The total accumulation of heavy metals in body in connection with the dairy productivity of cows

Emerging insights into the impacts of heavy metals exposure on health, reproductive and productive performance of livestock

Heavy metals, common environmental pollutants with widespread distribution hazards and several health problems linked to them are distinguished from other toxic compounds by their bioaccumulation in living organisms. They pollute the food chain and threaten the health of animals. Biologically, heavy metals exhibit both beneficial and harmful effects. Certain essential heavy metals such as Co, Mn, Se, Zn, and Mg play crucial roles in vital physiological processes in trace amounts, while others like As, Pb, Hg, Cd, and Cu are widely recognized for their toxic properties. Regardless of their physiological functions, an excess intake of all heavy metals beyond the tolerance limit can lead to toxicity. Animals face exposure to heavy metals through contaminated feed and water, primarily as a result of anthropogenic environmental pollution. After ingestion heavy metals persist in the body for an extended duration and the nature of exposure dictates whether they induce acute or chronic, clinical or subclinical, or subtle toxicities. The toxic effects of metals lead to disruption of cellular homeostasis through the generation of free radicals that develop oxidative stress. In cases of acute heavy metal poisoning, characteristic clinical symptoms may arise, potentially culminating in the death of animals with corresponding necropsy findings. Chronic toxicities manifest as a decline in overall body condition scoring and a decrease in the production potential of animals. Elevated heavy metal levels in consumable animal products raise public health concerns. Timely diagnosis, targeted antidotes, and management strategies can significantly mitigate heavy metal impact on livestock health, productivity, and reproductive performance.

Arsenic Levels and Seasonal Variation in Pasture Soil, Forage and Horse Blood Plasma in Central Punjab, Pakistan

The present study aimed to determine the accumulation levels of arsenic in pasture soil, forage and animals. An atomic absorption spectrophotometer was used to determine the concentration of metals in the samples of soil, forage and blood plasma of horses. The level of arsenic ranged between 4.26 mg/kg (summer) and 4.66 mg/kg (winter) in soil samples and 2.67 mg/kg (summer) and 2.94 mg/kg (winter) in forage samples. In blood plasma samples, the mean arsenic (As) values varied between 1.38 and 1.52 mg/L. In the blood plasma samples, the mean As values varied between 1.38 and 1.52 mg/L. No statistically significant changes were observed for arsenic concentrations in plasma samples of horses for sampling seasons (p > 0.05). A positive correlation was observed for forage and blood plasma to a certain degree for arsenic but for other media, arsenic correlations were negative and insignificant. It is therefore suggested that regular monitoring of heavy metals in soils/plants/animals is essential to prevent excessive build-up of arsenic.

Elemental composition of the hair and milk of black-spotted cows and its relationship with intestinal microbiome reorganization

Background and Aim

The cattle breeding system is facing severe problems associated with the increased negative impact of various human activity areas on the environment and the bodies of farm animals. The use of heavy metals in different production areas leads to their accumulation in the environment due to the ingestion of animals and humans through animal products. This study aimed to assess the elemental composition of the hair and milk of black-spotted cows and to identify the relationship between the content of toxic and essential elements and the state of the intestinal microbiome.

Materials and Methods

The element status was estimated by studying the chemical composition of the biosubstrates using inductively coupled plasma-mass spectroscopy. Based on the analysis of hair, the elemental composition, and the use of the coefficient of toxic load, two groups of animals were formed: Group I, which included cows with a lower load factor, and Group II, which included cows with a higher load factor.

Results

An increase in the heavy metal concentrations in the hair and milk of animals in Group II was observed. The As, Fe, Pb, Al, Co, Ni, and V concentrations in the hair of cows from Group II increased relative to Group I by 19%, 29%, 24.5%, 32.3%, 35.6%, 21.5%, and 18.2%, respectively. There was a significant increase in the level of Fe by 11.5%, Cr by 8.25%, Mn by 17.6%, Pb by 46.1%, and Cd by 25% in Group II compared with Group I in the assessment of elemental milk composition. There were no apparent changes in the intestinal microbiome of Group II.

Conclusion

Some heavy metals were accumulated in the bodies and milk of animals. This shows a high probability of heavy metals causing harm to the health of animals and humans.

Trace element status of highly productive cows in different physiological conditions under increased technogenic load

Microelements play a vital role in the maintenance and intensification of metabolic and regulatory processes in the body of animals. For a more complete study of provision of body of highly productive animals with microelements and diagnosis of metabolic disorders, especially under anthropogenic load, it is necessary to conduct biochemical blood tests. The article presents the results of studies on the content of trace elements (iron, copper, zinc, manganese) in the whole blood of cows from two farms in the Voronezh region, one of which (farm 2) is located in an area with increased technogenic load. In whole blood, the content of iron, copper, zinc, and manganese was determined by atomic absorption using a Shimadzu AA-6300 spectrophotometer. Samples were prepared by wet ashing at elevated pressure in a MARS-5 microwave system. Blood samples were taken 2 weeks before calving, one week and one month after calving. A reduced level of copper and zinc was found in animals from both farms throughout the entire study period. The dependence of the content of microelements on the physiological state of animals (before and after calving) was not revealed. It was shown that the content of iron in the blood of highly productive cows from farm 2 was lower throughout the study, and manganese - a week and a month after calving. The amount of manganese in blood of farm 2 animals was less than the lower limit of the physiological norm, while in farm 1 animals its concentration was within the reference normal range.

Retrospective diagnosis of intrauterine diselementosis in newborn calves

One of the methods in diselementosis diagnosis, i.e. in determination of the trace elements content excess, deficiency or imbalance in the organism, is screening the hair elemental composition. It is known that the tail brush hair growth in cattle begins from the 7th month of gestation. The authors suggested that the tail brush hair elemental composition in newborn calves could be used for integral evaluation of the trace elements supply to the fetus in the last months of its intrauterine development. In order to elaborate criteria for retrospective diagnosis of the intrauterine diselementosis, 125 clinically healthy 1-day-old calves (67 male and 58 female animals) were examined; they were obtained from Simmental cows with a physiological course of gestation under biogeochemical conditions of the Central Black Earth region of the Russian Federation. The concentration of 11 essential (Co, Cr, Cu, Fe, I, Li, Mn, Se, Si, V, Zn) and 8 toxic (As, B, Cd, Hg, Ni, Pb, Sn, Sr) trace elements were studied in samples of unpigmented guard hairs from the animal tail brush by inductively coupled plasma mass spectrometry (Nexion 300D, Perkin Elmer, USA). The results were expressed as mean ± standard error of mean, median, minimum, and maximum. Reference values of essential and toxic trace elements concentration in the hair of newborns were determined using the percentile scales separately for the groups of male and female animals. Group comparison was conducted using the independent samples Mann-Whitney U test. Research results demonstrated that physiologically determined the range of the trace elements concentration in the hair of newborn calves corresponded to the interval between the 25th and 75th percentiles. Values beyond the specified interval boundaries were proposed to be considered as deviations corresponding to the diselementosis.