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The objective of this study was to test the hypothesis that serum biotin concentration and biotin balance (consumed - [urinary output + fecal output]) measured as total avidin-binding substances (biotin + biotin metabolites) are responsive to changes in the proportions of dietary alfalfa meal and concentrate fed to sheep. Eight sheep (initial BW = 40 kg) consumed a pelleted alfalfa meal-based diet that had 95:5, 48:52, 23:77, or 9:91% alfalfa meal:concentrate ratios (DM basis) in a replicated 4 x 4 Latin square design with 20-d periods (10 d of acclimation, 7 d of adaptation, and a 3-d collection period with jugular blood drawn on the last day). Replacing alfalfa meal with concentrate in the pelleted diets decreased dietary concentrations of biotin proportionally. As the percentage of alfalfa meal in the diet decreased, there was a linear decrease in daily DM intake (1,128 to 901 g of DMI/d; P < 0.01), with a linear (P < 0.01) and quadratic (P < 0.01) increase in the apparent total-tract DM digestibility of diets (51.0 to 80.0%). The biotin consumed decreased with alfalfa meal proportion in the diet (linear, P < 0.01). Both fecal biotin concentration (linear, P < 0.01) and fecal biotin output (quadratic, P < 0.05) increased, reaching peaks at 23% alfalfa meal. Fecal biotin output was not correlated with biotin intake, DMI, or intake of digestible DM. Mean urinary output, urinary biotin concentration, urinary biotin output, and serum biotin concentration were not affected by treatments. Means of biotin balance were negative and revealed the same trends among treatments as did fecal output. Biotin balance was a quadratic (P < 0.05) function of decreasing alfalfa meal in the diet, with more negative values at the alfalfa meal:concentrate ratio of 23:77. Results suggest that the greatest synthesis of biotin in the total digestive tract occurs with diets of either 52 or 77% concentrate for sheep; however, research addressing the significance of biotin metabolites on biotin balance and plasma biotin pool is needed.

The objective of this study was to test the hypothesis that serum biotin concentration and biotin balance (consumed - [urinary output + fecal output]) measured as total avidin-binding substances (biotin + biotin metabolites) are responsive to changes in the proportions of dietary alfalfa meal and concentrate fed to sheep. Eight sheep (initial BW = 40 kg) consumed a pelleted alfalfa meal-based diet that had 95:5, 48:52, 23:77, or 9:91% alfalfa meal:concentrate ratios (DM basis) in a replicated 4 x 4 Latin square design with 20-d periods (10 d of acclimation, 7 d of adaptation, and a 3-d collection period with jugular blood drawn on the last day). Replacing alfalfa meal with concentrate in the pelleted diets decreased dietary concentrations of biotin proportionally. As the percentage of alfalfa meal in the diet decreased, there was a linear decrease in daily DM intake (1,128 to 901 g of DMI/d; P0.01), with a linear (P0.01) and quadratic (P0.01) increase in the apparent total-tract DM digestibility of diets (51.0 to 80.0%). The biotin consumed decreased with alfalfa meal proportion in the diet (linear, P0.01). Both fecal biotin concentration (linear, P0.01) and fecal biotin output (quadratic, P0.05) increased, reaching peaks at 23% alfalfa meal. Fecal biotin output was not correlated with biotin intake, DMI, or intake of digestible DM. Mean urinary output, urinary biotin concentration, urinary biotin output, and serum biotin concentration were not affected by treatments. Means of biotin balance were negative and revealed the same trends among treatments as did fecal output. Biotin balance was a quadratic (P0.05) function of decreasing alfalfa meal in the diet, with more negative values at the alfalfa meal:concentrate ratio of 23:77. Results suggest that the greatest synthesis of biotin in the total digestive tract occurs with diets of either 52 or 77% concentrate for sheep; however, research addressing the significance of biotin metabolites on biotin balance and plasma biotin pool is needed.

We tested the effects of substituting a whey protein concentrate for dam's colostrum at first feeding and of 1% brewer's yeast in dry feed on calf health and performance. Eighty-four calves were assigned to four preweaning and eight postweaning treatments based on feeding either dam's colostrum or a whey protein concentrate at birth and either yeast or no yeast in the dry feed both before and after weaning. After the first feeding, all calves were fed colostrum through 4 d of age and an all milk protein milk replacer from d 5 to 46 of age. Daily feed intakes, health measurements, and weekly BW were recorded. Calves fed whey protein concentrate at birth had similar health parameters and greater feed efficiency than calves fed colostrum over the preweaning period. Addition of 1% brewer's yeast to the dry feed apparently reduced the incidence of fever and the number of associated antibiotic treatments during the preweaning period, but had no effects thereafter. Under the conditions of this study, whey protein concentrate was an effective substitute for dam's colostrum at first feeding, and 1% brewer's yeast fed in dry feed may reduce susceptibility to infection prior to weaning.

EDITOR,--David Armstrong and Mick Nicoll do not provide any evidence to justify their assertion that the average consultant saw 1680 new patients in 1949,1 a year in which …

Skin tests were performed on 210 patients with house dust allergy and bronchial asthma or perennial rhinitis using extracts of Dermatophagoides pteronyssinus and of four storage mites most commonly found in house dust in the United Kingdom--Acarus siro, Tyrophagus putrescentiae, Lepidoglyphus (formerly Glycyphagus) destructor and Glycyphagus domesticus. The results of the skin tests were related to certain occupations and living conditions of the patients which could have exposed them to storage mites and some patients were included because their environment seemed especially likely to expose them to these species in order to assess the importance of these conditions. D. pteronyssinus was the most potent of the mite allergens and provoked the largest number of positive tests but a proportion of the storage mite species gave skin reactions which were larger or as large as those of D. pteronyssinus. No significant statistical correlation was found between reactions to D. pteronyssinus and any storage mite but highly significant correlations were found between some storage species. The frequency and strength of reactions to these species were unexpectedly high in view of their irregular occurrence and relative scarcity in house dust. It is suggested that sensitisation to these species occurs through exposure either to localised sources of infestation overlook during the random collection of floor or bedding dust or to infested materials encountered at work or other activities or to infested food or bedding of certain domestic pets. It is concluded that allergy to storage mites is more important and widespread that hitherto realised and is a considerable occupational hazard in farming communities and to those in occupations handling infested materials. Storage mites may also be important allergens for those living in very damp houses where the growth of moulds may encourage the development of Glycyphagus domesticus or other mites.

As part of a larger study of serial complement profiles in glomerulonephritis plasma C3 and C4 concentrations were measured using commercially available immunodiffusion plates. A total of 303 samples were obtained from 128 patients suffering from forms of nephritis associated with hypocomplementaemia-namely, lupus nephritis, mesangiocapillary glomerulonephritis (M.C.G.N.), and acute glomerulonephritis.These simple measurements of C3 and C4 gave clinically useful information. In lupus nephritis C3 and C4 generally correlated and C4 concentrations were more often and more profoundly depressed than C3 concentrations. Neither C3 nor C4 concentrations alone correlated well with the antinuclear factor titre.In both acute glomerulonephritis and M.C.G.N. the C3 concentrations were frequently lower than 20% of normal (which was never the case in patients with lupus), while the C4 concentration was usually normal and was almost never depressed in the absence of C3 depression. This suggests activation of complement at the C3 level by the "bypass" pathway in acute nephritis as well as in M.C.G.N., though both may be operating in some patients. In acute glomerulonephritis but not in M.C.G.N. C3 concentrations returned to normal within eight to 12 weeks.The two varieties of M.C.G.N. identified by the site of the deposits in the capillary glomerular walls differed in their C3 levels. In 10 patients with intramembranous dense linear deposits the C3 was always low over very long periods of time, rising in three out of four patients only after transplantation and immunosuppression. Other patients with M.C.G.N., in contrast, often showed normal C3 concentrations. Concentrations of C4 did not differ in either group, being normal in 80% of samples from all types.

Summary The relationships of total and specific IgE levels to the clinical manifestations and atopic status of ninety-two subjects, suffering from asthma, rhinitis and infantile eczema in varying combinations, were examined. No significant correlations were found between specific IgE levels to Dermatophagoides spp. and grass pollen or between total IgE levels, and the age of the patient, nor the age of onset, duration, severity and frequency of symptoms. A highly significant correlation was found between total IgE levels and the numbers of skin test reactions to a battery of twenty routine tests and to the sum total of the graded sizes of the reactions in each subject.