## 4 Discussion
### Chemical Composition of Pastures and Supplementary Feeds
#### 4.2.1 Effect of Pellet Supplementation on Liveweight, Concentrate Intake, Body Deformation  
There was no significant difference in the final LWT and ADG of grazing lambs with and without pellet supplementation. This result is in contrast to [PERSON] et al. [32] who reported that supplementation with concentrates at 2.5% of lamb body weight significantly increased the ADG of grazing lambs. Although the pastures in this study had ME that \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Pastures**} \\ \cline{2-4}
**Items** & **CFP** & **Lucerne** & \(p\)**Value** \\  & **(_n = 24_)** & **(_n = 24_)** & \\ \hline Pre-slaughter weight (kg) & 46.8 \(\pm\) 0.56 & 47.7 \(\pm\) 0.56 & 0.247 \\ HCW (kg) & 23.8 \(\pm\) 0.33  & 0.009 \\ Dressing percentage (\%) & 48.8 \(\pm\) 0.39 & 49.6 \(\pm\) 0.39 & 0.143 \\ Fat thickness (mm) & 7.6 \(\pm\) 0.50  & 0.021 \\ Body wall thickness (mm) & 18.6 \(\pm\) 0.74  & 0.011 \\ Rib eye area (cm\({}^{2}\)) & 14.9 \(\pm\) 0.35 & 15.8 \(\pm\) 0.35 & 0.080 \\ BCTRC\% & 47.8 \(\pm\) 0.16 & 47.3 \(\pm\) 0.16 & 0.051 \\ GR fat score (1–5) & 3.1 \(\pm\) 0.11 & 3.4 \(\pm\) 0.11 & 0.061 \\ OTH trade (\$AU) & 119.2 \(\pm\) 1.63  & 0.009 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Effect of different pasture types on carcass characteristics of prime lambs (LSM \(\pm\) SE) *. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Pastures**} \\ \cline{2-4}
**Items** & **CFP** & **Lucerne** & \(p\)**Value** \\  & **(_n = 24_)** & **(_n = 24_)** & \\ \hline Initial LWT (kg) & 41.7 \(\pm\) 0.37 & 41.1 \(\pm\) 0.37 & 0.057 \\ Final LWT (kg) & 48.9 \(\pm\) 0.62 & 50.6 \(\pm\) 0.62 & 0.247 \\ ADG (g) & 174.3 \(\pm\) 10.93  & 0.001 \\ Concentrate intake (kg DM/head/day) & 0.85 \(\pm\) 0.02  & 0.72 \(\pm\) 0.02  & 0.001 \\ FCE & 5.25 \(\pm\) 0.24  & 3.26 \(\pm\) 0.24  & \(<\)0.0001 \\ FCPUG (\$AU/kg) & 0.87 \(\pm\) 0.04  & 0.54 \(\pm\) 0.04  & \(<\)0.0001 \\ Initial BL (cm) & 64.6 \(\pm\) 0.18 & 64.5 \(\pm\) 0.18 & 0.630 \\ a BL (cm) & 3.7 \(\pm\) 0.27 & 4.3 \(\pm\) 0.27 & 0.137 \\ Initial WH (cm) & 62.6 \(\pm\) 0.29 & 62.3 \(\pm\) 0.29 & 0.427 \\ \(\Delta\) WH (cm) & 3.0 \(\pm\) 0.31  & 4.3 \(\pm\) 0.31  & 0.005 \\ Initial CG (cm) & 81.3 \(\pm\) 0.37 & 80.9 \(\pm\) 0.37 & 0.426 \\ \(\Delta\) CG (cm) & 4.2 \(\pm\) 0.39  & 6.6 \(\pm\) 0.39  & 0.001 \\ Initial BCS & 3.0 \(\pm\) 0.02 & 3.0 \(\pm\) 0.02 & 0.167 \\ \(\Delta\) BCS & 0.5 \(\pm\) 0.05  & 0.8 \(\pm\) 0.05  & 0.001 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Effect of different pasture types on liveweight, concentrate intake and body conformation of prime lambs (LSM \(\pm\) SE) *. was lower than the requirement for ideal lamb growth, lambs that ingested only pastures still had similar growth rates to lambs that were supplemented with pellets. This could be due to the grazing behaviour of lambs, which allowed them to selectively graze and obtain enough ME for growth, resulting in no significant differences in final LWT and ADG compared to supplementation. [PERSON] et al. [33] demonstrated that the diet selected by grazing lambs was mainly leaf, which had lower NDF content and higher organic matter digestibility than pre-grazing herbage samples. The result of our study was in line with the findings of [PERSON] et al. [34] who found no significant differences in liveweight and ADG when unprotected unsaturated fat was used as a supplement for grass-fed lambs. The FCPUG in our study ranged from 0.4 to 1.0 $AU/kg, which was considerably lower than FCPUG of RBO and CO supplementation in the indoor system of 3 $AU/kg [15]. The higher FCE in FFP grazing lambs supplemented with NOP could be the reason for greater FCPUG of the NOP treatment compared with that of the RBO treatment. The higher price of CO in comparison to RBO (AU$ 0.194/kg vs. AU$ 0.160/kg) resulted in the greater FCPUG of the CO treatment. The BL, WH and CG of grazing sheep have been shown to be highly correlated with body weight [35].