ABSTRACT A study was conducted to investigate the influence of breed and sex in the gross anatomy, digesta and histology of Ross 308 broiler and Venda chickens. Chickens were slaughtered at 90 days of age and the pH of the digestive organs was measured immediately after slaughter. The digestive organ weights and lengths of Ross 308 broiler and Venda chickens were measured. Tissue samples of the duodenum, ileum and jejunal from each treatment group were collected and histologically examined. Higher (p<0.05) gizzard pH values were observed in male and female of Ross 308 broiler and Venda chickens. The jejunal and ileal pH values were lower (p<0.05) for Venda chickens than in Ross 308 broiler chickens. The absolute weights of the gastrointestinal tract, crop, proventriculus and gizzard were lighter (p<0.05) in Venda chickens than in Ross 308 broiler chickens. The relative organ weights of the GIT, proventriculus, gizzard and caeca were higher (p<0.05) in Venda chickens than in Ross 308 broiler chickens aged 90 days. Male chickens had higher (p<0.05) relative organ weights than female chickens. Interactions between breed and sex influenced (p<0.05) the absolute weights of the crop, proventriculus, caeca and large intestine. Ileum villus heights of female Venda chickens were higher (p<0.05) than those of female and male Ross 308 broiler and Venda chickens. The male and female Ross 308 broiler chickens had higher (p<0.05) ileum and duodenum crypt depths than male and female Venda chickens. The duodenum and ileum villus height/crypt depth ratios were higher (p<0.05) in male and female Venda chickens than Ross 308 broiler chickens. In overall, male broiler chicken performed better.

Mammalian ovary development undergoes important changes during the perinatal period, moment when follicles are assembled and start to develop in a process not well known, involving endocrine and paracrine factors. In order to investigate the effect of two different hormonal environments on the early development of the ovary, we used an autologous transplant model in which Syrian hamster fetal ovaries were grafted under the kidney capsule of males hosts previously unilaterally or bilaterally orchidectomized. After 35 days of graft, ovaries and kidney parenchyme of the host male did not present signs of rejection. Ovaries contained primordial, primary follicles, secondary follicles and few tertiary follicles with morphological features similar to ovaries of control females of 35 days of age. Healthy primary and secondary follicles of experimental groups had frequency distribution and size similar to control ovaries but tertiary follicles were scarce in control as well as in grafts where they were mainly atretic. PCNA, marker of proliferation, was immuno detected in granulosa cells of growing follicles and the marker of apoptosis, Caspase 3 active, was evident mainly in secondary follicles. Immunoreactivity for steroidogenic proteins, StAR, 3-bHSD and aromatase detected in the follicular wall cells and the decreased serum levels of FSH without important changes in testosterone in bilateral orchidectomized males that received ovarian graft, and testosterone decreased without changes in FSH levels in unilateral orchidectomized males (UO) with ovarian graft, all together suggest the effect of steroid hormones produced by the ovary. In conclusion, the experimental model of autologous transplant presents evidence of early ovary development under the kidney capsule and its functional integration to the endocrine axis of the host male.

El desarrollo del ovario en mamíferos sufre importantes cambios durante el periodo perinatal, momento en el cual los folículos se ensamblan y comienzan a desarrollarse en un proceso no muy dilucidado que involucra señales endocrinas y paracrinas. Con el objetivo de investigar el efecto de dos ambientes hormonales sobre el desarrollo temprano del ovario de hamster, usamos un modelo de trasplante autólogo en el que ovarios fetales fueron trasplantados bajo la cápsula renal de machos receptores previamente castrados y hemicastrados. Después de 35 días de trasplante, los ovarios y el parénquima renal de los machos receptores no presentaron señales de rechazo. El ovario presentó folículos primordiales, primarios, secundarios y algunos folículos terciarios con características morfológicas similares a los ovarios de hembras controles de 35 días de edad. Folículos primarios y secundarios sanos de ambos grupos experimentales se encontraron en frecuencia y tamaño similar al de ovarios controles, los folículos terciarios fueron escasos tanto en controles como en ovarios trasplantados, siendo en éstos principalmente atrésicos. PCNA, un marcador de proliferación celular, fue detectado por inmunohistoquímica en células granulosas de folículos en crecimiento, mientras que caspasa 3 activa, un marcador de apoptosis, fue evidente en folículos secundarios. Por otra parte, inmunoreactividad para proteínas esteroidogénicas, StAR, 3-bHSD y aromatasa, fue detectada en la pared folicular. Esta observación, junto a la disminución de niveles séricos de FSH, sin cambios importantes en los niveles de testosterona en machos castrados que recibieron trasplantes ováricos, y la disminución en los niveles de testosterona sin cambios en los niveles de FSH en machos hemicastrados con trasplantes ováricos, sugiere que el ovario no solo produce hormonas esteroidales sino que además éstas modifican los niveles hormonales del macho receptor del trasplante. En conclusión, este modelo de trasplante autólogo agrega información del desarrollo ovárico temprano cuando éste se desarrolla bajo la cápsula renal de machos entregando evidencia de la integración funcional del ovario trasplantado al eje endocrino de los machos receptores.

Vachellia karroo (Acacia karroo) is promising fodder for goats in the critical dry season in communal rangelands. The only limitation to the use of this fodder tree is the presence of phenolic compounds, such as condensed tannins. A study was conducted to investigate the effects of tanniniferous V. karroo leaf meal feeding on blood profiles of indigenous Pedi goats fed a basal diet of Setaria verticillata grass hay. Twenty indigenous Pedi goats, weighing 18 ± 2 kg, were allocated in a completely randomized design to five dietary treatments containing V. karroo leaf meal at 20% (S80A20), 25% (S75A25), 30% (S70A30), 40% (S60A40) and 50% (S50A50) of the total diet in a 22-day trial. Twelve ml of blood were collected from the jugular vein from each goat before and after the experiment for haematological and serum biochemical assays. Daily dry matter intake (DMI) was similar across treatments, ranging from 633 g to 765 g per goat per day. There was no difference in initial and final bodyweights of goats consuming various experimental diets. However, bodyweight gains were significantly higher in goats fed a diet with 50% leaf meal as compared with other treatment groups. There were no differences in haematological indices of Pedi goats except for mean corpuscular haemoglobin (Hb) concentration. Goats fed 50% leaf meal had significantly lower mean corpuscular haemoglobin concentration (MCHC) values as compared with other treatment groups. Similarly, there were no differences in the blood serum chemistry of goats that consumed various inclusion levels of V. karroo, except for serum total protein (TP) and alanine aminotransferase (ALT). Goats fed 50% leaf meal had depressed serum TP, while serum enzyme Alanine aminotransferase (ALT) concentration decreased significantly in goats fed 25% leaf meal as compared with those on the 20% dietary treatment. Tannin concentration of 8.2 g/kg dry matter (DM) had no toxic effect on experimental animals. A 40 % inclusion of V. karroo in a Setaria verticillata hay-based diet may be fed to indigenous Pedi goats without compromising the immunity system and health of the animals.

This study was conducted to investigate the effects of different levels of coriander (Coriandrum sativum) seed powder and extract on the performance and carcass characteristics of broiler chickens. A total of 420 day-old broiler chicks (Ross 308) were allocated randomly into seven treatments of 60 birds per group. Each treatment had four replicates (15 chicks per replicate). The trial was designed with seven treatments, consisting of a control diet without coriander, this is, the control group (CG); three treatments, which included the control diet plus three levels of coriander extract in water (750, 1000, and 1250 mg/kg); and the another three, which received the control diet plus three levels of coriander powder (1.5%, 2.0% and 2.5%). Performance parameters were monitored throughout the experimental period. At 21 - 42 d old, the inclusion of 952 mg/kg of coriander extract in drinking water maximized weight gain, while the feed intake of the experimental period (1 - 42 d) was maximized at the coriander powder level of 1.2%. Feed conversion ratios improved with the inclusion of coriander powder in the diet throughout the experimental period. These results suggest that coriander powder in the diet and coriander extract in water could replace synthetic antibiotics and could be regarded as natural feed additives and growth promoters in poultry diets.

It has been proposed that vertical movements of planktonic organisms coupled to a horizontally or vertically stratified circulation pattern could describe a retention mechanism, with ecological advantages such as favoring recruitment success. The Patagonian stock of the Argentine hake Merluccius hubbsi spawns mainly from January to February in relation to a highly productive tidal frontal system. Although retention of fish eggs and larvae has been previously hypothesized for this system, it has not been fully proven and its mechanisms have not yet been proposed for hake early stages. To better understand the physical and biological processes involved in the survival and distribution of hake larvae, we focused on transport features and associated larval behavior governing the retention of larvae in the spawning area and their subsequent distribution to settlement and nursery grounds. To test this hypothesis at appropriate spatial and temporal scales, we analyzed acoustic records to describe vertical and horizontal distribution patterns of hake larvae, discrete plankton samples to confirm the identity of acoustic targets, and outputs from a numerical circulation model to estimate current patterns in the region during the hake spawning months. Coinciding with the development of a functional swimbladder, hake larvae of 4 mm and larger showed a strong vertical distribution pattern associated with a sound scattering layer migrating from the thermocline during the night to near-bottom depths during the day. This diel vertical migration pattern was associated with the circulation structure, equivalent to a two-layer flow, indicating a recirculation pattern in the vertical plane. The retention of early larval stages in the spawning area was evident from the acoustic data, indicating a persistent location for the bulk of hake larvae at the main spawning ground during summer months. The distribution extends to the rest of the nursery grounds as the breeding season advances in agreement with the general pattern of middle shelf bottom circulation vectors produced by the numerical model. The results are discussed within the framework of Bakun's fundamental triad, identifying its elements. In addition, a conceptual model for the main biophysical coupling processes during the early life history of M. hubbsi is proposed in order to gain insight about the recruitment mechanism of this species.

Se ha propuesto que movimientos planctónicos verticales acoplados a patrones de circulación horizontal o verticalmente estratificados podrían describir un mecanismo de retención con ventajas ecológicas como la mejora del reclutamiento. El desove del stock patagónico de la merluza argentina Merluccius hubbsi es principalmente de enero a febrero y está asociado a un frente altamente productivo. Aunque se ha hipotetizado sobre la retención de huevos y larvas de peces en este frente, esto no ha sido plenamente probado y sus mecanismos aún no han sido propuestos para los estadios tempranos de la merluza. A fin de comprender mejor los procesos físicos y biológicos involucrados en la supervivencia y distribución de las larvas de merluza, este trabajo se enfocó en los fenómenos de transporte y el comportamiento larvario asociado a ellos, los cuales permitirían la retención de larvas en el área de desove y su posterior distribución hacia las zonas de asentamiento y crianza. Para probar esta hipótesis a escalas espaciales y temporales apropiada, se analizaron registros acústicos para describir los patrones de distribución vertical y horizontal de las larvas de merluza, muestras discretas de plancton para confirmar la identidad de los blancos acústicos, y los resultados de un modelo de circulación numérico para estimar los patrones de corriente en la región durante los meses de desove de la especie. Coincidiendo con el desarrollo de una vejiga natatoria funcional, las larvas de 4 mm y mayores mostraron un marcado patron de distribución vertical asociado a una capa dispersora del sonido, que migra desde la termoclina, donde se encuentra durante la noche, hasta profundidades cerca del fondo durante el día. Este patrón diario de migración vertical estuvo asociado a la estructura de circulación, equivalente a un flujo en dos capas, lo que indica un patrón de recirculación en el plano vertical. La retención de estadios larvarios tempranos en el área de desove fue evidenciada por los datos acústicos que indican una ubicación persistente del grueso de las larvas de merluza en la principal zona de desove durante los meses de verano. La distribución se extiende al resto de la zona de crianza conforme avanza la temporada reproductiva coincidiendo con el patrón general de los vectores de circulación de fondo predichos para la sección media de la plataforma. Los resultados se discuten a la luz de la triada fundamental de Bakun identificando sus elementos. Además se propone un modelo conceptual acerca de los principales procesos de acoplamiento biofísico durante las primeras fases del ciclo de vida de la merluza para profundizar en el conocimiento de los mecanismos de reclutamiento de la especie.