In earlier studies, results from incubation experiments were combined with measurements of outflow rates of small particles from the rumen to predict the extent of degradation of dietary protein in vivo (Orskov & McDonald 1979). The degradability of a protein supplement was shown to decrease when fractional outflow rate increased (Orskov 1982). In a series of experiments, the factors affecting the fractional rates of outflow of dietary protein supplements from the rumen of sheep and lactating dairy cows were investigated (Agricultural Research Council 1984). In addition, outflow rate of soyabean meal from the rumen of dry and lactating Chios sheep and Damascus goats offered high concentrate diets was determined in recent studies (Hadjipanayiotou et al. 1988). Chromium-treated protein supplements were used to measure their outflow from the rumen using the marker concentration in faeces (Ørskov 1982). This paper reports outflow from the rumen of growing Chios lambs and Damascus kids offered concentrates ad libitum.

Japanese mint (Mentha arvensis Linn.), a succulent and multicut annual, has a very high water requirement because its active growth period coincides with premonsoon hot summer months, when soil moisture is inadequate and soil temperature is high. Maintenance of soil moisture and optimum N nutrition are important for realizing maximum yield potential. The effects of irrigation (Krupper et al. 1968; Duhan et al.1977; Clark & Menary 1980; Khera et al. 1986) and N fertilization (Singh 1986; Kothari et al.1987) in enhancing herbage and oil yields of mint have been well documented in the literature. There is, however, little information on the interactions of irrigation and N with growth and yield.