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1.
The presence of antibodies to two influenza viruses of the type A (H1N1 and H3N2) and to a porcine respiratory coronavirus was investigated in a study lasting a year. 735 blood serum samples were collected from 79 closed pig fattening farms in the province Segovia (Spain). Hemagglutination inhibition was used with influenza viruses. The percentage of positive results was 78.5% and 62.5% respectively for the serotypes H1N1 and H3N2. A clear reduction in the spread of antibodies was observed in the autumn. The ELISA technique was used with the porcine respiratory coronavirus. As antigen we used the antigenically related transmissible porcine gastroenteritis virus. Using this technique 87% of the sera were positive. Some of these sera with representative ELISA values were confirmed by means of serum neutralisation and radioimmune precipitation of the viral proteins. The incidence of these antibodies remained unchanged over the whole year of the investigation.  相似文献   
2.
We have performed a study on 11 human embryos regarding the development of the tympanic ossicles and their relationship with the first pharyngeal arch. After performing measurements to date the embryos and foetuses chronologically, we performed a meticulous dissection of the temporal bones. Subsequently, they were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in 7-mm sequences and stained with Martin's trichrome technique. In the 21- and 24-mm cranium-raquis (CR) length human embryos, we have observed the head of the malleus and the body of the incus close to Meckel's cartilage, in addition to the handle of the malleus, the long limb of the incus and the stapes. Between them there was a mesenchymal band inside the primordium of the tympanic cavity. In the 27-mm CR embryo, the various components of the malleus and incus were fusing, and in the 30-mm CR embryo the union was complete. From our observations, we can conclude that the malleus and the incus are derived from the first and second pharyngeal arches.  相似文献   
3.
The aim of this study was to compare the cumulative incidence of mortality, clinical diarrhoea and respiratory disease in calves, during their first six months of age, in herds with different bovine viral diarrhoea virus (BVDV) infection status. Calves’ health indicators were tested by comparing proportions in 101 farms with dissimilar infection condition. The results indicate that there was a significant relationship between the BVDV status (actively infected herd or not) and the cumulative incidence of mortality and respiratory disorders.  相似文献   
4.
A prospective study was conducted to assess the effect of introduction of piglets from farrow-to-finish farms on the global performance of all-in all-out fattening batches in Galicia (NW Spain). Two hundred and thirty-nine fattening batches from 48 fattening farms integrated in a cooperative were used in the study. All-in all-out fattening batches were classified according to the category of farm that supplied the piglets. Origin F was a fattening batch where all feeder piglets came from one or more farrow to feeder units versus origin FF, in case a group of piglets or all piglets of the batch came from farrow-to-finish farms. Productive parameters of fattening batches included in the study were recorded. Crude comparisons of performance of 37 fattening batches from origin F and 202 from origin FF were made. Mixed multiple linear regression models were used to assess the association between type of origin of feeder piglets and the following parameters: feed consumed per market hog, percentage of deaths (mortality) and time to slaughter. In all models, variables with presumable relationships with the outcomes were offered to the models as well as the biologically plausible interaction terms.

Mortality was higher in fattening batches with piglets coming from farrow-to-finish farms (0.67% higher than origin F; P < 0.05). Time to slaughter was longer when feeder piglets were from origin FF (3.1 days longer; P < 0.05).

We found a significant effect of type of origin on feed consumed per marketed hog. Additionally, a significant interaction was found: feed consumed per marketed hog was higher for fattening batches with all piglets from farrow-to-finish farms if slaughtered before 109 days and vice versa. A Monte Carlo simulation model was used to assess the economic impact of using origin F or FF as source of piglets. Results of the model indicated that the difference in expected profit per marketed hog between the types of sources of piglets was small (€11.50, S.D. 1.79 for origin F versus €10.44, S.D. 2.72, for origin FF).  相似文献   

5.
The study was designed to determine the relation between β‐hydroxybutyrate (BHB) concentrations in milk from dairy cows after calving and the length of the previous lactation, the dry period and the 305‐day normalized production, and to assess the influence of BHB concentrations on culling and test‐day milk productions and somatic cell counts (SCC) throughout the lactation that followed the BHB measurement. The data used in the study were obtained from 59 187 cows in the Galicia region (Spain). BHB determination was performed using Fourier‐transformed infrared spectrometry from the milk samples collected from each cow on the first post‐partum test day. For statistical analysis, the following methods were applied: (i) ordinal regression to assess the effect of the length of the previous lactation, the dry period and the 305‐day normalized milk production on milk BHB, (ii) a Cox model to estimate the influence of the BHB concentration on risk of culling (overall and for a variety of reasons) and (iii) linear regression to assess the link between BHB and the milk yield and SCC obtained from each of the tests day performed throughout lactation. The probability of having higher BHB concentrations increased when the length of the previous lactation (p = 0.006), the dry period (p = 0.003) and the 305‐day normalized milk yield (p = 0.005) increased. However, the slight increase observed (especially for the case of the dry period and the 305‐day milk yield) would not justify that measures be implemented to reduce these traits. Higher concentrations of BHB led to an increased risk of culling due to ‘death’ (p ≤ 0.001) and ‘urgent slaughter’ (p ≤ 0.002) (both causes of involuntary culling). It also led to a reduction in milk production (p < 0.001) and an increase in SCC (p < 0.001) in the post‐partum; from that moment onward (including peak lactation), there were no differences in those two parameters depending on the BHB levels.  相似文献   
6.
During 2004, a survey of Mycobacterium avium subspecies paratuberculosis (map) was conducted in 101 randomly selected dairy herds to investigate associations between the infection status of the herds, different management practices, and possible disease indicators, such as indices of mastitis and reproductive performance. Data were collected by means of a questionnaire through personal interviews with the farmers and veterinarians in charge of each farm. At the same time, blood samples were taken from cattle over one year old and analysed with a commercial elisa to detect antibodies to map. Statistical analyses indicated that the following management practices constituted major risk factors: utilisation of colostrum from cows with a previous positive map diagnosis, and housing replacement calves with adult cattle before they were six months old. Seropositivity to map was related to the herds' bulk tank somatic cell counts and incidence of clinical mastitis, but not to their reproductive performance.  相似文献   
7.
During the first 3 months of 2006, a study was performed on four dairy cattle herds with a history of clinical paratuberculosis, to evaluate different enzyme-linked immunosorbent assays (ELISAs). Serum samples obtained from 326 animals were analysed using four ELISAs to detect antibodies to Mycobacterium avium subsp. paratuberculosis (MAP). Kappa (kappa) concordance coefficients in pairwise comparisons of the ELISA outcomes ranged up to 0.22 (linear kappa) and 0.25 (quadratic kappa). When the borderline positives obtained were considered as negatives, kappa values remained low (kappa up to 0.19). Having performed the serological tests, faecal samples were then obtained from 55 animals (including all animals testing positive in two or more ELISAs) from the same herds. Faecal culture and faecal polymerase chain reaction (PCR) for the detection of MAP were negative in all cases. The results indicate that neither the currently available serum ELISAs nor faecal culture and PCR are effective for the early detection of MAP in dairy cattle.  相似文献   
8.
The purpose of this report is to contribute to the knowledge of the morphogenesis of the human stapedius muscle. We have studied the stapedius structure development in 17 temporal bones from human fetuses. Chronological ages were from 48 days (21 mm) to 29 weeks (270 mm). Samples were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in sequence of 7 microns and were stained with haematoxylin & eosin and Martins' trichrome. Four maturation stages were observed in the development of the stapedius muscle structure. First, the formation of the 'primordium muscularis' in the mesenchyme of the tympanic cavity (promyoblasts) was observed in a 36-mm embryo. Second, its differentiation into myoblasts, and its next cellular fusion to form muscle tubes, was seen in a 99-mm foetus. In the third stage, myofibrogenesis phenomena were developed, to synthesize, the myotube myoblasts, myofilaments, phenomena we observed that took place during the 14th to 17th weeks of development. The last stage was characterized by the presence of striated muscle fibres, at first intermingled with myotubes (18th to 26th weeks), until in the 29th week fetuses (270 mm) the skeletal muscle fibre was completely differentiated. We conclude that in the 29th week of development (270 mm) the stapedius muscle structure is completely differentiated, although the functional development is not complete until birth.  相似文献   
9.
The aim of the present study was to determine the serological response of heifers after vaccination with two inactivated bovine viral diarrhoea virus (BVDV) vaccines by means of various ELISA tests. Three dairy farms were selected from the Galicia region of Spain. In each herd, a batch of heifers to be vaccinated for the first time was selected and followed for 15 months. Heifers from farm 1 (n = 25) were vaccinated with Vaccine A, whereas heifers from farm 2 (n = 16) were vaccinated with Vaccine B. Heifers from farm 3 (n = 17), where no BVDV vaccines were used, acted as controls. Blood samples were analyzed periodically for BVDV antibodies, using five commercial ELISAs, based on BVDV p80 antigen or whole virus.At the end of the study, none of the animals vaccinated with Vaccine A seroconverted according to p80 antibody status, whereas up to 80% tested positive by ELISA against whole virus antigen. For the animals vaccinated with Vaccine B, 2/16 animals seroconverted according to p80 antibody ELISAs, whereas all had seroconverted according to the ELISA against whole virus antigen. In most cases, based on the use of ELISAs to detect specific antibodies against the p80 protein, at 15 months post-vaccination with inactivated BVDV vaccines the responses did not seem to interfere with detection of antibody to BVDV infection. However, the finding of a small proportion of vaccinated animals seropositive against BVDV p80 antigen suggests that antibodies that interfere with diagnosis of BVDV infection within the herd could exist, even when using p80 ELISAs.  相似文献   
10.
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