Effects of chromium nicotinate on performance, carcase characteristics and blood chemistry of growing turkeys

1. The objective of this trial was to study the effects of chromium nicotinate (Cr) supplementation on the performance, carcase characteristics and blood constituents of 9 to 22 week-old male turkeys. 2. Fifty-four 8-week-old male turkeys weighing 2.9 +/- 0.28 kg were allocated at random into 9 groups with 3 dietary treatments and 3 replicates. The dietary treatment was different dietary concentrations of chromium in the basal diet, to provide 0 (control), 1 or 3 mg/kg. The feeding trial lasted for 14 weeks. 3. Results showed that 1 mg/kg chromium supplementation significantly improved weight gain and food intake at 9 to 18 weeks of age but did not significantly influence performance at 19 to 22 week of age. The breast and thigh muscle were significantly increased in birds receiving 1 mg/kg chromium supplementation but were decreased by 3 mg/kg of supplementation. 4. Dietary chromium supplementation did not significantly influence other serum constituents, including insulin, HDL, VLDL+LDL, HDL-C, VLDL-C+LDL-C, total protein, albumin, and gamma-globulin at 18 and 22 weeks of age. 5. The serum triacylglycerol (TG) and uric acid contents were significantly increased, while glycerol and alpha-globulin were significantly reduced by 3 mg/kg chromium supplementation. However, 1 mg/kg chromium supplementation significantly reduced serum cholesterol and glycerol at 18-weeks old. At 22 weeks of age, 1 mg/kg chromium supplementation significantly increased serum glucose and decreased the uric acid concentration whereas 3 mg/kg chromium supplementation significantly increased the creatinine concentration and decreased beta-globulin concentration.

Effect of roxarsone inclusion in the diet on the performance and hepatic lipid metabolism of laying Tsaiya duck

1. The aim of this study was to examine the effects of roxarsone (3-nitro-4-hydroxyphenylarsonic acid) inclusion in the diet on the performance, liver function and lipid metabolism in the liver of laying Brown Tsaiya ducks. 2. Sixty 36-week-old laying ducks were selected and allocated at random into 4 dietary treatments with 3 replications for each treatment. Feeding was for 7 weeks with 3 weeks of experimental diets followed by a 4 week withdrawal period. The experimental diets were supplemented with 0, 50, 100 and 300 mg/kg roxarsone, respectively 3. Dietary inclusion of 50 or 100 mg/kg roxarsone did not significantly promote performance. Inclusion of 300 mg/kg significantly depressed (P<0.05) performance, liver weight and content, serum triacylglycerol (TG), serum nonesterified fatty acid (NEFA) and increased (P<0.05) cholesterol, creatine kinase (CK) and aspartate aminotransferase (AST) in the serum at the end of 3 weeks on the experimental diet. 4. Laying characteristics returned to normal 4 weeks after withdrawal of roxarsone. The liver weight, fat and TG in the liver and serum concentrations of TG, NEFA, high density lipoprotein (HDL) and AST increased significantly (P<0.05), while the level of very low density lipoprotein (VLDL) decreased (P<0.05) at the end of the withdrawal period. More prominent vacuolised hepatic fatty cells were observed in laying ducks treated with 300 mg/kg of roxarsone.

Effect of different sources of dietary fibre on growth performance, intestinal morphology and caecal carbohydrases of domestic geese

1. The aim of this study was to examine the effects of dietary fibre sources on growth and on the development of the gastro-intestinal tract in growing geese. 2. Six-week-old female White Roman geese were divided at random into 6 groups with 6 dietary treatments. Diets were isoenergetic and isonitrogenous and contained alfalfa meal, barley bran, rice hulls, cellulose, pectin or lignin as the major dietary source of fibre. 3. Food intake was significantly higher in the barley bran group than in the other groups. Both daily weight gain and food conversion of the pectin and alfalfa meal groups were lower than those of the other groups. 4. In the 9-week-old geese, the relative weight and the length of the small intestine did not significantly differ among treatment groups. However, the relative weight was significantly lightest and the caecal length was significantly shortest (P < 0.05) in the pectin group. 5. Activities of amylase and cellulose hydrolases of the caecal contents were also highest in the pectin group. 6. From SEM micrographs, no morphological damage of the villi was observable in the different intestinal segments of the geese in any of the treatments.

The effect of different fibre components on growth rate, nutrient digestibility, rate of digesta passage and hindgut fermentation in domesticated rabbits

Trials were conducted to study the effect of dietary fibre on performance and nutrient digestibility in growing rabbits. The basal diet was supplemented with 12% cellulose, pectin, lignin, or alfalfa, in four different treatments. Twenty-four 4-week-old California male rabbits were randomly allocated into four groups and placed in individual cages. The lignin supplement severely affected both feed intake and performance, pectin second, with dietary cellulose having the least effect. Dietary lignin significantly decreased the digestibility of crude protein, gross energy and dry matter content (P < 0.05). Rabbits on the pectin supplemented diet digested dry matter, crude fibre and neutral detergent fibre (NDF) better (P < 0.05) than other treatment groups. On the other hand, rabbits in the lignin group digested crude fibre, acid detergent fibre (ADF) and NDF significantly less well than rabbits in other groups (P < 0.05). Dietary lignin also significantly decreased the caecal concentration of volatile fatty acids (VFA, P < 0.05) but did not significantly affect the molar ratios of the VFAs among treatment groups. The turnover rate of the marker, chromic oxide, in the gastrointestinal (GI) tract of rabbits was 64.94, 51.81, 44.05 and 29.59 h in the pectin, alfalfa, lignin and cellulose treatment groups, respectively. The rate of turnover in the digestive tract significantly influenced digestibility of fibre components but did not significantly influence caecal fermentation.

Fish vaccine antigens produced or delivered by recombinant DNA technologies

Current efforts to develop vaccines, particularly for aquacultured species, have turned largely to biotechnology because it provides the means to inexpensively produce sufficient quantities of the immunoprotective antigen. These efforts have resulted in several prototype vaccines for fish and the publication of a large number of articles on the subject. However, there are only a few recombinant DNA-based vaccines for aquaculture in the licensing pipeline. Continued funding of research on recombinant DNA vaccines comes from the recognition by industry and government funding agencies that this research can lead to an increased understanding of the mechanisms in protective immunity. This is especially important for fish and shellfish species since our knowledge of the immune mechanisms in these animals is pitifully meagre. This presentation discusses the relative merits of the different recombinant DNA technologies that have been used to produce viral vaccines for fish and the promising approaches that are under consideration to increase the efficacy of these vaccines. There are many approaches to antigen production by recombinant DNA techniques including: (i) the preparation of purified antigenic proteins produced from the cloned viral genes in a variety of vector/host expression systems, (ii) chemical synthesis or the use of fusion vectors to produce peptides corresponding to known epitopes, (iii) defined attenuations, i.e. specific genetic alterations, of live virus vaccines, (iv) the use of live bacterial or viral vectors to deliver resistance genes or viral antigens, (v) anti-idiotype antibodies, and (vi) DNA vaccines where purified plasmid DNA expressing the pathogen gene under a eucaryotic promoter is injected. All of these technologies have been used more or less successfully in the development of vaccines for aquacultured species. However, the requirements for safety, effectiveness, ease of application and low cost/dose restrict their commercial development for aquaculture. The ideal viral vaccine for aquaculture must be effective in preventing death, be inexpensive to produce and license, provide immunity of long duration, and be easily administered. In addition, these vaccines must not only provide protection against the lethal effects of virus infection but prevent the formation of virus persistence. This is especially true for infectious haematopoietic necrosis virus (IHNV) which has been shown to persist in survivors in the presence of high antibody levels. Since resolution of virus persistence is thought to be correlate with cell-mediated immunity, vaccines designed to augment the cell-mediated immunity must be developed for fish. Approaches that are being considered include the use of cytokines in combination with subunit vaccines and the use of specific MHC-I inducer adjuvants with the vaccine. The "tailoring" of vaccine immunogenicity using different combinations of antigen and adjuvant will be presented.

Effects of crude fibre level in the diet on the intestinal morphology of growing rabbits

The experiment was conducted to study the effects of 5.5, 8.5, 11.5 and 14.5% dietary fibre levels on growth performance and intestinal villi in growing rabbits. After the 5-week feeding period, food intake and body weight gain increased with increasing dietary fibre levels, feed conversion was highest with 11.5% dietary fibre. Scanning electron microscopy showed slight changes to the jejunal villi and the caecal mucosa in rabbits fed high dietary fibre (14.5%), but the degree of damage was greater in the caecum than the jejunum. Flattened colon villi were seen in the low dietary fibre group whereas high levels showed no effect.

Effect of different components of dietary fiber on the intestinal morphology of domestic rabbits

A trial was conducted to study the effect of dietary fiber components (cellulose, pectin, lignin and alfalfa) on the performance and the intestinal structure of domestic rabbits. Different fiber components influenced villus height and muscle layer thickness of the jejunum and colon, and affected the crypt depth of the duodenum and ileum. A scanning electron microscope photograph showed a significant damage of the villi surface in the duodenum and jejunum by lignin supplementation; it also showed a significant damage in the cecal mucosa by cellulose, pectin and alfalfa supplementation.

The para-Bombay phenotype in Chinese persons

The para-Bombay phenotype occurs more frequently in Oriental than in white populations. This report describes the immunohematologic findings in 20 cases of the para-Bombay phenotype detected over a period of about 15 months in the Chinese population of Taiwan.

The B3 phenotype in Chinese

Sixteen cases of subgroup B3 and two cases of subgroup A1B3 were found among donated blood processed in Taipei Blood Donation Center. The frequencies of B3 and of A1B3 among group AB Chinese in Taiwan are about 1 in 900, and about 1 in 1800, respectively. The B3 red cells showed 1 to 2+ mixed field agglutination with anti-B, 2 to 3+ mixed field agglutination with anti-A, B, and 4+ agglutination with anti-H. Reverse grouping showed anti-A but no anti-B activity; saliva of secretors contained B and H substances. The significant low avidity of subgroup B3 and subgroup A1B3 red cells with both polyclonal and monoclonal antiserums, as compared with normal group B cells, coupled with the difference in the avidity of the reaction between monoclonal and polyclonal antisera with B3 and A1B3 red cells, suggest the possibility of a qualitative as well as a quantitative difference in the B antigen of B3 red cells.