Effects of cage shape,colony size,floor area and cannibalism preventatives on laying performance

1. Wire cages of variable width and depth, with a floor slope of 1 : 12, were used in two experiments to study the effects of cage depth, feeding space (= cage width), floor area, colony size and two methods of controlling cannibalism in White Leghorn x Australorp laying hens.

2. The least floor area (0.035 m²/bird) depressed production in two‐bird cages. Floor area had little effect on the performance of larger colonies.

3. Birds in colonies of three, four or six laid and survived equally well when feeding space/bird and floor area/bird were constant.

4. Production per hen d and food intake were higher, but return on estimated capital outlay was lower, with 102 mm than with 76 mm feeding space/bird when colony size and floor area/bird were constant.

5. Production and food intake of birds which were not treated to prevent cannibalism declined, and mortality increased, as cage depth increased from 385 to 915 mm concomitantly with increasing colony size from 2 to 7 birds and decreasing feeding space from 152 to 43 mm/bird.

6. Increasing cage depth did not increase the proportion of cracked eggs.

7. Mortality was higher among birds fitted with plastic spectacles than among debeaked birds.     

Traits influencing the hatching performance of Japanese quail eggs

1. Japanese quail eggs from moderately heavier sires showed superior fertility; while fertile eggs from moderately heavier dams hatched slightly better than the eggs from lighter dams.

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.     

Battery cage shape: Its effect on diurnal feeding pattern,egg shell cracking and feather pecking

1. Battery cages 460 mm in depth (deep) were compared with 305 mm cages (shallow); the two shapes provided equal areas per bird.

2. More eggs were produced per hen housed from 30 to 70 weeks in the shallow cages; the difference approached significance.

3. The pattern of feeding activity over the day was significantly more U‐shaped in the shallow cages; this pattern accords more closely with physiological requirements.

4. Feather damage caused by pecking was slightly but significantly more severe in the deep cages at 70 weeks.

5. The proportion of cracked eggs (collected from 60 to 70 weeks) was significantly lower in the shallow cages.

6. The arrangement of the hens was such that within the shallow cages a higher proportion of birds was present in the front half.

7. It is suggested that some of the advantages conferred by the shallow cage may be related to the greater accessibility of the food trough.     

Effect of cuticle removal on the water vapour conductance of egg shells of several species of domestic bird

1. The effect of egg shell cuticle removal, using a 14.7 mM solution of sodium hypochlorite, on the water vapour conductance of egg shells was studied in 5 species of domestic bird.

2. The water vapour conductance of fowl and Muscovy duck egg shells was not affected by the treatment.

3. Cuticle removal increased the conductance of turkey and goose shells, particularly those already relatively porous to water vapour.

4. Removal of cuticles from domestic duck egg shells increased water vapour conductance. In this case the effect was most marked for eggs with lower initial conductances.

5. The differing patterns of resistance to water vapour loss associated with egg shell cuticle are related to the ultrastructure of the cuticle itself, especially the number and size of cuticular fissures.

6. The results suggest that egg shell cuticle is a component in a series of resistances associated with the egg shell and that the use of Fick's Law is insufficient to explain water vapour diffusion across the shell.

7. Embryo survival may be improved by cuticle removal, though this may be limited to those species in which the cuticle restricts water vapour loss in initially low conductance egg shells.     

Caegal growth in the domestic fowl following surgical manipulation

1. Some effects of removing increasing proportions of the left caecum on the remaining caecal tissue and on the right caecum were studied in young chicks during a period of 35 d. The chicks were 22 d old when the operations were carried out.

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.     

Vibration on poultry transporters

1. This research established the magnitudes and frequencies of vibration acceleration on two typical broiler bird transporters, one with leaf and the other with air suspension.

2. Vibration measurements were made using triaxial accelerometers mounted on the chassis and in the bird containers, with vehicles both loaded and unloaded.

3. In the vertical axis the fundamental vehicle frequency is between 1 and 2 Hz with a secondary peak at 10 Hz.

4. In the lateral axis with air suspension, the maximum level of vibration on the chassis occurred at 12 to 18 Hz; this was less evident with leaf suspension.

5. The magnitudes of vibration acceleration occurring in the bird containers would be fairly uncomfortable for the seated human. Frequency weightings and response to different axes and magnitudes of vibration must be established before the response of birds can be predicted.     

Economic effects of increased vitamin E supplementation of broiler diets on commercial broiler production

1. The economic effects of increased vitamin E supplementation in 168 commercial broiler flocks incorporating over 3 million birds was assessed using a computerised data retrieval system.

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.     

Influence of stocking density and layer age on production traits and egg quality in Japanese quail

1. Japanese quail hens were housed from 6 to 26 weeks of age in cages providing areas of 150, 180, 210 and 240 cm²/bird.

2. Body weight gain, age at 50% egg production, mortality, hen‐day egg production and food conversion values showed significant improvement with proportionate increase in cage space per layer.

3. Egg weight gradually increased with age but shell thickness was influenced neither by age of the hen nor by stocking density.

4. Yolk index and colour were superior in the lowest stocking density (more cage space) group; other egg quality traits and egg weight were not influenced by stocking density.

5. The albumen index, internal quality unit, yolk index and yolk colour values increased with age.     

Effects of food intake regulation on the energy metabolism of laying hens

1. The effects of dietary energy restriction on the energy metabolism of post‐peak‐of‐lay hens of two hybrid layer strains were studied by indirect calorimetry.

2. Starving and resting rates of heat production (SHP and RHP) were measured, over 1‐d periods, at intervals during a 25‐week period in which the experimental birds were individually restricted to 80% of their previous energy intake ad libitum.

3. In both strains mean RHP per bird was about 7% lower in the restricted birds than in controls fed ad libitum, but when RHP was expressed in terms of metabolic body size (kg^0.75) the two groups did not differ.

4. Mean SHP per bird was about 18% lower in the restricted birds of both strains than in the corresponding controls; the decrease in SHP per kg^0.75 was 12%.

5. Heat increment of feeding and calculated maintenance energy were higher, and net availability of metabolisable energy for maintenance and production was lower, in the restricted than in the control groups.

6. Gross efficiencies of egg production, in terms of both mass and energy, increased in the restricted birds.

7. Live‐weight and total carcass energy after 25 weeks of restriction were respectively about 15% and 30% lower in the restricted groups of both strains than in the groups fed ad libitum.     

Metabolic and anatomical adaptations of light‐bodied chicks to intermittent feeding

1. Chicks of a light‐bodied strain were deprived of food on alternate days from 15 to 46 d of age.

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.     

Factors affecting hatchability during commercial incubation of Ostrich (Struthio camelus) eggs

1. A batch of 320 ostrich eggs from 9 different farms in Zimbabwe were incubated in a single stage operation and the fate of each was recorded.

2. Hatchability was only 37.2% and the result of high rates of infertility and contamination (22.2% and 22.8% respectively); it varied between eggs from different farms.

3. Embryonic mortality was high at the start and end of incubation, a pattern similar to that of other domestic birds.

4. Mortality of late stage embryos was related to percentage water loss and mass specific water vapour conductance of the shell, with extremes of the ranges causing the highest mortality.

5. Microbial contamination of the eggs was a significant problem and varied in eggs from different farms indicating that more attention is needed in both breeder bird and nest management.     

Influence of Plasma Lipid Composition on Activity of Factors V,VII and X in Single Comb White Leghorn and Fatty Liver Haemorrhagic Syndrome-Susceptible Laying Hens

1.?Plasma lipids were investigated to determine whether they influence the biological activities of specific coagulation proteins Factors V, VII and X.

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.     

Photoperiod and seasonal influences on the growth of turkey hens

1. The influence of photoperiod and time of year on the growth of hen turkeys was investigated.

2. Photoperiod treatments consisted of computer simulations of day lengths which occur naturally in the spring and autumn of the year. Both photoperiod treatments were given to hens in the autumn and spring.

3. Data were collected for growth evaluations at 2‐ to 4‐week intervals to 16 weeks of age. No significant season × photoperiod interactions occurred.

4. The spring trial resulted in greater body weights and better food conversions (food/gain) than the autumn trial.

5. Simulated autumn daylengths resulted in greater body weights and improved food efficiency at 16 weeks of age compared with simulated spring daylengths.

6. The pattern of growth (period changes) was influenced by season, but not photoperiod.

7. Season and photoperiod both have important and independent influences on the growth of the turkey hen.     

Model of current pathways in electrical water bath stunners used for poultry

1. The paper explains the use and method of operation of electrical water bath stunners, and explains the possible current pathways through a single bird and through a number of birds.

2. A mathematical model has been formulated to demonstrate the effects of bird resistance and physical attitude of the bird on the current received by individual birds in a water bath stunner.

3. The model shows that readings from ammeters installed in series with commercial stunners, or the values shown on voltmeters, are not an accurate indicator or a guarantee that individual birds are effectively stunned.

4. The model demonstrates the need for a stunner to supply a constant current to each bird, rather than operate at a constant voltage where the current which the bird receives is dependant upon its own resistance.     

Comparison of the productive perform. Ances of the Sinai Bedouin fowl,the white leghorn and their crossbreds: Study under laboratory conditions

1. A comparison of the productive performances of the Sinai Bedouin fowl (from the Sinai desert), the commercial White Leghorn and their reciprocal crossbreds was made under uniform normal conditions.

2. The Sinai produced significantly fewer, smaller eggs, resulting in lower egg mass output (g/bird d), than the Leghorn and the crossbreds.

3. Egg weight of both crossbreds was intermediate between Sinai and Leghorn but laying rate was closer to that of the Leghorn.

4. Differences in egg mass output apparent at 8 to 10 months of age decreased considerably with age.

5. These findings suggest that selection or crossbreeding of the Sinai might improve productive performance while maintaining improved eggshell quality.     

Effects of short intermittent lighting on food consumption and performance of dwarf broiler breeders and progeny

1. Two hundred and sixty four dwarf broiler breeder hens were subjected to ad libitum or restricted feeding and to four lighting patterns: 15L (bright light):9D (dark), 15L:9d (dim light), 2L:10d: 1L:11d, (0.5L:3.5d) × 6.

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.     

Inheritance of body weight and rate of gain in Japanese quail

1. The effects of hatch date, location and sex on the body weight and rate of gain in Coturnix coturnix japonica were examined.

2. The data conformed to a mixed model and adjustments were made for the fixed effects sex, hatch date and location. Adjustment improved the precision of the estimates by reducing the error variances significantly.

3. Rearing equal numbers of birds from each family at different locations made the interactions negligible.

4. Weight gain was greater if illumination intensity up to 35 d was less.

5. Females were not heavier on the 1st day but were heavier on the 14th and 35th days than males.

6. Variance components and genetic parameters were estimated.     

High‐fibre sunflower meal as a replacement for soyabean meal in layer diets

1. Dietary fibre content of a layer diet was increased by substituting a high‐fibre sunflower meal for soyabean meal.

2. Gizzard weight and intestine length were significantly increased by increased dietary fibre.

3. Efficiency of food conversion decreased but egg production, egg weight, shell breaking strength and mortality were not affected by dietary sunflower meal.     

Digestibility studies in broiler chickens: Influence of genotype,age, sex and method of determination

1. The influences of genotype, age and sex on droppings digestibility coefficients of a compound food were studied using male and female broiler chickens of three different genotypes at 2, 4 and 6 weeks of age.

2. Because the traditional method of determination of droppings digestibility coefficients of nitrogen may lead to systematic errors in estimating the feeding value of foodstuffs, a method is proposed to determine the ileal digestibility coefficients. The ileal method is compared with the droppings method for a mixed food and for two foodstuffs: wheat and solvent‐extracted soyabean meal.

3. Birds selected for efficient food conversion showed distinctly higher digestibility coefficients for all nutrients than birds selected for high growth potential or birds from a commercial strain.

4. The influence of age on digestibility coefficients was not consistent.

5. Female birds showed digestibility coefficients which were, in general, 3% higher than those of male chickens.

6. Interactions between genotype and sex and between genotype and age for energy metabolisability were the only interactions observed for digestibility measurements.

7. The method of determination influenced the amino acid digestibility coefficients of the mixed food and the relative feeding values of wheat and soyabean meal.

8. It is important to use well defined animals (genotype, sex, age) in evaluating foodstuffs.

9. The preferred method for determination of digestibility coefficients of nitrogen and amino acids is based on ileal sampling, although the differences in amino acid digestibility coefficients were small between methods.     

Comparative analysis of pre‐laying behaviour in battery cages and in three alternative systems

1. Pre‐laying behaviour was compared in battery cages (C) and in three alternative husbandry systems: perchery (P), deep‐litter (DL) and covered strawyard (S).

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.