The operation and reliability of urea dispensers to supplement sheep via drinking water.

Abstract

Three urea dispenser designs were evaluated in terms of administering accurate and uniform amounts of urea into trough water. The uniformity of urea concentration in troughs at different times of the day during summer was also investigated. The effect of urea intake (c. 8 g per head daily) on the concentration of ammonia in rumen liquo~ was determined by measuring the concentration before and after ewes drank from a supplemented trough. The uniform (6.4 to 8.3 g per head daily) and compulsory supplementation of urea per medium of the drinking water is a practical consideration in semi-arid Merino districts where water troughs make up a large proportion of existing water facilities. The ammonia concentrations (c. 10 mg%) of supplemented ewes suggest that urea provided sufficient nitrogen to ensure maximum rumen function. The slow decrease in post supplementation concentration of ammonia indicates the usefulness of the extra nitrogen intake to sheep grazing mature pastures. The potential for using the water medication concept for other husbandry procedures is also high- lighted.