Feeding management of poultry during heat stress at tropical countries

LtvEr-rgooo DEvELopMENT eNo SusrerxarLe ENvTnoNMENTAL M.q,xacrur,NT IN THE Courexr or CrrlvtArs CnaNcr

Feeding Management of PoultrY

During Heat Stress at Tropical Countries

Ncuveu Duv HoRtl, Tnuoruc Huu Dut'tc, TnnN THnus Vlt't

ThaiNguyenlJniversityof AgricultureandForestry,Th:,1::#::;r;r::';::,

ABSTRACT

The ambienttemperature during the summer in the tropical countries, including Viet￾nam often very high (the average temperatuie in the summer can be up to 30-32"C),

this is detrimental to poultry (Star et ol., 2OO8; Deng et al., 2012; Hoan et al., 2014).

Poultry can only regulate their body temperature within a narrow range of environ￾mentaltemperatures (between 16-26'C).ln the tropics, environmentaltemperatures

are usually above this zone during most part of the year. High ambient tempera￾tures adversely affect the performance of poultry with meat-type birds being more

susceptible than egg-type birds (Van ef al.,ZAM). The poor performance of poultry

under high ambient temperatures is mainly as a result of decreased feed intake which

consequently reduces growth and meat quality, egg production, egg quality and effi￾ciency of feed utilization (Niu etaL, 2009; lmiket a1.,2A12; Shane, 1988; Yahav, 2000).

Several feeding practices have been used to alleviate the adverse effects of

high temperatures on poultry performance. Although most studies on nutritional

management of heat stress have been carried out in broilers, there are also few

reports on nutritional management in laying hens under heat stress condition. Feed

form (particle size, moisture content), nutrient manipulation (especially energy and

protein), electrolyte, vitamin supplementation, feeding time/feed restriction, choice

feeding and drinking water management have all proven to be beneficial to heat￾stressed poultry. The present paper reviews some common feeding management

practices used to alleviate the effect of high ambient temperatures on poultry

performance as well as their limitations.

Key words: High temperatures, poultry performance, feeding management

1. INTRODUCTION

The ambient temperature during the summer in the tropical countries, including Vietnam

often very high, this ii detrimental to-poultry. High temperature is causes of heat tress on poultry

production. Heat stress (HS) is o.r. of the most important environmental stressors challenging

po,rltry production woridwide. Stress, a response to adverse stimuli, is difficuit to define and

understand because of its nebulous perception. Understanding and controlling environmental

conditions is crucial to successful pouitry production and welfare. The environmental temperature

range within which poultry ur. ubl" to keep a constant body temperature with minimum effort

('coLfort zone') is runge. from16-26oC. In the tropics, environmental temperatures are above this

range during most parl of the year, except summer. In Vietnam and some others tropical countries,

summer temperatures can reach 35-38'4. As temperature rises above the "comfottzone" (common

in the tropics), poultry are susceptible to heat siress because they can no longer keep a balance

between body heat production and heat loss (Van et a1.,2015) lll'

TLre effects of heat stress in poultry are varied and range from decreased feed intake (NRC,

1994, L\);yahav, 2000[3]; Sohail er a 1., )UZ [4]), reduced weight gain and meat quality in broilers

Sur-roric a

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