Abstract

The fate of mineral solutions when drenched was assessed in cows slaughtered after drenching using a dye visible in gut contents. Seven groups of 10 cows were drenched with water or solutions of magnesium oxide, magnesium chloride, magnesium sulphate, sodium chloride, sodium bicarbonate or zinc oxide in Trial 1. Frequency of closure was higher (P<0.05) for sodium bicarbonate (60%) than for magnesium oxide or magnesium chloride (10 to 20%). Five cows drenched with water alone showed bypass of the rumen. In Trial 2 four groups of 6 or 7 cows were drenched with water or solutions containing selenium. Hydromin or copper sulphate. Frequency of closure was higher (P<0.05) for copper sulphate (70%) than for water or selenium (0%). The results suggest that bypass of the rumen in response to drenching may contribute to apparent failures of bloat drenches, particularly when certain minerals are added to the drench.

CW, Rogers, and GA Wickham

Proceedings of the New Zealand Society of Animal Production, Volume 53, , 423-426, 1993