2. Dietary corticosterone reduced the titre to sheep red blood cells, while it was unchanged by clenbuterol.
3. Clenbuterol exerted a promoting effect on gain‐to‐food ratio, carcase protein and hepatic microsomal cytochrome P‐450 content.
4. Addition of clenbuterol to the corticosterone‐containing diet prevented the increase in abdominal fat weight and uric acid excretion induced by corticosterone, but did not affect total fat mass.
5. The results showed that clenbuterol reduced abdominal rather than carcase fat and prevented protein degradation in the body when chicks were treated with corticosterone. Clenbuterol also influenced the content of cytochrome P‐450, but not the humoral immunity. 相似文献
2. High ND diets increased body weights, eviscerated carcase weights, relative carcase yields and carcase skin yield, but not breast or total meat yields.
3. Feeding a low ND diet to 6 weeks followed by diets with progressively increasing ND yielded performance and carcases with qualities comparable to feeding diets of constant medium or high ND; consequently cost savings could be made.
4. Increasing E:Ps reduced body weights, eviscerated carcase weights and carcase yields. Breast and total meat yields from male but not female carcases, and skin yield of female but not male carcases decreased with higher E:Ps.
5. The fat contents of breast and thigh meat samples increased with ND. The fat content of breast but not thigh meat decreased with higher E:P. Dry matter contents of meat samples did not vary consistently with changes in fat content. 相似文献
2. Food intake was measured daily for 21 d. Body composition was determined at 42 d and gains in body mass, protein, fat and gross energy calculated by comparison with a group analysed at 21 d. Heat production was calculated by difference between AME intake and energy gain.
3. Decrease of food mass intake with increased dietary AME concentration limited the increase in AME intake to about 25%, despite the near 2‐fold range of AME concentrations.
4. There was no effect of CP concentration on food mass intake. CP intake was directly related to CP: AME ratio.
5. When body weight differences were taken into account, heat production was independent of dietary AME concentration, but increased by about 8% on the higher‐protein diets.
6. There were strong linear correlations between dietary CP:AME ratio and carcase protein: energy ratio, carcase fat content and carcase protein content.
7. It was concluded that the growing fowl responded to dietary nutrient: energy ratio, and the associated differences in nutrient and energy intakes, by varying the rate of energy deposition as fat, without regulatory variation of energy dissipation as heat. 相似文献
2. Six diets varying in protein from 160 to 300 g/kg and containing approximately 11–72 MJ/kg ME were fed for 5 weeks and analysed for dry matter, protein, fat and ash.
3. Treatments affected carcase weight, dry matter, protein, ether extract and ash
4. The water content of the carcases decreased with increasing dietary protein concentrations, while the carcase protein content increased with higher dietary protein. The carcases with the highest fat content were obtained from quail receiving the low protein diet. 相似文献
2. Plasma α‐tocopherol was significantly correlated with α‐tocopherol concentrations in thigh and breast muscle.
3. The fatty acid profiles of muscle lipids reflected dietary fatty acid composition.
4. The consumption of heated sunflower and linseed oils reduced α‐tocopherol status, altered fatty acid composition of muscle lipids and increased susceptibility of muscle to lipid oxidation.
5. Supplementation of diets containing heated oils with α‐tocopheryl acetate resulted in some alleviation of these effects.
6. The results indicate that caution should be exercised in the use of thermally oxidised oils in poultry diets if undesirable changes in composition and oxidative stability of carcase lipids are to be avoided. 相似文献
2. Predation was higher in BA than HB.
3. Mortality through disease was higher in RIR than BA and HB.
4. Crossbred HB birds show the lowest combination of mortality and predation, suggesting a heterosis effect.
5. Mortality did not differ on farms and in field environments, suggesting an inability to improve biosecurity in farm conditions.
6. There was a positive relationship between eggshell strength and mortality. Calcium depletion from the birds’ bones, limiting foraging and escaping ability may be the explanation, which ultimately increases susceptibility to disease and predation. 相似文献
2.?A total of 1500 hen eggs (Ross-308) were measured by TOBEC, and eggs with extremely high (10%, n = 150), extremely low (10%, n = 150) and average (10%, n = 150) electrical conductivity values were chosen for further investigation.
3.?During the incubation period, it was observed that eggs with high electrical conductivity had a significantly higher mortality than eggs with low electrical conductivity.
4.?It was observed that both the increase in electrical conductivity at the same egg weight, and the increase in egg weight at the same electrical conductivity resulted in an increase in the hatching weight.
5.?It was found that the dry matter, protein and fat content of the chicks hatched from eggs with low electrical conductivity was higher at hatching than that of the chicks hatched from eggs with high electrical conductivity.
6.?At 42 d of age the liveweight of cocks and pullets hatched from eggs with low electrical conductivity was 3·2 and 8·2% higher than the liveweight of cocks and pullets hatched from eggs with high electrical conductivity.
7.?Because of the higher liveweight at slaughter, there was a significant superiority of the chicks hatched from eggs with low electrical conductivity in the case of the examined carcase traits at slaughter.
8.?Similar tendencies were found also in the ratios of carcase variables to liveweight, but the between group differences were not statistically significant in this case.
9.?Based on the results it was concluded that TOBEC seems to be a useful method for separating eggs with different composition.
10.?This could be a good starting point for further in vivo investigations in order to clarify the effect of egg composition on hatchability and further development. 相似文献
2. At 42 d of age, when the quail had started to lay and hen day production was about 60%, layers were heavier and contained more carcase fat than those that were not laying.
3. The liver and the ovary weight were greater following the onset of sexual maturity than 1 or 2 weeks before (35 and 28 d respectively).
4. Carcase fat as well as age are critical requirements for the onset of sexual maturity in quail. 相似文献
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
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 12 treatments were: 2 completely balanced diets fed as mash or pellets, 8 choice fed diets containing maize or sorghum as the energy source (whole or mash) and protein concentrate (pellets or mash) and 2 unbalanced mixed mash diets containing 50% grain (maize or sorghum) plus 50% protein concentrate.
3. For the choice treatments, one food, grain (maize or sorghum) or protein concentrate (mash or pellets), was placed in each feeder. Broilers fed the complete pelleted or mash diet received the diet in both feeders. Food consumption was recorded weekly. Broilers were weighed at 42 and 56 d of age.
4. There were no significant differences between treatments and the pelleted control diet with regard to body weight, food consumed, food efficiency, carcase ash, dressing percentage and mortality.
5. Choice fed broilers receiving the energy source as whole grains had larger gizzards while the higher protein diets (50/50) resulted in a higher carcase moisture and protein but lower carcase fat than the broilers fed the pelleted control diet.
6. The main advantage of choice feeding appears to be the economical savings of feeding whole grains as the energy source. 相似文献
2. Higher rates of fertility and hatchability of Japanese quail eggs were observed from parents of 10 to 19 weeks of age, with peak fertility and hatchability at 14 and 12 weeks of age, respectively.
3. Sex ratios of 1:2 to 1:5 gave comparable fertility and hatchability results.
4. The hatching performance of quail eggs from cage and deep litter reared breeders was comparable.
5. Fertility and hatchability were directly proportional to the egg weight.
6. Quail egg shell colour, tints and blotches were found to influence hatching performance.
7. Storing quail eggs at 16 ± 2°C and 75 ± 5% relative humidity for more than 4 d reduced hatchability.
8. Hatchability of eggs stored at room temperature was improved if they were sealed in polyethylene bags.
9. Provision of light during the first 14 d of incubation resulted in a photo‐acceleration of about 3.2 h. 相似文献
2. Females compared with males, and GT chickens compared with LR and EC chickens were characterised by increased carcase fatness and an increased lipid level in thigh meat.
3. In both breast and thigh meat, the percentage of monounsaturated fatty acids was increased and the percentage of polyunsaturated fatty acids was decreased. However, these effects did not affect sensory characteristics of meat particularly those of roasted breast fillets containing very low lipid level by comparison with thigh meat.
4. Finally, in our study, high carcase fatness was related to high intermuscular fatness affecting the nutritional characteristics of meat but not its sensory attributes. 相似文献
2. Male broilers (24) were given either a grower food in the air‐dry form with access to drinking water or the same food mixed with 2–0 parts of water (700 g water/kg of mixed food) with no drinking water from 28 to 49 d of age. From 49 to 63 d all birds were given dry food and drinking water and were then killed for carcase analysis. Food intake and weight gain were significantly increased during the wet‐feeding period, as was carcase protein but not abdominal or carcase fat at the end of the experiment.
3. Five male broilers were given each of 5 dietary treatments containing 0 (control), 1.5, 1.75, 2.0 and 2.25 times added water (640, 673, 700 and 723 g water/kg) from 28 to 49 d. Food intakes, body weight gains and carcase weights were significantly increased for all water additions compared with dry food, but there were no significant differences between different water additions.
4. Female broiler chicks responded to wet feeding (700 g water/kg) in a similar manner to males and the dry matter approximate digestibility was increased from 0.65 for the dry food to 0.73 for the wet.
5. Cockerels of an egg‐laying strain did not increase their intake of dietary dry matter when it was fed in the wet form (700 g water/kg), but there was a significant increase in body weight gain.
6. Male broilers were offered wet food (700 g water/kg) with or without access to drinking water. There was equal stimulation of food intake, growth and carcase weight with both wet‐feeding treatments.
7. Providing food mixed with sufficient water to give a porridge‐like consistency significantly increased weight gains in each of the five experiments and significantly improved food conversion efficiency in three of the five. It is not necessary to withold drinking water in order to obtain this effect. 相似文献
2. Hyperphagia, amounting to twice the intake of control birds early in the experiment, occurred on the repletion day.
3. Final body weight attained 80% of that of the controls.
4. Body fat concentration decreased at first but returned to that of controls after 3 weeks.
5. A consistent hyperlipaemia was observed after food deprivation or restoration.
6. There was a marked increase in the digestive enzymes found in the small intestine, but not in the pancreas during the repletion day.
7. These responses may be considered as mechanisms to reduce the physiological manifestations of starvation. 相似文献
2. Samples which had undergone different degrees of portioning, from whole birds to individual retail portions of poultry meat, were collected at points along the portioning line. Equipment surfaces, utensils and hands/gloves of factory personnel were examined.
3. In general, microbial numbers on carcase sampling sites were related to ‘exposure factor’, that is, the length of time the site was exposed to potential contamination during processing and portioning.
4. When results for individual sampling sites were analysed separately, no significant differences were found between sites on whole birds and the corresponding half bird sample sites. Comparison of numbers on half birds and on portions revealed a more variable situation.
5. Sites touched by rubber gloves when carcases were hung on the automatic portioning lines had greater contamination than other sites.
6. Provided factory and operative hygiene standards are high, portioning does not significantly increase numbers of microorganisms. 相似文献
2. Lighting affected growth pattern but had no effect on body weight at 118 d or overall food to gain ratio.
3. Both INC and DID lighting reduced overall mortality in comparison to CON light primarily because of a reduction in the incidence of skeletal disease and spontaneous cardiomyopathy. INC and DID lighting increased the incidence of cannibalism.
4. Turkeys given INC or DID lighting had a superior ability to walk in comparison to those birds given CON light.
5. INC and DID males stood, ate and drank more frequently, and sat less often than CON turkeys during behavioural observation.
6. There were no lighting effects on carcase composition except that INC and DID birds had heavier keel bones. The ultimate force per cm2 (stress) required to break femora was greater for turkeys given INC and DID lighting (P = 0.065).
7. Plasma testosterone concentrations at 117 d were 272.5, 115.2 and 29.5 pg/ml for turkeys given CON, INC and DID lighting, respectively (P= 0.072). Testosterone concentration was not related to growth rate. 相似文献
2. Rocking embryo cultures during the first half of incubation enhanced embryo growth.
3. Embryos explanted into ‘surrogate’ eggshells of either other individuals or other species have been successfully ‘hatched’.
4. A normal chorioallantois is formed in these surrogate eggshells. This enables a functional albumen sac to form and eggshell resorption to be achieved.
5. Embryos grown in ‘surrogate’ eggshells are slightly smaller than controls but otherwise normal.
6. The technique provides opportunities for genetic engineering experiments. 相似文献
2. Males grew faster between 14 and 56 d of age and contained less fat and more protein and water in the eviscerated carcase at 56 d than females.
3. For both sexes, food : gain ratio deteriorated as food intake increased from 0.49 ad libitum intake to ad libitum intake. Growth rate, carcase weight and carcase fat content increased linearly with increase in food intake. Carcase fat content at 56 d was more sensitive to change in the amount of food consumed than either growth rate or carcase weight.
4. Between 0.42 kg (14 d) and 2.50 kg live body weight, growth rate and food :gain ratio improved as food intake was increased from 0.61 ad libitum to ad libitum. Males grew faster and produced leaner carcases than females.
5. Carcase fat content at 2.50 kg live body weight (1.60 kg carcase) increased in a curvilinear fashion with increase in food intake, and the magnitude of the response was lower for females than for males. A similar interaction existed between the effects of sex and the amount of food consumed for the proportions of protein and water in the eviscerated carcase at 2.50 kg live body weight. 相似文献
2. Breeder hens fed ad libitum and subjected to either conventional or intermittent lighting ingested respectively, 25 g and 14 to 17 g more than hens restricted to 115 g/d.
3. Body weight was greater in hens fed ad libitum irrespective of the lighting pattern and of the amount of food intake.
4. Persistency of egg production was impaired by intermittent lighting.
5. Ad libitum feeding reduced egg fertility. The decrease was larger in breeder hens on intermittent lighting.
6. Hatchability was increased in hens submitted to the symmetrical lighting pattern (0.5L:3.5d).
7. Egg and chick weights were higher in hens fed ad libitum.
8. Shell index and shell breaking strength increased in restricted hens on the intermittent lighting pattern (0.5L:3.5d) × 6.
9. The best performance was obtained in restricted hens on the conventional lighting pattern. 相似文献