RESUMEN
ABSTRACT A substantial proportion of beef production in Colombia originates in its extensive Eastern Plains. However, in this scenario and in a global context, demand for cattle production increasingly requests that it satisfies social and environmental expectations in addition to being economically efficient. A dataset containing five-year long records of cow-calf production systems collected at Carimagua Research Centre located in the Meta Department was retrospectively interrogated to understand the liveweight (LW)-derived flux matrix dynamics of methane (CH4) emissions. Estimated total CH4 (kg) emissions during the gestation period, were similar between conventional weaned (CW; 37.86 ± 0.506 kg) and early weaned (EW; 37.47 ± 0.476 kg) cows. However, averaged over two lactations, total CH4 emissions were larger (p < 0.0001) in CW cows (38.67 ± 0.456 kg) than in their EW (14.40 ± 0.435 kg) counterparts. Total gas emissions from birth to comparable commercial yearlings age were higher (p < 0.0001) for CW (43.11 ± 0.498 kg) calves than for EW (40.27 ± 0.472 kg) calves. It was concluded that mid and long-term pastoral datasets and new concerns are well suited to understand different contexts and adaptations to the contemporary weather conditions. Nevertheless, conventional farming systems will be less environmentally vulnerable if EW management practices involve the strategic and temporal use of improved pastures. The roles of veterinary medicine and animal sciences are briefly discussed in the context of unprecedented climate variability to provide a guide to the uncertain future.
RESUMEN Una proporción substancial de la producción de carne de res en Colombia se origina en sus Llanos Orientales. Sin embargo, allí, así como en un contexto global, dicha producción ganadera debe ser económicamente eficiente y satisfacer expectativas sociales y ambientales. Considerando algunos de esos intereses, se analizaron cinco años de eventos productivos y de manejo del destete implementados en el Centro de Investigaciones Carimagua, localizado en el departamento del Meta, para interpretar en vacas de carne y sus crías las dinámicas de peso vivo asociadas con emisiones derivadas de metano (CH4). Emisiones totales de CH4 (kg) durante la gestación fueron similares entre las vacas destetadas convencionalmente (CW; 37.86 ± 0.506 kg) y aquellas destetadas tempranamente (EW; 37.47 ± 0.476 kg). Sin embargo, el promedio de dos lactancias demostró mayores (p < 0.0001) emisiones en vacas CW (38.67 ± 0.456 kg) que en vacas EW (14.40 ± 0.435 kg). Emisiones acumuladas entre el nacimiento y el levante fueron mayores (p < 0.0001) en terneros CW (43.11 ± 0.498 kg) que en terneros EW (40.27 ± 0.472 kg). Se concluyó que nuevos cuestionamientos y datos de pastoreo de mediano y largo plazo son apropiados para entender contextos innovadores y adaptaciones a las condiciones climáticas actuales. Sin embargo, el manejo convencional en las fincas será menos vulnerable al medio ambiente si prácticas de destete temprano son introducidas considerando el uso estratégico y temporal de pastos mejorados. Los roles de la medicina veterinaria y las ciencias animales se discuten brevemente en el contexto de la variabilidad climática existente.
RESUMEN
Avaliou-se o efeito do sorgo inteiro em comparação ao milho sobre o rendimento de carcaça, rendimento de cortes comerciais e a composição química da carcaça de frangos machos e fêmeas aos 42 dias de idade. Foram utilizados 960 frangos da linhagem Hubbard Flex. O experimento foi conduzido num delineamento inteiramente casualizado com esquema fatorial 3 x 2, sendo 3 rações - milho grão moído (Mm), sorgo grão inteiro (Si) e sorgo grão moído (Sm) - e 2 sexos. No 42o dia 12 frangos de cada tratamento, metade de cada sexo, foram abatidos e determinados o rendimento e a composição de carcaça. Não houve interação entre os fatores estudados. As fêmeas apresentaram maior percentagem de vísceras, rendimento de asa e peito e carcaças mais calóricas. Os machos apresentaram melhor peso vivo e peso de carcaça. O sorgo, independente da forma física, melhorou parâmetros da carcaça sem interferir na sua composição química e no rendimento de cortes. Conclui-se que o sorgo inteiro pode substituir o milho sem prejudicar o rendimento de cortes comerciais bem como as características bromatológicas da carcaça.
Was evaluated the effect of whole sorghum compared to corn on carcass yield, commercial cuts and chemical carcass composition of male and female chickens at 42 days of age. Were used 960 Hubbard Flex broilers. The experiment was conducted in a completely randomized design with 3 x 2 factorial design, with 3 rations - ground corn grain (Mm), grain sorghum (Si) and ground sorghum grain (Sm) and 2 sexes. In the 42nd day 12 chickens from each treatment, half of each sex, were slaughtered and determined the performance and carcass composition. There was no interaction between the factors studied. Females had a higher viscera percentage, wing and breast yield and more caloric carcasses. Males showed higher liveweight and carcass weight. Sorghum, regardless of physical form, improved carcass characteristics without interfering in their chemical composition and cuts yield. It was conclude that the whole sorghum can replace corn without harming the commercial cuts as well as the bromatologic characteristics of the carcass.