2. Treatments consisted of two cereals (maize- or wheat-based diets) and three levels of SKEO)0, 250 and 500 mg/kg).
3. Feed intake (FI) and body weight gain (BWG) decreased in broilers fed on the wheat-based diets compared to the control diet. Dietary supplementation of 500 mg/kg SKEO increased FI and BWG. Dietary SKEO supplementation was effective in improving FI and BWG only in wheat-based diets and was effective in improving feed conversion ratio (FCR) in both diets.
4. Dietary supplementation of 500 mg/kg SKEO caused a significant decrease in plasma cholesterol and triglycerides. Also, plasma low-density lipoprotein concentration was decreased in broilers fed on 250 and 500 mg/kg of SKEO. Plasma cholesterol levels in birds fed on the wheat-based diets were lower than in those fed on maize-based diets.
5. Dietary supplementation of 500 mg/kg SKEO increased caecal population of Lactobacillus and reduced total bacterial and Escherichia coli count. Caecal population of Lactobacillus decreased in broilers fed on the wheat-based diets.
6. Digesta viscosity was increased in broilers fed on the wheat-based diets and decreased in broilers fed on 500 mg/kg SKEO compared to the control diet. Dietary SKEO supplementation was effective in reducing digesta viscosity values only in wheat-based diets.
7. Villus height of the duodenum and jejunum decreased in broilers fed on the wheat-based diets. Dietary supplementation of 500 mg/kg SKEO increased villus height and villus height-to-crypt depth ratios and decreased crypt depth of the duodenum compared to the control diet.
8. It can be concluded that dietary SKEO supplementation was effective in improving FI, BWG and FCR values in wheat-based diets. 相似文献
2. Egg weight was poor with the low fat basal diet but increased in relation to the amounts of maize oil (4 and 30 g/kg) included in the diet.
3. With a diet containing 30 g olive oil/kg, egg weight was similar to that obtained with the diet containing the same amount of maize oil.
4. Rearing the birds on diets containing low or moderate amounts of linoleic acid did not affect the response to fatty acid content of the layer's diet.
5. It is concluded that the requirement of the laying hen for linoleic add is not higher than 9 g/kg but that egg weight does respond to higher dietary amounts of readily absorbable fatty acids. 相似文献
2. In 4 consecutive trials, 4752 hens were recorded for keel bone status. Evaluation of plumage condition was made for 1440 hens and bone breaking strength was recorded for 1200 hens. A total of 4962 eggs were analysed for internal and external egg quality traits. Analyses involved 30 small group compartments per trial.
3. The layer line had a much more pronounced influence on humerus breaking strength than on tibia breaking strength.
4. Plumage condition, particularly on the neck, was positively correlated with humerus breaking strength in both layer lines.
5. An average of 34% of LB and 23% of LSL hens showed keel bone deformities, with higher proportions of slight deformities.
6. Slight keel bone deformities, rather than moderate to severe, increased significantly during the laying period.
7. Stocking density had no influence on bone breaking strength, keel bone status and egg quality traits.
8. LB layers had a 1.4-fold higher humerus, but only a 1.06-fold higher tibia breaking strength compared to LSL layers.
9. Tibia breaking strength was significantly affected by the interaction of group size and layer line. LSL layers in small groups had lower tibia breaking strengths than those of the large groups. 相似文献
2. Dietary supplementation of FPB linearly increased the weight gain and feed intake of broilers with linear reduction in feed conversion ratio.
3. The crude protein, iron, magnesium, and sodium content were linearly higher, whereas cholesterol was linearly lower in the breast meat of FPB-supplemented broilers. In thigh meat, linearly lower ether extract and cholesterol with higher moisture was noted in response to increasing levels of FPB.
4. The proportion of saturated fatty acids was both linearly and quadratically lower in breast and thigh meat, whereas those of monounsaturated fatty acids of breast (linear and quadratic) and n-3 fatty acids of breast and thigh (linear) meat was higher in the FPB-supplemented broilers. The n-6/n-3 ratio of breast meat was linearly lower in response to FPB supplementation. The hypocholesterolaemic to hypercholesterolaemic ratio of thigh meat was higher in the FPB-supplemented groups.
5. The thiobarbituric acid reactive substances and pH value were lower in the breast and thigh meat of FPB-supplemented broilers.
6. Thus, additive supplementation of the diet with up to 2% FPB improved the nutritional quality, fatty acid profile and shelf life of broiler meat. 相似文献
2. The low AME was due to a reduced starch digestibility and was not improved by grinding the wheat finely or by steam pelleting the diet.
3. Higher AME values were obtained when determinations were made with adult cockerels than with growing broilers when the conventional technique was used.
4. AME values determined using a rapid bioassay technique (Farrell, 1978) with growing broilers or adult cockerels were considerably higher than values determined using the conventional procedure with growing broilers.
5. Inter‐laboratory studies showed that the true metabolisable energy (TME) assay gave reproducible values for individual and blended wheat samples, but that these values were higher than AME values determined by the conventional procedure. Similar TME values were found with growing broilers and adult cockerels. 相似文献
2. Broiler growth, efficiency of food utilisation and mortality were not significantly improved as a result of air filtration.
3. Histological examinations of lung tissue indicated that the structural changes and lymphocytic reactions were less severe in broilers reared with filtered air than those observed in broilers reared with unfiltered air. However, the lung damage observed in broilers in this experiment was much less severe than that which has been observed in commercial flocks.
4. Air filtration reduced dust content in the air by up to a half, whereas the concentration of bacteria was reduced by more than 100 fold by the time the broilers were 21 days of age. 相似文献
2. Protein and energy metabolism were studied in males from these selected lines fed on a diet of intermediate protein content.
3. All selected birds retained more nitrogen than those studied 10 years previously.
4. There was no difference in nitrogen retention between groups, although relative growth rate of group B birds was higher.
5. Heat productions relative to gross energy intake were 0.38 (group B) and 045 (group A). Energy retentions relative to gross energy intake were 0.39 (group B) and 0.35 (group A); the difference being primarily due to higher fat retention in group B.
6. Using a common maintenance requirement for metabolisable energy, group B utilised metabolisable energy for growth (0.78) better than did group A (0.71).
7. At 53 d of age plasma glucose (10%) and insulin (50%) were higher in group B than in group A. 相似文献
2. Reduction in the duration of illumination did not impair growth rate.
3. The sexes showed a differential response to the treatments.
4. There was evidence that the enhanced performance of females was due to an improvement in food conversion efficiency. 相似文献
2. A total of 192 one-d-old randomly divided chickens of both sexes (Ross 308 hybrid broilers) were divided into 4 treatment groups of 48 birds each.
3. The first group was fed on a nutritionally balanced basal diet (BD). The other three groups received BD supplemented with 0.5 g/kg thyme oil, or 0.4 mg Se/kg DM, or both feed additives together.
4. The results for the evaluated feed additives were (1) thyme oil – decreased malondialdehyde (MDA) concentration in duodenal mucosa and kidney, increased immunoglobulin A (IgA) concentration in duodenal mucosa, stimulated phagocytic activity in blood, improved intestinal barrier integrity (2) selenium – increased glutathione peroxidase (GPx) activity in blood and liver as well as thioredoxin reductase (TrxR) activity in duodenal mucosa, liver and in the kidney, (3) EO with selenium – increased thioredoxin reductase (TrxR) activity in duodenal mucosa.
5. These results demonstrated that thyme oil alone showed more effective potential to improve intestinal barrier integrity and antioxidant status as well as evoking an immune response in chickens, than if diets were supplemented with both thyme oil and selenium. 相似文献
2. Growth was significantly enhanced by regular handling in broilers and the females of the layer strains and gain : food ratios were generally greater in the handled birds.
3. There were no significant treatment effects on growth or gain : food ratios in males of the layer strains.
4. Males had higher relative weight gains and gain : food ratios than females. 相似文献
2. Increased mortality, perosis and other pathological changes involving a number of tissues were observed in birds fed on a low‐choline diet.
3. Methionine replaced part of the dietary requirement for choline at low dietary choline concentrations.
4. High dietary concentrations of choline (> 1 750 mg/kg) increased the requirement for dietary TSAA.
5. Increasing the dietary choline while maintaining the TSAA at an inadequate level may decrease performance. 相似文献
2. Sixty‐three male and 47 female broilers sampled at 63 d of age from an unselected control line were used to examine the accuracy of the caliper measure in predicting abdominal fat.
3. Phenotypic correlations between caliper measure and the proportion of abdominal fat were + 0.80, +0.79 and +0.81 in males, females and the heaviest 20% of males respectively.
4. The application of the technique as an indirect means of selecting for decreased abdominal fat in commercial broiler breeding programmes is discussed. 相似文献
2. Male broilers grew linearly up to 76 d whereas the females grew more slowly after 35 d. At 364 d the difference in live body weight was small.
3. Up to 56 d, males had a slightly higher eviscerated yield. There was no significant difference between the sexes beyond this age.
4. The proportional yield of breast muscle was variable with age, whereas that of thigh and drumstick increased with age in the male, particularly at 175 and 364 d.
5. After 35 d the proportion of skin was larger in females, whereas the gizzard as a proportion of live body weight in both sexes decreased rapidly between 21 and 76 d. Blood loss during killing was always higher in male broilers after 21 d. 相似文献
2. Broilers were fed on diets either with a low-oxidised oil (peroxide 23 mEq O2/kg) or with a high-oxidised oil (peroxide 121 mEq O2/kg), with or without an algae-based antioxidant and organic mineral antioxidant supplement for 42 d.
3. Fatty acids and radical scavenging activities of the diets were estimated. Meat colour, pH, myofibrillar protein profile and textural traits were measured.
4. Diets with high-oxidised oil reduced stearic, linoleic and linolenic acid content compared to low-oxidised oil samples, regardless of antioxidant supplementation. Meat colour and pH varied among dietary treatments throughout storage. Meat samples from the antioxidant dietary group, irrespective of oil oxidation level, had lower amounts of purge and cooking losses compared to the unsupplemented diets. For all packaging systems, meat shear force was significantly higher for broilers fed on high-oxidised diets.
5. The results demonstrate that dietary antioxidant supplementation can minimise the negative impact of oxidised oil on the quality of broiler meat packaged in different atmospheric environments. 相似文献
2. Birds exposed to a 2 h light(L): 10 h dark(D) lighting schedule with feeding restricted to the light periods ate significantly less food and grew more slowly than conventionally‐reared birds. Satisfactory growth and efficiency of food utilisation were obtained by allowing these birds access to food during the dark periods.
3. Altering the lighting schedule to 2L:6D resulted in birds with food intakes and growth rates similar to those reared conventionally, even when feeding was restricted to the light periods.
4. Releasing birds from the light and food restriction for the 2 weeks preceding slaughter resulted in greater food consumption which was not characterised by significantly better growth or food utilisation.
5. Feeding a diet of high energy or pelleting a diet of low energy during the period of restriction increased food intake and improved growth rate.
6. The response of broilers to intermittent lighting and feeding was not significantly influenced by ambient temperature within the range 16 to 35 °C or by the energy concentration of the diet fed before the introduction of the intermittent schedule. 相似文献
2. Eighty broilers were randomly divided into two groups. Birds in the control group were fed on maize–soybean-based diets. Birds in the treatment group were provided the same diet supplemented with 2 g/kg BA encapsulated in a vegetable oil matrix.
3. At the end of the trial (d 35), pH, bacterial composition and metabolites were determined in the crop, jejunum, ileum and caecum.
4. Growth performance variables and pH were not significantly different.
5. BA concentration decreased rapidly in the proximal gut. However, the treatment diet showed higher BA in the crop, jejunum, ileum and caecum.
6. Total lactate in the crop and D-lactate in the jejunum was higher in the BA treated group. Caecal total and branched chain fatty acids were decreased due to the treatment.
7. Lactobacilli populations were significantly altered by BA supplementation. A trend for increased lactobacilli was observed in the crop, while it became significant in the jejunum and ileum. Lactobacillus species responded differently to the treatment. Four of 5 measured Lactobacillus species, particularly in the ileum, followed the course observed for total lactobacilli; only Lactobacillus salivarius was not modified.
8. Correlation analysis showed that BA modified the intestinal microbiota. Lactobacilli correlated negatively to all studied clostridial clusters and enterobacteria. Clostridial clusters IV and XIVa were significantly increased in the jejunum, whereas only clostridial cluster XIVa was increased in the caecum.
9. Encapsulated BA modified the intestinal microbiota which can lead to the conclusion, that the main beneficial mode of action of BA in the gut appears to be the enhancement of lactic acid bacteria, which in turn may act as a vanguard against pathogens. 相似文献
2. Time of day of injection did not modify the response to corticosterone of 3‐week‐old chicks kept under natural daylight nor of 7‐week‐old broilers receiving additional illumination.
3. Pure White Rock chicks and Cornish x White Rock crossbred chicks responded similarly to corticosterone injections at 3 weeks of age.
4. Seven‐week‐old female birds treated with corticosterone had significantly larger abdominal fat pads than similarly treated males.
5. Corticosterone injection was more effective in increasing the proportion of liver fat in 7‐week‐old birds than in 3‐week‐old ?hicks.
6. The increased amount of abdominal and liver fat due to corticosterone injections administered at 3 weeks of age disappeared after 3 weeks, but growth depression was still evident. 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. IBV variants were isolated from broiler flocks with enteric and respiratory problems in two regions of Brazil. The USP-10 isolate, of enteric origin, was inoculated via the oral oroculonasal routes into IBV-antibody-free broilers and specific pathogen-free (SPF) chickens to determine tissue tropism and pathogenicity and compared with an IBV variant (USP-50) isolated from chickens showing signs of respiratory disease only.
3. Both USP-10 and USP-50 strains caused similar pathological patterns by either route of inoculation. Both variants were detected in respiratory and non-respiratory tissues, including the kidney, intestine and testis.
4. Broilers were more susceptible to infection than SPF chickens, and seroconversion was detected in all of the chicks. 相似文献
2. A total of 260 Pharaoh quails (Coturnix coturnix Pharaoh) aged 6 weeks were equally divided into 5 groups of 65 (4 replicates of 13 quails each). The mixture of diets was as follows: a control treatment with 0 mg volatile oil/kg of diet; (1) 200 mg/kg rosemary volatile oil; (2) 200 mg/kg oregano volatile oil; (3) 40 mg/kg rosemary volatile oil plus 160 mg/kg oregano volatile oil (ratio 20:80) and (4) 160 mg/kg rosemary volatile oil plus 40 mg/kg oregano volatile oil (ratio 80:20). The diets were prepared fresh for each treatment. The experimental period lasted 10 weeks.
3. At the end of the experiment, there were no significant differences amongst the groups in body weight, egg weight, egg mass, egg shape index, Haugh unit, egg shell thickness or egg shell–breaking strength.
4. Diets containing rosemary volatile oil increased the egg production significantly. Feed intake significantly increased in the groups containing volatile oil mixture (groups 4 and 5). The inclusion of rosemary volatile oil at 200 mg/kg improved feed efficiency.
5. Egg albumen and egg yolk index values showed significant increases in the group given diets containing rosemary volatile oil. Egg yolk colour became darker with the addition of rosemary and oregano volatile oil. The treatment group had lower egg yolk MDA concentration than the control group.
6. It is concluded that, alone or in combination, rosemary and oregano volatile oil can be used in quail diets without adverse effects on the measured parameters. Inclusion of rosemary and oregano volatile oil in quail diets enhanced the antioxidant status of eggs. 相似文献