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The aims of this study were (i) to evaluate the effect of density, lineage, age, and time of day on dorsal surface temperature and (ii) to evaluate the effect of density and lineage on performance and carcass condemnations in broiler grillers. The evaluations were carried out in barns with the Dark House system, with two densities, 17 and 19 chickens/m2 and two lineages, Cobb and Ross. The dorsal surface temperature of the chickens was measured by infrared thermography at 7, 14, 21, 23, 25 and 27 days of age, four times a day. The average daily weight gain, feed conversion, mortality, partial carcass condemnations, as well as those due to arthritis and dermatosis were also evaluated. The highest dorsal surface temperatures were observed in Cobbs housed at a density of 17 chickens/m2, and in Ross housed at a density of 19 chickens/m2. Cobbs housed at a 17 chickens/m2 density showed the lowest feed conversion compared to Ross at the same density. Ross showed higher dorsal surface temperatures when compared to Cobbs at 14, 21, and 27 days. Cobbs showed higher percentages of partial carcass condemnation and arthritis compared to Ross. The higher density of broiler grillers in the Dark House system does not influence the dorsal surface temperature, performance, dermatosis, arthritis, and partial carcass condemnations.
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OBJECTIVE: The aim of this study was to evaluate heat tolerance using heat tolerance indices, physiological, physical, thermographic, and hematological parameters in Santa Ines and Morada Nova sheep breeds in the Federal District, Brazil. METHODS: Twenty-six adult hair sheep, one and a half years old, from two genetic groups (Santa Ines: 12 males and 4 females; Morada Nova: 7 males and 3 females) were used and data (rectal temperature, respiratory rate, heart rate, skin temperatures; hematological parameters) were collected during three consecutive days, twice a day (morning and afternoon), with a total of six repetitions. Also physical parameters (biometric measurements, skin and hair traits) and heat tolerance indices (temperature-humidity index, Iberia and Benezra) were evaluated. The analyses included analyses of variance, correlation, and principal components with a significance level of 5%. RESULTS: The environmental indices, in general, indicate a situation of thermal discomfort for the animals during the afternoon. Breed significantly influenced (p<0.001) physiological and physical characteristics of skin, hair, biometric measurements and Iberia and Benezra heat tolerance indices. Santa Ines animals were bigger and had longer, greater number and darker hair, thicker skin, greater respiratory rate and Benezra index and lower Iberia index compared with Morada Nova breed. CONCLUSION: Although both breeds can be considered adapted to the environmental conditions of the region, Morada Nova breed is most suitable for farming in the Midwest region. The positive correlation found between the thermographic temperatures and physiological parameters indicates that this technique can be used to evaluate thermal comfort. Also, it has the advantage that animals do not have to be handled, which favors animal welfare.
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The objective of this study was to compare physiological and thermographic responses to heat stress in three breeds of cattle. Fifteen animals of each of the Nelore, Pantaneiro and Curraleiro Pe-Duro breeds, of approximately two years of age, were evaluated. Heart and respiratory rates, rectal and surface temperature of animals as well as soil temperature were recorded at 8:30 and 15:30 on six days. Variance, correlation, principal factors and canonical analyses were carried out. There were significant differences in the rectal temperature, heart and respiratory rate between breeds (p < 0.001). Nelore and Pantaneiro breeds had the highest rectal temperatures and the lowest respiratory rate (p < 0.001). Breed was also significant for surface temperatures (p < 0.05) showing that this factor significantly affected the response of the animal to heat tolerance in different ways. The Curraleiro Pe-Duro breed had the lowest surface temperatures independent of the period evaluated, with fewer animals that suffered with the climatic conditions, so this may be considered the best adapted when heat challenged under the experimental conditions. Thermography data showed a good correlation with the physiological indexes, and body area, neck and rump were the main points.
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In this study, a multivariate analysis of morphological and physiological characteristics was performed on clinically healthy rams from six breeds (Santa Ines, Bergamasca, Dorper, Texel, Ile de France and Hampshire Down) to determine if these characteristics were able to separate and determine the most important variables in the differentiation of breeds for heat adaptation. To characterize the thermal environment, mean temperature was 23°C and relative humidity ranged between 30.6-55.6%. Morphological and physiological data were subjected to multivariate statistical tests including principal components (PRINCOMP), clustering (CLUSTER), discriminant (DISCRIM), step-bystep (STEPDISC) and canonical (CANDISC) analyses, using the Statistical Analysis System (SAS®). A multiple analysis of variance (MANOVA) was carried out with the variables defined as important by the discriminant analysis. The principal components analysis for biometric characteristics and scrotum-testicle, for physiological characteristics and body temperature as well as the characteristics of the skin and hair explained 60, 70 and 67 % of the total variation, respectively. The dendrogram showed a clear separation between the breeds studied and the existence of two distinct groups, one formed by the Texel and the other by the other breeds, considering all the characteristics used in the study. The most useful morphological parameters to explain heat tolerance were diameter of hair, layer thickness of hair at withers, 12th thoracic vertebra and rump, withers height, thoracic and scrotal circumferences, body weight, anterior and posterior shin perimeters, hair and epidermis brightness as well as the content of red and yellow in the epidermis. Among physiological characteristics, respiratory rate was better than rectal temperature and heart rate to explain changes caused by thermal stress. From the multivariate and variance analyzes it can be concluded that the Santa Ines breed was the most tolerant to heat stress as it presented a highly pigmented epidermis, a shorter hair of larger diameter, the lower layer thickness of hair at withers, 12th thoracic vertebra and rump, the lower temperatures in the testicle and at the 12th thoracic vertebra as well as the lower respiratory rate and rectal temperature value.
Neste estudo, foram realizadas análises multivariadas das características fisiológicas e morfológicas em carneiros clinicamente saudáveis de seis raças (Santa Inês, Bergamácia, Dorper, Texel, Ile de France e Hampshire Down) para determinar se essas características foram capazes de separar as raças e determinar as variáveis mais importantes na diferenciação das raças na adaptação ao calor. Os dados foram submetidos a testes estatísticos multivariados, incluindo as análises de componentes principais (PINCOMP), agrupamento (CLUSTER), discriminante (DISCRIM), step-by-step (STEPDISC) e canônica (CANDISC), utilizando o pacote estatístico SAS®. A análise variância de múltipla (MANOVA) foi realizada com as variáveis definidas como importante pela análise discriminante. A análise dos componentes principais para características biométricas e escroto-testiculares, para as características fisiológicas e de temperatura corporal e para as características da pele e pelo explicaram 60, 70 e 67% da variação total, respectivamente. O dendrograma mostrou uma clara separação entre as raças estudadas e a existência de dois grupos distintos, um formado pela raça Texel e o outro pelas raças Dorper, Hampshire Down, Ile de France, Santa Inês e Bergamácia, considerando todas as características avaliadas. As características morfológicas mais importantes para explicar a tolerância ao calor foram o diâmetro do pelo, as espessuras das camadas de pelo na cernelha, na décima segunda vértebra torácica e na garupa, a altura da cernelha, as circunferências torácica e escrotal, o peso corporal, os perímetros das canelas anterior e posterior, as luminosidades da pele e do pelo, bem como os teores de pigmentação vermelho e amarelo na epiderme. Entre as características fisiológicas a frequência respiratória foi melhor que a temperatura retal e a frequência cardíaca para explicar as mudanças causadas pelo estresse térmico. A partir das análises multivariada e de variância pode-se concluir que a raça Santa Inês foi a mais tolerante ao estresse térmico, uma vez que apresentou epiderme altamente pigmentada, pelo mais curto e de diâmetro maior, menores espessuras das camadas de pelo na cernelha, na décima segunda vértebra torácica e na garupa, menores temperaturas no testículo e na décima segunda vértebra torácica, bem como as menores frequência respiratória e temperatura retal.
Asunto(s)
Ovinos , Termotolerancia , CalorRESUMEN
The aim of this study was to evaluate the antioxidant effect of dietary supplementation of plant oil resins in laying hens on the oxidative stability of cooked egg yolk kept at 4ºC for 30 days, and fresh eggs stored under refrigeration (R) at the same temperature for 60 days or kept in room temperature (RT) for 30 days. Hens were fed corn- and soybean-based diets (15% CP and 2,900 kcal kg-1) and supplemented with two levels of Copaifera langsdorffii oil resin (CP-0.03; 0.06 and 0.09%) or Pterodon emarginatus oil resin (SC-0.03 and 0.06%), plus a negative control (CN). At 37 weeks of age, 667 eggs were collected and randomly distributed in different storage conditions, in natura or cooked. The progression of lipid oxidation of egg yolk in natura was quantified in quadruplicate and cooked egg yolks in duplicate, using pool of 3 egg yolks/treatment to analyze TBARS (thiobarbituric acid reactive substances) concentration in quadruplicate. Data analysis was performed using a mixed model and Tukey test, at a 5% significance level. The storage period was considered a longitudinal factor, which varied from five times, for R cooked yolk and TA fresh yolk (0-30 days), to nine times, for R fresh yolk (0-60 days). For fresh eggs stored at RT or R, the supplementation of plant oils did not protect egg yolks from lipid oxidation, compared to NC. However, for cooked egg yolks, the addition of 0.03 and 0.06% of CP oil resin showed antioxidant activity since it reduced lipid oxidation up to day 21 of storage, but had a prooxidant effect for 0.09%. Therefore, it can be concluded that the supplementation of copaíba oil resin had an antioxidant protection of cooked egg lipids...
O objetivo deste trabalho foi avaliar a atividade antioxidante da adição de óleos de copaíba (CP) e sucupira (SC) na alimentação de poedeiras sobre a oxidação lipídica de ovos in natura armazenados em temperatura ambiente (TA) por 30 dias e sob refrigeração (R) a 4ºC por 60 dias, e de gemas cozidas mantidas sob R por 30 dias. As poedeiras foram alimentadas com ração isoproteica (15% PB) e isoenergética (2900 kcal kg-1) à base de milho e farelo de soja, com inclusão de óleo de Copaifera langsdorffii (CP) nas proporções de 0,03; 0,06 e 0,09% ou de Pterodon emarginatus (SC) nas proporções de 0,03 e 0,06%, mais um controle negativo (CN). Foram coletados 667 ovos às 37 semanas de idade e distribuídos aleatoriamente nas diferentes condições de armazenamento (TA ou R). A oxidação dos lipídios de ovos in natura foi quantificada em quadruplicata e das gemas cozidas em duplicata, utilizando-se pool de 3 gemas/tratamento para as análises de TBARS (thiobarbituric acid reactive substances). Os dados foram avaliados adotando um modelo misto e as médias foram comparadas pelo teste de Tukey em 5% de nível de significância e o período de armazenamento foi considerado como um fator longitudinal, variando de cinco tempos no experimento com gemas cozidas, e nos ovos in natura sob R e em TA (0 a 30 dias), até nove tempos sob R (0 a 60 dias). Foi observado que a adição de óleo de CP e SC não reduziu os valores de TBARS em ovos in natura armazenados em TA e sob R em relação ao CN. No armazenamento de gemas cozidas, a inclusão CP (0,03 e 0,06%) protegeu os lipídios até os 21 dias, mas apresentou efeito pró-oxidante quando suplementado a 0,09%. Concluiu-se que a inclusão de até 0,06% de óleorresina de CP nas rações de poedeiras pode proteger os lipídios da gema cozida contra a oxidação durante o armazenamento refrigerado por até 21 dias...