Effect of dietary supplementation with carnosic acid or vitamin E on animal performance, haematological and immunological characteristics of artificially reared suckling lambs before and after road transport

ABSTRACT

To elucidate the influence of dietary carnosic acid (CA) and vitamin E on animal performance, immune response indicators and haematological parameters before and after transport stress, 24 lambs were individually fed ad libitum with milk replacer (MR) using an auto-feeder. Once daily the lambs received MR alone (Group CON, n = 8), MR + 0.096 g CA/kg live weight (LW) (Group CARN, n = 8) or MR + 0.024 g of α-tocopheryl acetate per kg LW (Group VitE, n = 8). After reaching the target slaughter weight (12 ± 0.5 kg), blood samples were collected to measure haematological and immunological parameters. Then, lambs were subjected to 4-h road transport and blood samples were collected again for haematological assessment. The animals were subsequently slaughtered. Before road transport, dietary CA supplementation promoted a descent of circulating white blood cells (WBC), red blood cells (RBC), haematocrit and haemoglobin concentration when compared with Groups CON and VitE (p < 0.05), but it did not affect production of cytokines by blood mononuclear cells. Road transport did not affect either RBC or haematocrit significantly. Nevertheless, transport affected leucocyte profile similarly in all the treatments, increasing granulocytes and monocytes proportions and decreasing lymphocytes. In contrast, after transport, WBC was increased in Group CARN, reaching similar values than Groups CON and VitE. However, under conditions of the present study, those modifications did not influence animal performance or immunity parameters of artificially reared suckling lambs.

KEYWORDS:

• Carnosic acid
• feed supplements
• haematology
• lambs
• stress
• transport of animals

Acknowledgements

The authors thank the farm and technical staff for their assistance in conducting this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Spanish National Research Council CSIC [Proyecto Intramural Especial; Project 201540E084]. Lara Morán was supported by a JAE-Predoc grant from the CSIC under the program “Junta para la Ampliación de Estudios” (CSIC-European Social Fund). Julio Benavides and María Martínez-Valladares were supported by two JAE-Doc contracts. Carolina Blanco was supported by a contract for young researchers (Council of Castile and León and European Social Fund).