Effect of sperm numbers and concentration on sperm transport and uterine inflammatory response in the mare

• Published in: Theriogenology Vol. 67; no. 3; pp. 556 - 562
• Main Authors: Fiala, Sandra Mara, Pimentel, Cláudio Alves, Mattos, Ana Luiza Gelpi, Gregory, Ricardo Macedo, Mattos, Rodrigo Costa
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2007
• Subjects: Animals; artificial insemination; Cell Count; Cell Count - veterinary; cytology; Female; Horse Diseases; Horse Diseases - physiopathology; Horses; Inflammation; Inflammation - physiopathology; Inflammation - veterinary; Insemination, Artificial; Insemination, Artificial - veterinary; Leukocyte; leukocyte count; Male; Mare; mares; Milk; Milk - physiology; neutrophils; Neutrophils - cytology; physiology; physiopathology; semen extenders; seminal plasma; skim milk extender; Sperm; sperm concentration; Sperm Count; Sperm Count - veterinary; sperm transport; Sperm Transport - physiology; spermatozoa; temporal variation; time after insemination; Time Factors; Uterine Diseases; Uterine Diseases - physiopathology; Uterine Diseases - veterinary; Uterus; veterinary; Inflammation; Mare; Uterus; Sperm; Leukocyte
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2006.09.005

Our objective was to determine whether the concentration of cooled sperm inseminated influenced sperm transport and intensity of the uterine inflammatory reaction 2, 4 and 24 h after insemination. Experimental subjects were 189 estrous mares with a dominant follicle ≥35 mm in diameter and no bacterial growth or neutrophils detected in uterine smears. Each mare was randomly assigned to receive one of the following intrauterine treatments (volume, 20 mL): insemination with 5 × 10 6 mL −1 or 25 × 10 6 mL −1 or 50 × 10 6 mL −1 sperm diluted in 3 mL seminal plasma (SP) and 17 mL skim milk; seminal plasma or skim milk extender. Mares in a control group received no intrauterine treatment. Mares were slaughtered 2, 4 or 24 h after insemination or infusion. Oviducts were separated from the uterus, and uterus and oviducts were then flushed with phosphate-buffered saline (PBS). After flushing, an endometrial sample was collected for further histopathological examination. The grade of uterine fibrosis and the amount of neutrophils in the stratum compactum were evaluated. A sample of each tubal flushing was examined for sperm count, and a sample of each uterine flushing was examined for PMN count. It was concluded that compounds in the insemination dose provoked a uterine inflammatory response, which was more rapid and intense as sperm concentration increased. In contrast, sperm transport through 4 h after insemination was not influenced by sperm concentration.