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 total of 280 laying hens from 14 free-range mountain farms (4 organic, 10 conventional) were randomly collected at the end of the laying period. Faecal samples were taken to analyse faecal egg counts (FEC) and faecal oocyst counts (FOC). The gastrointestinal tracts were removed post mortem and examined for the presence of helminths.

3. In faeces, FEC values averaged 258 eggs per g of faeces, which were dominated by Ascaridia galli and Heterakis gallinarum. Mean FOC was 80 oocysts/g. In the gastrointestinal tract, at least one nematode species was found in 99.3% of the examined hens. H. gallinarum was the most prevalent nematode (95.7%), followed by Capillaria spp. (66.8%) and A. galli (63.6%). Thirty per cent of the chickens were infected with cestodes (tapeworms). Correlation coefficients between worm counts of H. gallinarum, Capillaria spp. and A. galli ranged from 0.41 to 0.51.

5. The helminth prevalence did not differ between conventional and organic farms, whereas total worm burden was higher in organic compared with conventional farms (318.9 vs. 112.0). Prevalence and infection intensity did not differ between farms that used anthelmintic treatments and those that did not.

6. In conclusion, free-range laying hens under the studied mountain farming conditions are at high risk of nematode infection, especially in organic systems. The vast majority of hens are subclinical infected with at least one helminth species.  相似文献   

2. Half the hens had undergone beak trimming at 18 weeks, but in many cases regrowth had occurred.

3. Plumage damage and loss was significantly reduced in beak‐trimmed birds compared with birds with normal beaks. Tier and cage design had no effect.

4. This finding supports the idea that feather pecking is the important factor in causing plumage damage, rather than abrasion.

5. A comparison between 64 birds in which beak regrowth had occurred, and 64 in which it remained truncated, showed that both groups had similar plumage scores.

6. It appears to be the beak‐trimming procedure which is important; subsequent regrowth being irrelevant.  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. Storage of uneviscerated Wrolstad turkeys at 4 °C for 10 days caused no statistically significant changes in meat flavour or texture.

3. During further storage at —2 °C, however, there was a slight but significant change in flavour, which became more marked with time in birds which had been eviscerated after the initial period at 4 °C.

4. Both eviscerated and uneviscerated birds became slightly tougher during storage.

5. Initial holding at 4 °C increased the numbers of psychrotrophic bacteria on the skin by about 10³ but subsequent changes at — 2 °C were slight for uneviscerated birds.

6. Eviscerated carcases had higher counts than uneviscerated birds after storage at — 2 °C and, although ‘off’ odours were not detected, spoilage appeared to be imminent at the end of the 20‐d period.  相似文献   

2. In each group of birds the concentration of plasma GH was inversely related to age. The mean prolactin concentration was highest in the youngest (20‐d‐old) birds.

3. The concentration of plasma GH in the intermittently‐fed birds deprived of food for 24 h (depleted birds) was significantly higher than that in the controls at 33, 56 and 83 d of age. The mean GH concentration in the intermittently‐fed birds 24 h after refeeding (repleted birds) was less than that in the depleted ones.

4. The overall mean concentration of plasma prolactin in the depleted birds was significantly less than that in the control and repleted birds.

5. These results are consistent with the effects of fasting on GH and prolactin secretion and demonstrate that growth retardation in the intermittently‐fed birds was not due to impaired GH secretion.  相似文献   

2. No differences were detected between the gains in weight of the control and experimental groups of birds.

3. A marked negative linear relationship was observed between the dry weight of the amount of caecal tissue removed when the birds were 22 d old and the weight of the left caecum at the end of the experiment.

4. The average growth rate of the left caecum (g dry tissue/week) was found to be dependent on the estimated weight of caecal tissue remaining after surgery.

5. No evidence was obtained to indicate that the growth of the right caecum responded to the removal of the left caecal tissue.

6. The morphology and histology of the operated caeca were found to be similar to the equivalent regions of the unoperated caeca. Surgical interference was not followed by any major changes in mucosal architecture.

7. In birds which had experienced unilateral caecectomy, the discharge of caecal faeces usually stopped for about 2 d. When caecal defaecation was resumed, the pattern of defaecation appeared to be the same as that observed in sham‐operated birds with both caeca intact.  相似文献   

2. Quails were divided into High-FE and low-FE groups and maintained in a comfortable or heat stress (HS) (38°C for 24 h) environment to evaluate changes in insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), adenine nucleotide translocator (ANT), uncoupling protein (UCP) and cytochrome oxidase subunit III (COX III) messenger ribonucleic acid (mRNA) expression in liver and muscle tissues.

3. High-FE quails (0.28 g/g) presented a higher final body weight, greater weight gain and a better feed conversion ratio than low-FE birds (0.18 g/g). High-FE birds showed greater IGF-I mRNA expression in the liver and muscle and greater GHR mRNA expression in the muscle.

4. Environmental effects only affected GHR expression in the liver, with quails under comfortable conditions exhibiting greater GHR expression than quails subjected to HS.

5. There was a significant interaction between FE and environmental temperature on ANT mRNA expression in the liver. The greatest ANT mRNA expression was observed for high FE-birds that remained under comfortable conditions.

6. In the liver, UCP mRNA expression did not differ among the quails and was not affected by environment or efficiency. However, comparisons of the low- and high-FE birds revealed higher levels of UCP mRNA in the muscle of low-FE birds.

7. COX III mRNA expression in the liver was dependent on environmental temperature and FE. Higher COX III mRNA expression was observed in animals that remained under comfortable conditions, and high-FE birds exhibited higher expression levels compared to low-FE birds.

8. These results suggest a correlation between IGF-I, GHR, ANT, UCP and COX III gene expression and FE and that environmental temperature could affect the expression of some of these genes.  相似文献   

2. Salmonellae were not isolated from the empty, cleaned and fumigated houses and only on one occasion from the foodstuffs.

3. Salmonellae were isolated from the environment of the chicks and spasmodically from the litter, water troughs and dust.

4. The incidence of infection of the chicks did not influence the number of isolations of salmonellae from the environment of the birds during rearing.

5. Water in the water troughs rather than foodstuffs appeared to be the major oral route of infection or re‐infection of birds during rearing.  相似文献   

2. Food passage in the crop was significantly reduced by intraperitoneal (IP) injection of LPS while it did not affect the number of defecations, suggesting that LPS may affect food passage only in the upper digestive tract.

3. Similar to LPS, prostaglandin E2 (PGE2), one of the mediators of LPS, also reduced crop-emptying rate in chickens while it had no effect on the number of defecations.

4. Pretreatment with indomethacin, which is an inhibitor of cyclooxygenase (COX), a prostaglandin synthase, had no effect on LPS-induced inhibition of crop emptying.

5. IP injection of LPS did not affect the mRNA expression of COX2 in the upper digestive tract of chickens.

6. It is therefore likely that LPS and PGE2 reduced food passage rate in the crop by a prostaglandin-independent pathway in chickens.  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. A 4 × 4 × 4 factorial design (batch × device × bird type + age) was employed. Ten bird cadavers per bird type and age were tested with each of the 4 devices (N = 160 birds). All cadavers were examined post-mortem to establish the anatomical damage caused.

3. NMCD, MARM and MZIN demonstrated killing potential, as well as consistency in their anatomical effects. NMCD had the highest killing potential, with 100% of birds sustaining the required physical trauma to have caused rapid death.

4. The MPLI was inconsistent, and only performed optimally for 27.5% of birds. Severe crushing injury was seen in >50% of MPLI birds, suggesting that birds would die of asphyxia rather than cerebral ischaemia, a major welfare concern. As a result, the MPLI are not recommended as a humane on-farm killing device for chickens.

5. This experiment provides important data on the killing potential of untried novel percussive and mechanical cervical dislocation methods, informing future studies.  相似文献   

2. A total of 160 Hy-Line Brown layers (45 weeks old) were randomly assigned into 4 treatments on the basis of laying performance. Each treatment had 4 replicates with 10 birds each.

3. Dietary treatments were basal diet supplemented with 0 (control), 2.5, 5.0 and 7.5 g/kg diet G. procumbens during 56-d feeding period.

4. Serum (d 21, 42 and 56) and egg yolk (d 28, 42 and 56) cholesterol and triglycerides concentrations were linearly reduced with increasing dietary concentrations of G. procumbens.

5. Increasing dietary concentrations of G. procumbens linearly reduced the excreta total anaerobic bacteria (d 28), Clostridium sp. and Escherichia coli (d 28 and 56) populations.

6. Overall egg production and egg mass were linearly increased, and overall feed efficiency was linearly improved with increase in dietary G. procumbens.

7. Dietary increasing concentrations of G. procumbens linearly improved egg yolk colour (d 28 and 56) and breaking strength of eggs (d 56).

8. The results obtained in the present experiment indicate that dietary supplementation with G. procumbens could reduce the egg yolk cholesterol, suppresses harmful excreta microflora and improves layers performance.  相似文献   

2. By 2004, however, residues of the side-chain metabolite, 3-amino-2-oxazolidinone (AOZ) of furazolidone, were detected in chicken meat produced in Northern Ireland.

3. With the random spread of positive results across farms of a single integrated organisation, including organically reared flocks, it seemed unlikely that the source of residues was due to illegal use of the drug, but more likely caused by a source of contamination.

4. Potential sources investigated were as follows: furazolidone contamination of feedstuffs, a “hot spot” of furazolidone in poultry houses, contamination occurring within breeding stocks and transferred with the birds to broiler growing houses, and furazolidone contamination of the water supply.

5. Furazolidone contamination was associated with birds reared in houses more than 10 years old.

6. Contamination was traced to the water supply of poultry houses, where un-dissolved furazolidone, legally administered prior to 1997, had settled to the bottom of water storage tanks. It remained un-disturbed until 2004 when the integrator changed the procedure for cleaning water tanks between crops of birds.

7. The use of Proxitane, a hydrogen peroxide disinfectant, caused effervescence within the tank such that small quantities of furazolidone were dissolved, delivered to birds via drinkers and subsequently caused residues in the broiler meat.

8. The environmental impact of the contamination was investigated by testing soil and grass from land adjacent to an organic poultry house to which birds had access.

9. Mechanisms of contamination and how residues may be spread throughout a large integrated poultry system are not restricted to furazolidone. Incidents of contamination are even more likely when using licensed drugs where the drugs may be present on-farm in large quantities.  相似文献   

2. Increments of 25 g grass meal/kg and 7.3 g maize oil/kg replaced a mixture of soyabean, wheat and barley meals in the control diet.

3. Gain: food ratio (y) of the birds decreased linearly as dietary grass meal content (x) increased such that y = 0.4295 ? 0.0032x.

4. Carcass analyses indicated that the decrease in gain : food ratio was caused by less deposition of body fat.

5. Skin colour became significantly yellower as the dietary grass meal content increased.  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. 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. When changed to feeding ad libitum the restricted birds gained weight rapidly, but stabilised at a mean body weight 500 to 700 g less than that of controls fed ad libitum. Egg production was similar to that of controls.

3. Birds maintained at low mean body weight (2 224 g at 42 weeks) by continued restriction did not come into lay. In groups maintained at somewhat higher mean body weights (2 300 to 2 700 g) for periods of up to a year, some birds came into lay.

4. Birds fed ad libitum showed accelerated development of comb, ovary and oviduct and weighed 2 300 to 2 700 g between 14 and 15 weeks of age, but did not come into lay until 20.5 weeks of age.

5. These results suggest that a minimum body weight and age may be required for the onset of lay in this strain.  相似文献   

2. The open-reading frame of goose Pax7 is composed of 1509 bp, which encodes a protein of 503 amino acids and shares high homology with Pax7 of other birds.

3. Ten single-nucleotide polymorphisms were identified in the genomic DNA sequence, 8 located in the intron region and two located in the exon region.

4. Association analysis showed the C122T locus was significantly associated with the body weight of Zhedong-White geese in week 4, 6, 8, 10 and 12.

5. It was concluded that the goose Pax7 gene may be an important candidate gene for goose growth traits and marker-assisted selection.  相似文献