2. In experiment 1 with hens caged individually, treatment groups comprised relocated hens given 5 new neighbours and hens not relocated but given 0, 2 or 4 new neighbours.
3. In experiment 2 with hens housed two per cage, treatment groups comprised relocation with or without that hen which shared the cage before the move.
4. In both experiments relocated hens laid fewer eggs in the week following social reorganisation.
5. Relocated hens in experiment 1 ate less food in the week following the shift at 42 weeks of age than did hens not moved. In experiment 2 in which all hens were moved, food consumption was not affected. 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
2. Food intake was high just after ovulation, decreased during the first 16 h of egg formation, rose transiently 20 to 22 h after ovulation and was minimal just before oviposition.
3. Oyster shell intake was characterised by three peaks, two coincided with those of food diet but the third, occurring between 8 and 12 h after previous oviposition, could be related to the immediate calcium need of shell formation.
4. Water intake followed a similar pattern to food intake but there was an independent rise during albumen plumping (6 to 8 h after previous oviposition). 相似文献
2. An Individual Poultry Weighing System (IPWS) was developed to record time, duration, location and body weight of visits of individual hens to 4 weighing scales.
3. The number of hens that visited the weighing scales per 3 h period varied from less than 10 during the dark‐period to more than 60 during the light‐period.
4. The average number of visits per individual hen was 1–4 and the average number of successful weighings per hen was 0–6 during the light‐period.
5. Body weight showed a diurnal rhythm: the difference between the maximum body weight at night and the minimum body weight in the morning was 63 g.
6. The location of the scales influenced number of visits, number of weighings, mean body weight, flock‐uniformity and duration of visits.
7. Body weight per 3 h period did not differ between hens which were individually recognised and those which were not.
8. Flock‐uniformity was 2–6% higher during the light‐period if it was based on weighings of identified hen visits.
9. The average duration of the visits to the scales in the middle of the feeding tier during the light‐period was 63 s.
10. Of all the hens that visited the scales during a 24 h period, 54% visited them only once.
11. Automatic weighing systems without individual hen recognition can deliver reliable management information on mean body weight and flock‐uniformity in aviary systems if the weighing scales are located on the feeding tier in the middle of the house and if they are used during the light‐period. 相似文献
2. The “ overconsumption “ in dw hens was greater than in the Dw hens.
3. Food intake and shell thickness were correlated, the relationship being particularly close in dw hens.
4. There was a consistent and positive correlation between food intake and weight of egg laid on the same day in both Dw and dw hens. 相似文献
2. Four of the birds maintained a circadian rhythm, in two the rhythm was 24 h while in the other two it was slightly in excess of 24 h.
3. In all birds, feeding activity was less in the 12 h before oviposition than in the 12 h after.
4. When only the first egg of a clutch was considered, it was found that a low level of feeding activity was associated with the release of luteinising hormone (32 h before oviposition), there was then a sharp increase at ovulation to a new level which was maintained from about 23 to 18 h before oviposition and then a decline in feeding occurred until a few hours before laying.
5. There was variation in the amount of feeding activity shown in the few hours before oviposition. 相似文献
2. The rate of lay in both strains was lower in the older hens. The 82‐week‐old hens were subdivided into good and poor layers: the poor layers produced eggs at about half the rate of the good layers.
3. The yellow‐yolky ovarian follicles in both strains were smaller, more numerous and more closely ranked in hierarchies in 26‐week‐old hens than in 82‐week‐old hens.
4. No marked differences were seen between the strains at 26 or 82 weeks of age in the sizes, numbers or hierarchical arrangements of yellow‐yolky ovarian follicles.
5. The ovaries from 82‐week‐old good and poor layers from both strains contained similar numbers of yellow‐yolky follicles.
6. After feeding a fat‐soluble dye, the number of days over which eggs containing dye were laid did not differ between 26‐, 52‐ and 113‐week‐old hens from an egg laying strain. However, fewer eggs with dyed yolks were laid by the older hens.
7. These observations suggest that the decrease in egg production with age is due initially to a reduction in the rate of recruitment of yellow‐yolky follicles. Towards the end of the laying year it may also be due to an increased incidence of follicular atresia, internal ovulation and the production of membraneous or soft shelled eggs. 相似文献
2. Hens identified as broody and removed from the flock had higher plasma prolactin concentrations than the laying hens at each of the three experimental stages.
3. Confinement in sand and wire floored pens, induced a decline in plasma prolactin concentrations. This decline probably impeded immediate development of broody behaviour. Alternately, levels of prolactin higher than those of laying hens were again measured 7 and 14 days after treatment during third week but not after the 10 th and 16th week of production.
4. Confinement did not induce consistent changes in luteinising hormone (LH) and progesterone concentrations from one period to an other.
5. An increase in the plasma concentration of D‐(/?)‐hydroxybutyrate was observed in the hens which had an egg present in the oviduct on day 2, 3 and/or 4 of the treatment. Subsequently, a decrease in ovulation rate was observed in the hens with higher concentrations of D‐(β)‐hydroxybutyrate while under treatment, during the 10th week of production.
6. These data confirm that the effectiveness of the traditional methods for broodiness prevention under commercial conditions is related to the induction of a decrease of prolactin. 相似文献
2. Treatments did not affect egg numbers, food consumption, conversion efficiency of food to egg, bodyweight gain or mortality.
3. Increasing dietary calcium (Ca) significantly increased plasma Ca and inorganic phosphorus (P), breaking strength at the radius and egg specific gravity and significantly decreased plasma alkaline phosphatase and egg weight.
4. Increasing dietary phosphorus increased plasma P and decreased egg specific gravity significantly.
5. Plasma Ca, P and alkaline phosphatase and radius breaking strength were suitable indices of the Ca status of the hens. 相似文献
2. Hens of the population with the high incidence of whitening appeared to be more fearful than hens of the population with the low incidence of whitening.
3. Brown colouration of the egg shell and the incidence and degree of shell whitening declined as the hens aged.
4. Brown colouration and egg shell whitening were most pronounced on the blunt ends of the eggs.
5. A large part of the variation in egg shell whitening was attributable to the individual (hen) component of variance.
6. Differences in egg shell whitening, between the two populations, were detectable throughout the 26 weeks of the experiment.
7. Oviposition intervals were similar for normal and coated eggs when birds were not exposed to disturbance.
8. Disturbance of hens increased oviposition intervals and the incidence and degree of shell whitening, to a similar extent, in both populations.
9. It is concluded that stress‐related egg retention is not the sole factor responsible for abnormal egg shell whitening. Shell whitening may occur as a consequence of the premature termination of shell pigmentation as well as a consequence of the retardation of oviposition which occurs when hens are disturbed. 相似文献
2. Diet B, as mash, showed a lower apparent physical density than the others. The hardness and durability of the pelleted diets were similar.
3. Hens fed the mash diet B could not completely adjust their food intake to compensate for the dilution and showed reduced egg output and body weight gain compared to the other groups.
4. Video observation of each hen for 14 consecutive hours showed that mash‐fed hens ate for longer periods than pellet‐fed hens during the first 11 h (proportion of time spent eating: 41.3% mash B, 32.5% mash A and 20% to 25% for all the pelleted diets). These differences were less pronounced during the last 3 h of the photoperiod.
5. Trough‐oriented stereotypies were noted in 14 out of 22 mash‐fed hens and in 12 out of 47 pellet‐fed hens. Dilution of the diet did not appear to exacerbate stereotyped behaviours under the conditions of the study.
6. This experiment demonstrates that the feeding behaviour of laying hens is affected by the physical characteristics of the diet and that this may lower their productivity.
7. Low‐energy pelleted diets might be used to feed hens efficiently in tropical countries where cereal by‐products are abundant. 相似文献
2. Following an injection of 0.5 or (H mg progesterone/kg between 6 and 15 h after ovulation, oviposition of the resulting egg was generally delayed by between 15 and 28 h and occurred at the same time of day as the next ovulation, which was delayed as in the first experimental situation. Subsequent ovulations were resynchronised and followed at intervals according to the normal sequence established before the injection.
3. Injection of 0.5, 0.1 or 0.05 mg progesterone/kg between 12 and 9 h before an expected ovulation advanced the oviposition of the egg already in the uterus (shell gland) by about 3 h. The succeeding ovulation was either advanced or blocked.
4. These observations suggest that the pre‐ovulatory surge of progesterone is directly or indirectly involved in the timing of oviposition and ovulation. 相似文献
2. Twenty ISA Brown hens were observed in each system for 60 min before oviposition and 5 min afterwards.
3. There were significant between‐system differences in a number of behavioural elements associated with the nest. Most varied along the sequence: C, P, DL, S, but the differences between the three alternative systems were generally less than between them and C.
4. The main factor governing the expression of pre‐laying behaviour appeared to be the availability, the number and the arrangement of littered nests.
5. Behaviour elements preceding nest entry and which were associated with area per bird again varied along the sequence C, P, DL and S with the major discontinuity between P and DL.
6. In P and C the searching phase was extended, in C at the expense of sitting. In P much time was spent inspecting the nests and many nest entries were made.
7. The Gakel call appeared to be related to finding a suitable nest site. In P the number of calls and the mean duration per nest inspection declined in a parallel fashion towards oviposition. In C, where no suitable nest could be found, Gakel calling remained high during the whole observation period.
8. These behavioural differences suggested that pre‐laying behaviour was poorly expressed in C and most fully in S, but that expression was in general relatively complete in all three alternative systems.
9. The ability of hens to express pre‐laying behaviour fully and coherently may be relevant to their welfare. 相似文献
2. In a period of sexual quiescence on short photoperiods (6L : 18D) LH concentrations were higher during the hours of darkness in both sexes.
3. Transfer to long photoperiods (16L : 8D) stimulated a rapid increase in LH and FSH concentrations. This was maintained for between 2 to 3 months when the concentrations of both gonadotrophins decreased as the birds became photorefractory.
4. Return to short photoperiods had no immediate effect on the concentrations of LH and FSH in females. The concentration of LH was increased during the 3rd week of short photoperiods when the hens were moulting.
5. LH concentrations fluctuated during the ovulatory cycle and were highest about 6 h before ovulation. 相似文献
2. After magnal insemination, the fertility of eggs collected during the first week was 36.2% and only 3.6% during the second week.
3. In the case of intramagnal insemination, egg fertility in the first week was 88.1%, in the second week 81.8% and the third week 52.3%.
4. The eggs laid during the first day after intramagnal insemination were 83.3% fertile, indicating that treated spermatozoa fertilised the newly ovulated egg within 20 minutes of ovulation. 相似文献
2. Battery caged hens had the poorest bones, as assessed by measurements of cancellous bone volume, radiographic density, cortical thickness and three‐point breaking strength.
3. Humeri from birds in the Litter and Wire system were less dense radiographically and weaker than those from Perchery or Naturel birds but leg bone characteristics were similar with these three systems.
4. There were no differences in bone characteristics between birds in Perchery and Naturel systems.
5. There were strong correlations between radiographic densities and strengths of contralateral humeri and tibiae over all husbandry systems. Humerus structural and strength characteristics may be the best criteria of osteoporosis in hens.
6. It is concluded that the extent of movement allowed by different husbandry systems affects structural bone loss and bone strength in laying hens.
7. It is further concluded that the breaking strength of a hen's bone is closely related to morphometric measures and radiographic density of its structural components. 相似文献
2. In hens receiving a normal diet containing a calcium supplement in a powdery form Pi increased from 25 to 42 mg/1 during an entire shell formation cycle (from 10 to 22 h after oviposition of the previous egg), while in cockerels Pi decreased slightly during the night.
3. This increase in Pi in hens, was not related to cessation of feeding at the onset of darkness but was specifically connected with the beginning of shell secretion.
4. When hens received calcium as crushed sea‐shells separately from the diet, the nocturnal peak in Pi virtually disappeared and only a temporary increase of 4 mg/1 between 10 and 14 h after oviposition remained.
5. These results indicate that the beginning of shell secretion is always accompanied by an increase in Pi and that a separate presentation of dietary calcium reduces the bone mobilisation at night. 相似文献
2. Shell formation began 9–5 to 11 h after the oviposition of the previous egg, increased linearly for 13 h and then plateaued at 1–5 h before oviposition.
3. The variation in egg shell quality observed in two experimental groups of hens was 75% attributable to differences in the rate of shell deposition and 25% attributable to difference in the duration of shell deposition.
4. The mean interval between ovipositions increased with age but neither shell weight, nor rate or duration of shell depositon were affected. The increase in egg weight with age accounted for the decrease in shell quality.
5. Intervals between ovipositions were positively correlated with the duration of shell formation, especially its latter stages.
6. Egg production was negatively correlated with the interval between ovipositions but not with the duration or rate of shell deposition. There was a negative correlation between duration and rate of shell deposition, except in the case of the hens producing eggs of poor shell quality. 相似文献
2. A 25000 kDa purified recombinant derived turkey prolactin (rtPRL), the biological activity of which was tested using a crop sac assay, was used as immunogen for the production of rabbit antiserum. In this biological test, the rtPRL was as active as the ovinePRL.
3. The radioligand (rtPRL) was labelled with 125I and the assay allowed the detection of standard doses of rtPRL ranging from 400 pg/tube to 50 ng/tube.
4. No cross reaction with chicken luteinising hormone and recombinant chicken growth hormone was detected.
5. The within and between assay coefficients of variability were 5.0 ± 2.7% and 16.3%, respectively. The overall mean recovery ratio was 1.01.
6. The dose‐response curves obtained with serial dilution of plasma and pituitary from turkey hens at different physiological stages and from male turkeys were parallel to those obtained with standard rtPRL.
7. The measured concentration of prolactin was 5 times higher in plasma from incubating than laying turkey hens, and the pituitaries from incubating hens contained 2 and 4 times more prolactin than those of laying and out of lay hens or males, respectively.
8. To further assess the validity of the assay, we measured changes in plasma concentration of prolactin in turkeys following stimulation with chicken vasointestinal peptide (cVIP). A single injection of 1 or 10 μg/kg body weight of cVIP to laying hens produced a large and rapid increase in plasma prolactin.
9. This new radioimmunoassay appears to be highly specific and sensitive for the measurement of turkey prolactin. 相似文献
2.?Factor activities decreased when lipids were depleted from the plasma of Single Comb White Leghorn (SCWL) and Fatty Liver Haemorrhagic Syndrome-susceptible (FLHS) laying hens.
3.?Addition of lipids removed from SCWL laying hens and FLHS-susceptible laying hens into lipid-depleted plasma of both bird strains caused an increase and decrease, respectively, in Factors V and X activities.
4.?Omega-3 fatty acids were negatively correlated to Factors V, VII and X activities. When bird strain was considered, it was significant for Factor X in SCWL laying hens. Omega-6 fatty acids were positively correlated with Factors VII and X for FLHS-susceptible laying hens.
5.?The results suggest that the type of fatty acid in plasma phospholipids influences the activities of Factors V, VII and X and by altering lipid composition in the plasma, activities of coagulation factors may be affected. 相似文献