Efeitos da aplicação de prostaglandinas intervaladas de 10 dias sobre características reprodutivas de cabras leiteiras nulíparas cíclicas

Relataram-se os efeitos da aplicação de prostaglandina sobre características reprodutivas de cabras leiteiras nulíparas cíclicas. Cabras Alpinas (n=9) e Saanen (n=9) receberam duas doses de 22,5mg PGF2a com 10 dias de intervalo. A progesterona plasmática (ng/mL) foi determinada a partir de amostras de sangue coletadas nos dias 0 (primeira dose), 5, 10 (segunda dose), 15, 20, 25 e 30. Após início do segundo estro, as fêmeas foram monitoradas por ultrassonografia transretal a cada quatro horas até oito horas após a ovulação. A gestação foi verificada por ultrassonografia transretal nos dias 20, 25, 30, 35 e 90 após a segunda dose. As características estudadas foram semelhantes entre as raças (P>0,05). Animais em estro e o intervalo parto-estro de, respectivamente, 78,9% e 50,6±17,2h e 88,9% e 50,0±14,8h após a primeira e segunda administrações de prostaglandina, não diferiram (P>0,05). Todas as cabras ovularam e registraram-se valores do intervalo parto-ovulação após a segunda aplicação de prostaglandina de 64,5±19,5h e após início do estro de 18,0±9,1h, a taxa de ovulação de 1,3±0,5 e diâmetro do folículo ovulatório de 8,1±1,1mm. Perda embrionária ocorreu antes de 30 dias de gestação. O estro pode ser eficientemente sincronizado em cabras leiteiras núliparas com duas doses de prostaglandina intervaladas de 10 dias. _________________________________________________________________________________________ ABSTRACT: This study reported the effects of prostaglandin (PGF2a) administration 10 days apart on reproductive parameters of cyclic artificial inseminated (AI) nulliparous Alpine (n=9) and Saanen (n=9) goats. Animals received two doses of 22.5mg PGF2a 10 days apart. After 1st and 2nd PGF2a administrations, estrus was monitored at 12 h intervals, with a buck teaser. Plasma progesterone concentration (ng/mL) was determined from blood sampled on day 0 (1st PGF2a) and the following 5, 10 (2nd PGF2a), 15, 20, 25 and 30 days. After the onset of the second estrus, females were transrectally (5 MHz probe) scanned at 4 hour intervals until at least 8h after ovulation. Pregnancy was checked through transrectal ultrasound on days 20, 25, 30, 35 and 90 after insemination. All parameters studied did not differ between breeds (P>0.05). Estrous response and interval to estrus, respectively, after 1st (78.9% and 50.6±17.2h) and 2nd PGF2a (88.9% and 50.0±14.8h) administration did not differ (P>0.05). Overall animals ovulating (100.0%), interval to ovulation after 2nd PGF2a (64.5±19.5h) and after estrous onset (18.0±9.1h), ovulation rate (1.3±0.5), diameter of ovulatory follicle (8.1±1.1mm) were recorded. Embryo loss occurred before day 30 of pregnancy. Estrus can be efficiently synchronized in nulliparous Alpine and Saanen goats with two doses of prostaglandin 10 days apart

Sperm Morphology

Abnormal spermatozoa have been historically associated with male subfertility and sterility. As early as 1927, an insightful report by Williams and Savage in the Cornell Vet stated that "the dimensions of sperm heads from good fertility bulls are remarkably uniform". This is still true. Presence of abnormal spermatozoa in semen is one of our most sensitive indications that spermatogenesis of a male has been impaired. In addition, occurrence of certain types of abnormal sperm are more dangerous, and can indicate that normal-appearing sperm in the same sample may also be abnormal or incompetent in fertilization or sustaining embryogenesis once initiated. In this paper, we will summarize current concepts of how sperm morphology impacts fertilization rate, as well as early embryogenesis, by examining their transport in the female and engagement of the ovum. Also discussed is the relationship of sperm morphology as we measure it in the breeding soundness exam to what we recognize as the two main components comprising seminal deficiencies in artificial insemination: 1) those deficiencies which can be overcome by raising the sperm dosage to the female (compensable) 2) and those deficiencies where subfertility exists regardless of sperm dosage (uncompensable).</jats:p