Triploidy and intersexuality in adult commercial layers.

The cause of masculinisation of the left ovary and the outgrowth of the vestigial right gonad was investigated in intersexual hens. Tumour-like cell masses, resembling mouse tubular adenomas of the ovary, were observed in the majority of masculinised left gonads. Except for one male and two intersexuals, testosterone concentrations were below detectable levels.

Non-infective factors in the aetiology of synovitis in chickens.

A study was conducted to elucidate the relative susceptibility of broiler breed birds to synovitis and the relative resistance of laying breed birds to this disease. It was shown that difference in structure and chemical composition of fibrous connective tissue can be associated with this difference in susceptibility. A loose structure of fibrous connective tissue (common in broiler breed birds) appears to predispose to synovitis, whereas a compact structure (common in laying breed birds) can be associated with resistance to synovitis.

A case of Aujeszky's disease virus infection in young chicks.

On a rearing farm with 96,000 birds, 10,000 three and four days old chicks died with nervous symptoms. A virus was isolated from the brains and identified as an Aujeszky's disease virus. The isolate was very pathogenic for chickens up to about 7 days of age, causing mortality after parenteral injection (intracerebral, intraperitoneal, intramuscular) but not after oral, eye drop or spray application.

Contribution to the aetiology of synovitis in chickens, with special reference to non-infective factors. V. Extractability of glucosaminoglycans/mucoproteins from tendon tissue.

A comparative study was undertaken regarding the extractability of glucosaminoglycans and mucoproteins in the tendon tissue of birds highly susceptible to synovitis, viz.broiler breed cocks (BB cocks), and of birds highly resistant to synovitis. viz.

Contribution to the aetiology of synovitis in chickens, with special reference to non-infective factors. IV.

The comparative study reported in the present paper was undertaken to collect data on the collagen content and collagen quality of tendons showing high (low) tensile strength levels and a compact (loose) histological structure. It was shown that tendon tissues of these two groups do not differ in this regard. The effect of administering a number of mutrients (known to be essential in collagenesis) was tested during this study.

Contribution to the aetiology of synovitis in chickens, with special reference to non-infective factors. IV.

Summary The comparative study reported in the present paper was undertaken to collect data on the collagen content and collagen quality of tendons showing high (low) tensile strength levels and a compact (loose) histological structure. It was shown that tendon tissues of these two groups do not differ in this regard. The effect of administering a number of nutrients (known to be essential in collagenesis) was tested during this study.

Infectious proventriculitis causing runting in broilers.

Proventriculitis, runting and poor feed conversion sometimes associated with rachitis, was seen in chickens on a large broiler farm. It was shown that the proventriculitis was caused by an infectious agent.

Contribution to the aetiology of synovitis in chickens, with special reference to non-infective factor. III.

A comparative histological study of the tendon tissues of laying-breed hens and broiler-breed cocks was undertaken. This study was a continuation of a previous study which showed that the tendons of laying-breed hens are relatively more resistant to mechanical stress than are those of broiler-breed cocks. The study was particularly concerned with the following types of tendon tissue: tendon of the gastrocnemius muscle, tendon of the flexor muscle of the third digit, hypotarsal sesamoid (HS).

Contribution to the aetiology of synovitis in chickens. With special reference to non-infective factors. II.

The main purpose of the studies reported in the present paper was to test the theory that the tendon tissues of birds predisposed to synovitis, will show qualitative and (or) quantitative deficiencies. The tensile strength (TS) (maximum stress in kg/sq.mm.

Contribution to the etiology of synovitis in chickens, with special reference to non-infective factors.

A study of the literature showed that a large number of micro-organisms have been designated as causative agents of synovitis. These micro-organisms cause almost identical clinical pictures. Particular birds are also found to be markedly prediposed to synovitis (broiler breed cocks), whereas the disease only occurs sporadically in other birds (hens of light-weight laying breeds).