It has been nearly 30 years since the last FAO/WHO recommendations on calcium intake were published in 1974 (1) and nearly 40 years since the experts' meeting in Rome (2), on whose findings these recommendations were based. During this time, a paradigm shift has occurred with respect to the involvement of calcium in the etiology of osteoporosis. The previous reports were written against the bac...

Trace minerals such as zinc, copper, and manganese are essential cofactors for hundreds of cellular enzymes and transcription factors in all animal species, and thus participate in a wide variety of biochemical processes. Immune development and response, tissue and bone development and integrity, protection against oxidative stress, and cellular growth and division are just a few examples. Defi...

Major advances in the field of trace mineral nutrition occurred in the twenty century. All of the trace minerals recognized as being important in ruminant nutrition were first shown to be essential in the 1900's with the exception of iron. Between 1920 and 1960 naturally occurring deficiencies of iodine, copper, cobalt, manganese, selenium, and zinc were first reported in cattle. Today it is co...

279 14.1 Role of vitamin B12 in human metabolic processes Although the nutritional literature still uses the term vitamin B12, a more specific name for vitamin B12 is cobalamin. Vitamin B12 is the largest of the B complex vitamins, with a relative molecular mass of over 1000. It consists of a corrin ring made up of four pyrroles with cobalt at the centre of the ring (1, 2). There are several vi...

Among deciduous fruit crops, maximum sustained yields under ideal conditions reportedly range from 22 MT/ha in sweet cherry to 112 MT/ha in apple: about a 5-fold difference. Root length densities under fruit trees, however, range from about 0.2 km/m in apple to about 12 km/m in kiwifruit: a 60-fold difference. What causes these differences among the root systems of different fruit crops? Patter...

Minerals can be divided into two main categories, 1) macro-minerals and 2) micro or trace minerals. Macro minerals are minerals that are needed/required in relatively large amounts in comparison to micro or trace elements which are needed/required in relatively small amounts. In general macro minerals are required at concentrations greater than 100 ppm of the diet and are often expressed as a p...

145 8.1 Nutrients with an antioxidant role The potential beneficial effects of antioxidants in protecting against disease have been used as an argument for recommending increasing intakes of several nutrients above those derived by conventional methods. If it is possible to quantify such claims, antioxidant properties should be considered in decisions concerning the daily requirements of these ...

Ethylene is a gaseous plant hormone involved in many aspects of plant life, including seed germination, flower senescence, abscission, and fruit ripening (Abeles et al., 1992). It also plays a very important role in the responses of plants to both biotic and abiotic stresses (Abeles et al. The production of ethylene is tightly regulated by internal signals, and usually increases in response to ...

Requirements have been published for 13 different minerals in beef cattle diets. Other minerals such as chlorine, chromium, molybdenum, and nickel are known to be essential for beef cattle; however, there is currently not enough data available to accurately determine requirements. For some of the required minerals, requirements vary depending on cow size and stage of production. This variabilit...