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61.
Heritability values of glycerol, glycogen and pigment concentrations measured on muscle biopsy samples from longissimus dorsi obtained from 85?kg boars of Danish purebred pigs (Landrace, Yorkshire, and Duroc) and their genetic correlations to performance and meat quality traits were calculated. The heritability values of glycogen, pigment, and glycerol were 0.38±0.02, 0.17±0.02, and 0.065±0.016, respectively. Glycogen was negatively related to the feed conversion ratio (FCR) (r g =?0.25±0.06) and ultimate meat pH (r g =?0.41±0.04), and positively to the carcass meat percentage (r g =0.35±0.04), L* (lightness of meat, r g =0.32±0.04) and a* (redness of meat, r g =0.12±0.03). Pigment was positively related to the FCR (r g =0.12±0.05), the meat percentage (r g =0.28±0.05), and a* (r g =0.59±0.04), and negatively to the L* (r g =?0.46±0.06). The concentrations of pigment and glycogen (r g =0.27±0.05) were interrelated. Based on the heritability values and the signs of the genetic correlations the present data suggest that it is possible to select for higher ultimate pH and improved colour by selection for either lower muscle glycogen or higher pigment concentration, respectively. However, the positive genetic correlation between these two traits may restrict the efficiency of simultaneous selection for lower glycogen and higher pigment. All genetic parameter estimates presented are calculated across three purebreds. Values for each breed are warranted for use in pig production. However, this requires more animals per breed.  相似文献   
62.
Two experiments comprising a total of 80 Danish Landrace pigs in the period 20–90 kg live-weight were carried out to study the effect of dietary levels and ratios of Ca and P on serum values of Ca, inorg. P, and alkaline phosphatase and on the development of degenerative arthritis and atrophic rhinitis.In both experiments each kg feed (Table 1) was supplemented with 600 i. u. vitamin D3 and 80 p. p. m. Zn.In the first experiment the Ca:P ratio was 1.2 and the amount of Ca increased from 0.48 % to 1.20 % without influencing daily gain, feed conversion, carcass performance (Table 2) or frequency of atrophic rhinitis (Table 3). The Ca:P ratio in scapula was 2.15. Only when the diet was supplemented with 1.20 % Ga and 1.00 % P the bone quality was histomorphologically adequate (Figs. 1–4).In the second experiment various Ca:P ratios (ranging from 0.1 to 3.0) were compared with the recommended level and ratio of 0.72 % Ga and 0.60 % P. Performance of pigs on the normal level was better than for the other pigs (Table 4). Clinically, various degrees of leg-weakness and -deformation occurred, most pronounced in the high Ca — low P group. Very little lameness and no convulsions were observed. Marked hypocalcemia was not found. Unilateral high Ca intake increased serum Ca significantly, and serum alkaline phosphatase slightly, and decreased serum P (Figs. 5–7). Advanced pericytic osteolysis, poor mineralization and generalized osteodystrophia fibrosa were found in the low Ca groups (Figs. 8–13). The groups showed no differences in frequency of atrophic rhinitis (Table 5), and rickets was not observed.The incidence of degenerative joint lesions was not increased in pigs on the unfavourable Ca:P ratios, and depended apparently more on litters than on diets.  相似文献   
63.
The concentration of trimethoprim and sulphadoxine in plasma and tissue from goats and a cow have been determined after a single intravenous injection. Furthermore, the concentration of the two drugs and their metabolites in plasma and tissues have been determined after continuous intravenous infusion for 2½–3 hrs. Trimethoprim was present in all tissues but brain at higher concentrations than in plasma while the concentration of sulphadoxine in the different tissues were lower than in plasma. The highest concentration of the 2 drugs and their metabolites was found in the kidney. The distribution pattern of trimethoprim and sulphadoxine was similar in cow and goats.  相似文献   
64.
65.
Data for incidence of summer mastitis in 14 veterinary practices in Jutland (Denmark) were related to meteorological factors using statistical methods. A correlation and regression analysis showed that summer mastitis occurred earlier in years with high temperature and precipitation in early summer. The annual number of cases markedly increased over the years 1953 to 1980. This increase was described by applying a linear increase with with year to a logarithmic transformation of the annual incidence.Analysis of 10-day incidences from the veterinary practices and daily incidence from a test site at St. Vildmose (Jutland) showed that incidence of summer mastitis could be related to temperature and wind velocity within the previous 10 days. High temperature and low wind velocity in this period increase the incidence. This indicates that the incubation period of summer mastitis is at maximum about 10 days. The activity of the fly (Hydrotaea irritans Fall), which acts as mechanical vector for the bacteria is influenced by temperature and wind velocity. This may explain the variation in incidence of summer mastitis during the season and from year to year.  相似文献   
66.
The objective of this experimental study was to determine the effects of aerial ammonia on disease development and bacterial colonization in weaned pigs inoculated with toxigenic Pasteurella multocida and Mycoplasma hyopneumoniae. Two groups of 10 pigs each were continuously exposed to 50 and 100 p.p.m. ammonia, respectively, and compared to a non-exposed control group of 20 pigs. Following aerosol inoculation with M. hyopneumoniae at day 9, all pigs were aerosol-inoculated with toxigenic P. multocida type A at days 28, 42 and 56. At day 63 they were euthanized. Clinical signs including coughing and respiratory distress were present in all groups following inoculation. No significant differences could be established in the extent or frequency of pneumonia between ammonia-exposed pigs and controls, or in the extent of conchal atrophy, the frequency of isolation of toxigenic P. multocida from conchae, tonsils, lungs and kidneys, or the average daily weight gain. The recovery of toxigenic P. multocida from nasal swabs following inoculation was significantly greater in pigs exposed to 50 p.p.m. ammonia or more as compared to the control group. In conclusion, high levels of ammonia combined with inoculations with M. hyopneumoniae and toxigenic P. multocida had no significant effect on disease development, but may have enhanced colonization by toxigenic P. multocida on the nasal turbinates.  相似文献   
67.
Preweaning mortality in pigs. 2. The perinatal period   总被引:3,自引:0,他引:3  
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68.
Summary A method for a quick inspection of wound periderm formation is described. Sections are freehand cut into a stain solution, and microscopic examination is accomplished with an epiplanatic lens.  相似文献   
69.
Three hundred sixty-five S1 and 234 S2 seedling populations of timothy (Phleum pratense L.) were examined for their segregations for chlorophyll deficiencies. Arrays of both self-and open-pollination families indicated a lack of concentration at definite levels, with ratios expressed forming a continuous series from 4.6:1 to 572:1 for green: chlorophyll-deficient types in the S1 generation. The S2 populations examined ranged from 1.8:1 to 244:1. Arrays were very similar in their distributions.Sixty-three plants yielded chlorophyll-deficient types in both S1 and S0 populations. From these, it was calculated that 7 to 8 percent of natural self-pollination may occur in timothy.Except at two levels (28:1 and 143:1 tetradisomic) assumption of tetradisomic or simpler inheritance patterns resulted in lower calculated percentages of natural self-pollination than resulted from assumed hexasomic inheritance. No apparent explanation is available to account for these divergences from the regular pattern encountered.Results of cooperative work of the Crops Research Division, Agriculture Research Service, U.S. Department of Agriculture and the Wisconsin Agricultural Experiment Station, Madison.Research Agronomist, Crops Research Division, Agriculture Research Service, U.S. Department of Agriculture and Associate Professor, and Professor of Agronomy, Wisconsin Agricultural Experiment Station, respectively.  相似文献   
70.
During the period from Dec. 7th 1972 to Jan. 8th 1973 76 cattle deaths were reported in 20 herds on the island of M?on and the adjacent south-eastern area of Sealand. The disease was characterized by a sudden onset and a rapid and invariably fatal course. Initially, there was a loss of appetite, depression, excessive salivation and incoordination. These symptoms progressed to paralysis and, in some animals, trmor and convulsions. Death usually ensued less than 2 hours after the first observation of symptoms. Losses in the herds varied from 1 to 12 animals. In herds with multiple incidents the majority of deaths occurred in the 24-hour-period following observation of the first case. Pathology: Gross lesions were few and inconclusive. Histology revealed marked dilatation of cerebral and maningeal blood vessels (arterioles, venoles and capillaries), with perivascular edema and haemorrhage. Adjacent neurons and glia cells showed various degrees of degeneration, apparently secondary to the vascular lesion. In all affected herds sugar beet pulp from one particular sugar mill had been used during the period preceding the outbreak. The syndrome was reproduced by feeding sugar beet pulp from this batch to two heifers. The heifers showed symptoms after 19 and 32 days' feeding, resp. and died after a few hours. Clinical and pathological features were identical with those observed in the spontaneous disease. Thus, it was proved that the particular batch of pulp was responsible for the disease. The investigation did not, however, reveal a toxic factor in this batch. Analyses for lead, arsenic, mercury, nitrite, alkyl phosphates, chlorinated insecticides and Cl. botulinum toxin were negative. Batches of the sugar beet pulp showed pronounced microbial deterioration, the flora being dominated by yeasts and filamentous fungi (moulds). Several species of fungi have been isolated but so fat their possible role in the etiology of the syndrome remains unsettled. The syndrome bears some resemblance to cerebrocortical necrosis (C.C.N.) but differs in several clinical and pathological details. It is tentatively suggested that the beet pulp may have contained one or more toxic substances that interfere with microbial activity in the rumen, resulting in a disturbance of synthesis or absorption of essential metabolites. The clinical, epidemiological and pathological findings are compatible with the hypothesis that the syndrome might be due to fungal toxins. Accordingly, the isolated fungi are now being studied in more detail.  相似文献   
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