Seasonal status of magnesium in soil, feed, fodder and blood serum of livestock animals from Solapur district of Maharashtra

Introduction

India has a large bovine population and is one of the world's leading milk-producing countries; however, productivity per animal can be limited by inadequate nutrition and mineral imbalances. Magnesium is an important mineral involved in several biochemical and physiological processes, and inadequate magnesium intake can adversely affect animal health, production, and reproductive performance (Maguire and Cowan, 2002; Martens et al., 2018; Pinotti et al., 2021) [9,10,15] . Livestock maintained under crop-residue-based feeding systems and grazing conditions may be exposed to mineral deficiencies when diets are not routinely supplemented with mineral mixtures (Ranjan et al., 2012; Mathur et al., 2017) [17,11] . Mineral deficiencies can interfere with enzymatic and hormonal functions and may consequently affect fertility and productivity (Shukla et al., 2007) [20] . Magnesium supplementation has been associated with improved animal performance and may help prevent hypomagnesemia-related disorders (Zang et al., 2014; Schonewille, 2013; Zelal, 2017) [23,18,24] . The magnesium available to grazing and forage-consuming livestock is closely related to the magnesium status of soil and plants. Soil Mg availability is influenced by soil properties, fertilization, moisture and plant uptake (Gransee and Führs, 2013; Martens et al., 2018) [5,10] . Seasonal assessment is therefore important because rainfall, soil moisture and plant growth can alter mineral availability. Earlier studies have demonstrated regional variation in the mineral status of soil, feed, fodder and livestock (Choudhary et al., 2015; Panda et al., 2015; Ramesh et al., 2014; Patodkar et al., 2023) [3,13,16,14] . The present study was undertaken to assess the seasonal status of magnesium in soil, feed, fodder and serum of livestock in four tehsils of Solapur district, Maharashtra, and to examine whether the seasonal changes in environmental and dietary magnesium were reflected in the serum mineral profile of animals.

Materials and Methods

Sample collection

The study was conducted in Solapur district of Maharashtra, India. Samples of soil, concentrate feed, roughage/fodder, and animal serum were collected randomly from Madha, Mohol, Sangola, and Akkalkote tehsils. Soil samples were collected using a pickaxe and trowel and processed for magnesium analysis according to Jackson (1973). Samples of concentrate ingredients and roughages were collected from individual farmer families once during each season. Serum samples were collected from cattle and buffaloes of participating farmers during each seasonal visit and stored at -20 °C until analysis.

Sample processing and magnesium estimation

Soil, feed/fodder and serum samples were digested using the procedures described by Francek (1992), Trolson (1969) and Kolmer et al. (1951), respectively. Reagent blanks were processed simultaneously. Magnesium concentrations were estimated using an atomic absorption spectrophotometer (ELICO Ltd., Hyderabad, India).

Statistical analysis

The percentage of deficient samples was calculated using the reported critical values for magnesium in soil, feed, fodder and animal serum (McDowell et al., 1984 [25]; McDowell et al., 1993) [12] . Seasonal differences were evaluated using a Completely Randomized Design (CRD), following Snedecor and Cochran (1994), with analysis performed using the Web Agricultural Statistical Package (WASP) of ICAR, Goa.

Results and Discussion

The mean ± SE values of soil magnesium are presented in Table 1. All recorded values were above the critical soil Mg level of 22 ppm. In Madha, soil Mg increased from 300.75 ± 15.56 ppm in summer to 303.00 ± 13.04 ppm in winter and 324.58 ± 8.40 ppm in the rainy season, with an overall mean of 310.44 ± 11.42 ppm. Mohol showed lower values, increasing from 267.00 ± 6.71 ppm in summer to 281.25 ± 11.62 ppm in winter and 296.50 ± 14.17 ppm during the rainy season, with an overall mean of 281.58 ± 7.07 ppm. Sangola recorded 315.00 ± 7.04 ppm in summer, 305.00 ± 9.65 ppm in winter, and 340.00 ± 8.88 ppm in the rainy season, giving an overall mean of 320.00 ± 6.63 ppm. Akkalkote showed 321.75 ± 20.90 ppm in summer, 306.67 ± 8.90 ppm in winter, and 343.75 ± 14.21 ppm in the rainy season, with an overall mean of 324.06 ± 11.35 ppm. Although the rainy-season values were numerically highest in all four tehsils, the superscripts in Table 1 indicate that seasonal differences were not statistically significant (P>0.05). The absence of deficient soil samples further indicates an adequate soil Mg status in the study area. The higher numerical values observed during the rainy season may be associated with improved soil moisture and nutrient cycling during periods of rainfall. Similar regional variation in soil mineral status has been reported in Rajasthan, Odisha and Andhra Pradesh (Choudhary et [3,13,16] .

Magnesium in feed

Feed Mg showed greater seasonal variation than soil. In Madha, the Mg concentration increased significantly from 0.28 ± 0.076% in summer to 0.47 ± 0.074% in winter and remained 0.47 ± 0.035% in the rainy season; the overall mean was 0.41 ± 0.058%. In Mohol, values increased from 0.39 ± 0.040% in summer to 0.46 ± 0.031% in winter and 0.65 ± 0.038% in the rainy season, with an overall mean of 0.50 ± 0.039%. In Sangola, feed Mg remained relatively stable, with values of 0.45 ± 0.057%, 0.48 ± 0.039% and 0.49 ± 0.033% during summer, winter and rainy seasons, respectively, and an overall mean of 0.47 ± 0.043%. Akkalkote recorded 0.46 ± 0.046% in summer, 0.54 ± 0.090% in winter and 0.60 ± 0.041% in the rainy season, with an overall mean of 0.53 ± 0.059%. The seasonal superscripts indicate significant increases in Madha, Mohol, and Akkalkote, whereas the seasonal differences in Sangola were not significant. The higher rainy-season feed Mg concentrations, particularly in Mohol and Akkalkote, may reflect improved mineral availability in locally produced feed resources during the monsoon. The overall feed Mg concentrations remained above the critical level reported for livestock mineral assessment, and no deficient feed samples were recorded. The seasonal pattern is broadly consistent with the importance of dietary mineral supplementation and areaspecific mineral management reported in earlier studies (Patodkar et al., 2023; Martens et al., 2018) [14,10] .

Magnesium in fodder

Fodder Mg concentrations were comparatively stable in Madha, Mohol and Sangola. Madha recorded 0.41 ± 0.047% in summer, 0.45 ± 0.053% in winter and 0.46 ± 0.037% in the rainy season, with an overall mean of 0.44 ± 0.046%. Mohol recorded 0.35 ± 0.049%, 0.36 ± 0.041% and 0.40 ± 0.056% in summer, winter, and rainy seasons, respectively, with an overall mean of 0.37 ± 0.051%. Sangola showed values of 0.39 ± 0.054% in summer, 0.40 ± 0.066% in winter, and 0.41 ± 0.064% in the rainy season, with an overall mean of 0.40 ± 0.061%. In these three tehsils, the common superscript indicates that the seasonal differences were not significant. In contrast, Akkalkote showed a clear and significant seasonal increase: 0.30 ± 0.030% in summer, 0.39 ± 0.047% in winter, and 0.51 ± 0.388% in the rainy season, with an overall mean of 0.41 ± 0.046%. The particularly low summer value in Akkalkote may be related to reduced moisture availability and lower mineral uptake by mature forage. In contrast, improved rainfall and plant growth during the monsoon may enhance mineral accumulation. The absence of deficient fodder samples suggests that, despite seasonal variation, the available fodder generally supplied adequate magnesium. Similar regional differences in mineral content of feeds and fodders have been reported previously (Bhagat et al., 2017; Patodkar et al., 2023) [1,14] .

Serum magnesium

Serum Mg showed the clearest seasonal response among the four sample types. During summer, serum Mg was 3.00 ± 0.054 mg/dL in Madha, 2.62 ± 0.065 mg/dL in Mohol, 2.30 ± 0.048 mg/dL in Sangola, and 3.03 ± 0.113 mg/dL in Akkalkote. Thus, Sangola had the lowest summer value, while Akkalkote and Madha recorded the highest numerical values. During winter, serum Mg was 3.04 ± 0.052 mg/dL in Madha, 2.64 ± 0.040 mg/dL in Mohol, 2.64 ± 0.106 mg/dL in Sangola, and 3.42 ± 0.115 mg/dL in Akkalkote.

Akkalkote recorded the highest winter value. During the rainy season, serum Mg increased to 3.15 ± 0.057 mg/dL in Madha, 2.69 ± 0.230 mg/dL in Mohol, 3.99 ± 0.259 mg/dL in Sangola, and 3.68 ± 0.106 mg/dL in Akkalkote. The rainy-season values in Sangola and Akkalkote were significantly higher than those recorded in the other seasons, as indicated by the superscripts in Table 1. The overall means were 3.06 ± 0.020 mg/dL for Madha, 2.66 ± 0.040 mg/dL for Mohol, 2.91 ± 0.175 mg/dL for Sangola, and 3.35 ± 0.117 mg/dL for Akkalkote. Table 2 shows that the overall percentage of deficient serum samples was 1.85%, with the highest deficiency recorded in Sangola (5.56%) and Akkalkote (1.85%). The overall serum values were generally above the critical level, but the presence of deficient samples indicates that individual animals may still require attention to dietary mineral supply. The seasonal increase in serum magnesium during the rainy season, especially in Sangola and Akkalkote, likely results from improved availability of Mg in feed and fodder, along with higher dietary intake. This aligns with the idea that mineral levels in soil and forage ultimately influence the mineral status of livestock grazing or fed forage (Martens et al., 2018; Pinotti et al., 2021) [10,15] . Additionally, regional variations in serum mineral levels in dairy livestock have been observed across different areas of India (Bhagat et al., 2017; Indira and Samuel, 2014; Patodkar et al., 2023) [1,6,14] .

Conclusion

The present study demonstrates that magnesium status varied with sample type and season in Solapur district. Soil Mg remained above the critical level in all four tehsils and showed only non-significant seasonal variation, although the highest numerical values were generally observed during the rainy season. Feed Mg showed a stronger seasonal response, with significant increases in Madha, Mohol and Akkalkote. Fodder Mg remained relatively stable in Madha, Mohol and Sangola, whereas Akkalkote showed a significant increase from summer to rainy season. Serum Mg displayed the most evident seasonal response, with particularly high rainyseason values in Sangola and Akkalkote. Overall, the findings suggest that the magnesium status of the soil and available feed resources in Solapur was generally adequate, but seasonal and tehsil-wise differences can influence the mineral status of individual animals. Periodic mineral profiling and area-specific mineral supplementation may therefore be useful, particularly during periods when forage quality or mineral availability is expected to decline.

Acknowledgement

AcknowledgmentWe wish to thank the Associate Dean, Krantisinh Nana Patil College of Veterinary Science, Shirval, Satara, for kind support during the research work.

References

1. Bhagat DJ, Burte RG, Kumar S, Pawar JK, Dhopavkar RV, Gurav SS. Assessment of mineral status in feed and fodder, soil and blood serum of dairy animals in Sindhudurg district of Maharashtra, India. Advanced Agricultural Research & Technology Journal. 2017;1(1):52-56.
2. Chojnacka K, Saeid A. Recent advances in trace elements. Chichester: Wiley; 2018.
3. Choudhary S, Choudhary SDR, Yadav P. Mineral status of livestock, soil, feeds and fodders in Ajmer district of Rajasthan. In: 13th International Grassland Congress; 2015 Nov 24. International Journal of Advanced Biochemistry Research https://www.biochemjournal.com
4. Francek MA. Soil lead levels in a small town environment: a case study from Mt Pleasant, Michigan. Environmental Pollution. 1992;76(3):251-257.
5. Gransee A, Führs H. Magnesium mobility in soils as a challenge for soil and plant analysis, magnesium fertilization and root uptake under adverse growth conditions. Plant and Soil. 2013;368:5-21. doi:10.1007/s11104-012-1567-y.
6. Indira D, Samuel A. Mineral status of dairy buffaloes in West Godavari District of Andhra Pradesh in India. International Journal of Innovative Research & Development. 2014;3(5):358-361.
7. Jackson ML. Soil chemical analysis. New Delhi: Prentice Hall of India Pvt. Ltd.; 1973. p. 498.
8. Kolmer JA, Spanbling EH, Robinson HW. Approved laboratory technique. New York: Appleton Century Crofts; 1951. p. 1090-1091.
9. Martens H, Leonhard-Marek S, Röntgen M, Stumpff F. Magnesium homeostasis in cattle: absorption and excretion. Nutrition Research Reviews. 2018;31(1):114-130. doi:10.1017/S0954422417000257.
10. Mathur R, Singh SK, Yadav PS. Mineral imbalances in livestock: challenges and strategies for improvement. Annals of Arid Zone. 2017;56(3-4):1-7.
11. McDowell LR, Conard JH, Henry GF. Minerals for grazing ruminants in tropical regions. Gainesville: University of Florida, Centre for Tropical Agricultural, U.S. Agency for International Development and Caribbean Basin Advisory Group (CBAG); 1993.
12. Panda MK, Panda N, Swain RK, Behera PC, Sahoo SP, Jena SC. Mineral profile of soil, feed fodder and serum of dairy cattle in North Eastern Ghat (NEG) of Odisha. Journal of Animal Research. 2015;5(2):341-346.
13. Patodkar VR, Sardar VM, Mehere PV, Jadhav SN, Barate AK, Bhalerao SM. Assessment of seasonal changes in magnesium in soil, feed fodder and serum of livestock from Sangli district of Maharashtra. The Pharma Innovation Journal. 2023;12(5):466-469.
14. Pinotti L, Manoni M, Ferrari L, Tretola M, Cazzola R, Givens I. The contribution of dietary magnesium in farm animals and human nutrition. Nutrients. 2021;13(2):509. doi:10.3390/nu13020509.
15. Ramesh S, Nagalakshmi D, Reddy YR, Reddy AR. Mineral status of soils, water, feeds and fodders of dairy animals in Mahaboobnagar district of Andhra Pradesh. Global Journal of Bio-Science and Biotechnology. 2014;3(3):273-277.
16. Ranjan A, Pathak AK, Verma DN. Mineral imbalances in livestock: a review. Journal of Animal Science Advances. 2012;2(5):394-403.
17. Schonewille JT. Magnesium in dairy cow nutrition: an overview. Plant and Soil. 2013;368:167-178. doi:10.1007/s11104-013-1665-5.
18. Sharma MC, Joshi C, Gupta S. Prevalence of mineral deficiency in soils, plants and cattle of certain districts of Uttar Pradesh. Indian Journal of Veterinary Medicine. 2003;23:4-8.
19. Shukla S, Tiwari DP, Kumar A, Mondal BC, Upadhyay AK. Animal husbandry practices in Pithoragarh district of Uttarakhand state. Indian Journal of Animal Sciences. 2007;77(11):1201-1204.
20. Snedecor GW, Cochran WG. Statistical methods. New Delhi: Iowa State University Press, Oxford and IBH; 1994.
21. Trolson JE. Outline for in vitro digestion of forage samples. Research Station, Swift Current, Saskatchewan, Canada; 1969.
22. Zang J, Chen J, Tian J, Wang A, Liu H, Hu S, et al. Effects of magnesium on the performance of sows and their piglets. Journal of Animal Science and Biotechnology. 2014;5(1):39. doi:10.1186/2049-1891-5-39.
23. Zelal A. Hypomagnesemia tetany in cattle. Advances in Dairy Research. 2017;5:178. doi:10.4172/2329-888X.1000178.
24. McDowell LR, Conard JH, Ellis GL. Pretoria, South Africa; 1984. p. 67-68.