In old age, the complex relation of food consumption with energy and nutrient requirements finds expression in both single and multiple nutritional problems. Addressing conditions affecting intake -- either from foods or from supplements -- endogenous production, bioefficacy and/or requirements can benefit nutritional health in old age through balancing requirements and supply.

When developing animals encounter nutrient restriction, most tissues stop growing. Some vital tissues, however, such as the brain, continue to grow. Now, Cheng et al. (2011) identify Alk as the kinase that allows the Drosophila brain to continue growing during nutrient restriction by bypassing the requirements for insulin receptor and TOR activation.

Nutritional requirements are typically estimated based on feeding trials with animals or birds offered several amounts of the critical nutrient(s). A nutrient response function is then fitted to data from the feeding trials. Modern computer techniques allow for a variety of functional forms to be used as nutrient response functions. However, the performance of these models is almost undistingui...

Many equine nutrient requirements are based on certain assumptions about how well horses digest and absorb nutrients. Unfortunately, a great many questions remain unanswered about nutrient digestibility in horses. How well do horses utilize different sources of nutrients? What nutrients interact with one another to affect digestibility? Over the past five years, Kentucky Equine Research has con...

INTRODUCTION Dietary control and nutrient intake are critical aspects of any metabolic study, but this is especially true in the case of bed rest studies. We sought to define nutritional requirements, develop menus, and implement them during long-duration head-down bed rest studies. METHODS The dietary goals were to provide 100% of subjects' nutrient requirements and to maintain subjects' bod...

Infancy and early childhood (ie, birth through age 24 months) represent a period of life with both exquisite opportunity and vulnerability for neurodevelopment. This is due to rapid brain development, both anatomic and functional, as well as to high nutrient requirements during a time of dependence on human milk and complementary foods. Complex interactions exist among nutrition, social, and ph...

A factorial experiment was conducted to assess nutrient utilization by growing lambs maintained on three levels each of digestible energy (high: HE, medium: ME, low: LE) and protein (high: HP, medium: MP, low: LP) in nine combinations (HEHP, HEMP, HELP, MEHP, MEMP, MELP, LEHP, LEMP, LELP). The experiment was conducted during the hot season in a semiarid location. Daily dry matter intake (DMI) w...

We evaluated and compared various broken-line regression models and SAS (SAS Inst. Inc., Cary, NC) procedures for estimating nutrient requirements from nutrient dose response data. We used the SAS (Version 9) procedures NLIN and NLMixed and the response data of Parr et al. (2003), who evaluated the isoleucine requirement of growing swine. The SAS NLIN was used to fit 2 different broken-line reg...

Over the last two decades, an additional ‘tool’ to measure nutrient intake has been introduced by the UK Government. This is the ground-breaking National Diet and Nutrition Survey (NDNS), which has revealed widespread risk of micronutrient deficiency. For each NDNS, about 2000 people are selected at random from postal codes to reflect the age, sex, income, and geographical distribution of the U...

background and objectives: the quefts model is using for optimizing fertilizer managements in crops, but it has not been used in iran yet. quefts accounts for interactions among npk affecting the ie of n, p and k and allows differentiation according to different yield levels targeted. it is necessary to determine crops parameters before application the model in the studying area. the first step...