Emisión de metano en ovinos alimentados con Pennisetum purpureum y árboles que contienen taninos condensados

El objetivo fue evaluar el efecto de los taninos condensados (TC) contenidos en el follaje de arbóreas tropicales, sobre el consumo de materia seca y orgánica (CMS, CMO), la digestibilidad de la materia seca (DMS) y emisiones de metano (CH4) en ovinos alimentados con una ración basal de pasto Pennisetum purpureum. Cuatro ovinos de pelo con un peso vivo promedio de 21.6±2.0 kg se sometieron a cuatro tratamientos en un diseño cuadro latino 4 x 4. Los tratamientos fueron P. purpureum (PP), P. purpureum + Havardia albicans (PPHA), P. purpureum + Bursera simaruba (PPBS), y P. purpureum + Acacia pennatula (PPAP); el follaje de las arbóreas se incluyó en 300 g/kg de MS de la ración. El consumo, la digestibilidad y la producción total de metano entérico se midieron por periodos de 23 h. La producción de metano se midió en cajas de respiración de circuito abierto. El consumo y digestibilidad de la MS y materia orgánica (MO) entre los tratamientos PP, PPHA, PPBS y PPAP no se afectaron por la inclusión de los follajes de arbóreas en la ración (P>0.05). Cuando la producción de CH4 se expresó en L/kg del CMS, CMO o consumo de fibra detergente neutro los resultados fueron similares entre tratamientos (PP, PPHA, PPBS y PPAP) (P>0.05). Se concluye que los TC contenidos en el follaje de Havardia albicans, Acacia pennatula y Bursera simaruba no afectaron las emisiones de CH4 al nivel de incorporación de 30 % de la MS; tampoco se observaron efectos en el CMS, CMO, DMS y concentración molar de ácidos grasos volátiles

Relación entre el peso al destete y el comportamiento productivo de corderos de engorda en corrales elevados

The aim of the present study was to evaluate the effect of weaning weight on the productive performance of fattening lambs in raised pens. Data from 932 lambs from one farm over a period of two years were analyzed. The statistical model included the fixed effects of weaning weight (<11, 12-14, 15-17, >18 kg), year (2012 and 2013), season of the year (rainy, dry and northern winds) and simple significant interactions of year × season and the residual error, NID (0, σ2e) on average daily weight gain (GDP, g/d), final weight (PF, kg) and fattening period (PE, days). Weaning weight affected all the response variables evaluated (p<0.05). The weaned lambs between 12-14, 15-17 and >18 kg had a similar GDP, and in turn obtained a higher GDP than the weaned lambs with lower weight (<11 kg; p<0.05). The PF was similar for lambs weaned at 15-17 and >18 kg but higher than that obtained by lambs weaned at <11 kg (p<0.05). The PE was different (p<0.05) for each group of weaning weight, being greater the lower the weaning weight. In conclusion, weaning weight is a factor that affects the GDP, PF and PE of lambs in raised pens.El objetivo del presente estudio fue evaluar el efecto del peso al destete sobre el comportamiento productivo de corderos de engorda en corrales elevados. Se analizaron datos en un periodo de dos años de 932 corderos de una granja. El modelo estadístico incluyó los efectos fijos del peso al destete (<11, 12-14, 15-17, >18 kg), el año (2012 y 2013), la época del año (lluvias, secas y nortes) y las interacciones simples significativas del año × la época del año y el error residual, NID (0, σ2e) sobre la ganancia diaria de peso posdestete (GDP, g/d), el peso final (PF, kg) y el periodo de engorda (PE, días). El peso al destete afectó todas las variables de respuesta evaluadas (p<0.05). Los corderos destetados entre los 12-14, 15-17 y >18 kg, tuvieron una GDP similar, y a su vez obtuvieron una mayor GDP que los corderos destetados con menor peso (<11 kg; p<0.05). El PF fue similar para los corderos destetados con 15-17 y >18 kg, superior al obtenido por los corderos destetados a los <11 kg (p<0.05). El PE fue diferente (p<0.05) para cada grupo de peso al destete, siendo mayor para los de menor peso al destete. En conclusión, el peso al destete es un factor que afecta la GDP, PF y PE de corderos en corrales elevados

Residual feed intake and enteric methane production in growing Pelibuey sheep

SIMPLE SUMMARY: This study determined residual feed intake (RFI), volatile fatty acid (VFA) production and enteric methane (CH(4)) from growing Pelibuey sheep. In this case, 12 non-castrated Pelibuey were classified as low, medium, and high RFI. Efficient lambs (low-RFI) had lower intakes of dry matter, organic matter, crude protein and neutral detergent fiber. Those lambs produced less CH(4). Feed intake of low RFI lambs was approximately 16% lower (p < 0.05) while growth rate was not significantly different. Their average energy loss, expressed as CH(4) production per kilogram of metabolic weight, was 17% lower (p < 0.05). ABSTRACT: This study was carried out to evaluate the residual feed intake (RFI), volatile fatty acid (VFA) production and enteric methane (CH(4)) from growing Pelibuey sheep. In this case, 12 non-castrated Pelibuey with an initial average live weight (LW) of 21.17 ± 3.87 kg and an age of 3 months, were housed in individual pens and fed a basal diet with 16% of crude protein and 11 MJ ME for 45 days. Dry matter intake (DMI) was measured and the daily weight gain (DWG) was calculated using a linear regression between the LW and experimental period. Mean metabolic live weight (LW(0.75)) was calculated. RFI was determined by linear regression with DWG and LW(0.75) as independent variables. Lambs were classified as low, medium, and high RFI. Feed efficiency was determined as DWG/DMI. For determining rumen pH, ammonia nitrogen concentration NH(3)-N)(,) and VFA, ruminal fluid was obtained using an esophageal probe on day 40. Feed intake of low RFI lambs was approximately 16% lower (p < 0.05) while growth rate was not significantly different. Their average energy loss, expressed as CH(4) production per kilogram of metabolic weight, was 17% lower (p < 0.05)

Design and construction of low-cost respiration chambers for ruminal methane measurements in ruminants

Ruminant animals contribute significantly to methane emissions in tropical regions. Nonetheless, there are few facilities available in those regions of the world for in vivo measurement of methane production in cattle. The aim of the present work was to describe the design, construction and operation of respiration chambers for in vivo measurement of methane production in cattle in Mexico. Locally available materials were used in the construction. Walls, roof and doors were constructed of thermic panels with two windows of acrylic at the front so the animal can be observed at all times. Chambers have an air volume of 9.97 m3. Air is drawn from the chamber at a rate of 500 L/min by the effect of mass action flow generators. Methane was measured in air samples with an infrared analyzer. Chambers operate under a slight negative pressure of around -500 Pa. Air temperature inside the chambers is kept at 23 °C with an air conditioner, while relative humidity is maintained at 55 % with a dehumidifier. Functioning of the chambers was evaluated in Bos indicus, Nelore cattle fed Taiwan grass (Pennisetum purpureum) and a concentrate (18 % crude protein), and measurements were made during runs of 23 h duration. Methane production was on average 173.2 L per day, while the emission factor was 17.48 L methane per kilogram o dry matter consumed. It concludes that this respiration facility is capable of measuring methane production accurately in cattle fed tropical rations

Методология эконометрического анализа международных денежных переводов как формы вывоза капитала

ABSTRACTRuminant animals contribute significantly to methane emissions in tropical regions. Nonetheless, there are few facilities available in those regions of the world for in vivo measurement of methane production in cattle. The aim of the present work was to describe the design, construction and operation of respiration chambers for in vivo measurement of methane production in cattle in Mexico. Locally available materials were used in the construction. Walls, roof and doors were constructed of thermic panels with two windows of acrylic at the front so the animal can be observed at all times. Chambers have an air volume of 9.97 m3. Air is drawn from the chamber at a rate of 500 L/min by the effect of mass action flow generators. Methane was measured in air samples with an infrared analyzer. Chambers operate under a slight negative pressure of around -500 Pa. Air temperature inside the chambers is kept at 23 °C with an air conditioner, while relative humidity is maintained at 55 % with a dehumidifier. Functioning of the chambers was evaluated in Bos indicus, Nelore cattle fed Taiwan grass (Pennisetum purpureum) and a concentrate (18 % crude protein), and measurements were made during runs of 23 h duration. Methane production was on average 173.2 L per day, while the emission factor was 17.48 L methane per kilogram o dry matter consumed. It concludes that this respiration facility is capable of measuring methane production accurately in cattle fed tropical rations