Techniques have becn developed to produce microbial phytase for addition to diets for simple-stomached animals, with the aim to improve phosphorus availability from phytate-P in plant sources. The activity of the crude microbial phytase showed pH optima a t pH 5.5 and 2.5. The enzyme was able to degrade phytate in vitro in soya-bean meal, maize and a liquid compound feed for pigs. When microbial phytase was added to low-P diets for broilers the availability of P increased to over 60% and the amount of P in the droppings decreased by 50%. The growth rate and feed conversion ratio on the low-P diets containing microbial phytase were comparable to or even better than those obtained on control diets. Addition of microbial phytase to diets for growing pigs increased the apparent absorbability of P by 24%. The amount of P in the faeces was 35% lower.Phosphorus availability : Microbial phytase: Broilers: Pigs Feeds for poultry and pigs mainly contain ingredients of plant origin. About two-thirds of the phosphorus in these products is present as phytate-P which has a low availability in simple-stomached animals. It therefore contributes to the P pollution problems in areas having an intensive livestock production such as The Netherlands.Many fungi, bacteria and yeasts produce the enzyme phytase which is needed for the hydrolysis of phytate to inositol and inorganic phosphate. Nelson et ul. (1968) were the first to add phytase, produced by a culture of Aspergillusficuum, to liquid soya-bean meal. The feed was incubated for 2-24 h at 50". After drying, it was fed to 1-d-old chicks, Thc birds showed a considerable increase in bone ash percentage over controls receiving no inorganic phosphate. In a second experiment (Nelson rt ul.

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In the investigation of pre-sleep variables that affect sleep stage distribution and eye movement bursts during the rapid eye movement (REM) stage of sleep, 24 paid student volunteers slept three nights in the laboratory. Preceding sleep on the third night they underwent a four-hour learning task which involved either visual learning (Group VL), minimal visual learning (Group MVL), auditory learning (Group AL) or minimal auditory learning (Group MAL). Groups VL and AL showed significantly greater increases in percentage REM sleep than groups MVL and MAL from the control to the experimental night, while groups VL and MVL showed greater increases in rapid eye movement bursts occurring during REM than groups AL and MAL from control to experimental night. These results were interpreted to support the notion that memory consolidation occurs during REM sleep. It was speculated that actual eye movements represent a sensory scanning process of pre-sleep events.

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