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1.
The structure of the hoof epidermis is the link between nutrition and horn quality. The aim of this study was to demonstrate the relationship of single structures in the process of keratinization and cornification of bovine hoof epidermis to certain nutritional factors such as lipids, minerals and vitamins. Furthermore, we wanted to show the structural changes in the dyskeratotic epidermis caused by an insufficient supply of keratinizing epidermal cells. For our study we used samples of hoof epidermis from 25 dual-purpose dairy cattle, with ages ranging between 2.5 and 4 years. We also obtained a complete set of hooves from a biotin-deficient calf. All samples were investigated by light and transmission electron microscopy, using routine methods as well as histochemical and enzyme-histochemical techniques. We focused on epidermal structures that have a major influence on horn quality and are known to be related to single nutritional factors. The strength of the keratin filament bundles is determined by their cross-linking via sulphur-containing amino acids. Essential fatty acids are required for the synthesis of an intercellular cementing substance connecting the horn cells and establishing a permeability barrier in the stratum corneum. Minerals, in particular calcium, are essential for activation of enzymes that are a prerequisite for physiological keratinization and cornification. Furthermore, vitamins such as biotin are essential in the metabolism of the keratinizing epidermal cells.  相似文献   

2.
The laminar epidermis (epidermis parietis) of hooves from 14 clinically normal horses, 6 months to 15 years old, was examined by light and electron microscopy and immunofluorescence to measure the contributions of this region to the formation of the hoof wall. By their progressive keratinization to form primary epidermal laminae, the secondary epidermal laminae ultimately contributed about 20% of the thickness of the hoof wall (as revealed in the white line [zona alba]). The keratinized, primary epidermal laminae were developed to a height of 4 mm during their proximodistal-course, much of this obscured because of their basal portion being embedded in the cap horn epidermis. From evaluation of structural changes accompanying keratinogenesis in the cell and determination of the contribution of the laminar epidermis to the formation of laminar horn, cap horn, connecting horn, terminal horn, and the white line, we concluded that the sterile bed concept of a nongerminative role for the secondary epidermal laminae is no longer tenable.  相似文献   

3.
Farrier's Formula feed supplement was added to the diet of 18 horses with two types of hoof horn defects. The first group of horses showed sand cracks and crumbling horn around the nail holes; the second group suffered frequent bruising and had flat feet with collapsed heels. Hoof clippings from both groups were studied in the transmission and scanning electron microscopes. All the horses showed a progressive improvement in the gross and microscopic structure of the hoof horn, starting six weeks after the supplementation began. Once good quality hoof horn had grown there was no relapse during the two year period of the study.  相似文献   

4.
To gain a basis for diagnosing the frequent pathological changes of the porcine hoof, the fine structure of normal hoofs taken from landrace pigs was examined with the light microscope, the polarizing microscope and the electron microscope. The hoofs were taken mostly from 6 to 7 month-old slaughtered pigs, but also from younger animals, beginning at birth. The hoofs destined for light microscopical study were not softened before frozen sections were made; these sections were stained while floating on the stain. The hoof horn of the pig consists of mostly flat cells which are shaped like pancakes. The horn tubules often have oval cross sections and do not present a distinct boundary with the adjacent intertubular horn. The harder horn of the hoof has more horn tubules per mm2 than the softer horn.  相似文献   

5.
In horses with chronic laminitis, an abnormal horny structure called lamellar wedge, is generated between the hoof wall and the laminar epidermis. To be able to manage horses with chronic laminitis correctly, more information about the pathological state of this abnormal horn is required. The aim of this study was to collect and analyze objective morphological data about the abnormal horn in order to understand its morphology and development. In the study, the abnormal horn was grossly visible on the sagittal hoof section from approximately 20 days after the onset of disease. In the histological observations, the structural characteristics of this abnormal horn were similar to the white line tissue, suggesting it is an ectopic white line. Mean value of the cross-sectional area of the abnormal horn against the distal phalanx section area (A/D) was 0.29 cm(2) SD +/- 0.14 and it finally showed an eight-fold increase over the mean value of normal white line section area against the distal phalanx section area. In conclusion, a large amount of the ectopic white line is thought to be finally able to inhibit normal hoof wall growth, so that it should be resected at the optimum time when would be after one month from the onset of the disease.  相似文献   

6.
Locomotion scoring, lying behaviour and lesion recording during hoof trimming are all ways of evaluating hoof health in dairy cows. The objective of this study was to evaluate the relationship between these measures in a random sample of 1340 cows from 42 Danish dairy herds. The hypothesis was that locomotion scoring and/or the monitoring of lying behaviour could be used as tools to identify cows with hoof lesions, either of the horn or of the skin. Cows were locomotion scored, lying behaviour recorded and data on hoof lesions seen during hoof trimming collected. The results were analysed using logistic regression with hoof lesion as the outcome and locomotion score (1-5), mean duration of lying bouts, parity and lactation stage as explanatory variables. This analysis was undertaken for all types of lesions, for hoof horn lesions only and for skin lesions only. Odds of all hoof lesions and of skin lesions increased with increasing locomotion score and increasing mean duration of lying bouts. Odds of horn lesions also increased with increasing locomotion score, but there was no significant association between horn lesions and the mean duration of lying bouts. It was concluded that locomotion scoring and duration of lying bouts may be used as tools in the management of hoof health in dairy herds.  相似文献   

7.
The three superimposing strata of the coronet and the ageing process and decay of the hoof horn were studied in 56 fore hooves of 28 domestic horses of different age and sex. Except for horn clefts at the weight bearing margin, their hooves did not show any signs of pathological changes. Their hooves did not show any signs of pathological changes. The investigation comprised the analysis of the structure and the mechanical-physical measurement of horn hardness. The own results showed that the functional and clinical importance of the three strata of the coronet concerns the absorption and distribution of the horizontal and vertical pressure and the resilient-elastical fixatia of the suspensory apparatus of the coffin bone to the inner spongiforme Stratum medium. Disruptive pathological changes may spread out between the different horn layers which sometimes leads to the phenomenon of the "Hollow Wall". The hard and stable coronet is composed of tubular and intertubular horn. Distal of the crest of the coffin bone the horn hardness decreases and clefts are visible which are interpreted as ageing processes. The medullar horn decays much faster in certain regions, thus enabling ascending infections especially in the white line area, causing "White Line Disease". Under consideration of the references the own results proved, that regular and professional trimming of the hoof can prevent these diseases and improves the pododermal blood circulation and the orthokeratotic cornification. By improving the stable hygiene and adequate nutritional supply with minerals and vitamins these measures can be supported.  相似文献   

8.
Horn samples were taken from the hooves of eight horses with clinical signs of equine onychomycosis in at least one hoof capsule. None of the horses had a documented mycological history. The predominant alterations of the horn capsules were sand cracks, white line disease, brittleness (especially around the nail holes), parakeratosis and bruising. The horn samples were stored in sterile tubes for transportation and transferred onto Sabouraud Dextrose Agar and dermatophyte test agar for mycological examination within 6 h. Fungal cultures were incubated for 30 days at room temperature. Fungal identification was based on colonial morphology and microscopic examination of conidia. Horn samples were also stored at ?80°C until used for scanning electron microscopy (SEM). The fungal culture revealed that the hoof horn from all eight horses was infected with keratinophilic fungi. The keratinopathogenic fungi Trichophyton spp and Scopulariopsis brevicaulis were also detected in six horses. SEM revealed severe alterations of the horn structure in horn samples infected with keratinopathogenic fungi compared to horn samples from a sound hoof. The most evident changes were deterioration of the tubular structure of the horn wall, disruption of the horny layers, superficial lysis of cornified cells and the presence of fungal elements. Samples without dermatophyte or Scopulariopsis infection, in contrast, were similar to healthy hoof horn.  相似文献   

9.

The aim of this investigation was to establish genetic correlations between foot and leg traits in future potential AI bulls and body conformation traits in their daughters. Data consisted of records of 2394, 5002 and 1098 bulls of the breeds Danish Red, Danish Friesian and Jersey, respectively, which were correlated according to breed with 11846, 62875 and 10954 daughters sand their contemporaries, respectively. The bull traits included hoof measurements, horn characteristics and claw disease frequencies recorded at hoof trimming, while the data for the dairy cows contained the scores for rear leg side view, rear leg rear view, bone structure, quality of hocks and foot angle. The correlations between the claw diseases or horn characteristics on one side and the daughters' conformation on the other side were either negligible or inconclusive, while those between the bull's hoof measurements and the two conformation traits bone structure and hock quality were of statistical significance for all three breeds. Moreover, the stance of the rear leg showed a significant relationship to claw measurements in Danish Red and Jersey cattle. Small feet in bulls were correlated with a favourable expression of feet and legs in daughters. An improvement in foot and leg conformation traits in dairy cattle is possible by including claw measurements in the selection of future AI bulls.  相似文献   

10.
Twenty-three horses with persistent hoof horn defects were treated topically with a hoof disinfectant as part of a hoof care programme for a year. The active ingredients of the disinfectant were a poloaximer-iodine complex, ethylenediamine dihydriodide, isopropyl alcohol and propylene glycol. Hoof trimmings were taken at the start of the study and every six weeks, and examined by scanning and transmission electron microscopy. At the beginning of the study all the horn samples contained large numbers of bacteria, and samples from eight of the horses also had fungal hyphae intermingled with the bacteria. After the application of the hoof disinfectant and adjustments to their diet, there were rapid improvements in the gross appearance of the feet of all the horses; some of them improved within two to three weeks and by 12 weeks the horn quality of all the horses had greatly improved.  相似文献   

11.
Although not scientifically proven, hoof trimming has been empirically shown to increase milk yields in healthy dairy cows. In this study, we examined the effect of one-time hoof trimming on blood biochemical composition, milk yield, and milk composition in healthy dairy cows. Eleven cows in the mid to late lactation period that were clinically fit and without hoof disease were subjected to hoof trimming, and metabolic profile tests and dairy herd improving tests were performed before and three weeks after the hoof trimming. The metabolic profiles showed changes in albumin, blood urea nitrogen, ammonia, glucose, and beta-hydroxybutyric acid as a result of the hoof trimming. This was indicated by the fact that the cows began to intake more roughage after hoof trimming than prior to hoof trimming, and rumen fermentation became stable. There was no change in milk yield after trimming. However, the milk fat and milk protein compositions were significantly increased after trimming.  相似文献   

12.
Diseases of the hoof horn are the most common cause of lameness in the UK dairy herd, and diet, particularly starch intake, is commonly implicated in their development. This study assessed whether replacing starch carbohydrate with sugar beet pulp, in a diet containing 50 per cent of the dry matter as forage, would significantly reduce the development of hoof horn haemorrhages in dairy heifers after calving. It also investigated the effect of replacing wood shavings as cubicle bedding with chopped straw. The heifers fed the high-fibre diet had a significantly lower yield of milk protein and a significantly higher yield of milk fat than the heifers fed the high-starch diet, indicating that the change of diet had affected rumen fermentation. However, the change had no significant effect on the development of hoof horn haemorrhages. The change of bedding material also had no significant effect on the development of hoof horn haemorrhages.  相似文献   

13.
Shelly hoof in sheep occurs when the hoof wall becomes detached from the laminar corium; it often then becomes impacted with debris leading to infection, pain and lameness. The problem of shelly hoof is under-reported and is often confused with classical footrot. A study was conducted using data on 9,169 Blackface and Texel sheep from 22 farms in the UK. The aim of the study was to estimate the prevalence of shelly hoof in these breeds, to quantify the genetic basis to shelly hoof, and to describe a pilot trail to characterise the physical properties of horn using Transmission Electron Microscopy (TEM). The results showed that shelly hoof has a high prevalence (47% for Blackface and 24% for Texel ewes) and is under moderate genetic control (h2 = 0.3). The TEM images showed fragmented dorsal wall horn, microscopic crevices leading deeper into the hoof accompanied by bacteria and other micro-organisms. The invasion of bacteria was facilitated by separation of the cells in a characteristic ‘un-zipping’ phenomenon, poor attachment of the keratin to the cell membranes, poor cell membrane quality with a ‘lace-chain’ effect and incomplete keratinisation of the cells.  相似文献   

14.
This study investigated the effects of housing primiparous lactating Holstein heifers either in cubicles with butyl rubber mats, cubicles with thicker mattresses filled with chopped rubber, or straw yards, and supplementing them with methionine for the first 13 weeks of lactation on the rates of growth of their hoof horn and the conformation of their feet. Overall, the rate of growth of the hoof horn increased significantly after calving but the rate of wear did not increase. In contrast, the type of housing had no significant effect on the growth of the hoof horn, but the heifers in straw yards had significantly lower rates of lateral horn wear. The changes in growth and wear rates resulted in changes in hoof conformation, including the toe angle and the width of the bearing surface, which suggested that heel bulb hypertrophy occurred after the heifers had been moved from soft underfoot conditions on to concrete. Providing 115 per cent of their estimated methionine requirements had no significant effect on the rates of growth and wear of the hoof horn.  相似文献   

15.
The aim of this study was to evaluate the effect of daily biotin supplementation on the mineral composition and microstructure of the abaxial hoof wall in dairy heifers. The heifers were housed on a concrete floor and fed for weight gain more than 800 g per day, which is a challenging environment for the hoof. Twelve crossbred dairy heifers (Jersey × Holstein) were divided into two treatment groups. Animals in the control group (n = 6) received a diet without supplemental biotin, while the heifers in the biotin-supplemented feed group (n = 6) each received 20 mg of biotin daily for 120 days. Samples of the abaxial hoof wall were collected from the outer claw of the fore and hind limb, before and after supplementation. The samples were evaluated by X-ray fluorescence spectrometry, computed microtomography, atomic force microscopy and confocal laser scanning microscopy. Biotin supplementation increased the sulphur content and decreased the calcium and potassium content in the abaxial hoof wall. Biotin treatment also increased the percentage of horn tubules with smaller diameter marrow (17–51 µm). However, biotin did not influence the surface relief of the hoof wall, suggesting that its action is limited to the inner layers of the stratum corneum. Daily supplementation with 20 mg of biotin promoted changes in the mineral composition and microstructure of abaxial hoof wall of crossbred dairy heifers. These findings suggest biotin supplementation improves hoof quality and may help to understand the function of biotin in the stratum corneum.  相似文献   

16.
The unaltered epidermis of the hoof of 21 Landrace pigs of different ages was examined histochemically for substances which could be important for normal keratinization, quality of horn or in pathological processes. These were PAS-positive substances, SH- and SS-groups, lipids, calcium and phosphate as well as the enzymes lactate dehydrogenase, succinate dehydrogenase, ATP-ase, alkaline and acid phosphatase, beta-glucuronidase and non-specific esterase. The histochemical results can be very different in various pans of the hoof. The medullary spaces of the horn tubules in the stratum corneum contain carbohydrates as well as hydrolytic enzymes such as acid phosphatase, beta-glucuronidase and non-specific esterase. These enzymes and the carbohydrates may increase in pathological processes.  相似文献   

17.
The objective of this study was to investigate clinical signs indicating diseases with known or suspected hereditary components like equine sarcoid, insect bite hypersensitivity, osteochondrosis, allergic airway diseases, podotrochleosis, prognatism and wind-sucking in the franches-montagnes horse.We performed a clinical examination on 702 three-year-old, privately owned franches-montagnes horses, which were shown at the Swiss-Field-Tests in 2004.With the help of the owners a questionnaire on health, environment and feeding habits of the animals was completed. In 11.9% of the horses, sarcoids were detected, 6.2% carried one tumor and 5.7% had several. The prevalence was higher in chestnuts (16.6%) than in bays (10.1%). The prevalence of sarcoids in offspring from sires with known sarcoids (data from Station-Tests 1994-2005) was not significantly higher than in descendants from stallions without a known history of sarcoids. Clinical signs of insect bite hypersensitivity were only found in six horses (0.9%). In 12.0% hoof abnormalities like brittle horn, ring hoofs or hoof cracks of different degrees were recorded. The angle between hoof base and hoof wall was 56.7 +/- 0.1 degrees, the average hoof width was 13.7 +/- 0.3 cm in the front feet. For both of these measures we found no significant difference between left and right feet. With the exception of a high sarcoid prevalence, our results indicate that the franches-montagnes horse is a healthy breed overall.  相似文献   

18.
Hardness of bovine hoof horn was tested as ball indentation hardness and as shore D hardness post mortem in different segments of the hoof wall, in the sole and the hard bulb of sound claws of 10 Austrian Holstein Friesian cows. Both methods of hardness determination showed corresponding results, with shore D hardness between 52.2 and 63.9 hardness units (hu) and ball indentation hardness between 11.2 N/mm2 and 24.3 N/mm2. Bovine hoof horn becomes significantly softer from the coronary band towards the weight bearing border (vertical decrease) and from the dorsal wall towards the heel (horizontal decrease). Decreasing hardness was associated with decreasing dry matter content. Measurements of the claw capsule showed thickness of the hoof wall increasing from the coronary border towards the sole. In dorsopalmar/-plantar direction, bovine hoof wall at the weight bearing border decreases towards the heel.  相似文献   

19.
Keratinolytic properties of two dermatophytes (Microsporum gypseum, Trichophyton mentagrophytes) and three moulds (Scopulariopsis brevicaulis, Alternaria alternata, Geotrichum candidum) isolated from diseased equine hooves were examined to improve the understanding of pathogenic mechanisms leading to equine onychomycosis. Equine hoof horn material and skin, as well as hoof keratin and dermal keratin extracted from corresponding tissues, were used as sole carbon and nitrogen sources in five test tubes for each fungus. Within 18 days, supernatants of all tubes were repeatedly examined for keratinolytic activity by SDS-PAGE and Western blot analysis. In addition, fungal growth rates were determined to identify the preferred tissue of the individual fungi. Among the fungi examined, M. gypseum was the most keratinolytic species, followed by T. mentagrophytes and S. brevicaulis. In the concentration applied, the moulds A. alternata and G. candidum showed minimal keratinolytic activity. With respect to growth rates, M. gypseum favoured hoof horn material, S. brevicaulis and G. candidum preferred skin as a keratin source, whereas for the other two fungi no clear preference was detectable.  相似文献   

20.
Horses with weak hoof horn, which becomes misshapen and crumbles around the lower parts of the hoof walls, pose problems for treatment in practice. The effects of dietary supplementation with a high level of the B-group vitamin biotin (which has proved successful in the treatment of the similar condition in pigs) were investigated in more than 40 cases. Varying degrees of improvement in the hardness, integrity and conformation of the hoof horn were observed in all cases. The signs and progress seen in three typical cases are described. It is concluded that dietary supplementation with 10 to 30 mg biotin/day (depending on bodyweight) for not less than six to nine months is a useful treatment to support other remedial measures in such cases.  相似文献   

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