Thermal comfort index, physiological variables and performance of quails fed with protein reduction

Abstract

A B S T R A C TThe objective of this study was to determine the effects of environment and electrolyte balance on environmental, physiological and productive indices of Japanese quails. For the experiment, 288 quails were distributed in a randomized block design with six treatments and six replicates of eight birds per experimental unit. The treatments consisted of one basal feed with 20.0% of crude protein (CP) and the others with a reduction of 3.0% CP to achieve six electrolyte balance levels (166.54; 153.47; 139.63; 139.63; 117.13 and 166.49). As to the environment, there was an increase in air temperature and temperature-humidity index at the hottest hours of the day, causing discomfort to the birds, which increased respiratory rate, but with the maintenance of homeothermy. Differences were observed in feed consumption, water consumption, production, weight of eggs and mass of eggs, due to the electrolyte levels in the feed. For feed conversion, both per mass and per dozen of eggs, there was no statistical difference. The electrolyte balance and environmental indices at the hottest hours of the day did not affect quail production.Índice de conforto térmico, variáveis fisiológicas e desempenho de codornas alimentadas com redução proteica R E S U M O Objetivou-se, neste trabalho, determinar o efeito do ambiente e do balanço eletrolítico sobre os índices ambientais, fisiológicos e produtivos de codornas japonesas. Utilizaram-se 288 aves distribuídas no delineamento em blocos casualizados com seis tratamentos e seis repetições de oito aves por unidade experimental. Os tratamentos consistiram em uma ração basal com nível de 20,0% PB e os demais com redução de 3,0% PB, para alcançar seis níveis de balanço eletrolítico (166,54; 153,47; 139,63; 139,63; 117,13 e 166,49). Quanto ao ambiente, verificou-se uma elevação na temperatura do ar e no índice de temperatura e umidade nos horários mais quentes do dia, causando desconforto às aves, que elevaram a frequência respiratória, porém com a manutenção da homeotermia. Foram observadas diferenças no consumo de ração, consumo de água, produção, peso e massa de ovo, em razão dos níveis eletrolíticos da ração. Quanto à conversão alimentar tanto por massa quanto por dúzia de ovos, não foi observada diferença estatística. O balanço eletrolítico e os índices ambientais nos horários mais quentes do dia não interferiram na produção das aves.

Physiological variables and egg quality from quails (Coturnix coturnix japonica) that received water with increasing levels of NaCl and under different temperatures

“…Egg quality can be affected by the levels of salt in the water or feed. However, salinity levels of up to 6.0 dSm -1 did not change the weight and percentage of albumen, which were similar to those reported by Lima et al (2015) and Rodrigues et al (2016). The latter papers did not find an effect of increasing sodium levels in the feed and electrolyte balance, respectively.…”

“…The respiratory frequency of quails exposed to the heated environment was higher. This is a protection mechanism that increases evaporation in the exhaled air and releases internal heat in the evaporative form to maintain body thermal balance (Rodrigues et al, 2016;Silva et al, 2017), but it can lead to production losses. S. M. Santos et al (2014) reported this increase in the respiratory rate in quails kept at temperatures from 30 to 33ºC.…”

“…Quails raised under heat stress conditions modify their ingestive behaviour and trigger heat loss mechanisms, which can increase respiratory and heart rate, as well as cloacal and body surface temperature (Souza et al, 2013;Ribeiro et al, 2016;Rodrigues, Furtado, Costa, Nascimento, & Cardoso, 2016), affecting animal welfare (T. C. Santos, Gates, Tinôco, Zolnier, & Baêta, 2017) by compromising feed intake, assimilation, and metabolism, and causing a decrease in egg production, weight, and quality (Silva et al, 2017;Akdemir et al, 2019).…”

Magnesium in the water of Japanese quails kept under comfort zone and under thermal stress

“…The weight of a quail egg can vary between 10 and 13 g. Even under thermal stress, quails are able to maintain production and quality of the products (Guimarães et al, 2014;Rodrigues, Furtado, Costa, Nascimento, & Cardoso, 2016;Petrucci et al, 2017). However, these variables can be reduced in quails kept under thermal stress (El-Tarabany, 2016;Santos et al, 2017;Silva et al, 2017;Akdemir et al, 2019), due to the reduction in food intake, reduced digestibility of diet components, and mobilization and use of body reserves to maintain body temperature.…”

Effect of roof painting of aviaries on thermal comfort, productive performance and physiological variables of broilers chickens

“…Thus, the low applicability of the GTHI to assess the comfort of broiler chickens is emphasized, as well as the plumage, feather and skin characteristics of the broiler, the wind speed coming into the building and the intrinsic capacity of each species to eliminate endogenous heat are other variables that must be regarded for the elaboration of thermal comfort indexes for broilers. The rectal temperature and the surface temperature of the broilers are important physiological variables to verify whether the animal is in comfort (GUIMARÃES et al, 2014;RODRIGUES et al, 2016). No effect (P<0.05) of the roof paint was observed for the physiological variables.…”