A comparison of the osmotic pressures along the digestive tract of the domestic fowl and the rabbit

1. The osmotic pressures of the contents of the alimentary tract from the adult hen and cockerel and rabbit were measured.

2. In the rabbit osmolality of the fluids from the different segments of the digestive tract was similar (331 ± 12 mOsm) and slightly hypertonic to blood plasma (297 ± 0.12 mOsm).

3. In the hen osmotic pressures were: crop 537, gizzard 312, duodenum 571, proximal jejunum 650, distal jejunum 573, proximal ileum 514 and distal ileum 451 mOsm. Only osmolality of the crop contents was influenced by egg formation.

4. In the cockerel osmotic pressure in the alimentary tract followed the same pattern as the hen and was modified by the time of day.

5. Plasma osmolality in the fowl was about 320 mOsm. Absorption of water across the proximal jejunum is achieved therefore against a gradient of about 330 mOsm in the female and 420 mOsm in the male fowl.     

Genetic studies on primary antibody response to sheep erythrocytes in guinea fowl

1. The primary antibody response to sheep erythrocytes was determined by haemagglutination test in guinea fowl. The effects of various genetic and non‐genetic factors on immune response to sheep RBCs in guinea fowl were also estimated.

2. The immune response to sheep RBCs was normally distributed in guinea fowl with mean titre at 1.534 ± 0.014.

3. In guinea fowl, effects on titre values of sire and variety (feather colour) were significant whereas sex and sex × variety interaction effects were non‐significant.

4. The estimate of heritability for immune response to sheep RBCs in guinea fowl was 0.35 ±0.17.     

Effect of acute heat exposure on triglyceride transfer to the preovulatory follicles of the laying fowl (Gallus Domesticus)

1. The effect of acute heat exposure on triglyceride (TG) transfer to preovulatory follicles was studied in the laying fowl.

2. Heat exposure of laying fowl resulted in a 1.1°C rise in body temperature, a 10‐fold increase in respiration frequency and mild hypocapnia and hypoxaemia.

3. Plasma and follicular tissue TG concentrations were not significandy affected by heat exposure, but plasma TG specific radioactivity decreased significantly and was negatively correlated with body temperature.

4. The transfer rate of TG to the preovulatory follicles was not affected significantly by hyperthermia.

5. We conclude that nutrient supply to the developing follicles is not compromised in acutely heat‐exposed laying fowl.     

Responses of the reproductive vascular system during the egg‐formation cycle of unanaesthetised laying hens

1. Vascular adjustments to the process of egg formation were examined in the unanaesthetised laying hen, by the radioactive microspheres method.

2. Three‐ to four‐fold increases in blood flow were found in segments surrounding the egg during its passage along the oviduct, possibly due to an enhanced metabolic activity in the muscle layer of the oviduct.

3. Shell‐gland blood flow was minimal in the absence of an egg and increased gradually to a maximum (5‐fold) about 5 h after entrance of the egg into the shell gland. This parallels the rate of calcification of the egg shell.

4. Changes in blood flow in the ovarian follicles and other parts of the oviduct were small while the egg was in the shell gland. This might be typical for the reproductive system of the fowl, which undergoes little structural alteration during egg formation.     

Explanted embryo culture: In vitro and in ovo techniques for domestic fowl

1. Embryos of the domestic fowl (72 h old) have been explanted into shell‐less cultures or ‘surrogate’ eggshells, in order to investigate the possibility of rearing these embryos to hatching.

2. Rocking embryo cultures during the first half of incubation enhanced embryo growth.

3. Embryos explanted into ‘surrogate’ eggshells of either other individuals or other species have been successfully ‘hatched’.

4. A normal chorioallantois is formed in these surrogate eggshells. This enables a functional albumen sac to form and eggshell resorption to be achieved.

5. Embryos grown in ‘surrogate’ eggshells are slightly smaller than controls but otherwise normal.

6. The technique provides opportunities for genetic engineering experiments.     

Effects of anticoagulants and storage (4°C) on packed cell volume (PCV) of Nigerian domestic fowl (Gallus domesticus) and guinea fowl (Numida meleagris)

1. Studies were conducted to determine the effects of anticoagulants and storage (4°C) on the PCV of blood samples from Nigerian domestic fowl (DF) and the guinea fowl (GF).

2. Citrate significantly reduced pre‐storage PCV of the DF in comparison with the effect of ethylenediamine tetra‐acetic acid (EDTA).

3. It further decreased (P<0.05) the PCV of the blood of DF and GF over 3 d of storage; this was similar to the effect of EDTA on the PCV of the GF blood.

4. Citrate and oxalates induced haemolysis of blood of the DF and the GF in storage faster than EDTA, but overall the haemolysis was more pronounced from red cells of the GF than from those of the DF.

5. The mean fall in the PCV of the DF was significant at 3.0 mg EDTA/ml of blood in contrast to the fall in the PCV of the GF blood.     

Blood flow distribution during graded treadmill exercise in domestic cockerels

1. White Leghorn cockerels were exercised continuously for 45 minutes on a treadmill at work loads equivalent to 2.1 and 2.7 times pre‐exercise metabolic rates, the latter being close to the performance limits of the experimental birds.

2. Relative blood flow to the abdominal viscera and selected leg muscles was estimated using ¹¹³Sn‐, ¹⁵³Gd‐ and ⁴⁶Sc‐labelled microspheres, injected into the root of the aorta.

3. There was no significant shift of blood flow away from the viscera towards the leg muscles at either work load. However, relative colonic and duodenal blood flow fell significantly at both work loads and relative pancreatic blood flow doubled at the higher work load.

4. It is concluded that, as previously reported in female domestic fowl performing physical exercise close to their performance limits, male fowl are largely refractory to shifts in blood flow away from the viscera to the working muscles. Nevertheless, there is evidence of blood flow shifts between visceral organs, probably related to the intermediary metabolism of fuel substrates.     

Identification of antibodies against hydropericardium syndrome in wild birds

1. Domestic fowl and free-living birds were examined for the presence or absence of antibodies against hydropericardium syndrome (HPS) using an indirect haemagglutination assay.

2. Two-hundred and eighty serum samples of commercial (45 broilers, 20 adult layers and 15 Fayoumi fowl) and wild birds, including 65 peafowl, 45 pigeons, 10 crows, 30 house sparrows, 10 doves, 15 ducks, 10 parrots and 15 guinea fowl, were collected and examined.

3. The percentage of HPS-positive serum samples was 80% in house crows, 78% in pigeons, 7% in house sparrows and 6% in peafowl.

4. The sera obtained from parrots, doves, ducks and guinea fowl were all negative.

5. This study suggests that crows and pigeons could be carriers of the HPS agent.     

Exencephaly in chicken‐pheasant hybrids

1. The incidence of exencephaly was investigated in chicken‐pheasant hybrids.

2. With the pheasant as sire, fertility was 7.lb6%, but with the fowl it was 19.lb5%; hatchability of fertile eggs, however, was similar, 42% and 41% respectively.

3. Only one exencephalic hybrid was obtained when the sire was the pheasant but 70 were noted when the fowl was sire. The incidence of this malformation in hatched chicks was 12 times more in crosses with the fowl as sire than in the reverse cross.

4. The frequency of exencephaly was greater with Rhode Island Red, Barred Leghorn or White Leghorn roosters than with Columbian Rock roosters.     

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.     

Classification of the neurons in fowl hypothalamic nuclei based on their dendritic patterns

1. Dendroarchitectonic analysis of the hypothalamic nuclei in the fowl was investigated by the Golgi‐Cox, Nissl and silver impregnation techniques.

2. All hypothalamic nuclei appeared to consist of leptodendritic neurons constituting a variety within the isodendritic family. They showed triangular, spindle and round shapes and had a few long, relatively straight, fine dendrites bearing very fine dendritic spines.

3. Neurons in the nucleus preopticus medialis et lateralis showed a bipolar spindle‐shape and had stout, relatively long primary dendrites.

4. Those in the nucleus hypothalamicus rostralis medialis et lateralis were characterised by bipolar, spindle‐shaped and multipolar leptodendritic neurons and by short fine primary dendrites bifurcating to fine longer secondary segments.

5. Neurons in the nucleus hypothalamicus caudalis medialis et lateralis and nucleus hypothalamicus inferior were of the multipolar leptodendritic type and had thick, long, unbranching dendrites emerging directly from the cell body.

6. The fowl hypothalamus is dendroarchitectonically divided into preoptic, rostral and caudal hypothalamic regions; the borderlines separating them are the commissura rostralis and the region between the nucleus hypothalamicus rostralis medialis and nucleus hypothalamicus caudalis medialis, respectively.     

Manipulations of germ‐cell populations in the gonad of the fowl

1. Embryos of the domestic fowl have been partially sterilised by injecting the drug busulphan into 24‐h incubated eggs.

2. Some of these embryos were injected with primordial germ cells (PGCs) after 55 h of incubation to attempt to repopulate the gonads.

3. Primordial germ cells transfected with a defective retrovirus containing the reporter gene lac Z were shown to settle in these sterilised gonads.

4. Quantitative histology of 6‐d embryos showed that busulphan produced 75% sterilisation but that PGCs could repopulate these gonads.

5. The technique of producing such germ line chimaeras is of value in studying cell kinetics, gonad differentiation and the production of transgenics.     

Effect of gradual acclimation to high ambient temperatures on egg‐shell quality of the Sinai Bedouin fowl,the commercial white leghorn and their crossbreds

1. The effect of gradual acclimation to high ambient temperatures on egg‐shell quality was studied in the Sinai fowl, the commercial White Leghorn, and their reciprocal crossbreds.

2. The Leghorn egg was characterised by a thinner and weaker shell compared with the Sinai and the crossbreds, at all the experimental temperatures.

3. In contrast to other reports, high ambient temperatures for a long period had only mild effects on egg‐shell quality.

4. The results suggest that gradual acclimation to high ambient temperatures might improve the efficiency of the physiological mechanisms involved in the hen's response to heat. Consequently, the reproductive process adapts to the hot environmental conditions.

5. The results indicate that the Sinai breed might be used for future selection of a breed, highly resistant to extreme environmental conditions and with an improved shell quality.     

Fat deposition and heat production as responses to surplus dietary energy in fowls given a wide range of metabolisable energy: Protein ratios

1. Female broiler fowl between 21 and 42 d of age were given diets with apparent metabolisable energy (AME) contents ranging from 8 to 15 MJ/kg at each of two crude protein (nitrogen x 6.25; CP) contents (130 and 210 g/kg).

2. Food intake was measured daily for 21 d. Body composition was determined at 42 d and gains in body mass, protein, fat and gross energy calculated by comparison with a group analysed at 21 d. Heat production was calculated by difference between AME intake and energy gain.

3. Decrease of food mass intake with increased dietary AME concentration limited the increase in AME intake to about 25%, despite the near 2‐fold range of AME concentrations.

4. There was no effect of CP concentration on food mass intake. CP intake was directly related to CP: AME ratio.

5. When body weight differences were taken into account, heat production was independent of dietary AME concentration, but increased by about 8% on the higher‐protein diets.

6. There were strong linear correlations between dietary CP:AME ratio and carcase protein: energy ratio, carcase fat content and carcase protein content.

7. It was concluded that the growing fowl responded to dietary nutrient: energy ratio, and the associated differences in nutrient and energy intakes, by varying the rate of energy deposition as fat, without regulatory variation of energy dissipation as heat.     

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.     

Artificial lighting in poultry houses: Are photometric units appropriate for describing illumination intensities?

1. The quality and the quantity of poultry house lighting are important. Many research projects have been centred on temporal aspects of this illumination and on its spectral distribution ('colour') and illumination intensity. For this purpose illumination is measured at floor‐level in photometric units (lux or cd/m²).

2. The relevance of these measurements depends on an equivalence of the domestic fowl and the human photopic spectral sensitivity curves, because the latter (CIE) type of curve is the basis of photometric units.

3. A comparison of the data on domestic fowl spectral sensitivity and the CIE‐data, however, shows a serious discrepancy. For most purposes in poultry research, therefore, the lux‐meter is not an appropriate instrument.

4. A better way of presenting the relative luminance of a lamp for domestic fowl ('galluminance') is by multiplying the spectral power distribution of the lamp (E_λ)—as documented by the manufacturer— by the relative spectral sensitivity distribution of the domestic fowl (G_λ).

5. For this purpose we present the log G_λ data in relative units per 5 nm.     

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.     

The effect of continuous aeration on the fertility of fowl and Turkey semen stored above 0 °C

1. Fowl and turkey spermatozoa were found to utilise oxygen when stored in tubes at 5 and 10 °G respectively; the storage medium becoming rapidly anaerobic.

2. This aerobic metabolism was encouraged by continuous introduction of air into the semen during storage.

3. Fertility of turkey semen stored at 10 °C for 24 h in a diluent containing glucose was increased 24‐fold by simple aeration and reached 99% of that achieved with fresh semen.

4. Fertilities of greater than 90% were also achieved with fowl semen stored aerated for 48 h at 5 °C in a diluent with or without glucose. The increased fertility on aeration was greater (2.2‐fold) with fowl semen stored in the absence of glucose.     

Effect of age and sex on the chemical composition of edible offal and blood from broilers

1. The effects of age and sex on the proximate composition and inorganic constituents in edible offal and whole blood from a commercial British broiler chicken strain were studied.

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.     

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.