Red cell size and various lung arterial measurements in different strains of domestic fowl

Red cell size and various lung arterial measurements were examined in different strains of young commercial broiler and layer fowls. The broilers were: Marshall, Cobb, Ross 'selected', Ross 'relaxed' and the layers were: Isa Brown, Ross Brown and Hisex Brown. The Ross relaxed bird had a significantly larger red cell than any other strain. Overall, broilers had larger red cells than layers. The internal elastic lamina, a measure of arterial size, was small in the Ross relaxed bird (138 microns) and was at its maximum (163 microns) in the selected Ross strain. The medial area (muscle coat) was least in the Ross relaxed bird (984 microns2) and greatest in the Cobb strain (1516 microns2). In some strains there was a slight correlation among birds between red cell and arterial size but not with the medial area. The results appeared to indicate that red cell size may not be the only important correlating factor in the aetiology of pulmonary hypertension in fowls.     

The effect of nitrovin on the kinetics of sulphadimidine in domestic fowl of different ages

In experiment on cockerels, the interaction of sulphadimidine with nitrovin manifested itself in an effect on the distribution of sulphadimidine, and particularly on its bloodlevel; this depended, among other factors, on the age of the animals. At nitrovin medication, the bloodlevels of sulphadimidine were higher, mainly soon after administration, and their drop was quicker than in untreated animals. This effect on the levels of sulphadimidine in the blood was pronounced in three-week-old chickens, whereas in older birds it was feeble or absent. Except the higher level 30 min. after application to.five-week-old chickens given feed with 120 g t-1 of nitrovin, the differences were statistically insignificant. The changes in the concentration of sulphonamide in the liver and kidneys corresponded with the changes observed in the blood; the concentration in muscle was not affected by nitrovin under the given conditions. The favourable effect of nitrovin on weight gains, demonstrated in principle during the experiment, was directly dependent upon the concentration of nitrovin in feed. As to the effect of the length of its administratiion, the three-day administration of nitrovin (before weighing) to cockerels up to five weeks of age had a better influence on gains than administration from the sixth day after the medicated of the chickens. In older cockerels the gains were better in the groups treated for a longer time, i. e. from the sixth day from hatching.     

Rupture of gastrocnemius tendon in broiler breeder hens

Lameness and mortality of 0.55% to 1.00% per week occurred in 32-to-33-wk-old broiler breeder hens in a complex involving eight houses. Males were not affected. Laboratory evaluation of 19 birds, over 2 wk, revealed complete rupture or partial tear, primarily of the gastrocnemius tendon; the fibularis longus, fibularis brevis, and flexor muscles and their tendons were injured in a few birds. Rupture of the gastrocnemius tendon has been observed in broiler breeder chickens older than 12 wk of age and it is characterized by lameness secondary to unilateral or bilateral rupture of the tendon. The cause of this condition has been primarily attributed to reovirus infection but rupture by other causes can also occur. In this case, there was no evidence of synovitis or reovirus infection in the birds. The cause of the ruptures was attributed to aggressive males when the ratio of males to females was increased from seven or eight males per 100 females at 22-23 wk to nine or 10 per 100 at 31 wk of age.     

Effects of different lighting regimes on diurnal feeding patterns of the domestic fowl

1. Male hybrid chicks were, from hatching, subjected to either a 12‐h photoperiod with uniform light intensity or a 12‐h photoperiod with a simulated “dawn” and “dusk” or to continuous light.

2. At 10 weeks of age the birds exposed to “dawn” and “dusk” were significantly heavier than those exposed to 12 h uniform illumination and these were heavier than those in continuous light.

3. From 15 to 25 weeks of age the birds in continuous light showed a marked diurnal rhythm in food intake, eating most in the period corresponding to normal daytime, while all birds subjected to 12‐h photo‐periods ate most at the end of the day, apparently having learnt to anticipate when their day would end.

4. When the birds subjected to continuous light were given one of the two 12‐h photoperiods, those given 12 h of uniform light intensity started by eating most food in the mornings, but later ate more towards the end of the day, while those with the “dawn” and “dusk”, ate more food at the end of the day during most of the 20‐d experimental period.

5. It is concluded that the birds preferred to eat most at the end of the day, probably to ensure adequate stores of food in the crop during the night. However, it was necessary for them to learn when their day would end, and this they did much sooner with the presence of a “dusk” than without it.

6. It is suggested that the difference in growth rate among the three treatments can be accounted for by differences in the efficiency of food conversion and also by differences in food intake.     

Lighting and mortality rates in domestic fowl

1. Data from intermittent and conventional lighting trials were analysed to investigate the effect of daily illumination upon mortality during the laying period and in 49‐d‐old broilers.

2. Iiveability in laying hens was improved by the use of intermittent lighting: the degree of improvement was proportional to the reduction in daily illumination achieved by the intermittent programme.

3. The reduction in mortality with intermittent lighting in laying hens was not the result of intermittent lighting per se. Intermittent regimens which did not reduce daily illumination did not reduce mortality.

4. Mortality in both conventionally‐lit laying hens and 49‐d old‐broiler chickens increased with photoperiod.     

Variability in respiratory function of the domestic fowl

Several respiratory parameters were measured in five groups of hens to estimate the variation in respiratory function of the general hen population. A non-invasive technique was used to measure respiratory flow, with computer-aided analysis of the data, and the results were examined statistically. Using different groups of hens, additional information was obtained regarding possible sources of variation between individual hens, such as egg laying condition, age and health. Significant differences between individuals within the groups were observed, but there were also changes in breath-to-breath variation for individual hens. While some changes in the variation between birds were observed from one group to another, variation within individual birds made interpretation of the results difficult. Repeated measurements made on one group revealed significant changes in minute volume with time, but the changes were not related to learning. Significant interactions between hens and time of measurement occurred for certain parameters, showing that the individuals' responses changed with time in different ways. The groups of hens were compared to observe whether they represented the same or distinct populations, and were found to overlap to varying extents for different respiratory parameters. Single respiratory variables and weighted combinations of certain variables were also used to separate the groupings, as a possible diagnostic method for partitioning groups of hens.     

Capillariasis in the domestic fowl in New Zealand

Abstract

Extract

With the increase in more intensive methods of poultry production in recent years, worms of the genus Capillaria Zeder 1800 (hairworms) have become an important factor contributing to disease in chickens and turkeys. Apart from causing death, they are also responsible for lower growth rates, decreased egg production, and decreased fertility of the flock (Platt and Schwabe, 1958 Platt, C. S. and Schwabe, O. 1958. A notation on the egg production and mortality of pullets free of capillary worms. Poultry Sci., 37: 727–727.  [Google Scholar]; Geevaerts, 1962 Geevaerts, J. 1962. Bestrying van capillariose bij driven en kippern door methyridine. Vlaam. Diergeneesk. Tijschr., 31: 105–113.  [Google Scholar]; Norton and Joyner, 1965 Norton, C. C. and Joyner, L. P. 1965. Experimental chemotherapy of infection with Capillaria obsignata. J. comp. Path., 75: 137–145. [Crossref] , [Google Scholar]; Wakelin, 1965 Wakelin, D. 1965. A survey of the intestinal helminthes parasitic in the British domestic fowl. J. Helminth., 112: 191–200.  [Google Scholar]), Unfortunately, these parasites have been relatively neglected in research and survey work. Far more interest has been devoted to the more obvious nematode parasites of poultry, such as Ascaridia galli and Heterakis gallinarum. This can, in part, be explained by the facts that Capillaria spp. are difficult to work with, they are not easily detectable and infections are difficult to establish under experimental conditions.     

The growth of abdominal adipose tissue in various production-type of domestic fowl

At hatching, the abdominal fatty tissue is less developed than the subcutaneous fatty tissue. However, it grows more intensively during the post-incubation period through both the hyperplasia and hypertrophy of the fat cells. In the cocks, hyperplasia reaches its peak at the age of 9 weeks, followed by a decrease; then hyperplasia continues until the age of 25 weeks. In the hens the peak of hyperplasia comes later, at the age of 14 weeks; then it decreases until the age of 25 weeks is reached. Hyperplasia and hypertrophy are more pronounced in the early period and are somewhat higher in the cocks. During the period of sexual maturation both processes are more intensive in the hens; owing to them, the total weight of the abdominal fatty tissue of hens increases both absolutely and relatively in comparison with the cocks. The cellularity of the first population of adipocytes is assumed to culminate at the age of three to five weeks. Then follows the cellularity of the second population which persists throughout sexual maturation. The pictures of hyperplasia and hypertrophy are qualitatively the same in different production types of fowl, but the size is twice as large in the broiler type than in the laying type of fowl.     

The localisation of beta-N-acetyl-glucosaminidase in the oviduct of the domestic fowl.

1. Beta-N-acetylglucosaminidase [EC 3.2.1.30] activity in the oviduct of the domestic fowl has been studied using biochemical and histochemical methods. 2. The principal source of the enzyme was the isthmus, where the enzyme was localised within the less dense region of the dual density granules which characterise this portion of the oviduct.     

Diseases of the domestic fowl in Northern New Zealand

Abstract

Extract

Information about diseases in domestic fowls in New Zealand is contained in two books (Anon., 1965 Anon. Specimens for Laboratory Examination N.Z. Department of Agriculture 1965  [Google Scholar]; Anon., 1971 Anon. Diseases of Domestic Animals in New Zealand , 3rd ed. Editorial Services Wellington 1971  [Google Scholar]). The following diseases have been the subject of separate reports: Salmonella newington infection (Flannery, 1954 Bridges, C. H. and Flowers, A. I. 1958. “Iridocyclitis and cataracts associated with an encephalomyelitis in chickens”. In Diseases of Poultry, 4th ed, Edited by: Biester, H. E. and Schwarte, L. H. Ames, Iowa: Iowa State Univ. Press. In [Google Scholar]); lead poisoning (Salisbury et al, 1958 Salisbury, R. M., Staples, E. L. J. and Sutton, M. 1958. Lead poisoning in chickens. N.Z. vet. J., 6: 2–7. [Taylor &; Francis Online] , [Google Scholar]); Ornithonyssus sylviarum infestation (Thomas and Watson, 1958 Thomas, P. L. and Watson, H. H. 1958. The occurrence in New Zealand of the northern poultry mite, Ornithonyssus sylvarium (Canestrini and Fanzago, 1877). N.Z. vet. J., 6: 47–50. [Taylor &; Francis Online] , [Google Scholar]); infectious laryngotracheitis (Webster, 1959 Webster, R. G. 1959. Studies on infectious larvnsntracheitis in New Zealand. N.Z. vet. J., 7: 67–71. [Taylor &; Francis Online] , [Google Scholar]); mycoplasmosis (Pohl, 1966 Pohl, R. M. 1966. Mycoplasmosis in poultry. N.Z. vet. J., 14: 151–151. [Taylor &; Francis Online] , [Google Scholar]); infectious bronchitis (Pohl, 1967 Pohl, R. M. 1967. Infectious bronchitis in chickens. N.Z. vet. J., 75: 151–151.  [Google Scholar]); uraemia (Pohl, 1968 Pohl, R. M. 1968. Uraemia (infectious nephritis) in chickens in New Zealand. N.Z. vet. J., 16: 188–188. [Taylor &; Francis Online] , [Google Scholar]); coccidiosis (Pohl, 1969 Pohl, R. M. 1969. Coccidiosis of the fowl in New Zealand. N.Z. vet. J., 17: 249–250. [Taylor &; Francis Online] , [Google Scholar]); vibriosis (Pohl, et al, 1969 Pohl, R. M., Marshall, R. M. and Pearson, R. 1969. Vibriosis in chickens in New Zealand. N.Z. vet. J., 17: 51–52. [Taylor &; Francis Online] , [Google Scholar]) and capillariasis (Rickard and Pohl, 1969 Rickard, M. D. and Pohl, R. 1969. Capillariasis of the domestic fowl in New Zealand. N.Z. vet. J., 17: 130–136. [Taylor &; Francis Online] , [Google Scholar]).     

Follicular development in ovarian transplants in the domestic fowl

When the ovary was transplanted from the normal site to one near the posterior kidney on the body wall of a young bird, the ovary developed to maturity and appeared to be almost normal. However, using coloured dyes which were taken up by the yolks as bands of colour, it was established that the follicular development and ovarian organisation were upset, possibly due to the lack of a normal innervation of the ovary.     

The effect of an injection of corticotrophin on plasma concentrations of corticosterone,growth hormone and prolactin in two strains of domestic fowl

1. Three‐week‐old Light Sussex (LS) and Rhode Island Red (RIR) chicks were injected with long‐acting corticotrophin (ACTH: 30 IU/kg) and the plasma concentrations of corticosterone, growth hormone (GH) and prolactin were determined over a 6‐h period. Plasma concentrations of corticosterone and growth hormone were also measured after an injection of corticosterone (500 μg/kg).

2. The resting plasma concentration of corticosterone in LS was less than that in RIR birds. The increase elicited by ACTH was smaller in LS but, since it was maintained for longer, the plasma corticosterone response was at least 18% larger than that in RIR birds.

3. Plasma GH concentration was decreased after an injection of ACTH in both strains but the decrease lasted longer in the LS chicks.

4. Plasma prolactin concentration was unaffected by ACTH.

5. After intra‐abdominal injection of corticosterone, plasma GH concentration was depressed in both strains. It is concluded that ACTH‐induced depression of plasma GH and growth is mediated by corticosterone.     

Gordon memorial lecture. The biologists' debt to the domestic fowl

Although it is highly desirable to reduce the need for experiments with animals, in vitro methods cannot entirely supplant them. Observations made in simple systems must be checked in a live subject if they are to be relevant to man or other higher animals. Young growing chicks are very susceptible to vitamin deficiencies. Biological assays in chicks have been used to check the validity of chemical and microbiological methods of measuring vitamins in foods. Experiments with chicks and chick embryos deprived of vitamin B12 have served to predict the likely clinical effects of analogues of the vitamin. The discovery of the growth-promoting properties of dietary antibiotics stimulated research into the influence of the gut microflora on its host. Studies in germ-free and gnotobiotic chicks have implicated Streptococcus faecium as one of the organisms responsible for the growth depression reversed by antibiotics. In general the growth of conventional chicks given adequate diets is slightly less good than that of their germ-free counterparts, although small beneficial effects of the microflora have been observed in special circumstances. The most important function of the indigenous microflora appears to be as a barrier against invasion by pathogens. To sustain this protective barrier may incur a small cost to the host in terms of dietary energy and other nutrients.     

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.