Qualidade do sêmen em tilápia do Nilo (Oreochromis niloticus), alimentadas com dietas contendo diferentes níveis de vitamina C.

A vitamina C atua na proteção de danos celulares provocados pelos radicais livres, sendo a suplementação considerada essencial para a maioria das espécies de peixes, uma vez que não a sintetizam em função da ausência da enzima L-gulonolactona oxidase. Assim, avaliou-se o efeito da suplementação de 0, 75, 150 e 225 mg de vitamina C kg-1 de ração na qualidade do sêmen em tilápias do Nilo (Oreochromis niloticus). Os parâmetros quali-quantitativos do sêmen não foram influenciados pela suplementação de vitamina C, exceto a motilidade progressiva que aumentou linearmente com adição de vitamina C. Conclui-se que os reprodutores de tilápias do Nilo devem ser suplementados com 225 mg de vitamina C kg-1 de ração

Acute heat stress and dietary methionine effects on IGF-I, GHR, and UCP mRNA expression in liver and muscle of quails.

This study evaluated the expression of insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), and uncoupling protein (UCP) mRNA in muscle and liver of quails that were in thermal comfort or exposed to heat stress and that were fed diets with or without methionine supplementation. Meat quails were fed a diet that either met the nutritional demands for methionine (MS) or did not meet this demand (methionine-deficient diet, MD). The animals were either kept at a thermal comfort temperature (25°C) or exposed to heat stress (38°C for 24 h starting on the 6th day). RNA was extracted from liver and breast muscle, and cDNA was synthesized and amplified using quantitative reverse transcription-polymerase chain reaction. Animals that were fed the MS diet and remained at the thermal comfort temperature exhibited increased IGF-I mRNA expression in the liver (0.56 AU). The GHR mRNA expression in the liver and muscle was influenced by both the study variables. Animals receiving the MS diet showed higher GHR expression, while increased expression was observed in animals at the thermal comfort temperature. The UCP mRNA expression in the muscle was influenced by both methionine supplementation and heat stress. Higher expression was observed in animals that received the MD diet (2.29 vs 3.77 AU) and in animals kept in thermal comfort. Our results suggest that heat stress negatively affects the expression of growth-related genes and that methionine supplementation is necessary to appropriately maintain the levels of IGF-I, GHR, and UCP transcripts for animal metabolism

Digestible lysine effects on gene expression by Japanese quails in the pre-laying phase

This study aimed to determine the effects of digestible lysine levels in the diets of Japanese quail (Coturnix coturnix japonica) on performance, blood parameters and the expression of insulin-like growth factor I, and growth hormone receptor (GHR), apolipoprotein A-I (APOA-I), acetyl-CoA-carboxylase (ACC), and fatty acid synthase (FAS) genes. A total of 288 seven-day-old female Japanese quails were randomly assigned to one of three diets that contained 0.8%, 1.10%, or 1.40% digestible lysine. The birds were slaughtered at 42 days old, and relative gene expression was evaluated in the liver by qRT-PCR using the 2-ΔCT method. Lysine supplementation had no effect on weight gain and feed conversion. Abdominal fat was lower in birds supplemented with 0.8% digestible lysine than those supplemented with 1.10% and 1.40%. Increased total cholesterol and triglycerides were elevated in quails that received supplementation of 1.10% digestible lysine compared with the other diets. High density lipoproteins were decreased in birds that received 0.8% digestible lysine. Quails fed with 1.40% digestible lysine had greater expression of GHR and APOA-I than quails fed diets with 0.8 and 1.10% (P <0.05). The greatest expressions of ACC and FAS were observed in the liver of quails fed with 0.8% digestible lysine. The current results suggest that lysine supplementation in the pre-laying phase allows birds to deposit muscle mass to reach the optimal conformation and body fatness that provides an energetic reserve for the productive phase by modulating the expression of genes related to growth and lipid metabolism. Keywords: Coturnix coturnix japonica, growth, growth hormone, lipid synthesis, lipid metabolis

Compositional analysis and physicochemical and mechanical testing of tanned rabbit skins

[EN] Chemical composition and physicochemical and mechanical parameters of New Zealand White rabbit tanned skin were evaluated. Skin samples from 70-d-old males, in natura and semi-finished, were collected for evaluation. The in natura treatment comprise skins without any processing, while semi-finished treatment comprise skins after soaking, fleshing, liming, de-liming, purging, degreasing, pickling, tanning, neutralising, re-tanning and dyeing, followed by oiling, drying, stretching and softening. After tanning, samples from the dorsal and flank regions were removed for tensile and physicochemical testing in the longitudinal and transverse directions. A split plot design was used with plot treatments (leather regions: R1=dorsal and R2=flank) and subplots directions (S1=longitudinal and S2=transversal), using 10 examples per treatment. At the end of processing, the leather analysis revealed low moisture (31.76%), protein (46.48%) and fat content (24.95%), and a high ash content (8.58%). Leather presented a pH of 4.9 and contained 2.0% chromium oxide, 25.5% extractable substances in dichloromethane, and these characteristics were coupled with a higher tensile strength (10.84 N/mm2) in the dorsal region. However, samples in the same region proved to have higher elasticity (64.57%) in the longitudinal direction, although there was no difference in the progressive tearing analysis (21.07-23.50 N/mm). Overall, our analyses suggest that, in this case, the tanned leather product does not have sufficient resistance for application in clothing production.Souza, MR.; Hoch, AL.; Gasparino, E.; Scapinello, C.; Mesquita Dourado, D.; Claudino Da Silva, SC.; Lala, B. (2016). Compositional analysis and physicochemical and mechanical testing of tanned rabbit skins. World Rabbit Science. 24(3):233-238. doi:10.4995/wrs.2016.4037SWORD233238243ABNT. Associação Brasileira de Normas Técnicas. 2014. ABNT NBR ISO 3376: 2014 - Couro - Ensaios físicos e mecânicos – Determinação de resistência à tração e alongamento percentual. Rio de Janeiro, 1-5.ABNT. Associação Brasileira de Normas Técnicas. 2014. NBR - 2589: Couro - Ensaios físicos e mecânicos - Determinação da espessura. Rio de Janeiro, 1.ABNT. Associação Brasileira de Normas Técnicas. 2013. NBR - 11030: couro - Determinação de substâncias extraíveis com diclorometano (CH2Cl2). Rio de Janeiro, 1-3.ABNT. Associação Brasileira de Normas Técnicas. 2013. ABNT NBR 11032: 2013 - Pele e couro - Amostragem na amostra de teste - Procedimento. Rio de Janeiro, 1-4.ABNT. ABNT Associação Brasileira de Normas Técnicas. 2014. NBR – 5398-1: Couro – determinação química do teor de óxido de cromo Parte 1: Quantificação por titulação. Rio de Janeiro, 1-5.ABNT. Associação Brasileira de Normas Técnicas. 2014. NBR - 3377-2: Couro – Ensaios físicos e mecânicos — Determinação da força de rasgamento Parte 2: Rasgamento de extremidade dupla. Rio de Janeiro, 1-3.ABNT. Associação Brasileira de Normas Técnicas. 2014. ABNT NBR 10455: 2014 - Clima de materiais utilizados em calçados e artigos relacionados fabricar. Rio de Janeiro, 1-2.ABNT. Associação Brasileira de Normas Técnicas. 2006. NBR – 11057: Couro –determinação do pH e da cifra diferencial. 2. ed. Rio de Janeiro, 1-3.Cunniff P.A. 1998. Official Methods of Analysis of AOAC International. 16th ed. Arlington: Association of Official Analytical Chemists.Franco, M.L.R.S. 2007. Curtimento de pele de tilápia. In: Boscolo, W.r., Feiden, A. (Orgs.) Industrialização de tilápias. Toledo: GFM Gráfica e editora, 185-223.Freire M.C., Canl R.M. 2000. A pele bovina como matéria-prima. Revista Nacional da Carne, 24: 100-110.Gerhard J. 1998. Posibles fallas e el cuero y e su producción – conceptos, causas, consecuencias, remedios y tipos de cueros. Partner Rübelmann GmbH: Lampertheim (Alemania).Gutterres M. 2001. Distribuição, deposição e interação química de substâncias de engraxe no couro. In: Congresso da federação latino-americana das associações dos químicos e técnicos da indústria do couro, 15, Salvador. Anais... v.1, 108-119.Gutterres M. 2003. Efeito do Curtimento sobre a Microestrutura Dérmica. Revista do Couro Abqtic, Estância Velha, 26: 56-59.Oliveira A.C., Souza M.L.R., Hoch A.L.V., Gasparino E., Scapinello C., Kffuri V.R. Domingues M.C. 2007. Resistência dos couros de coelhos em função do sexo e da idade de abate. Tecnicouro, 28: 52-56.Prado M., Franco M.L.R.S., Uchimura C.M., Souza E.D., Bordignon A.C., Justen A.P., Silva S.C.C., Del Vesco A.P. 2013. Efeito da etapa de engraxe no processo de curtimento das peles de coelhos. Acta Tecnológica, 8: 8-11. http://portaldeperiodicos.ifma.edu.br/index.php/actatecnologica/article/view/131SAEG. 2000. Sistemas de Análises Estatísticas e Genéticas. Versão 8.0. Universidade Federal de Viçosa. Viçosa.Souza M.L.R. 2004. Tecnologia para processamento das peles de peixe. Maringá, PR. Coleção Fundamentum, 11: 14-55.Souza M.L.R. 2006. Tecnologia para processamento de peles de coelhos: peleteria e couro. In Proc: 3rd Rabbit Congress of the Americas, 2006, Maringá –Pr, Brasil. v. 1.Souza M.L.R. 2008. Tecnologia para processamento das peles de peixe. Maringá: Eduem. 3° Ed