Effect of Concentrate Supplementation of Lambs Born to Concentrate Supplemented Ewes under Range Conditions of Sudan

This work aimed to study the effect of feedlot performance of weaned lambs born to concentrate supplemented ewes of desert sheep (Hamari sub type) raised on natural range, western Kordofan state, Sudan. Thirty two weaned ram lambs of equal average weight of 25.75 kg and age(milk tooth)were used for the study. All lambs were allowed to graze on pasture during the day. Animals were watered every 2-3 days according to ambient temperature. Lambs were randomly divided into four lambs groups according to their dam's previous feeding program, which was concentrate supplement at a rate of 500 gm./ewe/day. Lambs of group A born to ewes given concentrate one month before mating, one month during mating, and one month before lambing, and lambs of group B were born to ewes given the supplement for one month during mating and one month before lambing, and lambs of group C and D were born to ewes kept on natural grazing only. Each group contained eight lambs. Lambs of group A, B and C were given the same concentrate supplement of their damson ad libitum base for 60 days. Lambs of group D was left on grazing only as a control. Concentrate supplement consisted of sorghum grains 15 %, groundnut cake 20 %, molasses 15 %, and wheat bran 25 %, groundnut hullus 23 %, 1 % salt and 1 % limestone. Lambs were treated against external and internal parasites, and vaccinated against diseases. General health of lambs was closely observed for any deviation. Live weight of lambs was recorded initially and thereafter every fortnight. Daily weight gain, total weight gain, and mortality were also taken. The results indicated that final live weight, total weight gain and daily weight gain were significantly (p<0.01) different between supplemented groups and the control. Regression coefficients between body weight and period of fattening were high in all lamb groups. Economical appraisal of fattening lambs showed that the high cost of concentrates affected total variable costs but the high sale prices of supplemented fat lambs reflected positively on profit increase. It was concluded that concentrate supplementation of grazing ewes before and during the breeding period and that for grazing weaned lamb's improved their production and increased their sales revenue. Thus it is recommended to adopt concentrate supplementation of ewes to enhance their lambs feedlot performance and sale revenues.

Keywords: Feedlot performance, Concentrate supplementation, Hamari sheep, Natural pasture, Sudan.