Chitosan level effects on fermentation profile and chemical composition of sugarcane silage

Foram avaliados os efeitos do aumento dos níveis de quitosana (CHI) sobre o perfil e as perdas fermentativas, a composição química e degradação in situ da silagem de cana-de-açúcar. Os tratamentos foram: 0, 1, 2, 4 e 8 g de CHI / kg de matéria seca (MS). Foram utilizados vinte silos experimentais (tubos de PVC com 28 cm de diâmetro e 25 cm de altura). Areia (2 kg) foi adicionada na porção inferior de cada silo para avaliar as perdas por efluentes e os silos foram pesados 60 dias após a ensilagem para calcular as perdas por gases. Amostras foram coletadas do centro da massa do silo para avaliar a composição química, degradação in situ, perfil fermentativo e a contagem de fungos e leveduras da silagem. Os dados foram analisados como um delineamento inteiramente casualizado e o efeito do tratamento foi decomposto usando regressão polinomial. A CHI aumentou linearmente a concentração de ácido acético e N-NH3, enquanto diminuiu a contagem de leveduras e bolores e a concentração de etanol. Os níveis intermediários de CHI (de 4,47 a 6,34 g/kg MS) mostraram os menores valores de perdas por efluentes, gases e totais. Houve efeito quadrático da CHI sobre o teor de carboidratos não fibrosos, fibra em detergente neutro e ácido e sobre a degradação in situ da MS. Os menores teores de fibras foram observados com níveis de CHI entre 7,01 e 7,47 g/kg MS, enquanto que os maiores teores de carboidratos não fibrosos e degradação in situ da MS foram encontrados com 6,30 e 7,17 g/kg MS de CHI, repectivamente. A CHI aumentou linearmente as concentrações de ácido acético e N-NH3, enquanto reduziu linearmente a concentração de etanol e a contagem de fungos e leveduras. Desta forma, níveis intermediários de CHI, entre 4,47 e 7,47 g / kg de MS, diminuem as perdas fermentativas e melhoram o valor nutricional da silagem de cana-de-açúcar.This study aimed to evaluate the effects of increasing levels of chitosan (CHI) on sugarcane fermentation profile and losses, chemical composition, and in situ degradation. Treatments were: 0, 1, 2, 4, and 8 g of CHI/kg of dry matter (DM). Twenty experimental silos (PVC tubing with diameter 28 cm and height 25 cm) were used. Sand (2 kg) was placed at the bottom of each silo to evaluate effluent losses, and silos were weighed 60 d after ensiling to calculate gas losses. Samples were collected from the center of the silo mass to evaluate silage chemical composition, in situ degradation, fermentation profile, and mold and yeast count. Data were analyzed as a completely randomized design, and the treatment effect was decomposed using polynomial regression. Chitosan linearly increased acetic acid and NH3-N concentration, while yeast and mold count, and ethanol concentration decreased. Intermediary levels of CHI (from 4.47 to 6.34 g/kg DM) showed the lower values of effluent, gas, and total losses. There was a quadratic effect of CHI on the content of non-fiber carbohydrates, neutral and acid detergent, and in situ DM degradation. The lowest fiber content was observed with levels between 7.01 and 7.47 g/kg DM, whereas the highest non-fiber carbohydrate content and in situ DM degradation were found with 6.30 and 7.17 g/kg DM of CHI, respectively. Chitosan linearly increased acetic acid and NH3-N concentration, whereas it linearly reduced ethanol concentration and count of yeast and mold. Thus, intermediary levels of CHI, between 4.47 and 7.47 g/kg of DM, decrease fermentation losses and improve the nutritional value of sugarcane silage

Carcass and meat characteristics of crossbred lambs from three genetic groups

Este trabalho teve como objetivo avaliar as características de carcaça e a qualidade de carne de cordeiros dos grupos genéticos ½Texel - ½Hampshire Down (THD), ½Texel - ½Ile de France (TIF) e ½Texel - ½Suffolk (TS). Foram utilizados 17 cordeiros castrados, sendo seis THD, seis TIF e cinco TS, confinados por 51 dias. Os animais receberam, diariamente, ração concentrada comercial (18% PB e 74% NDT) na proporção de 1,5% do peso vivo, mais cana-de-açúcar picada in natura à vontade. No início do experimento os cordeiros tinham idade e peso médio inicial de 120 dias e 31,0 kg. No final do período experimental os cordeiros foram abatidos após jejum de sólidos de 16 horas. Não houve diferenças significativas (P > 0,05) para peso e rendimento de carcaça fria. As médias gerais foram 17,30 kg e 41,94%, respectivamente. A composição regional (pescoço, paleta, costelas e pernil) e as características morfológicas (comprimento e compacidade) das carcaças também não diferiram (P > 0,05) entre os grupos genéticos. A composição tecidual do pescoço e a qualidade da carne (maciez, suculência e sabor), avaliada por um painel sensorial, também, foram similares (P > 0,05) entre os três grupamentos genéticos. Conclui-se que na produção de carne ovina qualquer um dos grupos genéticos estudados pode ser utilizado, pois apresentam características de carcaça e de carne semelhantes.The objective of this work was to evaluate carcass characteristics and meat quality of lambs from the genetic groups ½Texel - ½Hampshire Down (THD), ½Texel - ½Ile de France (TIF) and ½Texel - ½Suffolk (TS). Seventeen castrated lambs were used, being six THD, six TIF and five TS. Lambs were fed lot for 51 days, where they received daily a commercial concentrate ration (18% CP and 74% TDN), in the proportion of 1.5% of body weight, and had free access to chopped in natura sugar cane. The average age and weight at the initiation of the experiment were, respectively, 120 days and 31.0 kg. At the end of the experimental period lambs were slaughtered after 16 hours of fasting of solids. There was no significant difference (P > 0.05) for cold carcass weight and dressing percentage. Averages were 17.30 kg and 41.94%, respectively. Regional composition (neck, shoulder, ribs and leg) and carcass morphological characteristics (length and compactness) did not differed (P > 0.05) among the genetic groups. Tissue composition of the neck and meat quality (tenderness, juiciness and flavor), evaluated by a sensory panel, were similar (P > 0.05) among the three genetic groups. It can be concluded that in the lamb production any of the genetic groups studied can be used, for their carcass and meat characteristics were quite similar

Performance, carcass and meat quality of ewes supplemented with magnesium oxide

The objective of this study was to evaluate the performance, the carcass and meat characteristics of ewes supplemented with magnesium oxide. Eighteen 6-year-old Santa Ines ewes were used in a completely randomized experimental design, where three levels of supplementation (0.0, 0.1 and 0.2% magnesium oxide in the concentrate) were tested, with six replicates. Final weight, weight gain, feed intake and feed conversion were not affected by levels of magnesium supplementation. Hot and cold carcass weights showed linear increasing and quadratic responses, respectively, according to supplementation with magnesium. Carcass measurements such as length, depth, and measures of arm and leg were not affected by supplementation. Depth and width of the longissimus muscle and rib-eye area were not affected; however, marbling and ether extract increased linearly with supplementation. Water loss and color were not affected. Lipid oxidation and shear force were not affected by supplementation, while the myofibrillar fragmentation index showed a quadratic regression. There was a linear decrease in pH with magnesium supplementation. Supplementation with magnesium can improve carcass and meat pH, but can act negatively by increasing the amount of marbling and ether extract of meat

Ruminal degradability In Situ of nutritive components of some

As degradabilidades in situ da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente ácido (FDA) e da fibra em detergente neutro (FDN) do caroço de algodão integral (CAI), farelo de soja (FS), grão de girassol (GG), torta de nabo forrageiro (TN) e do milho triturado (MT) foram determinadas com a incubação de sacos de náilon no rúmen de cinco bovinos ½ sangue Simental-Zebu. As degradabilidades efetivas (DE) da matéria seca (MS) e da proteína bruta (PB) a taxa de passagem de 5%/h, foram, respectivamente, 40,93 e 48,95% para o caroço de algodão integral; 67,35 e 53,20% para o farelo de soja; 63,38 e 72,50% para o grão de girassol; 66,59 e 57,82 para torta de nabo forrageiro e 63,65 e 54,18% para o milho triturado. Por meio das taxas de fermentação dos diferentes componentes nutritivos determinadas neste experimento, pode-se concluir que a torta de nabo forrageiro tem potencial para substituir o farelo de soja como fonte protéica na alimentação de ruminantes; o grão de girassol apresenta elevada fração solúvel da proteína bruta e o teor de extrato etéreo presente no caroço de algodão pode afetar negativamente a degradação da matéria seca e da matéria orgânica deste alimento, principalmente quando este é fornecido triturado aos animais.Degradability “in situ” of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of whole cotton seed (WCS), soybean meal (SM), sunflower seed (SS), turnip cake (TC) and ground corn (GC) were determined with incubation of nylon bags in the rumen of five steers ½ Simmental-Zebu. The effective degradability (ED) of dry matter and crude protein with 5%/h of passage rate were respectively 40,93 and 48,95% for cotton seed; 67,35 and 53,20% for soybean meal; 63,38 and 72,50% for sunflower seed; 66,59 and 57,82% for turnip cake and 3,65 e 54,18% for ground corn. Through the fermentation rates of the different nutritious components determined on this experiment it was concluded that turnip cake has a potential to substitute soybean meal as a protein source in ruminant feeding; sunflower seed presents a high soluble fraction of crude protein and the cotton seed ether extract may affect negatively the degradation of dry matter and organic matter of this feed, specially when provided ground to the animals