Relationship of soil and forage Cobalt, Iron, Manganese, and Zinc contents with serum Cobalt, Zinc, vitamin B12 values and some hematological parameters in sheep of Ramhormoz city

In ruminants, cobalt is essential for synthesis of vitamin B12 by rumen microflora. Emaciation and anemia are the most important consequences of cobalt deficiency in ruminants. This study aimed to investigate the relationship between cobalt, iron, zinc, and manganese levels of soil and forage with each other and with serum levels of cobalt, zinc, and vitamin B12 in emaciated and normal sheep of Ramhormoz city. Eight soil and 8 forage samples were taken from four areas in Ramhormoz city. The soil and forage samples were analyzed. Blood samples were collected from 25 (15 emaciated and 10 normal) and 43 sheep (28 emaciated and 15 normal) from areas with more and less than 0.07 μg cobalt/Kg of DM forage, respectively and were analyzed to determine serum cobalt, zinc, vitamin B12 values and some hematological parameters. The forage cobalt value in Plim (0.052±0.02 mg/kg dry matter (DM)) and Larkiabad (0.054±0.00 mg/kg DM) regions was lower than the standard value. The mean soil iron value (15767±1333 mg/kg arid soil) was more than its critical level in Ramhormoz. The highest soil manganese values in Larkiabad and Plim regions were associated with the lowest forage cobalt values. There was no statistically significant difference between serum levels of cobalt, zinc, and vitamin B12 in the emaciated and normal sheep. It is possible that the high amounts of soil iron and manganese, due to their chelating effects, could reduce the cobalt bio-availability of forage. Contrary to the available literature, the presence of 0.05 μg cobalt/Kg of DM forage is capable of providing sufficient amounts of cobalt and vitamin B12 for sheep in the region.