Pre-weaning is an important stage in sheep production systems focussed on meat production. In this stage, maternal ability has a key role in lamb development and productivity. The objective of this study was to evaluate the effect of breed and litter size at birth on the ewe and lamb pre-weaning performance under tropical conditions. The lambs and their dams were managed in a feedlot system during 56 days in individual pens. Milk production was estimated weekly by the weight-suck-weight method. Daily milk production (DMY), total milk production (TMY), body weight change during the lactation (BWC), litter weaning weight (LWW) and ewe weaning efficiency (EE) were estimated as ewe pre-weaning performance; and, birth weight, weaning weight at 56 days and average daily gain were estimated as lamb pre-weaning performance. Katahdin ewes produced more TMY than Pelibuey ewes (p < .001) but ewes from both breeds had similar overall LWW and EE. Pelibuey ewes had a more negative BWC than Kathadin ewes (p < .05). Katahdin lambs had greater birth weights (p < .05), but similar preweaning growth and live weight at weaning compared with Pelibuey lambs. Litter size effect was significant for all the traits except for BWC in both breeds. Compared to Katahdin twin-born lambs, Pelibuey twin-born lambs were lighter at birth but of similar weight at weaning. Litter size is an important factor conditioning pre-weaning performance of ewes and lambs of Pelibuey and Katahdin breeds under humid tropical conditions. HIGHLIGHTS Some indicators of ewe and lamb pre-weaning performance of Pelibuey and Katahdin hair sheep under tropical conditions were evaluated. The Katahdin ewes produced more milk than Pelibuey ewes, yet ewes from both breeds had similar litter weaning weight. Litter size is an important factor determining pre-weaning performance in Pelibuey and Katahdin hair sheep breeds under humid tropical conditions. ARTICLE HISTORY
Feed intake and digestibility were evaluated in sheep fed low quality Taiwan grass supplemented with Tithonia diversifolia. Four wether hair sheep were housed in metabolic cages and fed with either Control concentrate 20%, Tithonia 20, 35 or 50% in a Latin Square design. Adaptation and, feces and urine collection periods were 14 and 7 days, respectively. Feed intake was increased (P \ 0.01) from 58.5 in control to 86.1 g/kg 0.75 in sheep fed Tithonia. NDF intake and digestibility were affected by Tithonia level. Nitrogen intake increased linearly (P \ 0.01) with increase in feces and urine excretion. N retention was similar (P [ 0.1) among sheep fed Tithonia, but different (P \ 0.05) from control. Inclusion of Tithonia foliage at 20% of the DM diet of hair sheep improved their intake of low quality Taiwan grass and nitrogen retention. Higher levels of Tithonia in the diet, however, increase nitrogen loss in feces and urine.
El objetivo del estudio fue determinar la cantidad óptima de alimento y peso del cerdo pelón mexicano (CPM) que se asocie a la máxima ganancia. Se utilizó la información de 22 hembras de CPM con un peso inicial de 5.07 ± 1.43 kg y final de 95.62 ± 12.09 kg; el ciclo de engorda se dividió en cuatro etapas. Para determinar los óptimos de consumo de alimento, peso y edad de venta del animal se empleó una función de producción representada por un modelo polinomial cuadrático; se consideraron precios de venta de 30.00, 35.00, 40.00 y $45.00 por kg de PV con alimentación 100% alimento balanceado y otro con restricción de 18%. En las etapas I y II se registró la mayor eficiencia alimenticia con 0.37 y 0.30 kg de ganancia por kg de alimento. El producto marginal promedio fue decreciente (0.24, 0.23, 0.21 y 0.15 por kg de alimento para las etapas I, II, III y IV). El peso óptimo de mercado se incrementó en el mismo sentido que el precio de venta del animal siendo: 15.50 a 75.00 kg en la alimentación de 100% alimento balanceado y 46.70 a 86.80 kg en la restringida. Debido al bajo valor de los parámetros obtenidos hacen necesaria la integración de la actividad primaria como parte de la cadena productiva con la finalidad de obtener la máxima ganancia y conservación de dicho recurso zoogenético.
This study determined productive performance, ruminal fermentation kinetics and rumen ciliate protozoa in hair sheep lambs fed different levels of olive oil. Twenty-four growing lambs were used, with an initial live weight of 10.5 ± 2.9 kg, and randomly assigned into four treatments (six animals per treatment) containing increasing levels of extra virgin olive oil (0, 2, 4 and 6% of dry matter). Animals were fed for 80 days, and sampling was carried out weekly. Intake of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and metabolizable energy (ME) differed between treatments (p < 0.05), with a linear and cubic tendency to decrease when oil concentrations were increased. Digestibility coefficients of OM, CP and NDF were not affected; however, the relationship between total intake and nutrient digestibility (DM, OM, NDF, ADF) increased with 2% DM olive oil. Compared with all treatments, the concentration of propionic acid increased by 16% with 4% olive oil. The intake of olive oil did not affect the protozoa population and live weight gain. Overall, the inclusion of olive oil in low concentrations (2% of DM) positively influences feed intake and nutrient digestibility in hair sheep lambs.
La apicultura en la región maya de Yucatán es una actividad milenaria que ha sufrido diversas transformaciones a partir de la sustitución de la abeja sin aguijón hasta la producción de excedentes para el mercado. La finalidad del presente estudio fue caracterizar las principales variables técnicas y socioeconómicas asociadas a la apicultura a pequeña escala. Se obtuvo información de campo mediante una encuesta por muestreo estadístico estratificado, los estratos considerados fueron productores con hasta 25 colmenas, de 26 a 50 y de 51 hasta 100. Se encontró que los apicultores tienen edad avanzada y escolaridad limitada; practican la actividad de forma complementaria y tienen una limitada organización grupal. Las prácticas generalizadas de manejo de las colmenas son la alimentación artificial, cambio de reinas, cambio de panales y división de las colonias. De los tres componentes analizados el factor económico es el que ejerce mayor influencia sobre la tenencia de colmenas.
El objetivo del estudio fue determinar el valor nutritivo, la fermentación ruminal y la producción de metano in vitro del follaje de especies arbóreas y arbustivas con potencial forrajero como estrategias de alimentación en época de secas y mitigación de las emisiones de metano. El líquido ruminal fue extraído por medio de una sonda esofágica. Se utilizó un diseño en bloques repetidos en el tiempo. El contenido de proteína cruda (PC) y fibra detergente neutro y acida fluctuaron de 6.14% a 21.78%, 44.34% a 77.43% y 16.12% a 49.53% de materia seca (MS). No se encontró diferencia en el volumen máximo de gas (p > 0.05). La degradabilidad fue diferente, observando la mejor en Tithonia diversifolia (760.40 g/kg de MS), Morus alba (800.66 g/kg de MS) y Hibiscus rosa-sinensis (800.16 g/kg de MS), mientras que la más baja fue Megatryrsus maximus (390.40 g/kg de MS y 287.40 g/kg de materia orgánica (MO)) (p < 0.05). No se observó diferencia en la producción de metano (CH4) (p > 0.05). Se concluye que L. leucocephala, P. piscipula, B. alicastrum y G. ulmifolia, T. diversifolia y M. alba tienen un alto potencial para ser incluidos en la dieta de rumiantes como fuentes de proteína en época de secas y estrategias para mitigar las emisiones de metano.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.