Tropical Animal Health and Production - The objective of this study was to evaluate carcass characteristics, meat quality, and organ and viscera weight of forty male sheep, not castrated, initially... 相似文献
1. Two experiments were undertaken to analyse the effects of selection for lowering carcase fatness and improving meat yield of Muscovy ducks. The control generation N and the selected generations N+ 3 and N+ 4 of the same heavy line (Grimaud) were reared under similar conditions.
2. We compared growth, carcase characteristics, chemical composition of breasts and plasma concentrations of very low density lipoproteins (VLDL), triglycerides and phospholipids.
3. Selection induced an increase of body weight ( + 8% to 10% at slaughter age), a decrease of abdominal fat percentage (? 10%) and an improvement of breast and thigh plus shank yields (+ 3% to 7% and + 4% respectively).
4. The lipid content of breast meat decreased in the selected ducks (? 14% to ?20%), particularly phospholipids and triglycerides. Breasts appeared paler and less red which suggested modifications of muscular fibre composition.
5. We found no significant correlations between plasma VLDL, triglyceride and phospholipid concentrations and carcase fatness. It therefore seems difficult to use these variables as selection criteria for lowering carcase fatness of Muscovy ducklings. 相似文献
Thirty-seven fluoroquinolone-resistant Escherichia coli strains from ruminants (according to Clinical and Laboratory Standards Institute guidelines) were screened by molecular methods for mutations in the quinolone resistance-determining region (QRDR) of the gyrA and parC genes and for the presence of the qnrA gene. One of the strains studied was an enterohemorrhagic E. coli (EHEC) strain potentially pathogenic for humans. Three E. coli strains resistant to enrofloxacin (minimal inhibitory concentration [MIC] = 2 microg/ml) but not to ciprofloxacin (MIC = 1 microg/ml) presented single mutations in the gyrA and parC genes, while 34 strains resistant to both fluoroquinolones presented double and single mutations in gyrA and parC, respectively (31 strains), or double mutations in gyrA and parC (3 strains). The EHEC strain presented a double amino acid substitution in the GyrA protein (Ser-83-->Leu and Asp-87-->Gly) and a double amino acid substitution in the ParC protein (Gly-78-->Cys and Ser-80-->Arg), one of which has not been previously described. The present study shows that most of the mutations in the QRDR of the gyrA and parC genes of fluoroquinolone-resistant E. coli strains from ruminants are the same as those seen in E. coli strains from other animal species and humans and that there are no differences in mutation patterns in the QRDR of E. coli strains from healthy ruminants and those with diarrhea. No strains carried qnrA, which indicates that this gene does not play an important role in the selection of fluoroquinolone-resistant E. coli strains from ruminants. 相似文献
Rabies remains an important public health issue in Bolivia, South America. Public concern and fears are most focussed on dogs as the source of rabies. The objective of the present study was to assess immunity of an inactivated suckling mouse brain vaccine against canine rabies used for the official vaccination campaigns under field conditions in an endemic area of rabies in Bolivia. A total of 236 vaccinated and 44 unvaccinated dogs in Santa Cruz de la Sierra, selected using stratified random sampling, were investigated in order to obtain owned dog characteristics and antibody titres against rabies in April 2007. The proportion of vaccinated dogs with an antibody titre exceeded the protection threshold value of 0.5 EU/ml was 58% [95% confidence intervals (CI): 52-65], indicating that vaccination is likely to elicit an antibody response (odds ratio 6.3, 95% CI: 1.2-11.5). The range of geometric mean of antibody titre for vaccinated dogs (0.89 EU/ml; 95% CI: 0.75-1.04) was considered to meet the minimal acceptable level indicating an adequate immune response to the vaccine. However, the titre level was not satisfactory in comparison with the results from other field investigations with inactivated tissue culture vaccines. It is recommended for public health authorities to (1) consider modernizing their vaccine manufacturing method because the level of immunity induced by the current vaccine is comparably low, (2) conduct frequent vaccination campaigns to maintain high levels of vaccination coverage, and (3) actively manage the domestic dog population in the study area, which is largely responsible for rabies maintenance. 相似文献