Distribution of selected trace elements in the major fractions of donkey milk

The aim of this study was to evaluate the concentrations of Zn, Cu, Mn, Se, Mo, Co, Li, B, Ti, Cr, Rb, Sr, Cd, and Pb in donkey milk and their distribution in major milk fractions (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were provided by 16 clinically healthy lactating donkeys. Subsequent centrifugation, ultracentrifugation, and ultrafiltration were carried out to remove fat, casein, and whey proteins to obtain skim milk, a supernatant whey fraction, and the aqueous phase of milk, respectively. Concentrations of the elements were measured in whole milk and fractions by inductively coupled plasma-mass spectrometry, and the concentrations associated with fat, casein, and whey proteins were then calculated. The effect of removal of fat, casein, and whey proteins was determined by repeated-measures ANOVA. The fat fraction of donkey milk carried a small (∼4.5% to 13.5%) but significant proportion of Mo, Co, Ti, Cr, and Sr. The casein fraction in donkey milk carried almost all milk Zn, a majority of Cu and Mn, and most of Mo, Ti, and Sr. Relevant proportions, between 20% and 36%, of Se, Co, and Cr were also associated with caseins. The majority of Se, Co, Li, B, Cr, and Rb, and relevant proportions of Mn, Mo, Ti, and Sr were found in soluble form (ultracentrifuged samples) and distributed between whey proteins and the aqueous phase of milk (ultrafiltered samples). Whey proteins in donkey milk carried the majority of milk Se and Co. All Li and B was present in the aqueous phase of milk, which also contained most Rb and Cr, and 17% to 42% of Mn, Se, Mo, Co, Ti, and Sr.

Ensiled biomass of Solaris tobacco variety used as forage: chemical characteristics and effects on growth, welfare, and follow-up of Holstein heifers

This study examined the use of an innovative tobacco variety, Nicotiana tabacum L., cv. Solaris, as forage. The whole plant biomass was ensiled, and the composition of SiloSolaris from bunker-silo and mini-silos was investigated. The effects of dietary inclusion of SiloSolaris on the growth, welfare, and nutritional profile of sixteen Holstein heifers, divided into two groups (n = 8), SiloSolaris (SS) and Control (CTR), were investigated. Heifers were group-fed diets with a 70:30 forage to concentrate ratio (on a DM basis). Both groups received 16.24 kg DM of concentrate mixture daily, including corn meal, wheat middlings and soybean meal. The CTR group was fed 39.43 kg DM of hay daily, and the SS group received 23.00 kg DM of the same hay and 12.69 kg DM SiloSolaris blended with the concentrate mixture. The feeding trial lasted eighty-one days with a thirty-six day adaptation phase. Data on forty-five days of diet administration are reported. At the end of the feeding trial, the plasma constituents of the heifers were studied. Moreover, heifers were monitored during a follow-up period, lasting up to 1 year after calving, for age at first insemination, age at first calving and daily milk yield. The SiloSolaris chemical composition showed an average DM content of 24.1 (±0.65) g/100 g. During ensiling, a decrease in CP and an increase in ammonia nitrogen contents were observed. The lactic acid content was variable (9.00 ± 2.66 g/100 g DM), while the acetic acid concentration was stable (4.27 ± 0.21 g/100 g DM). No butyric acid was detected in SiloSolaris, whose ammonia nitrogen content accounted for 15.7 (±1.86)% of the total nitrogen on average, and the mean pH value was 5.02 (±0.08). The SiloSolaris diet did not affect heifer growth performance. No differences were detected for body condition, fecal consistency, or locomotion scores. All the investigated plasma constituents were within or very close to the ranges reported for heifers; however, significant differences between the experimental groups were observed for triglycerides, cholesterol, albumin, and magnesium. The follow-up results did not differ between the experimental groups. These initial findings suggest that Nicotiana tabacum cv. Solaris is a promising ensiled forage for growing heifers that deserve to be further investigated.

Distribution of calcium, phosphorus, sulfur, magnesium, potassium, and sodium in major fractions of donkey milk

The aim of this study was to evaluate the concentrations of Ca, P, S, Mg, K, and Na, and their distribution in major fractions of donkey milk (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were collected by mechanical milking from 16 clinically healthy lactating donkeys. Milk yield per milking was recorded and milk gross composition, casein content, and pH were determined. Whole milk samples were centrifuged to separate fat and to obtain skim milk. Skim milk samples were ultracentrifuged to separate a sedimentable casein pellet and to obtain a supernatant whey (soluble) fraction, which was then ultrafiltered to obtain the aqueous phase of donkey milk. Whole milk and the processed samples were analyzed for the aforementioned elements by inductively coupled plasma-mass spectrometry. The concentration of elements associated with fat, casein, and whey proteins was then calculated. All the Na was present in the aqueous phase. The fat fraction in donkey milk carried very little or none of the investigated elements. The majority of Ca (62.9%) and P (53.1%) was associated with casein, and the rest of these elements was mostly present in the aqueous phase. The majority of Mg was present in the aqueous phase, but a relevant part (32.6%) was associated with the casein fraction. No K was associated with casein. On a molar basis, the ratio of colloidal Ca and P to casein (mmol/g of casein) was more than double the values reported in literature for cow milk. The correlation coefficient was negative between milk pH and P in the ultracentrifuged (r = -0.81) and ultrafiltered (aqueous) fraction (r = -0.66). Milk pH correlated positively with colloidal Ca (r = 0.59) and with the ratio of colloidal Ca to casein (mmol/g of casein; r = 0.68). Colloidal Ca and P were positively correlated (r = 0.64). These data suggest that the high ratio of colloidal Ca and P to donkey casein micelles is due to a larger amount of colloidal calcium phosphate bound to casein micelles compared with literature data on cow milk. The percentage of elements associated with whey proteins was less than 5% for Ca, P, and K, but Mg reached approximately 9% of total Mg. The majority of S (63.6%) was associated with whey proteins, and only one-fourth of this element was associated with casein, indicating a higher content of sulfur-containing amino acids in donkey whey proteins than in casein.

Respiratory cancer among soap production workers

Employment in the soap production industry in Italy has entailed some exposure to sulfuric acid vapors and nickel dusts, both agents under suspicion of being carcinogenic for the respiratory tract. A mortality study, together with an incidence study for laryngeal cancer, has been conducted among 361 men with a minimum employment of one year in soap production. Mortality from all causes was lower than expected, but lung cancer and laryngeal cancer deaths were increased, although without statistical significance. Five new laryngeal cancer cases were detected during the study period, while about one was expected. All the men with respiratory cancer had been working for several years, and the latency time was greater than 10 years. Even though the mechanism of a causal link is difficult to assess, the possibility of a carcinogenic effect of sulfuric acid is suggested.

Urinary kallikrein activity of workers exposed to lead

Two groups of men of different age ranges and with the same period of lead exposure were selected for study in a recently opened car-battery factory. Two other groups of age-matched men, not exposed to heavy metals in their work, were used as controls. Morning urines were collected from control and exposed groups for determination of urinary kallikrein activity, urinary delta-amino-levulinic acid (ALA) and lead levels. The environmental lead levels and the urinary ALA and lead values indicated that exposure in the factory was not heavy. The older group of lead-exposed workers showed greatly reduced urinary kallikrein activity compared with that of the age-matched controls. In contrast, the younger group did not show any significant alteration in urinary kallikrein excretion.