Deltamethrin Application on Pre-Weaned Calves Improves Feed Consumption, Stress and Fatigue Status under Heat Stress Conditions.

Konstantinos V Arsenopoulos,Elias Papadopoulos,Athanasios I Gelasakis,Eleftherios Triantafillou

doi:10.3390/pathogens11010085

Abstract

Fly infestation remains a universal problem for dairy cattle herds, affecting the animals’ health and welfare status. Pre-weaned dairy calves are significantly challenged by the direct and indirect consequences of severe fly infestation, heat-stress and their interaction, which contribute to a stressful and fatiguing environment. Among several physiological, behavioral, clinical and biochemical traits, serum cortisol (SC) and creatine kinase (CK) levels, as well as feed consumption can be used as valid indicators of potential stressful and fatiguing conditions and, therefore, can be efficiently used for stress analysis studies. Hence, the objective of the study was to assess the fly-repellency effect of deltamethrin on pre-weaned dairy calves exposed to heat stress conditions, as well as its association with SC, CK concentrations and feed consumption. Two commercial dairy cattle herds of the Holstein breed in Central Macedonia (Greece) were involved in the study during summer months and under heat stress conditions. Deltamethrin administration resulted in (i) a decreased fly population (100% Musca domestica) landing on pre-weaned dairy calves, (ii) a reduced SC (stress indicator) and CK (fatigue indicator) concentration, and (iii) an increased consumption of feedstuff in deltamethrin treated animals compared to the untreated ones.

Highlights

In recent decades, increasing ethical concerns regarding welfare implications of livestock farming practices have reshaped farmers’ and consumers’ perceptions
Serum cortisol (SC) and creatine kinase (CK) levels can be used as indicators of potential stressful and fatiguing conditions
Environmental conditions, which were prevailing in both farms, were similar and over the typical range expected for this summer season (July and August), according to the Hellenic National Meteorological Service (Table 1)

Summary

Introduction

In recent decades, increasing ethical concerns regarding welfare implications of livestock farming practices have reshaped farmers’ and consumers’ perceptions. It is difficult to describe what a “sufficient” level of welfare is; the use of objective welfare indicators is needed [3,4,5,6,7]. These indicators may be direct or indirect, including physiological, behavioral, clinical and biochemical traits [1]. Serum cortisol (SC) and creatine kinase (CK) levels can be used as indicators of potential stressful and fatiguing conditions. Conditions provoking restlessness (i.e., increased body exercise, disease, discomfort, etc.) are associated with muscle cell damage and increased CK level, due to the leak of the enzyme into blood circulation [8]

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Discussion

Conclusion