The effects of selenium-methionine (Se-Met) and
chromium-methionine (Cr-Met) supplementation on performance
and response to transportation stress were studied on
24 Baluchi ewe lambs (18–20 weeks of age) for 9 weeks. The
lambs were randomly assigned to four dietary treatments: (1)
control; (2) 1.5 mg supplemental Se-Met/kg dry matter (DM)
of diet; (3) 0.8 mg supplemental Cr-Met/kg DM of diet; and
(4) 1.5 mg Se-Met plus 0.8 mg Cr-Met/kg DM of diet (Se-CrMet).
At the commencement of week 8, a road transportation
stress (TS) was carried out for 30 min. Lambs fed Cr-Met and
Se-Cr-Met diets had higher feed intake than the control and
Se-Met animals (P<0.0001). Lambs on Cr-Met diet showed
higher average daily gain (ADG) compared to the control
group (P=0.007). Se-Met and Cr-Met supplementation alone
or in combination significantly (P<0.05) reduced feed conversion
ratio (FCR). The animals that received Se-Met (P=
0.014), Cr-Met (P=0.005), and Se-Cr-Met (P=0.003) supplemented
diets had lower glucose concentration than the control.
Lambs on Cr-Met had higher blood T
concentration than
control animals (P=0.040), while Cr-Met (P=0.039) and Se-
3
Cr-Met (P=0.032) supplementation increased triiodothyronine
(T
3
)tothyroxin(T
) ratio. Animals fed Se-Met and/or
Cr-Met supplements had lower blood malondialdehyde
(MDA) in week 9 of the experiment (P<0.05). Blood ferric-reducing antioxidant power (FRAP) tended to be higher in the
Se-Met- and Se-Cr-Met-supplemented groups (P<0.1).TS reduced
feed intake in lambs fed the control diet in week 8 of the
experiment (P=0.003). The lambs given with supplemental
Cr-Met exhibited lower glucose concentration before transportation
(BT) (P=0.029) and after transportation (AT) (P=
0.016) compared to the control. Lambs fed Se-Cr-Met had the
lowest cortisol concentration BT (P<0.05). It was concluded
that feeding Se-Met and/or Cr-Met supplements could improve
growth performance and be beneficial in attenuating
the adverse effects of transportation st