7FIELD A C ,KAMPHUES J ,WOOLLIAMS J A. The effect of dietary intake of calcium and phosphorus on the absorption and excretion of phosphorus in chimaera- derived sheep[J ].J Agr Sci, 1983,10l (3) :597-602.
8FIELD A C. Maintenance requirements of phosphorus and absorbability of dietary phosphorus in sheep [J].J Agr Sci, 1983,100(1) :231-233.
9B?e KE, et al. Outside enclosure and additional enrichment for airy goats a preliminary study [J]. Acta Veterinaria Scandinavica. 2012,54( 1 ):68-73.
10Nampanzira DK, ct al. Characterization of the goat feeding system among rural small holder farmers in the semi-arid regions of Uganda [J].SpringerPlus.2015,4:188-195.
