Biomedical subjects
Publications and source records attributed to M Perek.
Artificial insemination and natural mating were used for the crossbreeding of the Muscovy drake with the Pekin duck in order to produce the Mule duck. An average fertility rate of 48% was reached by artificially inseminating twice a week. In small flocks, however, when the male to female ratio was 1:2.5 (or higher), natural mating yielded a fertility rate of 80%.
An improved method for obtaining semen from the Muscovy drake using an "artificial vagina" was developed and employed on a commercial scale. With such a procedure, the ejaculate volume was 1.12 +/- .85 ml, semen concentration was 1.35 +/- .43 X 10(9) cells/ml with 8.6 +/- 6.3% abnormal sperm cells. Average spermatozoal motility was graded as 3.59 +/- .93 on a scale of 0 to 5 and the initial pH was found to be 7.30 +/- .23 within 5 min of ejaculation.
The effect of clomiphene-citrate (CC) on broody turkey hens was examined in three experiments. Turkey hens were categorized as broody if found in the laying nest during 6 successive checks per day, if they were reluctant to leave the nest for a period of 24 hr or more, if they had ruffled feathers, and if their cloacal orifices were contracted so as to prevent vaginal exposure by abdominal massage during artificial insemination. In each experiment, 20 hens, selected as broody from commercial breeding flocks, were treated; half were treated with CC at a dosage of 6 mg/kg body weight/day (per os) for 5 consecutive days, and the rest (control) received parallel treatment with a placebo (CaCO3). In all experiments, the CC administration alleviated brooding behavior and increased egg production.
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The effect of 24 and 48 hours of food and water deprivation on ascorbic acid, liver, leukocyte counts and internal lymphoid organ weights of crossbred chicks was examined. Starvation caused an increase in plasma ascorbic acid level, a significant decrease in leucocyte count in peripheral blood, significant loss in body weight and a profound loss in liver, bursa of fabricius, spleen and thymus weights. Deprived chicks were I.V. injected with Escherichia coli dead bacteria and sheep red blood cells at different times before and after onset of deprivation. Blood samples were taken 3, 6, and 12 days thereafter. A lower antibody titer was found on the 6th day post vaccination in the groups where deprivation started on the day before or on the day of vaccination.
Four spaced injections of Newcastle disease virus were given to laying fowls. A state of hyperimmunity was reached at the 42nd day and was maintained up to the 91st day when haemagglutination inhibition antibody titre started to fall. Haemagglutination inhibition antibody produced by the hen could be detected both in egg yolks and chicks although to a lower titre than in the serum of the hen. Fuctuation of antibody transmitted by the individual hens was observed.
Intracranial injections of 6-OHDA were used to destroy the following brain areas of male geese: bilateral VMH-mamillary (BL-VMH), unilateral VMH (UL-VMH), septal area, and bilateral hypothalamic areas located dorsal, lateral, caudal and rostral to the VMH. The brain damage was nonspecific, destroying cell bodies as well as axons. The effects of these lesions were determined on food intake, body weight, abdominal adipose tissue, liver weight and fat content, and on selected endocrine gland weights. The highest food intake, obesity and liver weight and its fat content were exhibited by the BL-VMH lesioned geese. The UL-VMH and the septal lesioned geese showed moderate increase in food intake, which eventually decreased in the UL-VMH but remained constant in the septal lesioned ones. The liver fat content of the latter groups of geese was higher than the controls. No differences were found between the controls and the group of geese lesioned in the various hypothalamic areas - excluding the VMH - in all parameters measured. While no significant differences were found in pituitary, thyroid and adrenal weights among all groups of geese, a decrease in testes weight was noted in the lesioned groups of geese as compared to the controls. The interrelationships between body weight, food intake, adiposity and liver weight are discussed.
Cocks were exposed to 1 or 2 h at 24 degrees C; blood samples were taken before and immediately after treatment and for a period of 20 h thereafter. 2. Heat caused a significant decrease in leucocyte counts, an increase in corticosterone concentration in plasma and an increase of ascorbic acid in plasma and in leucocytes. 3. These four measures can be used to indicate a stress response and the measurements can be done without harming the animal.
The response of awake and anesthesized cocks with sodium pentobarbital to stressful stimuli has been examined. The stressful stimuli was immersion in cold water. In the awake cocks plasma corticosterone concentration was increased about 4 fold; they started shivering shortly after immersion and recovered after cessation of the treatment. In the anesthesized ones there was no increase in plasma corticosterone concentration, they did not shiver and died shortly after immersion.
Various dosages of monosodium glutamate (M.S.G.) were injected to 5 day old male chicks. Body weights, food intake, rate of obesity, semen production, some endocrine criteria and brain pathology were studied til 235 days post injection. All M.S.G. treated birds showed brain damage in the rotundus nuclei, and in the area located dorsolaterally to the ventromedial hypothalamic nuclei (V.M.H.). In some of the M.S.G. treated birds, additional brain regions were damaged, i.e. V.M.H., mammillary nuclei, dorsomedial anterior nuclei, ovoid nuclei, subrotundus nuclei, archistriatum and lateral forebrain bundles. Some of the M.S.G. treated birds showed marked abdominal fat deposition or low spermatozoan motility. It was impossible to attribute these changes to the dosage of M.S.G. injected. No significant differences were found in these parameters between the treated birds and the saline injected ones. When the M.S.G. treated birds were categorized on the basis of brain damage in specific sites, the following was observed: 1) Birds with V.M.H. damage accumulated significant larger amounts of fat in the abdominal adipose tissue than the rest of the M.S.G. treated birds. 2) Those M.S.G. treated birds, showing brain damage in their mammillary nuclei, produced semen of a very low spermatozoan motility rate as compared to the rest of the M.S.G. treated birds and the controls.
The response of intact and bursectomized chicks to stressful stimuli has been examined. The stressors imposed were: a. fast-acting ACTH adminstration; b. immersion in cold water; c. starvation. In Bursa-intact chicks the results were as follows: 1. Plasma corticosterone was increased by all stimuli. 2. Adrenal corticosterone was decreased by ACTH treatment while it was increased by immersion in cold water and by starvation. 3. Plasma glucose was increased by ACTH administration and cold water immersion and decreased by starvation of the birds. 4. Adrenal ascorbic acid concentration was not influenced by all stimuli. 5. Adrenal weights were found to be increased by ACTH and starvation treatments only. 6. Bursa weights were increased by ACTH administration. 7. A very low concentration of corticosterone was found in the Bursa of Fabricius. Bursectomized chicks differed from the intact ones in the following: 1. Plasma and adrenal corticosterone concentrations were not increased by starvation. 2. Plasma glucose increased moderately with ACTH administration. 3. Adrenal ascorbic acid was depleted by all stimuli but was not related to the corticosterone level in the adrenals and blood plasma.
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