Evaluation of metal exposure through the composition of essential and toxic micro-minerals in freshwater turtles (Phrynops geoffroanus) from a Brazilian river.

This study aimed to evaluate metal exposure through the concentration of essential and toxic micro-minerals in biological samples of Phrynops geoffroanus from an anthropized river. The work was carried out in four areas with different flow characteristics and uses of the river, where individuals of both sexes were captured during the dry and rainy seasons. The elements Al, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, and Zn were quantified in samples of serum (168), muscle (62), liver (61), and kidney (61) by inductively coupled plasma optical emission spectrometry. The concentration of the elements varied according to the sample type, being higher in the liver and the kidney. In the serum, many elements were below the limit of quantification, but it was possible to determine Al, Cu, Fe, Mn, Pb, and Zn. The liver showed high levels of Cu, Fe, Pb, and Zn, and muscle for Fe, Ni, Pb, and Zn, with most of the elements accumulated in the kidney (Al, Cd, Co, Cr, Mn, Mo, and Ni) relative to other tissues. There was no significant difference between the sexes in the accumulation of elements. Between seasons, Cu was higher in serum and Mn in muscle and liver in the dry period, while in the kidney, almost all the elements were higher in the rainy period. The concentrations of the elements in the samples indicated a high degree of environmental contamination, representing risk in the use of the river and consumption of food from local fisheries.

Sugarcane yeast with urea in replace of soybean meal in the diet of Murrah buffaloes does not cause metabolic, endocrine, and mineral disorders.

The aim of this study was to evaluate the effect of the replacement of soybean meal by increasing levels of sugarcane yeast and urea on the energy, enzymatic, protein, mineral, and hormonal profiles of buffalo heifers. Twenty Murrah heifers with an average body weight of 168 ± 2.0 kg and 1 year old were used in a completely randomized design. The treatments consisted of the replacement of soybean meal by increasing levels of sugarcane yeast and urea (0, 33, 67, and 100% dry matter). The animals were weighed at the beginning and end of the experimental period, and blood was collected on the final day. The replacement of soybean meal with sugarcane yeast influenced the performance and metabolic dynamics, with total weight gain (P = 0.005) and average daily gain (P = 0.015), presenting, for both variables, a quadratic effect. Considering the biochemical profile, there was an influence on the serum concentration of triglycerides (P = 0.055), the serum activities of aspartate aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase (P < 0.05), in addition to the serum concentration of phosphorus (P = 0.007) and potassium (P = 0.053), which showed positive linear effects. The hormonal profile was not influenced by diets (P > 0.05). The elements copper, iron, and zinc were able to be quantified at all levels of sugarcane yeast and urea in the diets offered. The use of sugarcane yeast with urea promotes adequate metabolic response of buffalo heifers and can replace up to 100% of soybean meal in the concentrate.

Effect of Crude Glycerin in the Feed of Lactating Goats on Concentrations of Essential and Toxic Metals in Serum, Urine, Milk, and Artisanal "Coalho" Cheese.

Goat farming is concentrated in semi-arid and tropical regions in Brazil. From 2006 to 2017, the number of goats sold in the country increased by 65.7%. The dairy products from these animals present higher digestibility, high vitamin A and B content, hypoallergenicity, and less lactose compared to dairy products from cows, in addition to having a higher sales value. Since corn and soybean meal generate an expense for feed management, crude glycerin, originating from the manufacture of biodiesel, has been studied as an energy substitute. However, this product contains heavy metals, posing risks to animal and human health. Few data are available on trace elements in biological samples and products derived from goats' milk with the dietary introduction of glycerin. The objective was to quantify aluminum (Al), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), and zinc (Zn) in the serum, urine, milk, and artisanal "coalho" cheese of dairy goats fed different levels of crude glycerin in feed management. In total, 16 Saanen goats were selected, lactating females, that were distributed in four Latin squares and randomly treated with different levels of crude glycerin (0, 5, 10, and 15%). After the end of each experiment cycle, serum, urine, milk, and artisanal "coalho" cheese samples were collected at the four moments. The samples were submitted to digestion assisted by microwave radiation. The multi-element analysis was carried out using inductively coupled plasma optical emission spectrometry (ICP OES). There was no influence of crude glycerin levels replacing corn in serum, milk, urine, and artisanal "coalho" cheese. The serum concentration of the metals Cu, Fe, Zn, and Mn; urine concentrations of Cu, Zn, Mn, Mo, and Cr; and milk and artisanal "coalho" cheese concentrations of Cu, Zn, and Mn remained within the standards found in the literature. The inclusion of 5 to 15% of crude glycerin, derived from cotton oil, in the diets of dairy goats in partial replacement of corn, does not alter the concentration of essential and toxic metals in serum, urine, milk, and artisanal "coalho" cheese and does not, therefore, present a risk factor for intoxication.