NUTRITIONAL EVALUATION OF SOME CROP RESIDUALS AS A ROUGHAGE SOURCES FOR FEEDING LAMBS

Abstract

Twenty four Rahmany male lambs (25.6±1.69 kg; four months age) were divided into three similar groups, eight animals each. The animals were randomly assigned using a complete randomize design to receive one of the three rations as following for 90 day. All animal fed concentrate feed mixture at rate of 2% of live body weight and had ad libitum access to Faba bean straw (G1), Chick-pea straw (G2) and Lentil straw (G3). At the middel of the experimental period, three digestion trails were carried out by using metabolic cages to determine nutrients digestibility, nitrogen balance and feeding values of experimental rations. Data obtained revealed that Lentil and Chick-pea straws were higher OM, CP and NFE content than faba bean straw. On the other hand, the same straws were less ash and crude fiber content compared to Faba bean straw. Ration containing Lentil straw and chick-pea straw had significantly higher (P<0.05) crude protein intake (CPI) and total digestible nutrients intake (TDNI) as well as digestible crude protein intake (DCPI). In addition to DM, CF and NFE digestibility for ration G3 were (P<0.05) higher than G1 and G2. Concerning the nutritive values as TDN and DCP the results showed that G3 was higher (P<0.05) than G1 and G2. Insignificant differences (P>0.05) were noticed in rumen NH3-N after 6hrs feeding and TVFA's concentration among the groups at times 0 and 3 hrs after feeding. While, values of pH had significant higher in G3 after 3 and 6hrs feeding than G1 and G2. Nitrogen balance data clearly indicated that N retention was higher (P<0.05) for G3 and G2 comparable G1. Significant (P<0.05) increase in blood total protein, albumin and globulin concentration was recorded for G3 and G2 compared to G1. Lentil straw group (G3) had the highest total gain and average daily gain (ADG) being 16.0 kg and 178 gm, respectively, at the same time, feed conversion as kg DM/kg gain improved. While, Chick pea was more economic efficiency than Lentil straw (G3) and Faba bean straw (G1). However, ration containing Chick pea straw had cheaper cost for produce 1 kg gain than the others. So, it could be concluded that, chick pea straw and lentil straw had to be used as a good roughages in rations of growing lambs.