PREDICTION OF TOTAL ENERGY EXPENDITURE AND MODERATE-TO-VIGOROUS PHYSICAL ACTIVITY BY THE NHANES PAQ

R.P. McGrath*, A.J. Moshfegh**, M. Kramer**, W.V. Rumpler**, D.J. Baer**, C.A. Vella*, P.W. Scruggs*, & D.R. Paul* *University of Idaho, Moscow, ID; **U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Beltsville, MD The NHANES physical activity questionnaire (PAQ) is a popular self-report method for measuring physical activity, although the validity of total energy expenditure (TEE) and moderate-to-vigorous physical activity (MVPA) estimates have yet to be validated. PURPOSE: To compare estimates of TEE (TEE-PAQ) and MVPA (MVPA-PAQ) from the NHANES PAQ with TEE via doubly labeled water (TEE-DLW), and total physical activity (TPA) and MVPA (MVPA-A) via accelerometer. METHODS: 244 women (age 49.2 ±10.8 yrs. and BMI 26.2 ± 4.85 kg/m2) and 242 men (age 49.7 ±11.0 yrs. and BMI 26.7 ± 4.08 kg/m2) completed the NHANES PAQ (2001 version). TEE was measured by the doubly labeled water technique over a 2-week period. TPA and MVPA-A were measured via accelerometer for a minimum of 7 days. T-tests were conducted to compare differences between TEE-PAQ and TEE-DLW, and MVPA-PAQ and MVPA-A. To compare the predictions of TEE-PAQ and TEE-DLW, regression analyses were conducted utilizing TPA and body weight as independent variables. RESULTS: TEE-PAQ (9.61 ± 2.60 MJ/d) was significantly lower than TEE-DLW (10.6 ± 2.38 MJ/d) (pThese data indicate that the NHANES PAQ underestimates TEE when compared to doubly labeled water (1.0 MJ/d), with a large amount of variability present (2.17 MJ/d on average per subject). The lower residual variance in the comparison between TEE-DLW and TPA (when compared to TEE-PAQ and TPA) indicate that TEE-PAQ may be the less valid approach. Similarly the PAQ overestimates MVPA by 11.2 min/d when compared to accelerometry, with an average error of 21.1 min/d per subject. Therefore, estimates of TEE and MVPA from the NHANES PAQ should be interpreted with caution. This study was funded by the USDA

Desempenho e características de carcaça de cordeiros alimentados com dietas contendo alta proporção de concentrado adicionadas de agentes tamponantes Performance and carcass characteristics of feedlot lambs fed high grain diets with buffer compounds

Objetivou-se com este estudo avaliar os efeitos da adição de bicarbonato de sódio ou de fontes de calcário com diferentes granulometrias na ração, associadas ou não a monensina sódica, sobre o desempenho e as características de carcaça de cordeiros confinados recebendo dietas contendo alta proporção de concentrado. Quarenta e dois cordeiros Santa Inês com peso inicial de 21 ± 3 kg e 88 ± 5 dias de idade foram distribuídos em blocos completos casualizados em arranjo fatorial 2 &#215; 3, com seis tratamentos e sete repetições. Os animais foram alimentados com rações contendo 90% de concentrado, 10% de feno de "coastcross", uma fonte de calcário (calcário calcítico ou calcário calcítico tipo filler) ou bicarbonato de sódio (NaHCO3), com ou sem adição de monensina sódica (30 mg/kg da MS). Não foi observada influência dos agentes tamponantes no consumo de matéria seca e no ganho de peso médio diário. Entretanto, a conversão alimentar dos animais alimentados com as rações contendo monensina sódica (3,32 kg MS/kg de ganho) foi melhor que naqueles que consumiram as rações sem esse aditivo (3,58 kg MS/kg de ganho). Não houve efeito dos agentes tamponantes nos parâmetros de carcaça avaliados, observando-se valores médios de 50,4%; 2,4%; 13,9 cm² e 1,9 mm para o rendimento de carcaça quente, a perda por resfriamento, a área de olho-de-lombo e a espessura de gordura, respectivamente. A adição de monensina melhora a conversão alimentar e pode aumentar a rentabilidade do sistema de produção de cordeiros confinados.<br>The objective of this study was to assess the effects of adding sodium bicarbonate or limestone sources with different particle sizes to the diet, and their interaction with sodium monensin, on the performance and carcass characteristics of feedlot lambs fed fed high grain diets. Forty two Santa Ines lambs were used with 21 ± 3 kg initial average body weight and 88 ± 5 days old in feedlot, placed a randomized complete block design in a 2 &#215; 3 factorial arrangement with six treatments and seven replications. Animals were fed diet containing 90% concentrate, 10% "coastcross" hay, with one source of limestone (limestone or "filler" limestone) or sodium bicarbonate (NaHCO3), with or without monensin (30 mg/kg DM). No influence was observed of the buffering agents on dry matter intake or average daily gain. However, the feed conversion of the animals fed diet containing sodium monensin (3.34 kg DM/kg gain) was better than those fed diets containing monensin (3.32 kg DM/kg gain) compared to diets without monensin (3.58 kg DM/kg gain). There was no effect of the buffering agents on the carcass characteristics assessed: the mean values were 50.4%, 2.42%, 13.9 cm² and 1.9 mm hot carcass weight, chilling losses, longissimus muscle area and fat thickness, respectively. Adding monensin to the diet improves feed conversion and may make the feedlot lambs system more profitable