heifers with carcass data. All data were obtained from the American Simmental Association. No animal had both ultrasound and carcass data. Using an animal model and treating corresponding ultrasound and carcass traits separately, genetic parameters were estimated using restricted maximum likelihood. Heritability estimates for carcass traits were 0.48 +/- 0.06, 0.35 +/- 0.05, 0.46 +/- 0.05, and 0.54 +/- 0.05 for carcass weight, fat thickness, longissimus muscle area, and marbling score, respectively. Heritability estimates for bull (heifer) ultrasound traits were 0.53 +/- 0.07 (0.69 +/- 0.09), 0.37 +/- 0.06 (0.51 +/- 0.09), and 0.47 +/- 0.06 (0.52 +/- 0.09) for fat thickness, longissimus muscle area, and intramuscular fat percentage, respectively. Heritability of weight at scan was 0.47 +/- 0.05. Using a bivariate weight model including scan weight of bulls and heifers with carcass weight of slaughter animals, a genetic correlation of 0.77 +/- 0.10 was obtained. Models for fat thickness, longissimus muscle area, and marbling score were each trivariate, including ultrasound measurements on yearling bulls and heifers, and corresponding carcass traits of slaughter animals. Genetic correlations of carcass fat thickness with bull and heifer ultrasound fat were 0.79 +/- 0.13 and 0.83 +/- 0.12, respectively. Genetic correlations of carcass longissimus muscle area with bull and heifer ultrasound longissimus muscle area were 0.80 +/- 0.11 and 0.54 +/- 0.12, respectively. Genetic correlations of carcass marbling score with bull and heifer ultrasound intramuscular fat percentage were 0.74 +/- 0.11 and 0.69 +/- 0.13, respectively. These results provide the parameter estimates necessary for genetic evaluation of Simmental carcass merit using both data from steer and heifer carcasses, and their ultrasound indicators on yearling bulls and heifers.  相似文献   
53.
Relationship between free oestrone and boar taint compounds in adipose tissue were studied in two groups of entire male pigs of different breeds. Group A consisted of 33 entire crossbred male pigs (dam Yorkshire and sire backcross Yorkshire x Wild Boar, generation seven). Group B consisted of 194 entire male pigs of crossbreeds between Swedish Hampshire (H) and Finnish Landrace (L), LH x H, H x LH, LH x LH (dam x sire). The measurements of free oestrone in adipose tissue were performed with a new method developed and validated in our laboratories. The standard curve was linear for concentrations of free oestrone ranging from 0.13 to 5.10 ng/g. The method exhibited parallelism of results between serial dilutions and a mean recovery of 97 +/- 13.7%. Intra-assay variations for samples with concentrations of free oestrone from 0.67 to 2.08 ng/g were from 9.23 to 11.94%. Inter-assay variations for the samples with concentrations of free oestrone from 0.89 to 2.96 ng/g were from 3.78 to 10.11%. The levels of free oestrone in fat from group A were well correlated with fat levels of androstenone (r = 0.66; p < 0.001) and levels of oestrone sulphate in peripheral plasma collected at the same time as the fat (r = 0.74, p < 0.001). The levels of free oestrone in fat from group B were significantly correlated to fat levels of androstenone (r = 0.68, p < 0.001) and skatole (r = 0.29, p < 0.001). In group B, age-related differences in fat levels of free oestrone, androstenone and skatole were studied. Free oestrone and skatole levels increased simultaneously at the age of 22 week (p < 0.05 for both), and androstenone levels increased at the age of 26 week (p < 0.05). It was suggested that the levels of free oestrone in adipose tissue might be used for the evaluation of hormonal status of male pigs as an alternative to plasma levels of testicular hormones. The levels of free oestrone might be involved in the regulation of skatole levels in fat as indicated by both the simultaneous increases in skatole and free oestrone levels in fat and positive correlation between skatole and free oestrone.  相似文献   
54.
Sera of healthy pregnant (group I, n = 11) and non-pregnant (group II, n = 11) bitches were screened for autoantibodies (AAb). In both groups, blood samples were drawn every fifth day between days 5 and 55 after mating. Serum was analysed via indirect immunofluorescence (IIF) with the Canine ANA HEp-2 Screening Kit. In all animals, anticytoplasmic AAb were detected. Utilizing primate-heart substrate slides AAb against contractile proteins of the cytoplasm could be observed. The predominating fluorescence pattern in pregnant animals resembled above all desmin, which was proven via Western blot. The sera were then pre-incubated with tropomyosin, actin, vimentin, vinculin and keratin solutions, and assessed on HEp-2 slides and on human and canine fibroblasts as well. The latter substrate was used to verify whether the detected Ab were in fact AAb. Utilizing tropomyosin, revealed elimination of the cytoplasmic fluorescences on all three substrates. It is therefore assumed, that in sera of healthy dogs, AAb against contractile structure proteins of the cytoplasm are present regularly. The majority of pregnant bitches presented with higher end-point titres (EPT), than to be found in non-pregnant dogs. AAb against desmin played the key role in those patterns. In addition, sera were screened for thyroid specific AAb, namely thyroglobulin, thyroid peroxidase (TPO), T3 and T4, and for AAb against insulin by ELISA or Western blot (TPO). Only in two of the pregnant bitches a weak positive reaction (1:100) for T3-AAb was detected.  相似文献   
55.
The effect of Human chorionic gonadotropin (hCG) stimulation on the concentrations of free and conjugated androstenone in plasma was studied in 34 crossbred entire male pigs (Landrace x Swedish Yorkshire). Seventeen pigs were treated with hCG 4 days prior to slaughter and the remaining pigs were treated with sterile saline and served as controls. Blood samples were taken prior to hCG or saline injection and on the day before slaughter and analysed for concentrations of free and conjugated androstenone. Testicular tissue samples were taken at slaughter and analysed for the levels of cytochrome b5 (cyb5) protein. Here we have demonstrated for the first time that hCG stimulation causes an increase in the plasma levels of both free and conjugated androstenone. Not all animals responded in the same way to hCG treatment regarding levels of free and conjugated androstenone demonstrating that individual animals can have differences in their capacity to produce free and conjugated androstenone. We suggest that hCG treatment is a good way to determine the potential for androstenone conjugation when androstenone synthesis in the testis is high. The levels of cyb5 protein in the testis were slightly related (r=0.41, p < 0.10) to free androstenone levels in the pigs after hCG administration, although levels of cyb5 protein were not affected by hCG treatment.  相似文献   
56.
The aim of this study was to assess the ultrasonographic characteristics of ovulatory follicles in cyclic Western White Face ewes (December) that had received intravaginal sponges containing medroxyprogesterone acetate (MAP; 60 mg) for 12 days, with or without an injection of 500 IU of equine chorionic gonadotropin (eCG) at sponge removal. We hypothesized that quantitative echotextural attributes of the follicles in ewes treated only with MAP would differ from those in MAP/eCG-treated ewes, reflecting the increased antral follicular growth and secretory function under eCG influence. Digital images of ovulatory follicles obtained at 0 and 24 h after MAP sponge removal and at 24 h before ovulation in the eCG-treated (five ewes, 13 follicles) and control (six ewes, 9 follicles) animals, were subjected to computerized analyses. The mean diameter of ovulatory follicles increased (p < 0.001) 24 h after eCG treatment. The mean pixel intensity and heterogeneity of the follicular antrum (p < 0.001), as well as mean pixel intensity of the follicular wall and perifollicular ovarian stroma (p < 0.05), were greater in eCG-treated animals compared with control ewes 24 h after sponge removal and at 24 h before ovulation. Mean serum concentrations of oestradiol-17beta tended to increase (p = 0.06) 24 h after eCG treatment and the eCG-treated ewes exceeded (p < 0.05) control animals in progesterone concentrations from days 9-15 after ovulation. Our results support the hypothesis that large antral follicles in eCG-treated ewes exhibit distinctive echotextural characteristics. Follicular image attributes in eCG-treated ewes appear to be indicative of the changes in follicular morphology and secretory activity caused by the administration of the exogenous gonadotropin, which has both FSH- and LH-like activities.  相似文献   
57.
The interferon system is part of the innate immune system in vertebrates. It represents the first line of host defence against viral infections. Virus entry triggers intracellular signalling pathways which lead to the secretion of soluble factors such as interferons and other cytokines. Interferons signal to neighbouring cells that a viral infection has occurred and induce an "antiviral state" resulting in inhibition of virus replication. The first recombinant interferons were produced in the 1980ies and were considered to be a major breakthrough. At present, interferons are routinely used in the therapy of certain viral and autoimmune diseases as well as for neoplastic disorders in man. In 2001 the first interferon preparation for veterinary use was licensed in the European Union. This review summarises the molecular mechanisms of the interferon system and the viral counteractions. The current type I interferon therapies in humans are described and an overview of recent clinical studies in veterinary medicine, including cat, dog, horse, cow, sheep, pig, and poultry, is given. We review the potential application of interferons and arguments in favor or against its therapeutic use in veterinary medicine.  相似文献   
58.

Objective

To evaluate the effect of Equivac® HeV Hendra virus vaccine on Thoroughbred racing performance.

Design

Retrospective pre‐post intervention study.

Methods

Thoroughbreds with at least one start at one of six major south‐eastern Queensland race tracks between 1 July 2012 and 31 December 2016 and with starts in the 3‐month periods before and after Hendra virus vaccinations were identified. Piecewise linear mixed models compared the trends in ‘Timeform rating’ and ‘margin to winner’ before and after initial Hendra virus vaccination. Generalised linear mixed models similarly compared the odds of ‘winning’, ‘placing’ (1st–3rd) and ‘winning any prize money’. Timeform rating trends were also compared before and after the second and subsequent vaccinations.

Results

Analysis of data from 4208 race starts by 755 horses revealed no significant difference in performance in the 3 months before versus 3 months after initial Hendra vaccination for Timeform rating (P = 0.32), ‘Margin to winner’ (P = 0.45), prize money won (P = 0.25), wins (P = 0.64) or placings (P = 0.77). Further analysis for Timeform rating for 7844 race starts by 928 horses failed to identify any significant change in Timeform rating trends before versus after the second and subsequent vaccinations (P = 0.16) or any evidence of a cumulative effect for the number of vaccines received (P = 0.22).

Conclusion

No evidence of an effect of Hendra virus vaccination on racing performance was found. The findings allow owners, trainers, industry regulators and animal health authorities to make informed decisions about vaccination.  相似文献   
59.
60.
Breeding for high‐amylose corn requires a rapid analytical method for determining starch amylose so that generating wet chemistry values does not pose a major limitation in the volume of materials that can be screened. Two methods for determining apparent amylose content (AAC) were examined and compared with an iodine‐binding method involving the solubilization of isolated starch in a sodium hydroxide solution (method 1). These methods included one based on near‐infrared transmittance spectroscopy (NIRT) (method 2) and another iodine‐binding method involving the solubilizing of starch from ground whole corn with a DMSO‐iodine solution (method 3). These methods were chosen because, aside from initial set up costs, they are relatively rapid and inexpensive to perform. The materials evaluated consisted of various exotic corn populations including plant introductions and experimental materials generated from the Germplasm Enhancement of Maize (GEM) project. Crosses were made between these materials and a Corn Belt dent hybrid (OH43 × H99) converted with the amylose‐extender (ae) allele. Grain from F2 ears, presumed to be homozygous for the ae allele based on visual selection of mutant kernels on F1 ears from which they were planted, were then evaluated to identify possible modifiers of ae conditioning high starch AAC. From a total of 1,006 F2 ears, a core set consisting of 155 samples was established and only these were subjected to starch AAC analysis, using all three methods to compare the methods. Method 2 showed poor correlation to method 1 (r = 0.88), however, NIRT did appear to discriminate between samples converted to ae vs. those with a normal or possibly segregating endosperm type. Method 3 showed a slightly better correlation with method 1 (r = 0.92) and appeared to more fully discriminate among samples with AAC values >65% from those at ≈55%. Results from this study suggest that NIRT may be useful when a quick screening method is needed to discriminate mutant from nonmutant genotypes within grain samples of exotic germplasm especially when visual identification is difficult. In addition, method 3 could be used to replace the more time‐consuming method 1 when trying to identify high AAC levels among ae genotypes, even though some inconsistency was observed between the two methods. Finally, this study revealed that exotic germplasm may be an important source of new modifiers to the ae allele because values as high as 70% AAC were identified.  相似文献   
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