Abstract
A feeding trial was conducted to study the effect of feeding Total Mixed Ration (TMR) with different levels of neutral detergent fibre (NDF), compared with the traditional feeding, on growth rate, carcass and meat quality measurements of growing lambs. Twenty growing lambs, 3 month old, were selected and randomly distributed to four different treatments as a complete randomized design as follow: Barley grain and alfalfa hay (BA); TMR1 (25.67% NDF; low level); TMR2 (30.88% NDF; medium level-recommended); TMR3 (55.93% NDF; high level). A significantly higher (P<0.05) average daily gain and lower value for the feed conversion ratio of lambs fed TMR2 compared with other dietary groups. There were no significant differences (P>0.05) between lambs fed TMRs with different levels of NDF for slaughter and body components parameters, except empty stomach (TMR2) and chill shrink (TMR1). Furthermore, the meat color (L*, a* and b*) values of lambs fed TMR2 were numerically higher compared with other groups with variable significant differences. A significantly lower values for the omental and mesentery fat were reported for lambs fed BA (0.55 and 0.67 kg, respectively), while the kidney knob and channel fat (KKCF) was significantly lower for lambs fed TMR2. In conclusion, feeding growing lambs a total mixed ration (TMR) with around 30% NDF improve the general performance and most of the required meat quality measurement.