Detecting reproductive system abnormalities of broiler breeder roosters at different ages          下载免费PDF全文

MA Lagares  R Ecco  NRS Martins  LJC Lara  JSR Rocha  DAR Vilela  VM Barbosa  PF Mantovani  JFV Braga  IS Preis  VA Gheller  PC Cardeal  NC Baião 《Reproduction in domestic animals》2017,52(1):67-75

The objective of this study was to detect the reasons of rooster's fertility decrease at 50 weeks of age. Therefore, the reproductive system of broiler breeder roosters was laparoscopic, macroscopic and histopathology evaluated, and a comparison of the anatomical aspect with the sperm analysis and birds’ age was realized. Cobb roosters (n = 59) were distributed into two groups (30 and 50 weeks). Evaluations were performed with laparoscopy, macroscopy and histopathology, and seminal quality, blood serum testosterone concentration and weight were also determined. The old roosters presented smaller testicle size, higher intensity epididymal lithiasis and lower testicle sperm production, compared to the young roosters. The use of the endoscope could easily distinguish a normal‐sized testicle than an atrophic one. Four old roosters with severe testicular atrophy did not show spermatogenesis, although three still had sperm in the ejaculate. This would falsely indicate a wrong diagnosis of normal fertility before the testicular atrophy took place. In conclusion, in addition to the weight increase with age, the testicular atrophy and impairment of sperm production seemed to be the main reason to the decrease in the rooster's fertility at 50 weeks of age. Therefore, the use of the laparoscopy as a way to detect the roosters with testicular atrophy before 50 weeks of age and their removal from them flock could be useful as a diagnostic tool to prevent the birds’ fertility loss.  相似文献   

Lateral spinal decompression in the dog: A review of 39 cases     

A. P. BLACK 《The Journal of small animal practice》1988,29(9):581-588

Lateral spinal decompression was performed in 39 dogs. Twenty-seven (67-5 per cent) showed significant neurological improvement within 72 hours of surgery. All 36 dogs included in the long term follow up walked or were pain free in an average time of two to two-and-a-half weeks.  相似文献   

Exocrine pancreatic adenomas in the greater redhorse, Moxostoma valenciennesi Jordan, and in the European flounder, Platichthys flesus (L.)     

J. W. FOURNIE  J. J. BLACK  A. D. VETHAAK 《Journal of fish diseases》1988,11(5):445-448

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LYMPHOCYTIC CHORIOMENINGITIS INFECTION IN NEONATALLY THYMECTOMIZED MICE BEARING DIFFUSION CHAMBERS CONTAINING THYMUS     

LEVEY RH  TRAININ N  LAW LW  BLACK PH  ROWE WP 《Science (New York, N.Y.)》1963,142(3591):483-485

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The pharmacokinetics and locomotor activity of alfentanil in the horse     

P. J. PASCOE  W. D. BLACK  J. M. CLAXTON  R. E. SANSOM 《Journal of veterinary pharmacology and therapeutics》1991,14(3):317-325

The pharmacokinetics of alfentanil were investigated in the horse. Four doses of alfentanil (4, 10, 20 and 40 micrograms/kg) were given to four horses at different times and their locomotor activity monitored. Doses of 20 and 40 micrograms/kg produced a significant increase in locomotor activity. The plasma concentrations of alfentanil were measured in six standing horses and the pharmacokinetics calculated. It was found that the decay curves were best described by a biexponential equation. The elimination half-life (t1/2 beta) was 21.65 +/- 3.99 min and the clearance (Cl) was 14.1 +/- 0.7 ml/kg/min. The same horses were anaesthetized with xylazine-ketamine and maintained with halothane in oxygen for the first experiment and isoflurane in oxygen for the second experiment. The pharmacokinetics were again calculated from measured plasma alfentanil concentrations. There were significant differences between the kinetics in the conscious and the anaesthetized animals but there were no significant differences in alfentanil kinetics between the two anaesthetic agents. The t1/2 beta for alfentanil under halothane and isoflurane anaesthesia were 55.95 +/- 20.77 and 68.03 +/- 23.22 min, respectively, and the Cl values were 14 +/- 1.7 and 13.6 +/- 1.32 ml/kg/min.  相似文献   

Rabies in cattle. V. Immunization of cattle in Brazil against exposure to street virus of vampire bat origin     

CARNEIRO V  BLACK J  KOPROWSKI H 《Journal of the American Veterinary Medical Association》1955,127(943):366-369

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New class of antihypertensive agents     

RUBIN AA  ROTH FE  WINBURY MM  TOPLISS JG  SHERLOCK MH  SPERBER N  BLACK J 《Science (New York, N.Y.)》1961,133(3470):2067-2069

Three pigeons were trained to peck at a horizontally oriented rubber srtip 10 in. long. The spatial distribution of responding along this strip is found to be nonrandom when every peck is reinforced with food. The degree of nonrandomness increases markedly when the pecking is intermittently reinforced  相似文献   

Heart rate: differential effects of hypothalamic and septal self-stimulation     

PEREZ-CRUET J  BLACK WC  BRADY JV 《Science (New York, N.Y.)》1963,140(3572):1235-1236

Heart rate in rats was recorded during self-stimulation with electrodes permanently implanted in both the hypothalamus and the septal region. Acceleration was observed during stimulation of the hypothalamus, and deceleration during stimulation of the septal region. In both areas self-stimulation reduced variability in heart rate.  相似文献