2. Biotin deficiency decreased hepatic activity of pyruvate carboxylase [EG 6.4.1.1] but activity of acetyl‐CoA carboxylase [EG 6.4.1.2] was comparatively unaffected.
3. Increasing dietary protein increased the severity of biotin deficiency as assessed by skin lesions and decreased plasma biotin concentrations.
4. The severity of the skin lesions over all the treatments was most closely related to plasma biotin concentration. 相似文献
2. Lower body weights and lower feed consumption were observed in 4-week-old poults given 10 and 20 g/kg of AT-402 compared to poults given 0 or 5 g/kg.
3. Floor-reared poults, given either 5 or 10 g/kg AT-402 to 4 weeks of age, were significantly heavier than controls (0 g/kg AT-402), and feed conversion ratios for AT-402 given poults were improved.
4. Xylose uptake in 5 g/kg AT-402-fed poults was significantly greater than in poults given AT-402 at 0 and 10 g/kg, reflecting increased body weights of 5 g/kg AT-402-fed poults.
5. Delayed access by poults to the AT-402 until 10 d of age also improved 4-week body weights, suggesting that the AT-402 might improve performance as soon as it is given.
6. AT-402 at 5 g/kg was most efficacious as demonstrated by improved body weights and feed conversions. 相似文献
2. The poults were free from contamination on arrival at the rearing house but were contaminated via the water supply from troughs which had been ineffectively fumigated.
3. Foodstuffs did not appear to be a source of contamination.
4. The spread of salmonellae in this turkey rearing enterprise was very similar to that in chicken rearing houses. 相似文献
2. Turkeys kept on wet litter were less active and expressed fewer unique sequences of behaviour than poults kept on dry litter, suggesting that high FPD scores are associated with pain during movement.
3. Heavier lines of turkeys had higher mean foot scores that developed earlier, than those in a traditional line, but the effect was relatively small and not statistically significant after 6 d, whereas there were large differences between individuals within line.
4. Body weight gains were greater, and feed intake was lower in the commercial lines kept on dry litter compared with wet litter. There were no differences in water intake between poults kept on wet or dry litter. 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. Data were analysed for species differences in food consumption, body weight, food utilisation, mortality and liver pathology.
3. There were no significant effects of aflatoxin in broiler and Leghorn chicks. Aflatoxin at 0.7 mg/kg decreased the body weight of turkey poults but tended to increase the growth rate of goslings. At 1 ‐4 mg aflatoxin/kg food consumption, body weight and weight gain of goslings were adversely affected.
4. Liver damage occurred in goslings and quail chicks at all inclusions of aflatoxin and was extensive at 2.1 mg/kg.
5. Poults and goslings appeared to be the most sensitive, quail were intermediate and domestic chicks were most resistant. 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. Growth rate, food intake, food utilisation and proportion of dietary nitrogen retained were much poorer in chicks receiving salseed meal.
3. The chicks receiving salseed meal developed pathological lesions in liver and kidney.
4. The red blood cell count, white blood cell count, haemoglobin concentration and packed cell volume of the chicks receiving salseed meal were lower than those of chicks receiving maize.
5. The apparent metabolisable energy value of salseed meal was determined as 6.83 MJ/kg. 相似文献
2. Plasma VLDL plus LDL triglyceride concentrations were similar in males and females and only slightly higher in birds fed on the high‐fat diet. Concentrations at 3 weeks were similar to those at 7 weeks.
3. Body fat content was correlated more closely with plasma VLDL plus LDL triglyceride measured at 7 weeks than at 3 weeks.
4. Phenotypic correlations between body fat content and plasma VLDL plus LDL triglyceride concentrations at 7 weeks were 0.47 and 0.43 for males and females respectively fed on the high‐fat diet and 0.70 and 0.60 for males and females fed on the low‐fat diet.
5. Phenotypic correlations between body fat content and measurements with an abdominal caliper were 0.35 and 0.49 in birds fed on the high‐ and low‐fat diets respectively.
6. A possible procedure for selecting for leanness in broiler breeding programmes on the basis of measurements of plasma VLDL plus LDL triglycerides is discussed. 相似文献
2. Although the protein content of all tissues varied with age, the only statistically significant effect was on the level of protein in the gizzard.
3. The moisture content of the gizzard was significantly affected by age and blood by age and sex.
4. The fat content of the gizzard was significantly affected by age, as was the effect of sex on the fat content of blood.
5. The ash contents of heart and gizzard were significantly affected by age.
6. The phosphorus contents of the gizzard, heart and liver were significantly affected by age, as were the chloride content of heart and the calcium content of the liver. Blood potassium was significantly affected by sex. Fluctuations in the contents of other elements are discussed.
7. The variability in organ composition is discussed with respect to the degree of trimming and preparation of the samples. 相似文献
2. The taint was due to the inclusion of either 25 or 70 g Icelandic capelin fishmeal/kg of the diet.
3. Babcock hens produced significantly more (17%) tainted eggs than Warrens (1.2%).
4. Tainted eggs were significantly reduced to a very low proportion (1.3%) by the third day of feeding a fishmeal‐free diet.
5. The taint was due to the presence of up to 17 mg/trimethylamine kg in affected eggs. 相似文献
2. In chicks fed on diets containing urea, concentrations of urea were higher in the blood and digestive tract but not in the excreta, as compared with chicks fed on diets containing soyabean as the only source of protein.
3. Urea‐nitrogen was utilised better for growth when the diets were supplemented with methionine rather than unsupplemented.
4. Body fat content was decreased with the increase in protein content of the diet. Addition of urea decreased body fat less than an equivalent amount of protein.
5. There was no correlation between body fat and body weight in groups fed on diets containing 189 or 216 g protein/kg, but there was a significant correlation between these variables in groups fed on diets containing 292 g protein/kg or either concentration of urea. This phenomenon was much more pronounced in diets not supplemented with methionine. 相似文献
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. 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. Restricted birds were lighter throughout the experiment.
3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.
4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.
5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.
6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found. 相似文献
2. A circadian system was postulated to control the restriction of ovulation to an 8‐h period of the day under conventional 14 h light: 10 h dark regimes.
3. The final phase of follicular maturation was postulated to commence after ovulation of the preceding ovum in the hierarchy.
4. Ovulation was postulated to occur when a mature follicle was present in the ovary during the appropriate phase of the circadian‐linked system.
5. The predicted times of oviposition were within the standard error of the observed times of oviposition under 21‐, 24‐ and 28‐h photoschedules.
6. It was concluded that this hypothesis for the control of the ovulatory cycle of the hen is consistent with current knowledge. 相似文献
2. Dry plucking increased weight loss due to plucking and eviscerating, and reduced chilled carcass yield.
3. Dry eviscerating increased carcass water uptake during chilling.
4. Pre‐chilling with running water increased carcass water uptake compared with chilling in ice and water alone.
5. Water uptake during chilling appeared to be increased by longer eviscerating time. 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. 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