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The apparent digestibility of nitrogen and amino acids was measured by the ileal and faecal methods in pigs fed nine barleys differing in nitrogen content (from 1.73 to 2.16 per cent/DM). A positive (r = 0.87) and significant relationship was found between the apparent nitrogen digestibility at the end of the ileum and the crude protein content of barley. Generally, the higher the protein of the grain, the higher the ileal digestibilities of the amino acids. For most amino acids the faecal values were greater than the ileal ones. This being specially so for threonine, tryptophan, histidine and cystine belonging to the nutritionally important amino acid group. When the relationship between the amino acid and nitrogen digestibilities at the level of ileum is considered, the values were found to be similar to that of nitrogen in the case of tryptophan, higher for isoleucine, valine (both 2-3 units), cystine, histidine, leucine, methionine (all 5-6 units) and phenylalanine (10 units) and lower only for lysine and threonine (7-8 dig. units). 相似文献
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In studies to determine whether vaccination with one strain of Moraxella bovis would protect against challenge with virulent homologous or heterologous strains, calves were intramuscularly inoculated 3 times with formalin-killed M bovis, with 14 days between inoculations. Fourteen days after the 3rd vaccinal dose was given, all calves were exposed to homologous or heterologous virulent cultures of M bovis. The results indicated that vaccination with one strain of M bovis may induce protective immunity against homologous and heterologous challenge exposure; however, because vaccinated cattle resisted infection and disease produced by a homologous strain to a greater extent than they resisted those produced by heterologous strains, polyvalent vaccines or highly immunogenic common antigens may be needed to protect cattle against the numerous strains they might encounter under natural field conditions. There was minimal correlation between the presence of precipitating antibodies against the heterologous strains and the establishment of infection and disease. 相似文献
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Information about the annual variation of trichomoniasis in mourning doves (Zenaida macroura) may be important in understanding mechanisms affecting mourning dove populations. The objectives of this study were to monitor the presence and annual variation of Trichomonas gallinae for 6 yr in a local mourning dove population using hunter-killed doves. During 1998-2003, 4052 hunter-killed doves were sampled for the presence of T. gallinae; 226 (5.6%) tested positive (4.4%-10.6% range). Results of the monitoring effort were relatively consistent during the 6-yr period, with the presence of T. gallinae being within the range of previously reported estimates for mourning doves. Asymptomatic carriers in one segment of the dove population may provide a mechanism for spreading the disease to other segments of the mourning dove population. 相似文献
99.
The commercial housing of African Ostriches in Germany for the breed and meat production still represents a disputed topic under the criterion of the animal's welfare. Above all critics state that the frequently wet-cold weather in Germany impairs the well-being and health of the animals. So far however there are just a few scientifically documented data about requirements for housing conditions of ostriches in Central Europe and thus hardly answers whether housing in Germany is possible under the criteria of the animal's welfare. This study tried to evaluate ostrich housing under South German climatic conditions (Rhine level), on the basis of behavioral observations of breeding ostriches. The use of the stable and the influence of different climatic parameters on the behavior were considered. In addition the behavior of 18 adult animals in 5 breeding groups from January to December 2002 was observed. Parallel various climatic data were raised. The housing of the animals took place in open stables with unrestricted pasture possibility. The ostriches reacted in their behavior to different climatic conditions. Particularly at cold weather and adverse soil conditions they used the open stable increasingly as weather protection. In addition, with increased wind velocities the animals spent more time in the stables. The daily amount of precipitation showed no influence on the frequency or duration of the stable use. Rainfall did not animate the animals to look for protection within the stable, but more to set itself on the ground in the external enclosure. The locomotion activity of the animals was strongly in dependence to the reproduction time and the territorial behavior and therefore highest in spring. On cold days the animals performed their reproduction behavior mainly in the stable. For the comfort behaviour distinct weather dependence was seen particularly for sand bathing. Warm temperatures and dry sand were the preconditions for it. Regarding the results it seems, that with the conditions existing on the examined farm, housing of ostriches under respect of animal welfare in Germany is possible. New regulations are to be demanded, adjusted to the newest level of knowledge about ostrich husbandry, with requirements for care, support, accommodation and nutrition of the animals as well as about the qualification of the owners. An occasional hobby animal husbandry limited to few single ostriches is to be rejected. Further scientific investigations at other farms, possibly also under variable climatic conditions are however necessary. 相似文献
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