J.D. Roussel

High environmental temperature and humidity decrease oocyte quality in Bos taurus but not in Bos taurus cows

Two experiments were conducted to assess the effects of environmental temperature and humidity on the quality and developmental capabilities of bovine oocytes. In Experiment 1, Bos taurus (Holstein and crossbred Angus) cows were subjected to 5 weekly sessions of ultrasound-guided follicle aspiration from February 16 through March 23 (cool season) and 5 sessions from May 22 through June 20 (hot season). In Experiment 2, Bos taurus (Holstein) and Bos indicus (Brahman) cows were superstimulated (Super-Ov) during the months of August (hot season) or January (cool season), and each cow was subjected to a single oocyte aspiration session. In each experiment, oocytes were classified as normal or abnormal based on ooplasm morphology and cumulus cell layers. In Experiment 1, oocytes classified as normal were in vitro matured and fertilized (IVM/IVF), and the resulting embryos cultured for 8 d. All oocytes recovered from superstimulated cows in Experiment 2 were matured and fertilized in vitro and the subsequent embryos cultured for 8 d, regardless of their morphological appearance. In Experiment 1, Bos taurus cows produced a higher (P = 0.02) percentage of normal oocytes during the cool season (75.9 +/- 8.0) than during the hot season (41.0 +/- 9.5). The percentage of fertilized oocytes developing to the 2-cell (82.4), 8-cell (65.4) and morula (46.6) stages were also greater (P < or = 0.06) during the cool season than the hot season (45.0, 21.2, 6.0 for 2-cell, 8-cell and morula stages, respectively). In Experiment 2, Bos taurus cows (Holstein) had a lower (P = 0.01) percentage of normal oocytes in the hot season (24.5 vs 80.0) and a lower (P < or = 0.003) percentage of fertilized oocytes developing to the 8-cell, morula and blastocyst stages. No difference (P > or = 0.57) in the percentage of normal oocytes or in embryo development was detected between seasons in Bos indicus (Brahman) cows. In conclusion, high environmental temperature and humidity resulted in a marked decline in the quality of oocytes retrieved from Bos taurus cows and markedly decreased their in vitro developmental capabilities. In contrast, a high percentage of oocytes retrieved from Bos indicus cows exhibited normal morphology and yielded a high proportion of blastocysts, regardless of season.

Preservation of Channel Catfish Sperm

Abstract Three activators, eight extenders, and three protective agents at two concentration levels each were used to determine the best combination that will maintain in storage the viability of channel catfish (Ictalurus punctatus) sperm cells. There was a highly significant (P < 0.01) difference in motility score among activators. Saline (0.65%) gave the highest motility score. Extended sperm cells became motile when activated after 2 months of storage at 4 C. Extender I (Truscott and Idlers Hfx #1) with 10% dimethyl sulfoxide (DMSO) and 2 hours equilibration produced the highest motility scores after freezing of 24 hours or 1 week. Freezing rate was controlled by placing vials of sperm in a double-layered, kapok-lined paper bag and freezing at the height of 127 mm above the liquid nitrogen level.

Spermatozoal Morphology and Ultrastructure of Channel Catfish, Ictalurus punctatus

Abstract The morphology, dimensions, aberrations, and ultrastructure of channel catfish (Ictalurus punctatus) spermatozoa were studied. Spermatozoa of a wild catfish stock from Louisiana were compared to those of a domestic stock from Mississippi. The spermatozoon of channel catfish consists of a rounded dark head, a collar-dike midpiece, and a long flagellum. The average dimensions were: head length, 2.3 μm; midpiece length, 1.6 μm; midpiece width, 3.1 μm; and flagellum length, 94.9 μm. The flagellum had the classical (2.9 + 2) axoneme. On the average, 4.7% of the spermatozoa in the fish studied were biflagellar. Each flagellum arose from an individual centriolar complex. Domestic fish stock had a higher percentage of normal gametes compared to wild stock.

Intrauterine infusion of prostaglandin E2 and subsequent luteal function in cattle

The objective was to evaluate the effect of intrauterine infusion of prostaglandin E2 (PGE2) on luteal function in cattle. Heifers and cows were randomly assigned after two normal estrous cycles to either PGE2 or control treatment groups. Females in Treatment A were infused with 1 mg of PGE2 once daily into the uterine horn ipsilateral to the corpus luteum between days 7-10 of the estrous cycle with a 0.25 ml plastic semen straw and an artificial insemination pipette. Females in Treatment B were similarly infused with 1 mg of PGE2 once daily in 20 ml of a carrier vehicle via a catheter on days 10 and 11 of the estrous cycle. Control animals were infused with the carrier vehicle using either a semen straw (Treatment C) or via a catheter (Treatment D) on the same days of the estrous cycle. Blood samples were collected daily to monitor plasma progesterone concentrations during the treatment period. Females infused with PGE2 on days 7-10 of the estrous cycle returned to estrus in a mean of 23.5 days (range 22-25 days) and were similar (P > 0.05) to those infused on days 10 and 11 which returned to estrus in 23.5 days (range 22-25 days). Animals similarly infused with carrier vehicle on the same days of the estrous cycle returned to standing estrus in 20.2 days (range 17-23 days). Plasma progesterone concentrations indicated an extended period of elevated progesterone concentrations in PGE2-treated animals compared with control animals. These results indicate that short term administration of PGE2 early in the estrous cycle may result in extended luteal maintenance.

A Spermatology Study of Channel Catfish, Ictalurus punctatus

Abstract Forty m/ale channel catfish (Ictalurus punctatus) of two age groups and two stocks (domestic and wild) were compared in an experiment to study morphological and physiological characteristics of their testes and sperm cells from May through October. The gonosomatic index for 36 normal catfish examined averaged 0.25%. An average of 82.7% spermatozoa were alive with an average motility score of 2.96. These fish had an average gonadal sperm concentration of 7.1 X 109 spermatozoa per g wet testicular tissue. The testes were found to be composed of 2/3 spermatogenic and 1/3 glandular tissue. There were no morphological changes observed in the characteristics of the spermatogenic tissue during the period of study. The 3-year-old fish were consistently larger than the 2-year-olds, and the domestic fish were larger than the wild stock in each age group, which probably caused most of the differences in characteristics when comparisons were made.

Testicular and spermatozoal characteristics of channel catfish, Ictalurus punctatus, outside the spawning season

Abstract Several testicular and spermatological parameters of 48 male channel catfish, Ictalurus punctatus (Rafinesque) were studied during 6 months (November through April) outside the spawning season. Two stocks (a domestic and a wild one) and within each stock 2- and 3-year-old fish were compared. Within age-groups, the domestic fish were considerably larger than the wild ones. In each stock, the 3-year-olds outgrew the 2-year-olds. The testes consisted of a white spermatogenic and pink glandular part, averaging 1.14 and 0.56 g respectively. A significant increase in both parts was noticed in March, continuing during April. One 3-year-old male in each stock was azoospermic, even though these fish had well developed testes and exhibited secondary sexual characteristics. Viable sperm was present in every month at an average rate of 73.2% of the spermatozoa. The majority was in progressive motion with some vibrating in loco. The gonosomatic index averaged only 0.22%, and reached a peak value of 0.32% in A...

The effects of different types of syringes on equine spermatozoa

Control extender was incubated at 4 degrees C for 24 hours. Rubber or plastic syringe plungers were separately incubated in semen extender for 24 hours at 4 degrees C. Following incubation, the extender was stored at -20 degrees C until the time of semen collection. The treatments consisted of the following: Group A = equine semen plus control extender; Group B=equine semen plus extender incubated with rubber plungers and Group C=equine semen plus extender incubated in plastic plungers; Group D=equine semen plus control extended in rubber plunger syringes and Group E=equine semen plus control extender in plastic plunger syringer. Each group contained a 5-ml volume of semen and extender at a concentration of 1.0 x 10(8) sperm/ml. The number of live spermatozoa, percentage of progressively motile spermatozoa and rate of progressive motility were taken following collection and every 15 minutes for 1 hour following application of treatments. In experiment 2, treatments were allowed to incubate with semen for 45 minutes, then the extender was removed and was replaced with fresh extender. The rate of progressive motility and the percentage of progressively motile spermatozoa were taken immediately, at 45 minutes, and then every 15 minutes for 1 hour. In experiment 1, the number of live spermatozoa was not affected among the 5 groups. However, there was a decrease (P<0.01) in the rate of progressive motility and in the percentage of progressively motile spermatozoa in Group B compared with the remaining 4 treatment groups at 30, 45 and 60 minutes, with no differences noted when semen was held in syringes with a rubber or a plastic plunger. In experiment 2, the percentage of progressively motile spermatozoa increased after the addition of the control extender.

Frozen-thawed cumulus-granulosa cells support bovine embryo development during coculture *†*Supported by a grant from the Hillcrest Medical Center Foundation, Tulsa, Oklahoma.†Presented in part at the Conjoint Meeting of The American Fertility Society and the Canadian Fertility and Andrology Society, Montreal, Quebec, Canada, October 11 to 14, 1993.

OBJECTIVE To evaluate the ability of bovine cumulus-granulosa cells to survive cryopreservation and subsequently support bovine embryo development during coculture. DESIGN In vitro-matured and -fertilized bovine embryos (two- to four-cell) were allotted randomly to one of three treatment groups: [1] control medium alone consisting of Medium 199 containing 10% fetal bovine serum and antibiotics, [2] cocultured on fresh bovine cumulus-granulosa cells in control medium, or [3] cocultured on frozen-thawed cumulus-granulosa cells in control medium. Embryo development was assessed on days 7 and 8 after IVF. RESULTS Coculture improved embryo development on days 7 and 8 compared with the control group. However, embryo development on days 7 and 8 did not differ among coculture groups. CONCLUSIONS Frozen-thawed cumulus-granulosa cells enhance embryo development similar to fresh cells during in vitro coculture.