Título en español.

Pangolagrass (Digitaria decumbens) and stargrass (Cynodon nlemfuensis) harvested at 30, 45, and 60 days and made in to hay, were fed to four castrated male ruminants (goats and steers) in individual digestion stalls. The grasses were fertilized at the rate of 4,480 kg/ha/yr with 15-5-10, harvested, sun-dried for 2 days and cut in 3- to 6-cm pieces. Each experimental period lasted 21 days, divided into a 14-day preliminary feed ing period and a 7-day collection period. Each hay was offered at a level of 90% intake, as determined in the preliminary period. Hays, offered and refused, and feces were weighed and sampled daily. Representative samples were analyzed for dry matter, crude protein, neutral-detergent fiber, acid-detergent fiber, cellulose, lignin, and silica. Hemicellulose was determined as the difference between neutral-detergent fiber and acid-detergent fiber. Apparent digestion coefficients for each fraction were calculated on all hays and all ruminants. Pangolagrass dry-matter intake was significantly (P < .01) greater than that of stargrass hay by both goats and steers. No significant differences in dry-matter intake were obtained between hay ages of 30, 45, and 60 days. Goats had a higher dry-matter intake (P < .01) than steers. Significant differences were obtained between hays in neutral-detergent fiber (P < .01), hemicellulose (P < .01), and cellulose (P < .05) contents and between hay ages in crude protein (P < .05), cellulose (P < .01), lignin (P < .05), and silica (P < .01) contents. For digestibilities, significant differences were obtained between hays in dry matter (P < .05), neutral-detergent fiber (P < 05), and cellulose (P < .01); between hay ages in lignin (P < .01) and silica (P < .01); and between ruminants in dry matter (P < .01), neutral-detergent fiber (P < .01), acid-detergent fiber (P < .01), hemicellulose (P < .01), and cellulose (P < .01). Goats may not necessarily substitute for steers in digestion trials; and lignin, but not silica, tends to be a valid marker for determining digestibility.Las gramíneas Pangola (Digitaria decumbens) y Estrella (Cynodon nlemfuensis), cosechadas a 30, 45 y 60 días de edad y henificadas, fueron evaluadas en pruebas de digestibilidad con cuatro cabros y cuatro novillos castrados. Las gramíneas se abonaron a razón de 4480 kg/ha/año con un análisis 15-5-10, se henificaron por 2 días y se cortaron en trozos de 3 a 6 cm. Cada período experimental duró 21 días, de los cuales los primeros 14 días constituyeron un período preliminar de alimentación y los restantes 7 días uno de colección total. Cada heno se ofreció a un nivel de consumo de 90% del determinado en el período preliminar. Los henos, ofrecidos y rechazados, y las heces, se pesaron diariamente. Las muestras representativas tomadas diariamente se analizaron para materia seca, proteína bruta, fibra neutrodetergente, fibra ácidodetergente, celulosa, lignina y sílice. La hemicelulosa se determinó como la diferencia entre la fibra neutrodetergente y la fibra ácidodetergente. Se calcularon los coeficientes de digestibilidad aparente para cada heno en cada rumiante. El consumo de materia seca del heno de Pangola fue significativamente (P < .01) mayor que el de Estrella tanto por los cabros como por los novillos. No se obtuvieron diferencias significativas en consumo de materia seca entre henos, de edades de 30, 45 y 60 días. Los cabros consumieron más materia seca (P < .01) que los novillos. Se observaron diferencias significativas entre henos en contenidos de fibra neutrodetergente (P < .01), hemicelulosa (P < .01) y celulosa (P < .05) y entre edades de henos en contenidos de proteína bruta (P < .05), celulosa (P < .01), lignina (P < .05) y sílice (P < .01). Para las digestibilidades, se observaron diferencias significativas entre henos en materia seca (P < .05), fibra neutrodetergente (P < .05) y celulosa (P < .01) ; entre edades de henos en lignina (P < .01) y sílice (P < .01); y entre rumiantes en materia seca (P < .01), fibra neutrodetergente (P < .01), fibra ácidodetergente (P < .01), hemicelulosa (P < .01) y celulosa (P < .01). Los cabros no sustituyen necesariamente a los novillos en pruebas de digestibilidad. La lignina, pero no la sílice, tiende a ser un indicador válido para determinarla

Assessing the association between subsistence strategies and the timing of weaning among indigenous archaeological populations of the Caribbean

Human breastfeeding is a biocultural process shaped by the interaction of numerous biological, cultural, economic, and social factors. Although previous studies have found that a society's subsistence economy alone does not determine weaning timing, subsistence may still have a profound effect on weaning food choices. This paper analyses nitrogen and carbon stable isotopes in bone collagen and apatite of individuals from six precolonial Caribbean sites grouped into four subsistence categories: Hunter‐Fisher‐Gatherers (Cueva del Perico I and Cueva Calero, Cuba), Horticulturalists (Canímar Abajo, Cuba), Agriculturalists from the Antilles (Paso del Indio, Puerto Rico), and Agriculturalists of Mesoamerica (Marco Gonzalez and San Pedro, Belize) in order to explore how subsistence economy affected the different groups' breastfeeding and weaning practices. Ages for the start and the end of weaning, and the isotopic characteristics of possible food sources used as supplements during the weaning process, were assessed using the Bayesian probability model “Weaning Age Reconstruction with Nitrogen isotopes.” Model results indicate (a) a major dietary change around 2 years of age for most of the study populations, (b) that supplements seem to have been introduced into nonadults diet at earlier ages than has been observed in ethnographic populations of the area, (c) no direct correlation between the start of weaning and the availability of cultigens, but (d) that groups that had access to cultigens would appear to have weaned their children using foods with lower nitrogen isotope values, suggesting that plants (likely domesticates) may have had an important role as weaning foods

Pre-Hispanic Fishing Structures Preserved on the Central Coast of Ecuador

Marine resource exploitation is documented for the central coast of Ecuador from 10.000 yr B.P., with a wide range of fishing techniques developing through time. Most recently, dozens of stone fishing structures have been identified at the Liguiqui archaeological locality, on the Manta Peninsula of Manabí Province. These resemble fish traps such as have been recorded worldwide, though no similar devices have previously been reported on the Pacific coast of tropical or subtropical South America. A preliminary study of the Liguiqui structures is presented here, assessing their geologic, environmental, cultural and chronological context. It is hypothesized that they could have had a double function as fish traps and as fish attractors/containers, and that they were most likely built during the Pre-Hispanic Manteño cultural period.Fil: Favier Dubois, Cristian Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Storchi Lobos, Daniela. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lunniss, R.. Universidad Técnica de Manabí; EcuadorFil: Mora Mendoza, A.. Escuela Superior Politécnica del Litoral; EcuadorFil: Ortiz Aguilú, J. J.. Universidad Técnica de Manabí; Ecuado