2. Feeding refined or hydrogenated Span oil led to smaller body weights than feeding soybean oil, while refined Zephyr oil and crude Span oil supported a growth response similar to soybean oil.
3. The treatments had significant effects on the total lipid contents of heart (P ≤ 0.05) and spleen (P ≤ 0.001) but not liver.
4. There was no indication of lipid accumulation in the tissues of the chickens fed low erucic acid rapeseed oil as compared with those of the birds fed soybean oil.
5. Only small amounts of erucic acid were incorporated into heart, liver or spleen lipids when rapeseed oil was fed. 相似文献
2. In the first experiment the diets contained 0, 8 (with and without supplementary methionine, lysine, or methionine and lysine) or 16% lupin meal: addition of the lupin meal required a concomitant addition of 5 % rapeseed meal (by computer selection).
3. The diets were fed from 38 to 65 d and did not affect live‐weight but the efficiency of food utilisation was significantly worse on the 16 % lupin, 5% rapeseed meal diet than it was on the control diet.
4. The second experiment was designed as a 2 x 4 factorial to separate any effect due to rapeseed meal from that due to lupin meal, the treatments, which were applied from 1 to 62 d, being 0, 8, 16 and 24% lupin meal with and without 5 % rapeseed meal.
5. Birds gained more rapidly in the second experiment on diets containing 16 or 24% lupin meal whereas live‐weight was depressed when 5% rapeseed meal was included in the diets containing 0 or 8% lupin.
6. The 16 and 24% lupin treatments also had added dietary fat from 6 to 9 weeks of age and this may have ameliorated the adverse effect of rapeseed meal.
7. Up to 16% lupin meal and 5% rapeseed meal had no detectable effect on the colour, appearance, flavour or texture of roasted chicken meat when evaluated by a trained taste panel. 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
The mustard seed meal and rapeseed meals D and E caused large and significant mortalities among laying birds. Macroscopic observations suggested that the main cause of death was probably liver haemorrhage.
Egg production, after correction for mortality, was significantly decreased by rapeseed meals D and E, and egg weight by the mustard seed meal. There were no significant treatment effects on food intake and therefore the weight of food needed for each egg produced followed fairly closely the pattern of egg production.
Overall egg production was depressed by mustard seed meal and by rapeseed meals D and E. Rapeseed meal C decreased production but not significantly.
Liver weights were not influenced by treatment, but thyroid weights of groups given rapeseed meals were significantly increased.
Broiler production was not significantly influenced either by mustard seed meal or by any of the rapeseed meals. 相似文献
2. Plasma VLDL concentrations were consistently higher at all ages in fat line hens but were not affected by dietary treatment.
3. Mature body weight did not differ between the lines in birds fed ad libitum but with food restriction throughout life, fat line birds were lighter at 34 weeks.
4. There was little difference between the lines in abdominal fatness of birds fed ad libitum up to 60 weeks. Fat line birds were always fatter than lean line counterparts under food restriction.
5. Egg production was higher in lean line birds fed ad libitum but food restriction improved egg production in both lines. Peak egg productions were similar in both lines but there was evidence that the optimal food allowances for egg production was higher in the lean compared with the fat line.
6. Ovarian yellow follicle numbers were highest at 34 weeks in ad libitum fed lean line birds and declined linearly with decreasing body weight caused by food restriction but there was no such relationship in fat line birds.
7. White follicle numbers were higher and follicular atresia was lower in the lean line.
8. It is concluded that poor reproduction in fat line birds was associated with inhibition of follicular development and atresia rather than by high plasma VLDL concentrations promoting excessive yolk formation. 相似文献
2. Whole blood viscosity was more than twice as high, and plasma triglyc‐eride and haemoglobin concentrations were over 30% higher in fat line than in lean line females fed ad libitum or in restricted birds of both genotypes.
3. Mean cell haemoglobin concentration was higher and mean cell volume lower in fat compared with lean line females.
4. Food restriction was associated with lower plasma triglyceride concentrations, lower numbers of heterophils and monocytes and a lower heterophil‐lymphocyte ratio.
5. Fat line birds had a higher blood pCO2 and lower pH than lean line birds.
6. Thermal stress was associated in ad libitum‐fed birds with a rise in blood pH and a decrease in pCO2, and in restricted birds with a decline in blood pH and an increase in pCO2.
7. Blood creatine kinase activity increased in all groups under thermal stress. 相似文献
2. Food intake was least when restrictions were started at 3 weeks.
3. Sexual maturity was delayed in proportion to the severity of restriction and resulted in lower percentages of small eggs.
4. Egg numbers decreased as restriction increased.
5. Mortality in restricted groups during rearing and laying was higher.
6. Optimal restriction was apparently intermediate between treatments producing 88 or 76% of ad libitum‐fed body weight. Body weight was so excessively affected by the most severe restriction that total production was adversely affected.
7. Restriction from 3 weeks was more profitable than restriction from 6 or 9 weeks, resulting in lower food cost during rearing and higher total egg production. 相似文献
2. Food‐restricted birds spent a large proportion of time scratching and pecking the litter compared with birds fed ad libitum.
3. The heterophil/lymphocyte ratio and the proportion of basophils were raised at 8, 12 and 16 weeks, and the plasma concentrations of corticos‐terone were higher at 8 and 12 weeks of age in restricted birds compared with those fed ad libitum.
4. Creatine kinase activity was higher in broiler breeders fed ad libitum compared with layers and restricted broiler breeders. The activity of aspartate transaminase was higher in restricted layers compared with birds fed ad libitum and was similar in broiler breeders.
5. Plasma viscosity was lower in food‐restricted compared with ad libitum‐fed birds.
6. Limiting access to water had little or no effect on the welfare indicators although food‐restricted birds with free access to water spent more time drinking than birds fed ad libitum.
7. There were no important differences between the two broiler strains. Layers spent less time resting than broiler breeders and had higher plasma corticosterone concentrations at 3 and 16 weeks of age.
8. It was concluded that there was evidence for physiological stress associated with restricted feeding at least between 8 and 16 weeks of age. It was suggested that the altered behaviour of broiler breeders kept on litter may indicate that they can cope with food restrictions and that this may be acceptable in relation to the long‐term benefits of limiting body weight during rearing. The same may not be true for layers. 相似文献
2. There was little difference between the broiler breeder strains except in body weight at 16 and 18 weeks of age.
3. Food intake relative to body weight was higher in the broiler breeders compared with the layer strain.
3. The degree of restriction was defined as the food intake of re‐stricted birds as a proportion of the estimated intake of birds of the same body weight fed ad libitum. The value declined from 0.60 to 0.45 during the rearing period.
5. In the ad libitum treatments broiler breeders drank more than layers, whereas when restricted, layers drank more than broiler breeders.
6. Water intake was 2.50 times higher in restricted compared with ad libitum‐fed layers and 1.25 times higher in restricted than ad libitum‐fed broiler breeders, with free access to water. 相似文献
2. During the second and third weeks the incidence of tainted eggs exceeded 20% but fell to 11.4% during the final week.
3. Omission of the rapeseed meal from the diets halted the production of tainted eggs.
4. Neither egg production nor the health of the birds was adversely affected by the treatments.
5. The taint was described as “ fishy ” or “ crabby ” and was distinctive, but the source was not identified. 相似文献
2. Approximately half of the flocks were fed on either a high (163 mg/kg) vitamin E or on a normal (44 mg/kg) vitamin E‐containing diet throughout production.
3. Approximately half of the flocks were the progeny of breeder flocks which had been fed on a high vitamin E‐containing diet throughout production.
4. The improvement in target income in the vitamin E‐supplemented broiler flocks was 8–44% (P < 0.01).
5. The residual improvement in target income in these flocks, after the cost of the additional vitamin E was taken into account, was 2.74% and failed to reach statistical significance.
6. The increased net income was achieved by a significantly improved food conversion ratio and average weight per bird (P < 0.05).
7. There was no overall effect of vitamin E supplementation of broiler breeders on subsequent broiler performance. 相似文献
2. Body weight gain, and the efficiency of food conversion were improved when the diet contained 50 g DPM/kg but higher rates of inclusion (100 or 150 g/kg) depressed growth.
3. Birds fed on diets containing 50 g DPM/kg yielded meat of comparable quality to those fed on the control diet whereas those fed on diets containing more DPM yielded meat containing more fat and less water.
4. The percentage moisture in the meat was inversely related to the lipid content.
5. Nitrogen retention was comparable in all groups. 相似文献
2. It was fed at 16 weeks of age to five separate groups (groups 2 to 6) each of 50 to 60 birds.
3. Group 2 was fed on a normal layers’ diet at 23 weeks of age, group 3 at 27 weeks, group 4 at 31 weeks, group 5 at 35 weeks and group 6 at 55 weeks while the control group (group 1) of similar size to groups 2 to 6 was subjected to a normal commercial treatment for laying stock.
4. In all the experimental groups the onset of sexual maturity occurred normally, but only one or two eggs were laid before laying ceased under the influence of the treatment.
5. Laying re‐started when the hens were fed on a normal diet and production rapidly rose to a high level.
6. Groups 1, 2 and 3 differed little in the total number of eggs produced up to 72 weeks of age.
7. In all experimental groups there were fewer very small, small and medium eggs than in the control group.
8. It is suggested that the use of a low‐calcium diet before the onset of lay may have advantages which could be exploited on a commercial scale. 相似文献
2. Severity of response to E. coli challenge as measured by lesion scores, and mortality was greater for chicks fed ad libitum than those fed on alternate days. For chicks fed on alternate days, lesion scores were lower for those without access to feed for the 24‐h period immediately after challenge.
3. Spleen weights, the indicator of response to marble spleen disease virus challenge, were higher for chicks fed ad libitum than those fed on alternate days.
4. Antibody response to sheep red blood cell antigen was not affected by feeding regimen.
5. Ratios of heterophils to lymphocytes were higher for chicks given access to feed for the previous 24‐h period than for those fasted during the previous 24‐h or those that had been fed ad libitum.
6. Results of this experiment suggest that for alternate‐day feeding programs, vaccination be administered on the day that chicks are not fed. 相似文献
2. The rate of increase in deep‐body (rectal) temperature during exposure to 32°C was used as the index of thermoregulatory ability. Comb and foot surface temperatures were measured as indicators of peripheral vasomotor tone.
3. Because body temperature control depends on the balance between heat production and heat loss, heat production was measured to determine whether fat line hens had a higher heat production, which they would then have to dissipate.
4. During the first hour of heat exposure, rectal temperature in the ad libitum‐fed birds increased twice as rapidly as in the corresponding lean line sample and 6 times more rapidly than in the control‐fed fat‐line group.
5. Surface temperatures of comb and foot increased from 27°C to 37°C within the first hour at 32°C, with no effect of either genotype or feeding regimen on rate of increase.
6. Heat production was unrelated to genotype but was reduced by 23% by controlled feeding, largely because of the reduction in body weight.
7. The results demonstrated that ad libitum‐fed fat‐line birds are susceptible to heat stress and that this is related not to increased heat production, but to a decreased ability to lose heat. Elevation of blood viscosity by plasma triglycerides is suggested as a causal factor. 相似文献
2. As a proportion, mortality was 0.5 in turkeys fed ad libitum and 0.1 in those which were restricted. There were significantly fewer leg problems in the birds undergoing food restriction.
3. Sexual maturity was delayed 4 weeks by food restriction although semen quality was similar to that in ad libitum‐fed birds.
4. Individual semen production was lower after food restriction but, because mortality and food consumption were also lower, semen production per male housed and semen production per kg of food eaten were proportionally 0.30 and 0.32 greater in restricted‐compared with ad libitum‐fed turkeys.
5. Useable quantities of good quality semen were obtained from ad libitum‐fed turkeys at 23 weeks of age.
6. A short photoperiod (7L:17D) from 10 to 18 weeks of age in ad libitum‐fed turkeys produced more rapid development of normal semen production compared with turkeys given a longer photoperiod (14L:10D). 相似文献
2. Ligation of the caeca significantly improved nitrogen balance and utilisation by up to more than 2 times as much as those of controls (P< 0.05).
3. The treatment significantly decreased uric acid excretion by 77 mg nitrogen/day (P< 0.01) and also total nitrogen excretion (P<0.05): the former decrease almost explained the latter.
4. No effect of the ligation of caeca on urea and ammonia excretion was observed.
5. It is concluded that nitrogen metabolism in chickens is affected by possible changes in caecal fermentation by preventing entry into the caeca of substances from urine and digesta. 相似文献
2. Birds in conventional deep cages were more active than those in shallow cages in each of four different periods of day. Activity reached a peak between 11.00 and 13.00 h irrespective of cage shape.
3. Mean feeding activity was greater in the shallow (45.6%) than in the conventional deep cages (39.9%).
4. Mean feeding activity was greater in birds fed ad libitum (43.3%) than in those fed on a restricted diet (40.4%).
5. Although restricted birds in shallow cages showed more feeding activity than those in conventional deep cages they consumed less food (56% against 67%) in the 7 h between supply of their daily ration and the onset of the dark period.
6. Feather damage was greater in the conventional deep cages than in the shallow cages.
7. The more efficient utilisation of food by hens in shallow cages is probably due largely to three factors: reduced levels of motor activity and general disturbance, a more leisurely eating pattern and better feather cover. 相似文献
2. Autoclaving rice bran for 3 to 20 min significantly improved its feeding value as measured by growth rate of chicks; bran from parboiled rice was equivalent to the autoclaved rice bran and was not further improved by autoclaving.
3. The growth inhibition of rice bran is not due to its trypsin inhibitor activity.
4. Lipase activity in rice bran was destroyed by autoclaving or parboiling and may be a useful index to predict the adequacy of treatment to improve growth.
5. The metabolisable energy of the rice bran samples was about 12.55 kJ/g and was not influenced by treatment.
6. Ethoxyquin did not improve growth of chicks fed on diets containing rice bran and was less effective than autoclaving or parboiling in preventing the development of rancidity. 相似文献
2. The egg production of birds fed on the unsupplemented triticale diet was significantly higher than that of the birds fed on the unsupplemented maize diet, but was not significantly different from that of the birds fed on the maize plus meat meal diet.
3. Protein quality of the unsupplemented triticale diet as judged by efficiency of nitrogen retention was similar or inferior to that of the unsupplemented maize diet.
4. The higher protein content of triticale and the increased intake of these diets seemed to be responsible for the better performance observed.
5. Addition of groundnut oil to the triticale diet did not improve either egg weight or production.
6. It is concluded that the quantitative substitution for triticale of maize does not adversely affect egg production and egg weight. 相似文献