In a previous paper (1) we reported the results of a study of the blood chemistry of hens bearing the Rous sarcoma No. 1. In this paper it was shown that there were no changes in the nonprotein nitrogen, uric acid, creatinine, chlorides, cholesterol, serum calcium and inorganic phosphorus, hemoglobin, and bilirubin, of the bloods of sarcoma-bearing hens when compared with the same determination...

The maintenance of bone strength has been an important issue in the debate over cage use for laying hens. Bone strength depends on adequate mechanical load and cages restrict movement. Four laying crosses (Lohmann White, Lohmann Brown, H&N White, and Rhode Island Red × Barred Plymouth Rock cross hens) were housed in conventional cages or in floor pens equipped with perches and nest boxes to mea...

The objective of this study was to determine if thermally cooled perches improve hen immunity during hot summer. White Leghorn pullets at 16 week of age were randomly assigned to 18 cages of 3 banks at 9 hens per cage. Each bank was assigned to 1 of the 3 treatments up to 32 week of age: 1) thermally cooled perches, 2) perches with ambient air, and 3) cages without perches. Hens were exposed to...

Amylin is a member of the calcitonin family of hormones cosecreted with insulin from the pancreatic beta-cells that can act as an osteoblast mitogen and as an inhibitor of bone resorption in mice and humans. The aim of this study was to investigate the role of amylin on bone formation and some egg parameters in hens. The study was performed in 60 hens aged 10 wk. Thirty hens constituting the tr...

The third generation cephalosporin cefovecin has been shown to have an exceptionally long elimination half-life in dogs and cats, making it suitable for antibacterial treatment with a 14-day dosing interval in these species. Pharmacokinetic parameters for cefovecin were investigated in juvenile hens and green iguanas, following subcutaneous injections with 10 mg cefovecin/kg bodyweight. Prelimi...

Aggression and cannibalism in laying hens can differ in intensity and degree due to many factors, including genetics. Previous behavioral analysis of 2 strains of White Leghorns, DeKalb XL (DXL) and HGPS (a group-selected line for high group productivity and survivability), revealed high and low aggressive phenotypes, respectively. However, the exact genetic mechanisms mediating aggressiveness ...

In mammals, triacylglycerol (TAG) accumulation in nonadipose tissue, termed lipotoxicity, develops with obesity and can provoke insulin resistance, overt diabetes, and ovarian dysfunction. Leptin, an adipose tissue hormone, may mediate these effects. Feed-satiated broiler breeder hens manifest lipotoxicity-like symptoms. Changes in body and organ weights, hepatic and plasma TAG, nonesterified f...

Dustbathing is one of the major behavioural systems of domestic fowl that is constrained by commercial caging systems. Although research conducted over the last 20 years has revealed a great deal about causation of dustbathing, attempts at measuring the importance to hens of having access to dustbathing substrate have proven difficult. Various economic techniques, operant conditioning and learn...

A 12-wk experiment was conducted to study the effects of feeding regimen, inclusion of a fiber source, and CP content of the diet on performance of broiler breeder hens. In total, 360 hens and 60 males, 43 wk of age, were assigned to 60 floor pens (6 hens and 1 male each). There were 12 treatments arranged factorially with 2 feeding regimens [restricted (R) and liberal feeding (close to ad libi...

OBJECTIVE To verify the influence of traps with electric light and hens as factors that attract sandflies and compare results between capture methods. METHODS The study was conducted in the Palmital Farm, Southern Brazil. Sandfly collections were conducted with Falcão traps and an electric aspirator, fortnightly, between 8 p.m. and 11 p.m. in the presence or absence of light and hens in perid...