Comparison between infrared and hot-blade beak trimming methods in white and brown pullets: performance, organ and bone development / [Comparativo entre debicagem infravermelha e por lâmina-quente em linhagens de frangas leves e semi-pesadas: desempenho, desenvolvimento ósseo e de órgãos]

The purpose of this study was to evaluate infrared beak trimming versus hot-blade beak trimming on performance, organ and bone development of laying pullets, using 240 birds, at 0-16 weeks of age, from two strains (white layer - Hy-Line W36 and brown layer - Hy-Line Brown). Infrared debeaking was performed on the first day of life in the hatchery, whereas hot-blade beak trimming was performed at eight days of age. Zootechnical performance at 6, 9, 12 and 15 weeks of age was analyzed. At the end of the trial, one Bird per experimental unit was euthanized for liver, gizzard, proventriculus, heart and small intestine relative weight evaluation. Both tibiotarsus were collected to measure bone breaking resistance, bone mineral content and bone densitometry. There was higher body weight and feed intake in both bird strains submitted to infrared beak trimming. Additionally, hot-blade white layers presented lower body development and feed intake. The debeaking methods did not influence relative organ weights or tibiotarsus parameters evaluated. We conclude that the infrared beak trimming method promotes better pullet body development than the conventional hot-blade method, improving feed intake, without compromising organ and bone development, being a more adequate debeaking method to be used in layer production.(AU)

Para avaliar a debicagem infravermelha versus a debicagem pelo método da lâmina quente no desempenho, no desenvolvimento de órgãos e na qualidade óssea de poedeiras em recria, foram utilizadas 240 aves, entre zero e 16 semanas de idade, em duas linhagens (branca - Hy-Line W36 e vermelha - Hy-Line Brown). A debicagem por infravermelho foi realizada no primeiro dia de vida no incubatório, enquanto a debicagem com lâmina quente foi realizada aos oito dias de idade. Analisou-se o desempenho zootécnico na sexta, nona, 12ª e 15ª semanas de idade. No final do estudo, uma ave por unidade experimental foi eutanasiada para avaliação do peso relativo do fígado, da moela, do proventrículo, do coração e do intestino delgado, e ossos do tibiotarso foram coletados para avaliação da resistência à ruptura, do conteúdo mineral e da densitometria óssea. Houve maior peso corporal e consumo alimentar nas aves pertencentes às duas linhagens quando submetidas à debicagem por infravermelho, sem haver influência sobre o peso relativo dos órgãos e a qualidade óssea. Conclui-se que o método de debicagem por radiação infravermelha promove melhor desenvolvimento corporal das frangas em relação à debicagem por lâmina quente, melhorando consumo de ração, sem comprometer o desenvolvimento de órgãos e ossos, sendo mais adequada para utilização na avicultura de postura comercial.(AU)

Chemical composition, lipid peroxidation, and fatty acid profile in meat of broilers fed with glycerol monolaurate additive.

The objective of this study was to evaluate the chemical composition and fatty acid profile of broilers fed diets containing glycerol monolaurate (GML) in place of antimicrobials. Groups: T0 group used as control; T100, T200, and T300 groups received diets supplemented with 100, 200, and 300 mg/kg of GML, respectively. The feed mixture used in the poultry feed during the four phases of the production cycle (days 1 to 7; 8 to 21; 22 to 35; and 36 to 42 of birds age) showed similar levels of protein, lipid and ash, as well as fatty acid profiles. Samples of frozen breasts from chickens slaughtered at 42 days of age were used for chemical gross composition and fatty acid analysis. We observed lower lipid levels in the meat of broilers in the T200 and T300 groups than in the T0 group. Lower lipid peroxidation occurred in the meat of animals that consumed GML in respect to control. Total saturated fatty acid percentage was lower, while total polyunsaturated fatty acid percentage was higher in the meat of broilers fed GML than in the control group. We conclude that the increase in GML concentrations alters the lipid profile of broiler meat.

Miopatia White Striping em diferentes linhagens de frangos de corte e suas consequências sobre a composição e a qualidade da carne / The White Striping myopathy in different broiler strains and its influence on composition and meat quality

Avaliou-se a incidência da miopatia White Striping (WS) em três linhagens de frangos de corte machos e suas consequências sobre a composição química e a qualidade física da carne. Para determinação das porcentagens de incidência dos diferentes graus da miopatia WS (normal, moderada e severa) nas linhagens, foi utilizado um delineamento inteiramente ao acaso (DIC), com três tratamentos (linhagens A, B e C) e cinco repetições de 300 peitos cada. Para as variáveis químicas e físicas, utilizou-se um DIC em esquema fatorial 3 x 3 (três linhagens x três níveis de WS), com 15 repetições cada. Os dados foram submetidos à análise de variância e, em casos de diferenças significativas, utilizou-se o teste de Tukey (P≤0,05). As aves da linhagem A apresentaram 84,81% de peitos classificados como normais e 9,91% de peitos classificados como moderados, valores respectivamente maiores e menores que nas duas demais linhagens. Os peitos classificados com miopatia WS severa foram mais pesados e apresentaram maiores porcentagens de lipídios e umidade, e menor concentração de proteína bruta. As concentrações de colágeno total, termo solúvel e insolúvel variaram com o nível de acometimento por WS nos filés, com comportamento específico para cada linhagem.(AU)

The incidence of the White Striping (WS) myopathy in three male broiler strains and its consequences on the chemical composition and physical quality of the meat was evaluated. A completely randomized design (DIC) with three treatments (strains A, B and C) and five replicates of 300 breasts each were used to determine the incidence rates of the different degrees of WS myopathy (normal, moderate and severe) in each strain. For the chemical and physical variables, a 3 X 3 factorial scheme was used (three strains X three WS levels), with 15 replicates. The data were submitted to ANOVA and in cases of significant differences the Tukey test (P< 0.05) was used.The A strain chickens presented 84.81% of breasts classified as normal and 9.91% of breasts classified as moderate, respectively higher and lower values than in the other two strains. Breasts classified with severe WS myopathy were heavier and had higher percentages of lipids and moisture, and lower concentration of crude protein. However, the concentrations of total, soluble and insoluble collagen had interaction effects between lineage and WS level in the fillets, and therefore, the same behavior was not observed in the samples of the different strains.(AU)

Apparent metabolisable energy and amino acid digestibility of microalgae Spirulina platensis as an ingredient in broiler chicken diets.

1. This work investigates the apparent metabolisable energy (AME), its nitrogen-corrected form (AMEn) and amino acid (AA) digestibility coefficients of the microalgae Spirulina platensis as an ingredient in broiler chicken diets. 2. One group of birds was fed with a basal control diet (BD), and another was fed with a test diet composed of the BD with the addition of the microalgae at a proportion of 200 g/kg. AME and AMEn were assessed by total excreta collection and indigestibility analysis using acid-insoluble ash (AIA) as a marker. 3. The microalgae comprised 888.0 g/kg dry matter (DM), 18.42 MJ/kg gross energy, 514.7 g/kg crude protein, 9.9 g/kg ether extract, 10.6 g/kg crude fibre, 94.4 g/kg ash, 3.1 g/kg Ca and 11.0 g/kg P. 4. The values obtained for AME (13.48 MJ/kg DM) and AMEn (11.72 MJ/kg DM) were higher (p < 0.01) than those obtained using the AIA method (9.39-8.29 MJ/kg DM). The microalgae ileal digestibility coefficients were 0.80 ± 0.04 and 0.78 ± 0.04 for essential and non-essential AA, respectively. 5. Overall, the metabolisable energy content and digestibility of AA for S. platensis indicated that the microalgae are potentially an alternative nutrient source for broilers. The AIA method underestimated AME and AMEn in comparison to the total excreta collection method.

Anaemia, Serum Iron Concentrations and δ-Aminolevulinate Dehydratase Activity in Laying Hens Infected Naturally by Salmonella Gallinarum.

The aim of this study was to evaluate anaemia, serum iron concentrations and δ-aminolevulinate dehydratase (ALA-D) activity in laying hens infected naturally by Salmonella Gallinarum and having severe hepatic lesions. Liver and serum samples were collected from 27 laying hens (20 infected and seven uninfected). The δ-ALA-D activity, haematocrit and serum iron concentrations were evaluated. There were significant decreases in δ-ALA-D activity, haematocrit and serum iron concentrations (P <0.01) in birds infected by S. Gallinarum when compared with uninfected birds. There was a positive correlation (P <0.001) between serum iron concentration, haematocrit (r(2) = 0.82) and δ-ALA-D activity (r(2) = 0.75). A positive correlation was also observed between δ-ALA-D activity and haematocrit (r(2) = 0.78; P <0.01). Liver samples showed moderate focal coagulative necrosis associated with infiltration of lymphoplasmacytic cells, macrophages and heterophils. The anaemia in the infected hens may be related to reduction in δ-ALA-D activity and serum iron concentrations, since both are important for haemopoiesis.

Desempenho de frangos de corte alimentados com dietas contendo diferentes fontes de selênio, zinco e manganês, criados sob condições de estresse térmico / Performance of broilers fed diets containing different sources of selenium, zinc and manganese reared under thermal stress conditions

Avaliaram-se o desempenho e o rendimento de carcaça e partes de frangos de corte alimentados com dietas que continham selênio, zinco e manganês complexados ou não a moléculas orgânicas, criados em diferentes temperaturas. Foram utilizados 980 pintinhos machos de um dia de idade, de linhagem comercial, criados durante 42 dias em três câmaras climáticas, que proporcionaram temperaturas alta, termoneutra e baixa. Foi utilizado um delineamento inteiramente ao acaso, em esquema fatorial 3x2+1, sendo três temperaturas de criação, duas fontes de Se, Zn e Mn - inorgânica e orgânica, mais o tratamento testemunha - criação em câmara termoneutra sem adição de Se, Zn e Mn na ração, com sete repetições por tratamento. As aves criadas em condições de estresse térmico apresentaram piores resultados para consumo de ração, ganho de peso e viabilidade, sendo mais sensíveis ao calor do que ao frio. Quando criadas em ambientes quentes, a conversão alimentar foi melhor quando se utilizaram os minerais na forma orgânica. Sob temperatura neutra, as aves não necessitaram da suplementação da dieta com os minerais avaliados.

The performance and carcass yield of broilers fed supplemented diets with different selenium, zinc and manganese sources (organic and inorganic) and reared under different environmental temperatures were evaluated. A total of 980 one-day-old broilers were reared until 42 days of age. Three climatic chambers (high, neutral and low temperatures) and twenty chickens per pen, distributed in a 3x2 + 1 factorial arrangement with three breeding temperatures, two mineral sources and a control treatment that provided neutral temperature without mineral supplementation, with seven replicates each were used. The thermal stressed broilers showed lower results for feed intake, weight gain and viability, mainly under high temperature. The organic mineral utilization provided a better feed conversion ratio when high temperature was tested. Mineral supplementation under neutral breeding temperature was not necessary.

Coloração da gordura e qualidade da carne de ovelhas de descarte abatidas em distintos estágios fisiológicos / Fat coloring and meat quality of culling ewes slaughtered at distinct physiological stages

Avaliaram-se a qualidade física do músculo Longissimus lumborum de ovelhas de descarte da raça Santa Inês, abatidas em diferentes estágios fisiológicos, a cor da gordura subcutânea desse músculo e as possíveis correlações entre as variáveis de qualidade da carne. Utilizaram-se 21 ovelhas, distribuídas nos seguintes tratamentos: T1= ovelhas que permaneceram por 60 dias em lactação com seus respectivos cordeiros e abatidas um dia após o desmame das crias; T2= ovelhas que permaneceram por 60 dias em lactação com seus respectivos cordeiros e mais um período aproximado de 30 dias sem os cordeiros e posteriormente abatidas; e T3= ovelhas que não pariram durante o ano. A cor da carne e da gordura subcutânea não foram influenciadas pelo estágios fisiológico dos animais no momento do abate, com exceção da luminosidade da carne (T1= 41,13; T2= 37,56 e T3= 38,12 L*). A qualidade física da carne apresentou pouca variação entre os tratamentos, porém a força de cisalhamento (T1= 4,08; T2=2,86 e T3=2,35 kgf/cm²) e as perdas por cocção (T1=31,97; T2=35,70 e T3= 31,91 por cento) da carne diferiram entre os tratamentos. Não se observou alta correlação entre a maioria das características avaliadas.

The physical quality of the Longissimus lumborum muscle of Santa Inês culled ewes slaughtered at different physiological stages was evaluated as well as the color of the subcutaneous fat of the same muscle, and the correlations between meat quality traits. Twenty-one ewes were randomly allotted in the following treatments: T1= ewes which remained in lactation for 60 days with their respective lambs and slaughtered one day after weaning of the lambs; T2= ewes which remained in lactation for 60 days with their respective lambs, followed by an additional period of 30 days without the lambs and slaughtered afterwards; and T3= non pregnant ewes. The colors of meat and subcutaneous fat were not influenced by the physiological stage of the animals at the moment of slaughtering, except meat luminosity (T1= 41.13; T2= 37.56 and T3= 38.12 L*) . The physical quality of the meat presented little variation between treatments; however, shear force (T1= 4.08; T2=2.86 and T3=2.35 kgf/cm2) and losses by cooking (T1=31.97; T2=35.70 and T3= 31.91 percent) were affected by treatments. No high correlation between most of the evaluated traits was observed.