Physical characteristics and fertility of fractionated donkey semen cooled at 5°C / Características físicas e fertilidade do sêmen asinino fracionado e resfriado a 5ºC

The aim of this study was to evaluate the effect of two different extenders (Skimmed Milk Glucose - SMG or Lactose - Egg Yolk - LEY) on physical characteristics and fertility of fractionated donkey semen cooled at 5°C. For this, four Pêga donkeys were used as semen donors. The sperm rich fraction of the ejaculate was diluted preparing insemination doses containing 400 x 106 motile spermatozoa in a volume of 22 mL, cooled to 5°C and stored up to 48 hours in a container proposed by Palhares (1997). Sperm motility and vigor were assessed in fresh semen, after first semen dilution, before insemination, at 24 and 48 hours after storage. For the fertility evaluation, 44 mares were inseminated with semen stored for a period between 12 and 24 hours. The mares were inseminated on fixed days (Mondays, Wednesdays, and Fridays) after the detection of a follicle greater than a 30mm diameter in one of the ovaries through ovulation. Pregnancy diagnosis was performed on day 12 post-ovulation, using transrectal ultrasonography. Semen diluted in SMG showed superior sperm motility than LEY, at the Pre-AI evaluation (P<0.05). At 48 hours of storage, all donkeys had motility values between 45 and 53% for semen diluted in SMG, while only one donkey showed motility greater than 30% in the LEY treatment. The pregnancy rate/cycle for mares inseminated with semen diluted in SMG was superior than that obtained using LEY (56.52% vs 4.76%, respectively).(AU)

Objetivou-se com o presente experimento avaliar o efeito de dois diferentes diluidores (leite em pó desnatado glicose - SMG ou lactose gema de ovo - LEY) sobre as características físicas e a fertilidade do sêmen asinino coletado de forma fracionada e resfriado a 5ºC. Para isso, quatro jumentos da raça Pêga foram utilizados como doadores de sêmen. A fração espermática rica do ejaculado foi diluída preparando-se doses inseminantes contendo 400 x 106 espermatozoides móveis em um volume de 22 mL, resfriadas a 5ºC e armazenadas por até 48 horas em contêiner proposto por Palhares (1997). A motilidade e o vigor espermáticos foram avaliados no sêmen fresco, após a pré-diluição, antes das inseminações, às 24 e 48 horas de armazenamento. Para avaliação de fertilidade, 44 éguas foram inseminadas com sêmen armazenado por um período entre 12 e 24 horas, em dias fixos (segundas, quartas e sextas-feiras), após a detecção de um folículo de diâmetro maior ou igual a 30mm em um dos ovários, até a ovulação. O diagnóstico de gestação foi realizado a partir de 12 dias após a ovulação, por meio de ultrassonografia transretal. O sêmen diluído em SMG apresentou motilidade espermática superior à do LEY, já a partir do tempo pré-IA. Às 48 horas de armazenamento, todos os jumentos apresentaram valores de motilidade entre 45% e 53%, quando o sêmen foi diluído em SMG, enquanto apenas um jumento apresentou motilidade superior a 30% no tratamento utilizando LEY. A taxa de concepção/ciclo das éguas inseminadas também foi superior para o sêmen diluído em SMG em relação ao diluído em LEY (56,52% versus 4,76%, respectivamente).(AU)

Active and latent ovine herpesvirus-2 (OvHV-2) infection in a herd of captive white-tailed deer (Odocoileus virginianus).

Malignant catarrhal fever (MCF) is the clinical manifestation of infection of certain ruminant species with one of a group of pathogenic gammaherpesviruses known as MCF viruses. Cattle and numerous exotic ruminant species are susceptible to clinical disease that may be sporadic or occasionally epidemic in nature. The most common MCF virus worldwide is ovine herpesvirus (OvHV)-2. Reservoir hosts such as sheep, carry and excrete OvHV-2, but do not develop clinical signs, while clinically susceptible species develop severe and often fatal disease. The existence of latent infection in clinically susceptible hosts is poorly understood, but is documented in some ruminant species. Twenty-six animals from a captive herd of white-tailed deer (Odocoileus virginianus) died and were examined from October 2006 to December 2010. Fifteen of these animals (58%) showed clinical signs and gross and microscopical lesions consistent with MCF, while 11 (42%) did not. Polymerase chain reaction (PCR) amplification yielded product consistent with OvHV-2 DNA in samples of spleen from all 26 deer. To examine the possibility of latent infection in this herd, peripheral blood mononuclear cells were examined by PCR for OvHV-2 DNA, and the test was positive in 23/32 (72%) clinically normal deer. Archived serum samples were used to examine the history of MCF exposure in the herd using a competitive enzyme-linked immunosorbent assay, which demonstrated that 10/40 (25%) deer tested had MCF viral antibodies, with nine deer being seropositive over multiple years. Combined with previous observations in deer and other species, these results suggest the existence of latent infection of white-tailed deer with OvHV-2.