RESUMO
The aim of this study was determine the energy and protein requirements for maintenance and gain of Nellore steers. Thirty six Nellore steers with an average weight and age of 359±13 kg and 20 months at the beginning of the trial were individually fed for 56. The steers were fed the same diet (76.43% TDN and 13.62% CP) in three levels of dry matter (DM) intake, ad libitum, 75 g DM/kg BW0.75 and 60 g DM/kg BW0.75. The initial and final body composition was estimated with the marker deuterium oxide that allowed repeated water estimate in the same animal. Deuterium in blood samples was analyzed by mass spectrometry. The effects of intake levels, comparison of intercept and slope among feeding level, and equations were evaluated by the analysis of variance, adopting P<0.05 as a significant level. The net energy for maintenance was 75 kcal/kg EBW 0.75 or 70 kcal/kg BW 0.75. The net energy for gain for steers with 350 to 450 kg weight was 5.1 to 6.1Mcal. The efficiency of energy utilization for maintenance, km, was 0.7492 and for weight gain, kg, was 0.3404. The metabolizable protein requirement for maintenance was 4.32 * BW0.75and the net protein for gain was estimated with the equation NPg= (254.68*EBWG) (29.38*RE). The technique of deuterium oxide marker used to estimate energy and protein requirement for maintenance and weight gain at Nellore steers confirm the hypothesis presented in NRC, that NEmis lower than the requirement for taurine cattle. On the other hand, the reverse was true for the NP requirement for maintenance and for weight gain. We consider that indirect method using D2O for estimate body composition in zebu cattle was suitable to determine nutrient requirements.(AU)
Assuntos
Animais , Bovinos , Aumento de Peso , Composição Corporal , Crescimento e Desenvolvimento , Óxido de Deutério/análise , Necessidades Nutricionais , BiomarcadoresRESUMO
The aim of this study was determine the energy and protein requirements for maintenance and gain of Nellore steers. Thirty six Nellore steers with an average weight and age of 359±13 kg and 20 months at the beginning of the trial were individually fed for 56. The steers were fed the same diet (76.43% TDN and 13.62% CP) in three levels of dry matter (DM) intake, ad libitum, 75 g DM/kg BW0.75 and 60 g DM/kg BW0.75. The initial and final body composition was estimated with the marker deuterium oxide that allowed repeated water estimate in the same animal. Deuterium in blood samples was analyzed by mass spectrometry. The effects of intake levels, comparison of intercept and slope among feeding level, and equations were evaluated by the analysis of variance, adopting P<0.05 as a significant level. The net energy for maintenance was 75 kcal/kg EBW 0.75 or 70 kcal/kg BW 0.75. The net energy for gain for steers with 350 to 450 kg weight was 5.1 to 6.1Mcal. The efficiency of energy utilization for maintenance, km, was 0.7492 and for weight gain, kg, was 0.3404. The metabolizable protein requirement for maintenance was 4.32 * BW0.75and the net protein for gain was estimated with the equation NPg= (254.68*EBWG) (29.38*RE). The technique of deuterium oxide marker used to estimate energy and protein requirement for maintenance and weight gain at Nellore steers confirm the hypothesis presented in NRC, that NEmis lower than the requirement for taurine cattle. On the other hand, the reverse was true for the NP requirement for maintenance and for weight gain. We consider that indirect method using D2O for estimate body composition in zebu cattle was suitable to determine nutrient requirements.
Assuntos
Animais , Bovinos , Aumento de Peso , Composição Corporal , Crescimento e Desenvolvimento , Necessidades Nutricionais , Óxido de Deutério/análise , BiomarcadoresRESUMO
An objective method of assessing breastfeeding practices is required to evaluate progress toward the World Health Organization Global Target 2025: to increase exclusive breastfeeding (EBF) rates in the first 6 months to at least 50% by 2025. Currently, assessment of EBF at the population level is based on mother or caregiver reporting, which risks recall and social desirability bias. A more objective method is the deuterium oxide dose to mother (DTM) technique, in which lactating mothers are given a small amount of deuterium-labeled water. The infant receives deuterium during breastfeeding, and a compartmental model is used to determine the amount of human milk consumed by the infant, and the exclusivity of breastfeeding practices. If the amount of human milk consumed by an infant is determined using the DTM technique and the concentration of nutritional components or potentially toxic contaminants is measured, then the infant's intake of essential nutrients or environmental contaminants can be ascertained.
Assuntos
Aleitamento Materno , Óxido de Deutério/farmacocinética , Ingestão de Alimentos , Leite Humano/química , Adulto , África Subsaariana , Ásia , Peso Corporal , Óxido de Deutério/administração & dosagem , Óxido de Deutério/análise , Feminino , Infecções por HIV , Humanos , Lactente , Recém-Nascido , Masculino , México , Micronutrientes/análise , Resíduos de Praguicidas/análise , Saliva/química , Deficiência de Vitamina A/etiologia , Abastecimento de ÁguaRESUMO
Objetivo. Adaptar la metodología de evaluación de ingestión de leche humana con isótopos estables utilizando un espectroscopio infrarrojo en lugar de un espectrómetro de masas. Material y métodos. Previo consentimiento informado, 12 mujeres que estaban amamantando recibieron 30 g de D2O por vía oral. a las 4 horas y 1, 3, 6, 9 y 14 días depués de la dosificación, se les tomó una muestra de saliva. Las muestras de saliva de los bebés se tomaron a los 1,2,5,6,13 y 14 días. Todas las muestras fueron preparadas por sublimación y centrifucación y la determinación de la concentración de D2O se determinó por espectroscopía de infrarrojo. Resultados. La recuperación del sistema de sublimación fue superior al 95 por ciento del volumen total tanto de agua sola como de saliva. Se encontró que con tres evaluaciones se alcanza la misma confiabilidad que con 5 evaluaciones. Los volúmenes de ingestión de leche humana fueron similares a los informados por otros autores