Received February 24, 2015; accepted September 7, 2015 相似文献
2. Squilla meal contained less lysine (3.45 vs 6.74 g/16g nitrogen) and methionine (1.02 vs 1.86/16 g nitrogen) dian fish meal, had a lower protein digestibility coefficient (0.66 vs 0.72) and a lower gross protein value (68% vs 74%).
3. By gradually replacing the fish meal with squilla meal in isocaloric, isonitrogenous broiler diets it was shown that there was a linear decrease in broiler weight gain; efficiencies of food utilisation were also lower at all squilla meal substitution rates. Inclusion of squilla meal in the diets increased intestinal lengths.
4. Addition of a proteolytic enzyme to the diets containing squilla meal restored broiler weight gain and efficiency of food utilisation to that of birds fed on the control diet.
5. Diets containing autoclaved squilla meal resulted in reduced weight gain although efficiency of food utilisation was not affected. 相似文献
2. The optimum culture medium for maintaining gonadotroph responsiveness to GnRH‐I was bicarbonate‐buffered and phenol red‐free Medium 199 supplemented with 10% foetal calf serum.
3. Cultured pituitary cells from juvenile chickens were more responsive to GnRH‐I than cells from adult cockerels, while no LH was released in response to GnRH‐I from pituitary cells from laying hens.
4. Cultured pituitary cells from adult chickens of both sexes released LH in response to 12‐O‐tetradecanoyl‐13‐phorbol acetate (TPA), an activator of an enzyme involved in intracellular signalling, protein kinase C.
5. It is concluded that freshly‐dispersed and cultured gonadotrophs from adult chickens do not regain their responsiveness to GnRH‐I as well as freshly‐dispersed and cultured gonadotrophs from juvenile chickens. It appears that the stimulus‐secretion coupling pathway between the GnRH‐receptor and the activation of protein kinase C in gonadotrophs from adult chickens is more easily disrupted by dispersion and culture than in gonadotrophs from juvenile chickens. 相似文献
2. In fresh fish processed to whole fish meal the biological availability of selenium was estimated as 77%, in fresh fish processed to pressed‐cake fish meal it was 59% and in partly‐decomposed fish processed to whole fish meal it was 51%.
3. When the phosphorus content of the test diet was 2–51 g/kg the biological availability was 88% and unaffected by the condition of the fish and the method of processing. 相似文献
Received December 9, 2014; accepted February 7, 2015 相似文献
2. Selected ducks were larger but not fatter or older at sexual maturity, had more yellow follicles, giving a greater potential for multiple ovulation, and a higher proportion of atretic yellow follicles, compared with unselected ducks.
3. There was a linear relationship between the number of normal yellow follicles and body weight at the onset of lay which was similar in the two lines.
4. Several birds on the most severe regimen failed to lay and it was concluded that ducks should be at least 0–6 of unrestricted body weight for the onset of lay.
5. Weight of the ovary with follicles less than 8 mm diameter was greater in selected compared with unselected ducks and in birds fed ad libitum compared with restricted ones. 相似文献
2. IGF1 mRNA expression in breast muscle in Taihu geese was significantly higher than that in Wanxi geese and the MSTN mRNA level in leg muscle in Taihu geese was significantly higher than that in Wanxi geese.
3. There was no significant difference in breast muscle MSTN or leg muscle IGF1 mRNA expression between the two breeds.
4. Within the same breed, the IGF1 mRNA expression in leg muscle of male geese was significantly higher than that in female geese, and MSTN mRNA expression in leg muscle was significantly higher than that in breast muscle.
5. There was no difference in the IGF1 mRNA expression between tissues.
6. There was a positive correlation between IGF1 mRNA and MSTN mRNA and a negative correlation between IGF1 mRNA expression of breast muscle and leg muscle ratio.
7. In Wanxi geese, MSTN mRNA expression in leg muscle was negatively associated with body weight and leg muscle weight. 相似文献
Mean digestibility coefficients of the yeast were 72 per cent for dry matter, 74 per cent for organic matter and 80 per cent for protein. The mean metabolisable energy value was 2550 kcal/kg.
In one of the feeding experiments it was found that 7.5 per cent of the fish meal in the control ration could be replaced by the yeast with no adverse effect on performance. When all of the fish meal in the control ration, i.e. 10 per cent, was replaced by the yeast, the effect on live‐weight gain of the chicks was negligible. However, when all of the fish meal and part of the soyabean meal in the control ration was replaced by 15 per cent yeast, some depression in chick growth occurred.
Similar rations containing a commercial sample of torula yeast gave significantly poorer performance than the corresponding controls at both the 10 and 15 per cent levels of inclusion of the torula yeast. 相似文献
2. A total of 20 one-day-old Leghorn chicks (slow-growing) and 20 broiler (Ross 508) chicks (fast-growing) were reared to 100 and 45 d, respectively.
3. A small percentage of GF was seen in pre rigor muscle samples even at 3 min post mortem in both genotypes and in all muscle types studied.
4. From 3 min to 24 h post mortem GF increased both in Leghorn and broiler chickens but to a different extent according to muscle type and genotype.
5. The highest GF 24 h post mortem value was found in the PM muscles belonging to the fast-growing broiler line.
6. It was concluded that every type of muscle can develop GF, but this phenomenon is more evident in the PM especially in animals selected for increased growth rate. 相似文献
Received June 9, 2014; accepted September 19, 2014 相似文献
2. T. gallinae were collected by the wet mount method from infected free-living pigeons. The in vitro assay was performed using multi-well plates containing test compounds in final concentrations of 5, 10, 15, 20, 30, 50 or 100 μg/ml. The in vivo assay was done on 60 experimentally infected pigeons dosed with metronidazole at 50 mg/kg body weight (BW) or alkaloids at 25 mg/kg BW.
3. The 24 h minimum inhibitory concentration (MIC) of alkaloid extract was 15 µg/ml while that of metronidazole was 50 µg/ml. Harmine and harmaline revealed 24 h MIC of 30 and 100 µg/ml, respectively. Treatment of infected pigeons with alkaloids led to a full recovery after 3 d but with metronidazole total eradication of trophozoites was not achieved.
4. In conclusion, data of the present study suggested P. harmala is a potent natural anti-trichomonal agent, effective against T. gallinae. 相似文献
2. Quails were divided into High-FE and low-FE groups and maintained in a comfortable or heat stress (HS) (38°C for 24 h) environment to evaluate changes in insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), adenine nucleotide translocator (ANT), uncoupling protein (UCP) and cytochrome oxidase subunit III (COX III) messenger ribonucleic acid (mRNA) expression in liver and muscle tissues.
3. High-FE quails (0.28 g/g) presented a higher final body weight, greater weight gain and a better feed conversion ratio than low-FE birds (0.18 g/g). High-FE birds showed greater IGF-I mRNA expression in the liver and muscle and greater GHR mRNA expression in the muscle.
4. Environmental effects only affected GHR expression in the liver, with quails under comfortable conditions exhibiting greater GHR expression than quails subjected to HS.
5. There was a significant interaction between FE and environmental temperature on ANT mRNA expression in the liver. The greatest ANT mRNA expression was observed for high FE-birds that remained under comfortable conditions.
6. In the liver, UCP mRNA expression did not differ among the quails and was not affected by environment or efficiency. However, comparisons of the low- and high-FE birds revealed higher levels of UCP mRNA in the muscle of low-FE birds.
7. COX III mRNA expression in the liver was dependent on environmental temperature and FE. Higher COX III mRNA expression was observed in animals that remained under comfortable conditions, and high-FE birds exhibited higher expression levels compared to low-FE birds.
8. These results suggest a correlation between IGF-I, GHR, ANT, UCP and COX III gene expression and FE and that environmental temperature could affect the expression of some of these genes. 相似文献
2. In a completely randomised design, different probiotic strains were injected into the amniotic fluid of the 480 live embryos (d 18 of incubation), with 4 treatments and 5 replicates. Ileal MUC2 gene expression, microbial profile, growth performance and immune response were determined.
3. Injection of probiotic strains, especially B. subtilis, had significant effect on expression of the MUC2 on d 21 of incubation and d 3 post-hatch, but not on d 19 of incubation.
4. Injection of the probiotic strains decreased significantly the Escherichia coli population and increased the lactic acid bacteria population during the first week post-hatch.
5. Inoculation of probiotics had no significant effect on antibody titres against Newcastle disease virus, antibody titres against sheep red blood cell and cell-mediated immune response of chickens compared to control.
6. In ovo injection of the probiotic strains had no significant effect on growth performance of broiler chickens.
7. It was concluded that injection of probiotic bacteria especially B. subtilis into the amniotic fluid has a beneficial effect on ileal MUC2 gene expression and bacteria population during the first week post-hatch, but has no effect on growth performance and immune response in broiler chickens. 相似文献
Under the conditions of this study, the only consistent and significant effect due to the source of cereal grains was the reduction of egg size due to milo. Fish meal supplementation of milo diets almost, or completely, equalised egg weights, and some beneficial effects were also obtained from added methionine and soapstock.
The linoleic acid content of maize is decidedly higher than that of milo, a difference which is reflected in the fatty acid composition of the respective diets, and which causes corresponding changes in the fatty acid pattern of the yolk lipids of eggs produced by hens fed these diets. Soya soapstock added to milo diets tended to equalise the yolk fatty acid pattern obtained with milo and maize diets.
It is suggested that in milo‐soya diets methionine is the first limiting factor, and that linoleic acid is the next limiting factor in increasing egg size, after the first requirement has been met. 相似文献
2. This study aimed to investigate the effect of dietary BP on laying performance, egg quality and caecal bacterial populations in laying hens.
3. The dietary BP used in this experiment was a mixture of individual BP targeting Salmonella gallinarum, Salmonella pullorum, Salmonella typhimurium, Salmonella enteritidis, Salmonella derby and Staphylococcus aureus.
4. A total of 360 Hy-Line Brown laying hens of 32 weeks of age were allotted to one of three dietary treatments with 6 replicates in a completely randomised design. The basal diet was prepared, and 0.4 or 0.8 g/kg BP mixture was supplemented to the basal diet. Diets were fed to hens for 8 weeks.
5. Laying performance and egg quality were not affected by dietary treatments. As inclusion levels of BP mixture in diets were increased, the DNA copy numbers for Salmonella spp. in the caecal contents decreased linearly, whereas the DNA copy numbers for Escherichia coli in the caecal contents increased linearly.
6. Results indicate that dietary supplementation of BP mixture decreases the target Salmonella spp. populations but increases Escherichia coli populations in the gastrointestinal tract of laying hens with little impact on laying performance and egg quality. 相似文献
2. In the first experiment, 144 pullets, 72 each of Ff and ff pullets from F1 birds, were compared in a randomised complete block design (RCBD), with three villages and 4 batches of hatch as blocks and the two feather genotypes (Ff and ff) as the treatments.
3. The Ff pullets were superior (P < 0.05) to their ff counterparts in terms of the number of eggs per clutch, egg mass and hen-housed and hen-d rates of lay, whereas age at first egg was lower (P < 0.05) in ff layers compared to Ff ones.
4. The eggs of the F1 heterozygous frizzle (Ff) layers had higher values for albumen height, Haugh unit and yolk height compared with eggs from their normal feathered counterparts.
5. In the second experiment, 144 pullets, 48 each of FF, Ff and ff pullets, were compared in a RCBD, with three villages and 4 batches of hatch as blocks and the two feather genotypes (Ff and ff) as the treatments.
6. The F2 birds with genotypes Ff and FF were better than their ff counterparts in terms of the number of eggs per clutch, egg mass, and hen-housed and hen-d rates of lay. Age at first egg was significantly lower in ff layers compared to FF and Ff ones.
7. The Haugh unit value was higher in the homozygous and heterozygous frizzles compared to the normal feathered ones.
8. The presence of the frizzle gene (F) in egg type chickens led to an improvement in egg production and egg quality traits in village chickens, and the cross-breeding scheme evaluated in this project could contribute to improved productivity. 相似文献
2. At Ta 32 °G there was no panting. At Ta 35 °G panting occurred without any increase in Tr but there was a slight alkalosis (pH 7.55).
3. At Ta 38 °G Tr increased and panting was accompanied by moderate alkalosis (pH 7.58).
4. At Ta 41 °G Tr increased considerably and severe alkalosis developed (pH 7.65).
5. From the relation between Tr , f and pH it is concluded that some degree of alkalosis is a normal response to panting in the laying hen. 相似文献
2. Male and female day-old Ross 308 chicks were fed on a standard commercial diet containing 0, 2.5, 5 or 10 g/kg feed ground M. officinalis for 84 d before slaughter.
3. Weight gain and feed conversion ratio were significantly improved in the broilers receiving either 5 or 10 mg M. officinalis/kg feed.
4. Inclusion of M. officinalis did not affect muscle chemical and fatty acid composition.
5. On the basis of microbiological and sensory experimental data and subsequent extension of meat shelf life, M. officinalis did not reduce the microbial populations of the meat, but was effective in limiting lipid oxidation. 相似文献