TITLE:
Forage Nutrient Variability Associated with Hypomagnesemia and Hypocalcemia
AUTHORS:
M. H. Rahman, K. R. Islam, S. Chiba, A. Komuro, T. Kawakami, M. Tsuiki, S. Saiga
KEYWORDS:
Animal Disorders, Grass Tetany Index, Ryegrass, Alfalfa, Potassium, Temperate Andisol
JOURNAL NAME:
Open Access Library Journal,
Vol.9 No.9,
September
20,
2022
ABSTRACT: Seasonal variation of crown mineral concentrations in cool-season forages and hypomagnesemia (grass tetany), as well as hypocalcemia (milk fever) risk, were assessed using the grass tetany index (GTI) and dietary cationanion difference (DCAD). Thirty-three cultivars from orchardgrass, festulolium, smooth bromegrass, perennial ryegrass, meadow fescue, tall fescue, alfalfa, white clover and red clover were grown on Andisol in northern Japan. Plants were harvested thrice, and mineral contents were analyzed by energy reflectance X-ray spectrometry (XRF). Across harvests, highest K, Ca, and S contents were observed in alfalfa. The highest Mg content was recorded in white clover which was optimum for legumes and adequate for livestock. In contrast, Na and Cl contents were higher in perennial ryegrass and orchardgrass, respectively, irrespective of cultivars. Regardless of cultivars, K, Mg and Cl contents in forages across the harvests were adequate for grazing animals. Cultivars of Festulolium, perennial ryegrass, meadow fescue, alfalfa, and clover species did not show any GT risks over season. On the other hand, all cultivars of orchardgrass, smooth bromegrass, and tall fescue species showed GT risk [(K/(Ca + Mg) > 2.2] in the first harvest. Across harvest, the average value of DCAD in perennial ryegrasses was lowest among species. Our results suggested that perennial ryegrass and alfalfa spe-cies are the suitable cool- season forages for grazing animals in temperate re-gions of Japan.