Effects of mixed Blackseed with chromium-methionine or zinc-methionine supplementations on serum components and physiological responses in Sanjabi lambs during road transportation

Stress in livestock is characterized by changes in physiological and functional parameters. The importance of stress in ruminants is in maintaining health and increasing their productive capacity. Long periods of transport with vehicles, especially in adverse weather conditions, resulted in fatigue, lack of comfort, weight loss and an increase in the prevalence of infectious diseases. Different stress conditions increase the production of free radicals species and thus oxidative stress. Diets containing appropriate levels of antioxidants, by inhibiting free radicals, improve the harmful effects of stress. Studies have shown that the use of minerals and medicinal plants with antioxidant properties in livestock feed improves the physiological conditions and preventing production capacity by modifying antioxidants- pro-oxidants. The present study was conducted to compare the effect of chromium- methionine or zinc-methionine supplementations with black seed on transported stress and improve the livestock performance.

In this study, 18 Sanjabi lambs (24-26 weeks age) were randomly assigned to three dietary treatments two weeks before road transportation: (i) basal diet (control); (ii) basal diet with added 30 grams black seed + 50mg Zn-Met /Kg DM; and (iii) with added 30 grams black seed +1mg Cr-Met/Kg DM. During the experimental period, lambs performance and changes on blood parameters were performed. Lambs were transported after two weeks of starting the experiment for 3 hours. Blood samples were collected via jugular puncture before transportation (BT), after transportation (AT1), as well as 24h after transportation (AT2). Blood samples were placed on ice at once after collection and centrifuged at 3500 × g for 15 min at 4°C for serum harvesting. The serum was maintained at -20 °C until analysis.

Lambs fed on black seed +Zn-Met or black seed +Cr-Met diets had higher feed intake and average daily gain (ADG) than those of control (P<0.05). Lambs fed on black seed +Zn-Met diet had higher feed intake compared with the control group (P<0.05), while lambs fed on the black seed +Cr-Met diet showed lower feed conversion ratio (FCR) than that of the controls (P<0.05). The supplemented lambs on glucose, cortisol, albumin, lactate dehydrogenase (LDH) concentrations at AT1 than those of control (P<0.05). Lambs fed on black seed +Cr-Met diet had lower blood malondialdehyde (MDA) at AT1 when compared with the control (P<0.05).

It can be concluded that incorporation of black seed +Zn-Met or black seed +Cr-Met to the diet can reduce the adverse effects of transportation stress in lambs