The importance of semi-arid natural mountain pastures for feed intake and recycling of nutrients by traditionally managed goats on the Arabian Peninsula

Abstract

Goat husbandry in Oman’s Hajar Mountains supplies income and manure to farmers. An earlier analysis concluded that it uses purchased feeds inefficiently, but did not value the contribution of mountain pastures to goat nutrition and cropland fertilization. Therefore intake of pasture vegetation, cultivated forages and purchased feeds was determined in goats from three villages in spring and autumn 2005. Faecal excretion was quantified using TiO 2 and diet digestibility was calculated from faecal nitrogen (N). Organic matter (OM) intake varied from 71 to 107 g kg −0.75 d −1. Pasture vegetation supplied 45–71% of OM intake, and at least 28%, 33% and 42% of phosphorus (P), metabolizable energy (ME) and N intake. While ME intake just covered maintenance and locomotion requirements, N and P intake exceeded the animals’ requirements. Therefore faecal concentrations (g kg −1 OM) of 26–36 g N and 4–8 g P were high, making goat dung a key element of sustainability for the local cropping systems. Since mountain pastures supply nutrients to goats and cropland, their long-term productivity is crucial. Feeding cultivated forages seemingly reduces intake on pasture, but a comprehensive evaluation of nutritional and economic implications of this strategy and possible alternatives is needed.