RESUMO: Este estudo foi conduzido com o objetivo de avaliar os efeitos da suplementação dietética com selênio e cromo biocomplexados sobre o perfil de ácidos graxos do peito e da coxa de frangos de corte machos e fêmeas da linhagem Label Rouge. O delineamento experimental foi inteiramente casualizado em esquema fatorial 3 x 2 correspondendo a três dietas (controle; 0,40 ppm de cromo; 0,50 ppm de selênio) e dois sexos. Cada tratamento foi composto por três parcelas de cinco frangos de corte. O perfil de ácidos graxos foi avaliado nas amostras de peito e coxa. A adição de selênio biocomplexado na dieta de frangos de corte aumentou o teor de ácidos graxos de cadeia longa das séries ômega 3 e 6 (ácido docosahexaenóico - DHA e araquidônico, respectivamente), o total de ômega 6 e o conteúdo de ácido esteárico no peito (músculo pectoralis major). Além disso, a suplementação com selênio causou redução no teor de ácido oleico e no total de monoinsaturados no mesmo músculo. Os machos apresentaram maiores teores dos ácidos linoléico e linolênico e total de poliinsaturados; e menor conteúdo de ácido oleico, total de monoinsaturados e saturados na coxa. Os frangos suplementados com selênio biocomplexado e os machos apresentaram melhor qualidade lipídica no músculo do peito e coxa, respectivamente.

ABSTRACT: This study was conducted to evaluate the effects of dietary supplementation with biocomplexed selenium and chromium on the fatty acid profile of the breast and thigh of males and females broilers of the Label Rouge lineage. The experimental design was completely randomized arranged in a 3 x 2 factorial scheme corresponding to three diets (control; 0.40 ppm of chromium; 0.50 ppm of selenium) and two sexes. Each treatment consisted of three plots of five broilers. The fatty acid profile was evaluated in the breast and thigh samples. The addition of biocomplexed selenium in the broilers diets increased the content of long chain fatty acid of the omega 3 and 6 series (docosahexaenoic - DHA and arachidonic acids, respectively), the total of omega 6 and the stearic acid content on the breast (pectoralis major muscle). In addition, selenium supplementation caused a reduction in oleic acid content and in total of monounsaturated in the same muscle. Males had higher contents of linoleic and linolenic acids, and total of polyunsaturated; and lower content of oleic acid, total of monounsaturated and saturated in the thigh. The broilers supplemented with biocomplexed selenium and males presented better lipid quality in the muscle by breast and thigh, respectively.

RESUMO: Objetivou-se com este estudo avaliar os fatores relacionados a maciez da carne de frangos criados em sistema alternativo. Para o experimento foi avaliado a força de cisalhamento, diâmetro das fibras musculares do peito e da coxa, conteúdo de tecido conjuntivo através de histologia e teor de colágeno solúvel e total. O experimento foi executado em delineamento inteiramente casualizado (DIC) com uso de duas linhagens (Pescoço Pelado e Paraíso Pedrês) de ambos os sexos (macho e fêmea) e abatidos em quatro idades (65, 75, 85 e 95 dias), criados em sistema alternativo, sendo utilizado um total de 192 aves. Para força de cisalhamento (FC), ocorreu aumento nos valores em ambos os cortes em função da idade de abate e houve interação entre linhagem e sexo, com as maiores médias para os machos da linhagem Pescoço Pelado e diferença entre sexo para Paraíso Pedrês. A idade de abate influenciou o diâmetro das fibras musculares e o conteúdo de tecido conjuntivo do peito e da coxa, havendo aumento linear destes parâmetros em função da idade ao abate. O sexo não afetou o diâmetro das fibras musculares da coxa, enquanto na linhagem Paraíso Pedrês foram verificadas maiores médias em relação à Pescoço Pelado. A análise de componentes principais demonstrou a relação entre a força de cisalhamento e as demais variáveis analisadas. Assim, o aumento do diâmetro das fibras musculares do peito e da coxa também está relacionado à redução da maciez da carne de frangos caipiras, conjuntamente com o aumento da quantidade de tecido conjuntivo, teor de colágeno total e redução de sua solubilidade.

ABSTRACT: This study assessed whether the meat tenderness of broilers raised in a free-range system varies by sex, lineage, and age at the time of slaughter. Physicochemical parameters were measured to adequately assess breast and thigh muscle morphometry, including shear force (SF), muscle fibre diameter (MD), histological connective tissue (HCT) content, and total and soluble collagen contents (TCC and SCC, respectively). The experiment was conducted with a completely randomized design using two lineages (Pescoço Pelado and Paraíso Pedrês), with specimens of both sexes raised in a free-range system. Randomly selected broilers were slaughtered at 65, 75, 85, and 95 days old. A total of 192 birds were analysed. SF values correlated positively with age. The highest SF values were measured in thighs of the Pescoço Pelado lineage. Age also showed a positive correlation with MD and HCT content of the breast regardless of lineage. Gender did not have any significant correlation with physical parameters; although, higher values were measured in thighs of the Paraíso Pedrês than in those of the Pescoço Pelado lineage. There were no significant differences among treatments regarding the SCC and TCC of thighs and breasts. Principal component analysis (PCA) revealed relationships between SF and the rest of the measured attributes. PCA showed that age was positively correlated with the SF, MD, and HCT content of thighs and breasts. In contrast, SCC and TCC had negative correlations. The greatest breast and thigh MD values were associated with the least tender meat. Thus, age at the time of slaughter proved to be the most significant parameter impacting the physical characteristics of muscle morphometry and meat tenderness of breasts and thighs of broilers raised in a free-range system.

ABSTRACT Two experiments were carried with broilers from 29 to 42 days of age for the nutritional evaluation of dietary chia. Thus, the nitrogen-corrected apparent metabolizable energy (AMEn) and the apparent metabolizability coefficients of gross energy and ether extract of chia seeds and oil, toasted soybean grain (TSG), and soybean oil were determined in the experiment I, by total excreta collection method, using 120 broilers. Each experimental diet (reference diet [RD] and four diets with the tested feedstuffs) was evaluated in eight replicates of three broilers. The TSG and chia seeds replaced the RD in 250 g/kg, whereas soybean and chia oils replaced the RD in 100 g/kg. Simultaneously, a second experiment was carried subdivided into two trials. In the performance trial, we evaluated the dietary feedstuffs effects on performance, carcass and cut yields, blood parameters, and activity of lipogenic enzymes. The nutrient metabolizability coefficients and AMEn were evaluated in the metabolism trial. The AMEn values of 37.49, 37.35, 15.85, and 8.43 MJ/kg of dry matter were determined for chia oil, soybean oil, TSG, and chia seeds, respectively (experiment I). In the second experiment, the best feed conversion was observed in broilers fed diets containing chia oil and TSG. However, the diet formulated with chia seeds worsened broiler feed conversion, exhibited the smaller energy value and apparent metabolizability coefficient of the ether extract, and increased the activity of the malic enzyme and serum total cholesterol level. There was no difference for glucose-6-phosphate dehydrogenase activity and high-density lipoprotein cholesterol level. In general, chia oil showed to be efficient in replacing soybean oil in broiler diets.

RESUMO: As características climáticas dos locais de produção de suínos influenciam na produtividade do sistema, sendo as fêmeas em reprodução uma categoria extremamente sensível a elevadas temperaturas, principalmente, quando é atingida sua temperatura critica superior. Por meio desta revisão, avaliou-se os efeitos do sistema de resfriamento evaporativo sobre parâmetros ambientais, fisiológicos e de desempenho em fêmeas suínas em reprodução. Uma pesquisa bibliográfica foi realizada utilizando as palavras-chave: sow; swine; gilt e pig combinadas individualmente com a expressão ‘evaporative cooling’. Um total de 11 artigos atendeu aos pré-requisitos determinados para compor a revisão sistemática, sendo que os estudos envolveram fêmeas gestantes e lactantes mantidas em ambientes que apresentaram temperaturas entre 21,5 e 34,8 °C, e umidade relativa entre 32,2 e 84,2%. O sistema de resfriamento evaporativo foi usado de forma a resfriar o macro ou micro ambiente. Pode-se concluir que o uso do sistema de resfriamento evaporativo promove aumento do consumo de ração para porcas em lactação, diminuição da perda de peso na lactação, aumento do peso dos leitões ao desmame, redução da temperatura dos galpões e diminuição da frequência respiratória das porcas. Para porcas gestantes, não foram encontradas alterações no desempenho reprodutivo.

ABSTRACT: Climatic characteristics of the production sites of pigs influence the yield of the system, with breeding sows being a category extremely sensitive to high temperatures, especially when their upper critical temperature is reached. This review evaluated the effects of the evaporative cooling system on environmental, physiological and performance parameters in breeding sows. By means of this review, a bibliographic search was performed using the following keywords: sow; swine; gilt and pig combined individually with the expression ‘evaporative cooling’. A total of 11 papers met the prerequisites determined to compose the systematic review and the studies involved gestating and lactating sows maintained in environments that presented ambient temperatures between 21.5 and 34.8 °C and relative humidity between 32.2 and 84.2%. The evaporative cooling system was used in order to cool the macro or micro environment. It can be concluded that the use of evaporative cooling system promotes increase in feed intake per lactating sow, decrease in weight loss in lactation, increase of weight of piglets at weaning, temperature reduction of the barns and decrease of the respiratory rate of the sows. For gestating sows, no changes in reproductive performance were reported.

ABSTRACT We intended to evaluate the influence of supplementation with biocomplexed minerals on the performance and carcass characteristics of Label Rouge broilers of both sexes, as well as on the feed efficiency and feed costs. The experimental design was completely randomized arranged in factorial scheme (3×2) – three experimental diets (control, 0.50 ppm of selenium, and 0.40 ppm of chromium) and two sexes (male and female). Each treatment was composted of three plots, each one represented by 21 birds. The average weight (g/bird), weight gain (g/bird), feed intake (g/bird), and feed conversion in periods of 1 to 7, 1 to 21, 1 to 35, 1 to 49, 1 to 63, and 1 to 90 days were calculated. Weight and yield of carcass and cuts were determined. Both average feed cost (AFC, R$/bird) and cost per kg of weight gain (CWG, R$/kg weight gain) as well as economic efficiency index (EEI) were estimated. There was no influence of the diet on performance, carcass characteristics, and feed costs of the birds. The males presented higher means of average weight (3819.2 g/bird), weight gain (3780.9 g/bird), feed intake (11030.2 g/bird), and better feed conversion index (2.9) in the period of 1 to 90 days, besides presenting higher values of live weight at slaughter (3740.2 g), carcass weight (3117.5 g) and carcass yield (83.4%), breast weight (832.4 g), thigh weight (432.5 g), and thigh yield (13.9%); the females presented higher breast yield values (28.1%). The males presented higher AFC and lower CWG. The addition of minerals in the diet does not change performance, carcass characteristics and feed costs. The males present better performance and better carcass characteristics, in addition to being economically more viable.

Resumo Objetivou-se caracterizar a qualidade da carne de aves da raça Rodhe Island Red em função da diferença do tipo de corte e sexo. Foram utilizadas 30 aves em delineamento inteiramente casualizado em esquema fatorial (2 x 2), sendo dois cortes (peito e coxa) e dois sexos, com cinco repetições por tratamento. As aves foram abatidas aos 105 dias para realização das análises físico-químicas, composição centesimal e perfil lipídico do peito e coxa. A coxa apresentou maior média de pH final, teor de vermelho (a*) e força de cisalhamento (FC). Para luminosidade (L*), o peito obteve a maior média e as fêmeas maior média de FC. A coxa apresentou maior teor de extrato etéreo (EE) e umidade. O peito apresentou maior média de ácidos graxos saturados. As fêmeas obtiveram maior quantidade de ω3 e menor relação ω6/ω3. Foi observado maior índice de trombogenicidade no peito. A coxa mostrou menor conteúdo de ácidos graxos saturados e menor índice de trombogenicidade. As fêmeas apresentaram maior teor de ω3. O tipo de corte demonstrou maior influência que o sexo sobre os parâmetros estudados e a coxa apresentou melhores aspectos físico-químicos e de perfil lipídico para carne de aves neste sistema de produção relacionados à qualidade de carne desejável pelos consumidores.

Abstract This study aimed to characterize the quality of the meat from Rodhe Island Red poultry, considering the type of cut and sex. We used 30 birds in a completely randomized design in a factorial arrangement (2 x 2), two cuts (breast and thigh) and both sexes, with five replicates per treatment. The birds were slaughtered at 105 days to carry out the physical and chemical analysis, chemical composition and lipid profile of breast and thigh. The thigh showed the highest mean final pH, redness (a*) and shear force (SF). For brightness (L*), the breast had the highest average as well as females presented the highest SF average. The thigh presented the highest amount of ether extract (EE) and humidity. The breast presented the highest amount of saturated fatty acids. Females showed the highest amount of ω3 and the lowest ω6 / ω3 relation. There was a higher thrombogenicity index in breast meat. The thigh showed the lowest content of saturated fatty acids and a lower thrombogenicity index. Females had higher content of ω3. The cut showed greater influence then sex on the studied parameters and the thigh showed better physical and chemical aspects and lipid profile for poultry meat in such production system regarding the meat quality as desirable by the consumers.