Shading effect on physiological parameters and in vitro embryo production of tropical adapted Nellore heifers in integrated crop-livestock-forest systems

Wilian Aparecido Leite Da Silva,Fabiana De Andrade Melo-Sterza,Mirela Brochado Souza Cáceres,Fabiana Villa Alves,Caroline Carvalho De Oliveira,Eliane Vianna Da Costa E Silva,Ralf Poehland,Ricardo Garcia De Almeida,Eriklis Nogueira,Gustavo Guerino Macedo,Mariane Gabriela Cesar Ribeiro Ferreira

doi:10.1007/s11250-020-02244-3

Abstract

The aim of this study was to evaluate the impact of increased shadow supply in integrated crop-livestock-forest systems on in vitro embryonic development and physiological parameters related to stress response in Nellore heifers (Bos indicus). For the study, animals (n = 16) were randomly divided into two groups and kept in areas with different afforestation systems, the integrated crop-livestock-forest (ICLF) and the integrated crop-livestock (ICL) system. The microclimate of the ICLF system provided better comfort conditions than ICL. No differences of respiratory rate, rectal temperature, cortisol, T3, T4, oocyte quality, and cleavage rate between the systems were verified. A higher blastocyst rate was observed in the ICLF (p < 0.05). The results demonstrate that Nellore heifers managed in ICLF during summer in Midwest of Brazil showed higher production of in vitro embryos, without typical changes in its physiological parameters. The results observed in the present study indicate that zebu females are able to respond satisfactorily to the intense heat conditions; however, we believe that the long period to which these animals are exposed to these conditions interferes in the oocyte competence and embryo development.

Highlights

The environment in which animals live has important effects on animal welfare conditions and can affect the productive andIn reproduction, HS affects follicular development and oocyte quality (Roth et al 2001), interfering from the initialTrop Anim Health Prod (2020) 52:2273–2281 stages to the end of maturation (Paula-Lopes et al 2012), as well as the number and quality of embryos produced in vitro (Torres-Junior et al 2008)
Area 1 was characterized by the integrated crop-livestock-forest system (ICLF) with 6 ha divided into 4 paddocks, with a density of 227 trees ha−1 arranged in rows of eucalyptus trees (Eucalyptus grandis x urophylla, clone H13) with a distance of 22 m between rows
Area 2 was characterized by pasture with native afforestation of integrated crop-livestock (ICL) with 6 ha divided into 4 paddocks and presence of 5 trees ha−1

Summary

Introduction

The environment in which animals live has important effects on animal welfare conditions and can affect the productive andIn reproduction, HS affects follicular development and oocyte quality (Roth et al 2001), interfering from the initialTrop Anim Health Prod (2020) 52:2273–2281 stages to the end of maturation (Paula-Lopes et al 2012), as well as the number and quality of embryos produced in vitro (Torres-Junior et al 2008). The environment in which animals live has important effects on animal welfare conditions and can affect the productive and. HS affects follicular development and oocyte quality (Roth et al 2001), interfering from the initial. Shading decreases the incidence of radiation on the animal; it benefits the thermal comfort and favors the homeothermia (Geraldo et al 2012). The benefits of shade are most evident in Bos taurus, but positive shading effects have already been observed in Bos indicus (Navarini et al 2009). The positive effect of shading is known, important changes in the management of beef cattle in Brazil have not been observed over the years

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