Influence of seasonal changes on physiological variables, haematology and serum thyroid hormones profile in male Red Sokoto and Sahel goats

B Habibu,M U Kawu,T Aluwong,H J Makun

doi:10.1080/09712119.2016.1220384

Abstract

ABSTRACTThe aim of this study was to evaluate the physiological responses of adult male Red Sokoto goats (n = 10; indigenous to the Guinea Savannah climate) and Sahel goats (n = 10; indigenous to the Sahel climate) at the peak of the cold-dry (CDS), hot-dry (HDS) and rainy seasons prevailing in the Guinea Savannah zone of Nigeria. Results revealed that Red Sokoto goats had significantly higher rectal temperature (RT), PCV, red blood cell (RBC), Hb, thyroxin (T4), but lower respiratory rate (RR) and total leucocyte count (TLC) than Sahel goats during the CDS. Comparison within breeds for the three seasons showed that both breeds exhibited the highest (P < .05) PR, RT, neutrophil-lymphocyte ratio (N:L), but lower mean corpuscular volume and triiodothyronine (T3) during the HDS. In addition, Red Sokoto goats showed higher (P < .05) RR and T4, but lower RBC, Hb, lymphocyte counts and T3:T4. However, Sahel goats exhibited higher (P < .05) PCV, RBC, erythrocyte osmotic fragility, but lower circulating T4. It was concluded that the cold and hot seasons exerted different physiological effects on the two breeds of goats with marked variation in RT, composition of blood cellular components, thyroid physiology and erythrocyte membrane integrity.

Highlights

About 80% of goat production is confined to lowincome countries, in tropical Africa and Asia (Morand-Fehr et al 2004)
The result of this study showed that, though Red Sokoto and Sahel goats are assumed to be phylogenetically related and belong to the Savannah or Sahel type of goats, their physiological response differ in different seasons of the year
The Red Sokoto and Sahel goats experience an integrated physiological response in thyroid function, blood cellular components, erythrocyte osmotic fragility (EOF) and physiological variables so as to efficiently adapt to the existing meteorological parameters. In both breeds of goats, the CDS and HDS altered the composition of blood cellular components, thyroid physiology and decreased resistance and size of erythrocytes, with the HDS being more stressful

Summary

Introduction

About 80% of goat production is confined to lowincome countries, in tropical Africa and Asia (Morand-Fehr et al 2004). Promoting small-scale livestock ownership has been reported to be a potential way of reducing poverty and improving human nutrition in rural Africa (Azzarri et al 2014). The Red Sokoto and Sahel goats are important breeds of goat that are widely distributed in the West Africa subcontinent. Red Sokoto goats are indigenous to Niger Republic and the savannah region of Nigeria, while the Sahel goats are found in West Africa around the Sahel belt, south of the Sahara (Gall 1996). Adaptation of Sahel goats to the Northern Guinea Savannah zone of Nigeria, mainly by institutional and commercial farms, and unregulated livestock markets has been observed in recent years (Makun et al 2013)

Objectives

Methods

Results

Discussion

Conclusion