Effects of dietary corticosterone on peripheral blood lymphocyte and granulocyte populations in immature domestic fowl

Four-week-old chickens were fed on diets containing 0, 5, 10, 20 and 40 mg corticosterone per kg for eight days. Packed cell volume (PCV), the numbers of granulocytes (G) and lymphocytes (L), the G:L ratio and plasma corticosterone concentration were measured. Plasma corticosterone concentration was increased by dietary corticosterone from day 2 onwards. The number of lymphocytes was increased by serial bleeding but dietary corticosterone depressed the response and caused a dose-related lymphocytopenia from day 1. There was a dose related increase in granulocytes from day 4 and a dose-related increase in G:L ratio from day 1. A dose-related increase in PCV was evident only on days 2 and 4. Correlation coefficients showed little evidence of relationships between plasma corticosterone concentrations and the recorded blood variables.     

Use of alpha-naphthyl acetate esterase staining to identify T lymphocytes in cattle

Peripheral blood lymphocytes (PBL), lymph nodes, and/or spleens from clinically normal cattle were examined for cytochemical staining of alpha-naphthyl acetate esterase (ANAE). Two types of positive-staining patterns in ANAE staining resulted. By a combination of ANAE staining and latex-ingesting test, diffuse ANAE-positive cells were considered as mononuclear phagocytic cells. Using erythrocyte rosettes, erythrocyte antibody complement rosettes, nylon-wool column technique, surface immunoglobulin (SIg) staining, and the ANAE staining technique, granular ANAE-positive lymphocytes were shown to be T lymphocytes. The frequency of T and B lymphocytes in PBL, spleens, and lymph nodes of clinically normal cattle was measured, using ANAE staining and SIg staining. In PBL, 47.7% were ANAE-positive and 26.9% were SIg-positive; in spleens, 22.4% were ANAE-positive and 53.7% were SIg-positive; and in lymph nodes, 38.5% were ANAE-positive and 28.3% were SIg-positive. The frequencies of T and B lymphocytes in PBL, spleens, and/or lymph nodes from cattle with enzootic bovine leukosis (EBL) and cattle with persistent lymphocytosis and in tumor cells from cattle with EBL were measured. When compared with those of clinically normal cattle, PBL, spleens, and lymph nodes of cattle with EBL and the PBL of cattle with persistent lymphocytosis contained numerous SIg-positive cells and few ANAE-positive cells. Tumor cells from cattle with EBL contained 7.3% ANAE-positive and 78.0% SIg-positive cells.     

The effect of Escherichia coli endotoxins on the concentrations of corticosterone and growth hormone in the plasma of the domestic fowl

The intravenous injection of chickens aged six to 11 weeks with Escherichia coli endotoxins (serogroups O111 and O78) produced a large increase in the plasma corticosterone concentration which was maximal (five to 10-fold) after 1 h and still evident after 8 h. It did not vary with the dose over the range 0.1 to 2 mg/kg and was smaller than that produced by adrenocorticotrophic hormone (ACTH) (20 iu/kg). A decrease in growth hormone concentration was detected between 1 and 2 h after endotoxin administration in six- to seven-week-old birds, this change being opposite to that which occurs in man.     

The effects of restricted feeding on adrenal cortical activity in the immature domestic fowl

1. The effect of reducing food intake to 75% of the ad libitum intake was determined from hatching to 8 weeks in young Light Sussex chickens.

2. Restricted birds were lighter throughout the experiment.

3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.

4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.

5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.

6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found.     

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.     

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.     

The effects of progesterone on oviposition and ovulation in the domestic fowl (Gallus domesticus)

1. Following an injection of 0.5 or 0.1 mg progesterone/kg between 0 and 6 h after ovulation, oviposition of the resulting egg was delayed by 1 to 11 h and occurred 26 to 31 h after injection, depending on the dose. The injection terminated the laying of a sequence of eggs by causing the next ovulation to occur a day late. The delayed ovulation occurred at the time normally expected for the first ovulation of a sequence and became the first of a new sequence.

2. Following an injection of 0.5 or (H mg progesterone/kg between 6 and 15 h after ovulation, oviposition of the resulting egg was generally delayed by between 15 and 28 h and occurred at the same time of day as the next ovulation, which was delayed as in the first experimental situation. Subsequent ovulations were resynchronised and followed at intervals according to the normal sequence established before the injection.

3. Injection of 0.5, 0.1 or 0.05 mg progesterone/kg between 12 and 9 h before an expected ovulation advanced the oviposition of the egg already in the uterus (shell gland) by about 3 h. The succeeding ovulation was either advanced or blocked.

4. These observations suggest that the pre‐ovulatory surge of progesterone is directly or indirectly involved in the timing of oviposition and ovulation.     

Acceleration of hatching in the domestic fowl

Eggs of the domestic fowl were stimulated from the 19th day of incubation until hatching by artificial clicks at one of two rates which, in the quail, have been found effective (1) in accelerating and (2) in retarding the development and hatching time of the foetus. The time at which each stimulated egg hatched was determined and compared with those of three control eggs kept in the same incubator. All four eggs were kept as far apart from each other as possible. Of the ten eggs given accelerating stimulation all hatched before the mean hatching time of the controls and nine before any of the controls. Of those given retarding stimulation seven hatched after the mean hatching time of the controls but only five after all the controls.

It is concluded that hatching can be advanced in the domestic fowl if the egg is given the appropriate stimulation, but that there is no evidence of the retardation of hatching under the conditions provided.     

Ectopic pulmonary cartilage and bone in domestic fowl

The occurrence and histological appearance of ectopic pulmonary cartilage and bone in domestic fowl was investigated. Its incidence was shown to vary in different strains of birds. The structures may occur in newly hatched chicks and are similarly present in birds maintained on diets containing bonemeal and diets without it. They could not be experimentally induced by bronchial insufflation of fine bone particles. Previous theories of their genesis are discussed and it is concluded that they do not originate from either inhaled dietary bonemeal or disease processes but are probably abnormal embryonic induction of mesenchyme or cartilaginous germ cells displaced from adjacent bronchi.     

Reproductive senescence in domestic fowl: effects on egg production, sequence length and inter-sequence pause length

1. Age-related changes in egg production, oviposition sequence length and inter-sequence pause length were studied by analysis of oviposition records of 50 individually-caged broiler breeders from 24 to 62 weeks of age. 2. The 44 surviving hens exhibited a production profile characteristic of broiler breeders (184 eggs per hen), with a peak mean sequence length of 19 eggs at 32 weeks of age. Inter-sequence pause length was maximum (1.6 d) at 54 weeks of age. Overall, the hens averaged 48 sequences, with a mean sequence length of 4.1 d. 3. Most hens had a single characteristically long sequence about the time of peak egg production (average: 24.3 d). The term 'prime' is suggested to denote this sequence. 4. Sorting the hens into groups on the basis of total egg output (upper and lower 50% and upper and lower 25%) indicated that high producing hens (upper 50% and 25%) had a very long prime sequence early in lay, and had few inter-sequence pauses of greater than 1 d duration. The converse was true for low producers (lower 50% and 25%). 5. The length of the prime sequence may be a good indicator of reproductive efficiency of hens later in life.     

The effects of local irradiation on circulating lymphocytes in dogs receiving fractionated radiotherapy

Localized radiation therapy can be an effective treatment for cancer but is associated with localized and systemic side effects. Several studies have noted changes in complete blood count (CBC) parameters including decreases in the absolute lymphocyte count (ALC) and increases in the neutrophil:lymphocyte ratio (NLR). These changes could reflect immunosuppression and may contribute to decreased efficacy of immunotherapies used to treat cancer. We hypothesized that dogs would demonstrate decreased ALCs during a course of radiotherapy. A retrospective study was conducted on 203 dogs receiving definitive‐intent radiotherapy. Demographic information, CBC values and details of the radiotherapy protocol were collected. The mean lymphocyte count pre‐treatment was 1630.68 cells/μL (SD ± 667.56) with a mean NLR of 3.66 (SD ± 4.53). The mean lymphocyte count mid‐treatment was 1251.07 cells/μL (SD ± 585.96) and the mean NLR was 6.23 (SD ± 4.99). There was a significant decrease in the mean lymphocyte count by 351.41 lymphocytes/μL (SD ± 592.32) between pre‐treatment and mid‐treatment (P < .0001), and a corresponding significant increase in the mean NLR of 0.93 (P = .02). Lymphopenia grade increased in 33.5% of dogs and was significant (P = .03). The ALC decrease was not correlated with the volume irradiated (P = .27), but correlated with the irradiated volume:body weight ratio (P = .03). A subset of patients (n = 35) with additional CBCs available beyond the mid‐treatment time point demonstrated significant and sustained downward trends in the ALC compared with baseline. Although severe lymphopenia was rare, these decreases, especially if sustained, could impact adjuvant therapy for their cancer.     

Incidence of salmonellae in domestic fowl in Slovakia from 1971 to 1980

In flocks with latent infections, 2724 strains of salmonellae (19 serotypes) were isolated from the birds. The following species were represented as follows: S. gallinarum-pullorum (65.08%), S. typhimurium (9.10%), S. bareilly (6.90%), S. enteritidis (2.38%) and S. agona (1.98%). In the foci of salmonelloses 893 strains of salmonellae (19 serotypes) were isolated. The highest representation was found in the S. gallinarum-pullorum (54.20%), S. typhimurium (24.53%), S. bareilly (7.72%), S. choleraesuis (2.29%), S. enteritidis (1.68%), S. infantis (1.54%) and S. anatum (1.23%). Post-mortem examination resulted in recording 15 887 strains of salmonellae (41 serotypes). The following were represented by the largest proportions: S. gallinarum-pullorum (26.62%), S. typhimurium (25.20%), S. bareilly (18.93%), S. infantis (7.20%), S. enteritidis (4.62%), S. agona (3.51%), S. choleraesuis (3.17%), S. anatum (2.19%), S. lille (1.54%) and S. bredeney (1.16%).     

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.