We developed a method to evaluate bovine sperm membranes in normal (1G) and simulated microgravity (Sim-µG). Bovine spermatozoa are used as a model system because they have cellular membranes analogous to those of other cell types, and yet are much simpler because they have no cytoplasm and do not participate in DNA transcription or mRNA translation. They can be cultured as single cells and are easily evaluated for membrane characteristics using flow cytometry. These features make the mammalian spermatozoon a useful model for exploring the principles of membrane structure/function in the presence of a variety of environmental challenges such as simulated microgravity. Cryopreserved, washed beef bull sperm (4-8 × 106 mL −1 ) were incubated under non-capacitating conditions (modified glucose-free Tyrode's medium containing low bicarbonate, HEPES buffer, pyruvate and 3 mg mL −1 BSA V; 23 • C in air), and these spermatozoa remained alive for 24-48 h at 1G. To simulate µG, spermatozoa were incubated under the same conditions, in a HARV 10 rotating wall vessel (RWV, Synthecon, Inc, Houston,TX, USA) at 9 rpms. Spermatozoa were incubated in 1G and Sim-µG environments for 2.5-4.5 h and subsequently exposed to 0, 60 or 80 µg mL For further statistical analysis, and incorporation of non-parametric statistical tools (including pattern recognition using Support Vector Machines), the data were processed using a collection of Perl scripts and C programs. Results: Live/dead status: When Sim-µG + 60 µg mL −1 LC sperm were compared to 1G + 60 µg mL −1 LC, and 80 µg mL −1 LC sperm, their profiles were more similar to the 1G 80 µg mL −1 LC profiles. AR status: the Sim-µG + 60 µg mL −1 LC profiles were similar to the 1G + 60 µg mL −1 LC profiles. Mitochondrial Status: the Sim-µG + 60 µg mL −1 LC profiles were more similar to 1G + 80 µg mL −1 LC profiles. Summary: although Sim-µG sperm lost their motility within 3 h, they were alive. Cell profiles indicate that Sim-µG sperm nuclear membranes are less stable and their mitochondria are less functional than the 1G controls, but their acrosomes are intact indicating that fertilizing potential may remain. Additional experiments are needed to determine the time course for Sim-µG, induced changes, and whether Sim-µG sperm can penetrate eggs.

A robust body of evidence has demonstrated that the lunar cycle plays an important role in the reproduction of fish living in natural environments. However, little is known about the influence of the moon on tilapia reproductive activity in intensive fish farming systems. This study aims to evaluate the influence of the lunar cycle on the reproductive performance of tilapias in an intensive outdoor tropical production system in Latin America. Records of two tilapia strains (Nile tilapia [ Oreochromis niloticus; n = 75] and Red tilapia [ Oreochromis spp.; n = 1335]) reared in concrete tanks in a commercial fish farm were analyzed. Over a 3-year period, 60,136 captures were made in intervals of 12 to 14 days and 6,600 females were manually spawned. The number of females spawned and the volume of eggs collected from each tank ( n = 9) were recorded. Data was analyzed by the general linear model and means were compared by least squares means method. A very slight or no variation was observed when the lunar cycle was split into two halves (crescent and waning). The proportions of females spawned and the volume of eggs per spawned female and per female in the tank varied considerably across the eight periods of the lunar cycle, with greater values in the waning than in the crescent phase. A significantly greater proportion of tilapia spawned and yielded more eggs around the full moon than around the new moon and remaining days of the lunar cycle. The moon cycle affected the reproductive activity of tilapia, which were more reproductively active around the full moon and most of the waning phase.

Se estudió el efecto de incluir harina de hojas de morera (HM) (Morus alba) en la dieta sobre la morfometría de algunos órganos del tracto gastrointestinal y diversos parámetros bioquímicos en codornices de engorde. Se aplicó un diseño completamente aleatorizado con tres tratamientos, T0: 100 % alimento comercial (AC); T1: 90 % AC + 10 % de HM; T2: 80 % AC + 20 % HM. Se evaluó el peso del hígado, molleja, intestino delgado (ID) y ciego, y la longitud del ID y ciego. Se determinó la concentración sérica de proteínas totales (PT), albúmina (Alb), glucosa (Glc), creatinina (Ct), urea (U), Calcio (Ca), Fósforo (P), transaminasa glutámicooxalacética (TGO) y transaminasa glutámicopirúvica (TGP). Los datos fueron procesados mediante el procedimiento GLM del programa SAS. El peso y la longitud del intestino delgado fueron superiores en el T2 que en T1 y T0 (P < 0,01). El peso del hígado fue similar entre grupos. El peso de la molleja y del ciego, y la longitud del ciego aumentaron significativamente con el incremento del contenido de HM en la dieta. Con excepción del hígado, la relación porcentual entre el peso de los órganos digestivos y el peso corporal se incrementó con la adición de HM en la dieta. No se observaron diferencias significativas entre tratamientos en las concentraciones de PT, Glc, Ct, TGO, Ca y P. Se encontraron diferencias estadísticas entre tratamientos en las concentraciones de Alb, U y TGP. La inclusión del 20 % de HM en la dieta de codornices en crecimiento incrementó el peso y el tamaño de algunos órganos digestivos y modificó la concentración de ciertos metabolitos sanguíneos.

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Forage characterization in family dairy farms in Trujillo state, Venezuela.