2. Broiler chickens were randomly divided into 7 groups: control, carrier control, kaempferol (0·3%), kaempferol (0·6%), hypercholesterolemic (HLD), HLD and kaempferol (0·3%), HLD and kaempferol (0·6%).
3. Seven weeks after treatment, carcase characteristics, lipid levels in the blood and liver, expression of hepatic Angiopoietin-like protein 3 (ANGPTL3) mRNA, and expression of adipose lipoprotein lipase (LPL) protein were determined.
4. Treatment with kaempferol (0·3 or 0·6%) significantly increased plasma high-density lipoprotein cholesterol levels, decreased percentage of abdominal fat, thickness of subcutaneous fat, plasma and hepatic total cholesterol and triglyceride concentrations, muscle malondialdehyde level and down-regulated expression of ANGPTL3 mRNA concomitantly with up-regulated expression of LPL protein in normal and hypercholesterolemic broiler chickens.
5. Kaempferol (0·3 or 0·6%) treatment had no significant effect on the values of percentage of breast muscle, percentage of leg muscle, carcase weight and eviscerated percentage.
6. The results suggest that kaempferol improves carcase characteristics by decreasing expression of ANGPTL3 in broiler chickens. 相似文献
2. The commercial broilers were divided into 2 groups of 100 birds each; CoQ9‐treated group and non‐treated group.
3. The chickens were grown in a positive‐pressured house with double high efficiency particulate air filtered intakes and exhaust, and thus were strictly isolated from infectious agents.
4. The chickens (15 to 21 d old) were exposed to cold stress in order to induce ascites.
5. The number of birds with ascites in the C0Q3‐treated group was significantly lower than in the non‐treated group.
6. Survival and production rates were better in the CoQ^‐treated group than in the non‐treated group. 相似文献
2. Over the 6-week study, feed intake increased significantly with CTC supplementation and final body weight (BW) was significantly higher for 1·0?g/kg polysavone and 0·15?g/kg CTC treatments. Feed:gain ratio was not significantly affected by the dietary treatments.
3. At 3 weeks of age, serum total superoxide dismutase (T-SOD) activity for all polysavone treatments was significantly higher than controls, liver T-SOD activity in 1·5?g/kg polysavone group was significantly higher than the control and CTC groups, and serum glutathione peroxidase (GSHPx) activity for 1·5?g/kg polysavone and liver GSHPx activity in all polysavone groups were significantly higher than CTC.
4. At 6 weeks of age, serum and liver T-SOD activity in 1·5?g/kg polysavone group and liver GSHPx activity for all polysavone treatments were higher significantly than the control and CTC groups, and serum malondialdehyde (MDA) content for all polysavone treatments was significantly lower than CTC.
5. Breast muscle T-SOD activity and pH value at 6 weeks of age were significantly higher and MDA content was significantly lower in 1·0 and 1·5?g/kg polysavone groups than in the control and CTC groups. Breast muscle shear force was significantly lower in l·5?g/kg polysavone group compared with the control, and drip loss for all polysavone treatments was significantly lower than CTC.
6. It was indicated that polysavone modulates antioxidation and modifies meat quality, but with no adverse effect on performance of broiler chickens, and that CTC can be beneficial to performance but has no beneficial effect on antioxidant function or meat quality. 相似文献
2. At an energy retention of 179 kJ/kg W 0·75 d, only protein was retained. At higher energy intakes, each increment in retention had a rather constant composition: about 85% energy in fat and 15% in protein. At lower energy intakes body fat was mobilised whereas protein was deposited.
3. The efficiencies of energy retention in protein and fat were estimated to be 0·66 and 0·86 respectively.
4. The rather constant composition of additional retained energy after additional energy supply provides an explanation for a linear relationship between energy intake and energy retention. 相似文献
2. Xylanase supplementation improved food conversion ratios by 2·2–2·9% and body weight gain by 0·2–2·5%. This was independent of wheat characteristics but slightly dependent on the wheat content of the diet. These effects were related to a lowering of digesta viscosity.
3. Differences in extract viscosity of wheat were not reflected in broiler digesta viscosity.
4. Reduction of digesta viscosity resulted in only a slight improvement of litter score. Reduced intestinal viscosity decreased relative pancreas weight and to a lesser extent relative small intestinal weight.
5. Baking quality wheat Baldus gave better performance than the feed quality wheats Apollo and Slejpner.
6. It was concluded that xylanase supplementation of wheat‐based diets invariably had a positive effect on broiler performance. 相似文献
2.?Fifty-eight laying hen farms in France were studied, including 21 flocks housed in conventional cages, 7 in furnished cages and 30 kept on-floor.
3.?Sixty eggs per flock were analysed to obtain counts of the total mesophilic flora. Data on equipment and hen management were collected.
4.?Mean bacterial count on eggshells tended to be higher in on-floor systems (4·82 ± 0·51 log CFU/eggshell) than in cage systems (4·57 ± 0·58 log CFU/eggshell, P = 0·09).
5.?Contamination increased with age of the hens, airborne dust concentration, manual packing of the eggs, and packing in plastic rather than in recycled-pulp egg-flats.
6.?The effect of the housing system on eggshell contamination, previously described in experimental assays, was confirmed under production conditions. 相似文献
2. At 22°C, weight gain of LL broilers was the same as in FL chickens, but at the high temperature LL birds grew to a greater weight than FL ones.
3. Food conversion efficiency was not affected by ambient temperature in LL chickens but was depressed in FL ones at 32°C.
4. Increasing dietary protein content did not alleviate heat‐induced growth depression irrespective of the genotype.
5. Gross protein efficiency was higher in LL chickens and was less depressed at 32°C than in FL birds.
6. Fat deposition decreased with increasing protein concentration at normal temperature in both genotypes; at high temperature, high protein content enhanced fatness, particularly in LL chickens.
7. Thus, genetically lean broilers demonstrated a greater resistance to hot conditions: this was indicated by enhanced weight gain and improved food and protein conversion efficiencies. 相似文献
2. In meat‐type chickens food intake and growth rate were about 3‐fold those in egg‐type chickens. Food efficiency was superior in meat‐type chickens throughout the experimental period.
3. Meat‐type chickens hatched with disaccharidase activities exceeding those found in their egg‐type counterparts 2‐ to 5‐fold. From 7 d of age on, this trend reversed, i.e. activity was much higher in egg‐type than in meat‐type chickens.
4. Blood plasma amylase activity increased gradually in meat‐type chickens and was higher than in egg‐type chickens to 14 d of age. No breed differences were observed for alkaline phosphatase or lactate dehydrogenase activities during the experimental period.
5. Blood plasma concentrations of total protein, albumin, glucose, and calcium, were lower in meat than in egg‐type chickens. 相似文献
2.?Optimal water loss for maximal hatchability of layer eggs was found to be 12 to 13% of initial egg mass at d 18 of incubation.
3.?Mass specific water vapour conductance (GH2Osp) increased linearly with flock age from 0·31 mg/(d·g·Torr) at the beginning of the first breeding season to 0·40 mg/(d·g·Torr) at its end after 77 weeks (=4·21 and 5·44 mg/(d·100 g·kPa), respectively).
4.?After forced moulting GH2Osp increased from 0·35 to 0·41 mg/(d·g·Torr) (=4·76 and 5·58 mg/(d·100 g·kPa), respectively).
5.?The coefficients of variation of GH2Osp increased with flock age from 14% at the beginning of the breeding season to 31% at the end of the second breeding season.
6.?In order to preserve normal incubation water loss for maximising hatchability, the humidity setting of an incubator should increase gradually, with flock age, from 53% RH to 66% RH in the first laying season and from 61% RH to 67% RH after forced moulting.
7.?A 3·5-fold increase (from 2 to 7%) in the difference between mean and median GH2Osp of egg batches with flock age was found, indicating increasing frequency of microscopic cracks in eggshells with flock age. This has to be taken into account when setting the humidity regime in the incubator. 相似文献
2. The role of class IV MHC genes in resistance to Eimeria acervulina was assessed in F2 progeny of a cross between 2 meat‐type lines, selected divergently for immune response to Escherichia coli.
3. Disease susceptibility was assessed by lesion score, body weight, packed cell volume and carotene absorption.
4. Chickens with the “K” class IV MHC haplotype had lower lesion scores than chickens with “F” and “A” haplotypes.
5. Plasma carotene concentrations were higher in chickens with “K” haplotype and lower in chickens with “F” and “A” haplotypes whereas body weight and packed cell volume were less sensitive measures of Eimeria infection.
6. Eimeria acervulina resistance appears to be associated with MHC class IV genes; information about MHC haplotypes may be useful in selecting for increased resistance of meat‐type chickens to coccidiosis. 相似文献
Examination of the duodenum, small intestine and caecum showed very little multiplication of coli‐aerogenes bacteria during hanging, although there was some increase in the numbers of faecal streptococci. Psychrophilic clostridia, mainly Clostridium putrefaciens, were found in the small intestine after 8 d and these organisms increased in number up to the 15th d.
The muscle remained relatively free from bacteria for most of the hanging period, but at 15 d Cl. putrefaciens was found in two out of three muscle samples at io3 and io4 per g.
No signs of spoilage due to greening were observed.
Twelve 16½>‐week‐old chickens were also killed by dislocating the neck and hung without plucking for 12 d at 10 °C with the pheasants. Although initially there were no major differences between the intestinal flora of the chickens and pheasants, faecal streptococci and coli‐aerogenes bacteria multiplied rapidly in the small intestine of the chickens during the first week. Greening occurred around the vent within 5 d.
Reasons for the differences between the two types of bird are discussed, particularly in relation to the diet. 相似文献
2. Food, metabolisable energy (ME) and water intakes were significantly higher for ducklings than for chickens. The ratio of water : food was 4.2 : 1 and 2.3 : 1 for ducklings and chickens, respectively. The food conversion ratio differed between diets but not species. Performance was generally better for both species on the high‐energy diet.
3. Heat production, energy, fat and protein retentions were higher for ducklings than chickens, and ducklings retained 0.44 of their energy as fat compared with 0.37 for chickens. Overall the ratio of protein (g) to fat (g) retention was 2.2 : 1 and 2.8 : 1 for ducklings and chickens respectively.
4. For ducklings, metabolisability of the high‐energy diet declined from 0.774 to 0.747, and to a lesser extent of the low‐energy diet, as they aged. There was no such decline for chickens. Net efficiency of utilisation of ME for gain was 0.64 for ducklings compared with 0.50 for chickens.
5. Fractional retention of dietary nitrogen (N) was 0.62 for ducklings and 0.55 for chickens. Gaseous ammonia‐N was 4.5 and 2.2%, respectively, of N retained.
6. In a second experiment groups of ducklings only, were offered high‐and low‐protein diets from 12 to 22 d of age. Comparisons among four diets showed that food and energy intake was lower on the low‐protein diet than on the other three. Energy retention on the high‐energy diet was greater (P<0.05) than on the other three diets.
7. It was concluded that a high‐energy diet is important for ducklings and chickens for maximum biological performance during the first 4 weeks of life. 相似文献
2. Relative daily food intake and growth rate were much higher in meat‐than in egg‐type chickens. Relative daily food intake peaked at 30% of body weight at 3 d of age in meat‐type, and at 20% of body weight at 6 d of age in egg‐type chickens and then decreased gradually. The corresponding values for growth rate were 20 and 14%.
3. Allometric growth of the small intestine, intestinal contents and liver was greater in meat‐type chickens, but the growth of the pancreas attained a higher value in the egg‐type birds. Diminution of the vitelline residue was similar in the two breeds.
4. Pancreatic digestive enzyme activities were similar between stocks, but activities in the small intestinal contents were lower in meat‐type chickens.
5. The secretion of digestive enzymes in the newly‐hatched meat‐type chicken could be a limiting factor in digestion and, consequently, in food intake and growth. 相似文献
2.?In a preliminary study, 4 diets were given to chicks from 3 to 15 d of age: D1 (6·5 g P/kg and Ca:P = 1·5) and D2, D3 and D4 (6·0, 5·4 and 5·0 g P/kg, respectively, and Ca:P = 1·2). Growth performance was similar across diets. Tibia ash was similar in chicks given D1 and D2, but was gradually depressed from D2 to D4 (?22%).
3.?In the depletion period, two groups of chicks, with similar performance, but with different mineral status were achieved by feeding them, from 5 to 15 d of age, diets with a similar Ca:P ratio of 1·2, but containing 6·3 or 5·2 g P/kg.
4.?During the subsequent 11 d of the repletion period, chicks from each of the two previous groups were given one of the 4 diets containing 5·7 g P/kg, but differing in their Ca (8·3 and 5·3 g Ca/kg) and microbial phytase (0 or 1000 FTU, Natuphos®) levels in a 2 × 2 × 2 factorial arrangement.
5.?At the end of the repletion period, the initially depleted chicks could not be differentiated from the non-depleted chicks, indicating the capacity of chicks to compensate for their initial depleted mineral status.
6.?Interaction between dietary Ca and phytase levels was not significant. Phytase improved growth performance and bone characteristics. Reduced dietary Ca enhanced feed intake and growth rate, but depressed bone dry matter and ash weight.
7.?At the end, diets supplemented with phytase maximised bone ash weight when chicks were fed with a Ca:P ratio of 1·5 but elicited the highest growth rate when chicks were fed with a Ca:P ratio of 0·9. 相似文献
2. The relationship between early and final body weight was investigated for individual chickens.
3. The feasibility of automatic separation of birds into different weight groups was evaluated and consideration given as to whether this technique could be used for sex‐separation of an as‐hatched flock.
4. The results suggest that the present commercial practice of male selection at flock depopulation may be less reliable than many producers believe. 相似文献
2. A wide variation in protein (149 to 203 g/kg DM), starch (563 to 629 g/kg DM) and WSP (27·7 to 50·9 g/kg DM) was found between varieties.
3. The TMEn reproductibility was assessed in two laboratories, using Leghorn cockerels, Isabrown cockerels and 3‐week‐old chicks. There were no sismificant differences in the TMEn values (range 14·0 to 15·2 MJ/kg DM) between the two types of cockerel. The TMEn values of the varieties were similar for chicks (range 13·6 to 14·9 MJ/kg DM) and for cockerels, with the exception of one variety.
4. The bioavailability of starch (range 96·5 to 99·4%) of some varieties was higher for cockerels than for chicks. The mean bioavailability of amino acids for cockerels was 94·5%.
5. TMEn prediction equations were derived from the chemical composition of the varieties. Best‐fit equations were obtained for starch (R 2 = 0·62, RSD = 0·24), ash (R 2 = 0·58, RSD = 0·25) and WSP (R 2 = 0·52, RSD = 0·27). 相似文献
2. A total of 1056-d-old Cobb male broilers were housed in experimental pens (22 chickens per pen) for 42 d. Three levels of CaMont (0, 2.5 and 5 g/kg) and two levels of aflatoxins (0 and 3 mg/kg) were assayed. Each treatment had 8 replicate pens of 22 broiler chickens each.
3. Of all the chickens tested in the experiment, the ones treated with aflatoxins were the most adversely affected. CaMont treatment at concentrations of 2.5 and 5 g/kg improved body weight of chickens at 42 d of age by 13.3% and 22.7%, increased daily feed intake by 9.7% and 24.7%, and improved the productive efficiency index of chickens by 53% and 66.5%, respectively.
4. Dietary CaMont positively affected parameters such as weight of liver, heart and gizzard; however, serum potassium concentration decreased by 15.3% compared with that of chickens given only the aflatoxin-contaminated diet.
5. CaMont did not cause adverse effects in chickens that did not receive aflatoxins.
6. CaMont at pH 8.5 partially reduced the toxic effects of aflatoxins in broilers when included at levels of 2.5 and 5 g/kg in the diet. 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. No significant interactions occurred, so only the main effects were discussed. At 7–14?d, feed conversion ratio (FCR) showed a significant linear response with increased glycerol inclusion. However quadratic responses on FCR were observed for the 21–28?d period and 7–28?d.
3. Glycerol digestibility was significantly greater with birds offered the 67?g/kg and 100?g/kg glycerol-based diets in contrast to the digestibility of 33?g/kg glycerol-based diets.
4. Glycerol inclusion level also had an effect on AME, which increased linearly with increasing glycerol inclusion. Birds offered the diets containing glycerol also required less energy per unit gain in contrast to birds offered the control diet.
5. When examining the effect of source of glycerol, source A glycerol resulted in the highest AME (15·20 vs. 14·72?MJ/kg). There was no significant effect of glycerol source on the other performance parameters.
6. Glycerol digestibility was significantly greater with glycerol from source B (John Thompson and Sons, Ltd) with a mean value of 0·848 in contrast to source A (PRS Environmental), which had a somewhat lower mean glycerol digestibility of 0·757.
7. In conclusion, glycerol source did not affect performance and increasing level of glycerol improved FCR, with 67?g/kg inclusion resulting in the most efficient conversion of feed to gain without any negative effects upon nutrient digestibility. 相似文献
2. A total of 72 chickens from each of these breeds were randomly distributed to 4 pens to provide equal numbers of two replicate pens maintained as infected and control (uninfected). All chickens in infected groups were inoculated orally with 1 × 108 CFU (1 ml dose) of a field isolate of S. gallinarum, at the age of 8 and 16 weeks given over 5 consecutive days. Growth performance, clinical signs, gross pathological lesions and antibody responses were measured.
3. A significantly higher mortality was observed in the brown layers compared with the white layers, and clinical signs and mortality were absent in village chickens. However, a large number of birds with gross lesions and high antibody titres were detected in village chickens, indicating that birds had the disease subclinically. Commercial breeds had a significantly higher body weight, feed intake and feed conversion efficiency.
4. There was a significantly lower proportion of positive reactors in village chickens in the whole-blood agglutination test (35%) compared to brown (100%) and white (90%) layers even after the second inoculation. Uninfected birds were negative in all groups. The indirect enzyme-linked immunosorbent assay confirmed these observations.
5. These results suggest that the indigenous breed had superior natural resistance to S. gallinarum than the commercial breeds. 相似文献